OmniDICOM User Manual

OmniDICOM is a DICOM viewer for macOS and Windows for research and educational use. It is not a medical device and is not intended for diagnosis, primary interpretation or clinical decision-making. This manual describes OmniDICOM 1.1.6: the complete viewer that every plan includes, Denoise and the Process and Analyze workspaces of the Professional plan, and the 14-day Professional trial that starts by itself on the first launch. Where the software and this text differ, trust the software and tell us at contact@omnidicom.com.

Contents

On a Mac, read Ctrl in this manual as the Command key (⌘) and Alt as the Option key.

Getting started

What you need

Download either installer from https://omnidicom.com. The download section of that page also lists a SHA-256 checksum for each file, if you want to verify a download before you run it.

The current Mac installer does not support Intel Macs.

Install on macOS

1. Download the .pkg file.
2. Double-click it. The macOS Installer opens with the page Install OmniDICOM.
3. Click Continue, then Install, then Close.

macOS may ask for the password of your Mac account. That is the normal administrator approval for installing into the Applications folder. It is not your OmniDICOM license key.

The package installs OmniDICOM into your Applications folder, where Finder, Launchpad and the Dock list it as OmniDICOM DICOM Viewer. If OmniDICOM is already running, the installer asks you to quit it before it continues.

The installer is signed and notarized with Apple, so macOS normally opens it without a warning. If macOS asks you to confirm that you want to open a package downloaded from the internet, click Open. If macOS refuses to open the package at all, the download is probably incomplete or was changed on the way. Download it again from https://omnidicom.com and compare the checksum.

OmniDICOM can also update itself; see Updating OmniDICOM. Running a newer package by hand also works: it replaces the application in place, and your settings and your image files are not touched.

Install on Windows

1. Download the setup .exe file.
2. Microsoft Edge may hold the download back with a note that the file "isn't commonly downloaded". This happens with any newly released installer that few people have downloaded yet. To keep the file, open the Downloads list, point at the entry, click the ... (More actions) button, choose Keep, then Show more and Keep anyway.
3. Run the file. If Windows SmartScreen shows "Windows protected your PC", click More info. The publisher shown should be Youngrak Choi, the developer who signs OmniDICOM. Then click Run anyway.
4. Follow the setup wizard. The first page shows the Research Use Only notice; accept it to continue. Setup installs for your own Windows account by default, so no administrator password is needed. If you have administrator rights you can choose to install for all users instead. The option to create a desktop icon is off unless you tick it.
5. Leave Launch OmniDICOM DICOM Viewer ticked on the last page and click Finish.

Afterwards you start OmniDICOM from the Start menu, where it is listed as OmniDICOM DICOM Viewer. To remove it, open Windows Settings ▸ Apps (Installed apps on Windows 11, Apps & features on Windows 10), choose OmniDICOM DICOM Viewer and Uninstall; right-clicking the Start entry and choosing Uninstall works too. Installed by version 1.1.3 or earlier, it was listed as OmniDICOM, with an uninstall shortcut in the Start menu; the first update renames the entry and removes that shortcut.

Updating OmniDICOM

OmniDICOM looks for a newer version by itself: about ten seconds after the first window opens, and then once a day while it runs. The check reads a small file at omnidicom.com and sends nothing but the application version. When the computer is offline, or the check fails for any other reason, nothing is shown and OmniDICOM tries again later.

When a newer version exists, a bar at the top of every viewer window says that it is available and gives its version number. The bar has three buttons:

To check at any other time, choose Help ▸ Check for Updates…. The update dialog offers Update now, Later and Skip this version. A skipped version is no longer announced by the automatic check; a later version is, and Help ▸ Check for Updates… still offers the skipped one.

After Update now:

1. OmniDICOM downloads the update and shows how many megabytes have arrived. Cancel stops the download; nothing has changed yet.
2. It verifies the download. The file must match the checksum published with the release, carry OmniDICOM's own signature (Apple's Developer ID and notarization on a Mac, the Authenticode signature of Youngrak Choi on Windows) and contain exactly the version offered. A file that fails any of these checks is not installed.
3. The dialog says "Ready. OmniDICOM will restart to finish updating." Click Restart now.
4. Before anything closes, OmniDICOM asks omnidicom.com once more whether the version it downloaded is still offered. A version that has been withdrawn in the meantime is not installed: nothing closes, and the dialog says that the update to that version was withdrawn. The download is removed, and if another version is offered instead, Update now downloads that one. The daily check does the same if it finds the version withdrawn before you restart. If omnidicom.com cannot be reached at that moment, for example because the computer is offline, the update goes ahead: the download has already been verified.
5. If a window still holds work that restarting would lose, such as unsaved DICOM Meta edits, processing that has not been saved, a scan, export or transfer that is still running, or an archive import or export, OmniDICOM lists it and asks you to choose Restart anyway or Cancel. If OmniDICOM is also open in another window, or for another person signed in on this computer, it asks for those copies to be closed first (Try again or Cancel), because the update replaces the files they run from. Quit OmniDICOM there, or ask the other person to quit it or sign out, then click Try again. If a copy cannot be closed, restart the computer and update again.
6. OmniDICOM closes every window, installs the new version and starts again. The status bar then says "Updated to OmniDICOM" followed by the new version number.

An update does not touch your settings, your license or your image files.

On a Mac

When your Mac account may change the copy of OmniDICOM in the Applications folder, which is the case when an administrator account installed it, the new version simply replaces the old one and no password is asked for. On a standard account, or when another user installed OmniDICOM, the update runs the OmniDICOM installer package instead, and macOS asks for the name and password of an administrator. That is the normal approval for changing the Applications folder, not your license key. If you cancel that prompt, or the new version cannot be installed, OmniDICOM opens again on the version you had and tells you; see If an update fails.

On Windows

If OmniDICOM was installed from Microsoft Store, updates come from the Store. Help ▸ Check for Updates… asks Microsoft Store from inside OmniDICOM: it says "OmniDICOM … is up to date", or that an update is available, with Update now and Later. Update now has the Store download and install it; Windows closes OmniDICOM to finish, so save your work first. If the Store cannot be asked from the app, the OmniDICOM Store page opens instead; the automatic-update option in Viewer Settings is disabled and explains that the Store manages updates. This installation never runs the standalone setup EXE. The Store edition has the same viewer and licensing features as the direct-download edition.

The following applies to the standalone setup EXE from omnidicom.com.

The update runs OmniDICOM Setup in the background and starts OmniDICOM again when it has finished. A copy installed for your own Windows account, the default, updates without any prompt. If OmniDICOM was installed for all users, Windows may ask for administrator permission (User Account Control). If you decline that prompt, or the new version cannot be installed, OmniDICOM opens again on the version you had and tells you; see If an update fails.

If an update fails

If the download or its verification fails, OmniDICOM says what went wrong in a plain message, installs nothing, and the version you have keeps working. The message offers Download from omnidicom.com, so you can download the new installer and install it by hand as described above.

If the new version cannot be installed after Restart now, for example because the administrator prompt was cancelled, nothing changes: OmniDICOM opens again on the version you had and says "The update was not installed", with the version that is still running. This is the same on a Mac and on Windows. Try again later with Help ▸ Check for Updates…, or download the installer from https://omnidicom.com and install it by hand. If OmniDICOM does not open again at all, install it by hand the same way; your settings and license stay as they are.

If the installation stops partway, after some of OmniDICOM's files have already been replaced, OmniDICOM says "The update stopped partway" when it opens again and offers Download from omnidicom.com. It may not work correctly until it is installed again: download the installer and install OmniDICOM as described above. Your settings, license and image files stay as they are.

Turning the automatic check off

Open Settings and clear Check for updates automatically. OmniDICOM then checks only when you choose Help ▸ Check for Updates….

Updating from 1.0.6 or earlier

OmniDICOM 1.0.6 and earlier cannot update themselves. Download the current installer from https://omnidicom.com once and install it over your copy as described above; your settings and license stay as they are. From then on, updates arrive in the application.

First launch

OmniDICOM opens as a single window with a toolbar across the top, the series list on the left, an image area in the middle and a status bar at the bottom. The empty image area says Open a DICOM study and tells you to click the folder button or to drag files and folders into the window. Opening studies covers every way of opening a study.

Every picture in this manual was taken with a synthetic test phantom instead of patient images, which is why they show plain shapes and the patient always reads TEST HARNESS.

Keyboard note: this manual writes shortcuts with Ctrl. On a Mac, press ⌘ (Command) instead. The menus show the Mac symbols.

The trial starts by itself

The first time OmniDICOM runs with an internet connection, it starts your 14-day Professional trial on its own. Nothing is asked of you and no card is needed. The status bar shows a one-time message such as:

Your 14-day Professional trial has started — every feature is unlocked until 2026-10-01.

The end date in that message is your trial end date. You can see it again at any time under Help ▸ Licence….

Near the end, OmniDICOM reminds you once when three days are left and once when one day is left, in a small Professional trial window when it starts. It says what changes afterwards: the viewer keeps working in 5-minute sessions, Professional tools such as Denoise are locked, and exports stay watermarked until you subscribe. It also shows both plans with their prices: Basic (US$10 a month or US$99 a year) and Professional (US$45 a month or US$449 a year), per computer, excluding tax. Basic is selected first; choose a plan card and Monthly or Yearly. Later closes it; Subscribe to Basic… (or Subscribe to Professional…) opens Help ▸ Licence… and the checkout for that plan, and the key that arrives by email is entered in the licence dialog; Ask for a longer trial… opens the email described under "Asking for a longer trial" below.

On the first launch after the trial ends, a window titled Professional trial ended says once when it ended and what changes: sessions last 5 minutes, exported and copied images keep the watermark, and Denoise, Process and Analyze are locked. Basic lifts the first two; Professional lifts all three. It shows the same plans and buttons as the reminder.

If the computer is offline on the first launch, the status bar says instead:

Connect to the internet to check this computer's 14-day Professional trial. Until then, the viewer runs in 5-minute sessions.

Until a valid trial or paid licence is confirmed, the viewer runs in five-minute sessions with watermarked exports and Professional tools locked. OmniDICOM checks again on the next launch; Check trial availability in a locked-feature dialog can check immediately.

Reinstalling OmniDICOM or clearing its settings does not give a new trial. The license server remembers the original dates for this computer, so you get the remainder of the same 14 days.

Asking for a longer trial

If you need longer than 14 days, for a team or an institutional review, ask us. Ask for a longer trial… is in Help ▸ Licence… throughout the trial and after it ends; Help ▸ Ask for a Longer Trial… appears in the last three days of the trial and after it ends; and the reminder has the same button. Each opens the window Ask for a longer trial, which shows the whole email to contact@omnidicom.com before anything happens. Write email… opens it in your mail app, where you add what you are evaluating OmniDICOM for and send it. If no mail app opens, Copy email text copies the whole email, address and subject included, so you can paste it into any mail service; OmniDICOM does not change your clipboard unless you choose this.

The email ends with this computer's ID, which is how we find the trial and extend it. The Computer ID is a one-way code with no name, serial number or patient data in it; the privacy summary says what it can and cannot reveal. A trial is extended once per computer, by 14 days: a trial still running gets 14 days after its end, a finished one 14 days from the day we extend it.

You do not need to reinstall or enter anything. Once we have extended it, OmniDICOM picks up the new end date by itself while it is online: if you asked from the app, when you next start it or within an hour while it is open; otherwise within a day. The status bar then says "Your Professional trial has been extended until" followed by the date, a finished trial's five-minute sessions stop, and the reminders come again before the new end, without the ask.

The trial, sessions and subscriptions

Five-minute sessions

Without a current trial or paid licence, OmniDICOM still opens and still shows your studies, but each time you start it you get five minutes. The five minutes cover the whole program, every viewer window included: opening a new window, or closing one, does not start them again. Two minutes before the end, the status bar warns you:

Trial session ends in 2 minutes — save your work now. Restarting OmniDICOM gives you another 5 minutes.

With more than one viewer window open, the warning says the session ends for every window. If processing you applied in the Process panel has not been saved in any window, the warning says so instead.

When the time is up, a dialog titled Trial session ended shows both plans and offers Subscribe to Basic… (the label follows the plan you choose), Enter licence… and Close OmniDICOM. Subscribing opens the checkout for the chosen plan and period and keeps the licence dialog open for your emailed key. Close OmniDICOM closes every OmniDICOM window, including the Local archive and PACS windows. Restarting OmniDICOM gives you another five minutes. Entering a valid license key lifts the limit immediately, even in the middle of a session. The app continues checking while it stays open: if the trial or paid period ends, the same countdown starts without requiring a restart.

The watermark

While OmniDICOM is on a trial, or has no valid license, every exported image or movie and every image copied to the clipboard carries the banner "OmniDICOM trial — not licensed for publication" — from the viewer, the Local archive, and the MPR and 3D windows alike. A 3D model (STL) cannot carry the banner, so such a copy cannot save one. A NIfTI volume cannot carry it either; the trial can save one, but a copy whose trial or license has ended cannot. A paid license, Basic or Professional, exports without the banner and saves 3D models and NIfTI volumes.

Basic and Professional

OmniDICOM is sold as two subscriptions. Prices and the current plan details are at https://omnidicom.com/pricing.

A license covers one computer at a time. You can move it to another computer you own; see below.

Locked features stay visible on the toolbar so you can find them. If you click one without the right license, a dialog explains the situation instead of doing nothing. For example, clicking Process on an unlicensed copy opens Processing — Professional feature with these buttons:

If you subscribe to Basic and click a Professional feature, the dialog is titled … — Not included in Basic. Its status line reads "Basic licence on this computer — Professional features are not included", and the buy button reads Upgrade to Professional. Basic is a full license; it simply does not include the processing and analysis tools.

Upgrading from Basic to Professional

A Basic subscriber upgrades by paying for Professional. Your license key and the computer it is activated on stay the same, so there is no new key to enter.

1. Click a Professional feature, for example Process, and click Upgrade to Professional in the dialog. The computer must be online: the dialog shows "Checking your Basic subscription…" while OmniDICOM asks the license service whether your subscription can be upgraded.
2. The dialog then explains what the upgrade does: "Upgrading moves your existing licence key to Professional as soon as payment completes. We then cancel your Basic subscription and refund the unused part of your current Basic billing period to your original payment method. Your key and activated computer stay the same."
3. Click Continue to checkout. The checkout opens in your browser with Professional chosen, billed monthly or yearly like your Basic subscription, and repeats the same explanation. Leave the dialog open.
4. Pay for Professional with the email address you bought Basic with. The upgrade applies only to a payment made with that address; with any other address you receive a separate Professional license key instead, and Basic stays active.
5. Back in OmniDICOM, click Check upgrade. When your license comes back as Professional, the dialog closes, the feature you clicked opens, and the status bar says "Upgrade complete — your licence is now Professional." If the dialog says "Your licence is still Basic", the payment has not been confirmed yet; wait a few minutes and click Check upgrade again.

You can also close the dialog after paying. For seven days after you open the checkout, OmniDICOM checks for the upgrade every time it starts, and Help ▸ Licence… ▸ Check now checks straight away. If you click a Professional feature again before the upgrade arrives, the dialog puts Check upgrade first and says so, so that a payment still being confirmed is not paid for twice.

After the upgrade you receive an email titled "Your OmniDICOM licence is now Professional". It confirms that your Basic subscription was cancelled and states the refund for the unused part of your Basic billing period, or that no refund was due. The refund returns to your original payment method within Paddle's usual processing time.

Occasionally the license service cannot apply the payment to your existing key, for example when the upgrade link has expired by the time the checkout starts, or when you paid with a different email address. You still receive Professional: an email brings you a new license key instead of the confirmation above, and Check upgrade keeps saying "Your licence is still Basic". Enter the new key with Enter licence… and use it from now on. Your Basic subscription is not cancelled automatically then: to have it cancelled and the unused part of its current billing period refunded, write to contact@omnidicom.com from the email address you bought Basic with.

When an upgrade cannot be done this way, the dialog says so before anything is paid:

• The subscription cannot be upgraded, for example because Basic is already set to cancel or has a payment problem: the dialog shows the reason instead of the explanation above, and Continue to checkout opens the ordinary checkout.
• Too many requests reached the license service from your network (a shared hospital or university connection counts every computer on it): the dialog asks you to try again in a minute and opens nothing, because the ordinary checkout would not cancel Basic for you. Click Upgrade to Professional again a minute later.
• The license service cannot be reached or cannot upgrade right now: the dialog says so and opens nothing. Click Upgrade to Professional again later. If it keeps failing, Continue to checkout opens the ordinary checkout instead, and Professional is then a separate subscription: when its key arrives by email, choose Enter licence…, and cancel Basic from the link in your Paddle receipt email to avoid paying for both.

With the ordinary checkout, Professional arrives as a new license key, and your Basic subscription is not cancelled or refunded for you.

Entering your license key

Your key arrives by email after purchase. It looks like OMNI-XXXX-XXXX-XXXX-XXXX.

If you have not subscribed yet, Help ▸ Licence… shows both plans with their prices and a Subscribe to Basic… button (it follows the plan card you choose) while no working licence is active. During the trial its second line reads "Trial ends" followed by the date; after it, "Your Professional trial ended on" followed by the date. Existing customers can enter their emailed key without buying again. The shop opens in your browser, and the licence dialog remains available for activation.

1. Choose Help ▸ Licence… from the menu bar. (The menu uses this spelling.) The dialog OmniDICOM Licence opens. It shows the current state on its first line, the name of this computer, and a key box while no license is active.
2. Paste or type the key into the box and click Activate. The computer must be online for this step.
3. On success the key box disappears, the first line shows your plan, and the dialog says "Licence activated."

If this copy already has a licence but you purchased a separate Professional key, choose Use another key… in this dialog and enter the key from that purchase email. This does not buy another subscription or cancel the existing one. An in-place upgrade through the app keeps the original key; a separate purchase has its own key.

The Microsoft Store and website editions can keep separate settings on Windows. If you switch editions and the new copy shows a different plan or no licence, enter your existing key in that copy on the same computer. You do not need to purchase again.

You can also enter the key from the Enter licence… button in any locked-feature dialog and in the Trial session ended dialog.

If activation fails, the dialog tells you why. The most common messages:

Staying licensed

Once activated, OmniDICOM checks in with the license server in the background about once a day, including while it stays open, and sooner when its current token is about to expire. Nothing is shown when this succeeds. The license dialog shows the line "Checked in until" followed by a date; that is how long the license stays valid without contact, roughly five days. A computer that is offline for longer than that shows its saved plan and Licence lapsed in the dialog, and the 5-minute session limit applies. Connect to the internet, open Help ▸ Licence… and click Check now; the message "Licence is up to date." confirms it. This checks the key saved in this copy. It can renew an active subscription's check-in, but it does not switch to a separately purchased key or restore a subscription that has ended.

A canceled or refunded subscription is picked up the same way and is reported in the status bar.

Moving your license to another computer

A license is locked to the computer it was activated on. Copying OmniDICOM's settings to another computer does not move it. To move it:

1. On the old computer, choose Help ▸ Licence… and click Deactivate this computer. The dialog confirms: "This computer has been released. You can now activate the licence somewhere else."
2. On the new computer, choose Help ▸ Licence…, enter the key and click Activate.

Deactivating a computer does not cancel the subscription or start a fresh trial. The old computer restores any remaining original trial time; otherwise it uses five-minute sessions with watermarked exports. Previously saved processing settings are kept, but applying them requires Professional access. You can reactivate the original computer with the same key if the seat is available.

If the old computer is no longer available, email contact@omnidicom.com with your key and the support team can release it for you.

Where to get help

• Help ▸ User Manual (F1) opens this manual.
• Help ▸ Open-Source Licences… lists the open-source software OmniDICOM includes and the licence of each. Show Source Files opens the folder with the source code of the FFmpeg build that ships with OmniDICOM.
• Help ▸ About OmniDICOM (Ctrl+F1) shows the version and build. Its ... button offers Copy information, which is useful to paste into a support request.
• Help ▸ Request a Feature… shows a new email to contact@omnidicom.com with the subject "Feature request"; Write email… opens it in your mail app. OmniDICOM adds its version, your operating system and your licence type at the end, and nothing about your studies, files or licence key. If no mail app opens, Copy email text copies the whole email so you can paste it into any mail service. OmniDICOM sends nothing itself.
• Support: contact@omnidicom.com, or https://omnidicom.com/contact. Do not attach patient files to a first support request.

See also

• Opening studies — loading your first study
• Toolbar, layout and settings — what the buttons and menus do
• Analyze and Process — the two Professional workspaces
• Troubleshooting and Support — license messages, the log file and privacy

Opening studies

Ways to open a study

Opening replaces the current series list with the new study. Adding keeps the current list and puts the new series into it.

Open and Add share the last folder you chose for files, folders or ZIP archives. On first use, or if that folder no longer exists, the picker starts in Documents.

The Open button

Click anywhere on Open to show the full Open / Add menu. Its first three choices are Open DICOM files, Open DICOM folder and Open ZIP archive.... The same menu includes Open DICOM CD/DVD, Add DICOM images, New window (Ctrl+N), Duplicate window (Ctrl+Shift+N), Close window (Alt+F4), Exit (Ctrl+Alt+F4) and Export... (Ctrl+E). Open no longer has a separate arrow action.

Folders

Choose a folder and OmniDICOM scans it, including every subfolder. Files are recognized by their contents, so a DICOM file does not need a .dcm extension. If the folder contains a DICOMDIR index, OmniDICOM reads it to find the images faster.

The scan runs in the background. Series appear in the list as they are found, and you can start looking at the first ones while the rest are still loading. The status bar shows the progress line "Scanning for DICOM files..." with a Stop button; pressing Esc also stops it. When the scan finishes the status bar reports, for example, "Scan complete: 12 series (1240 files)."

Keep the original folder structure of a study, especially on a disc that has a DICOMDIR next to its image folders.

Files

The file picker lets you select several files at once. It filters for .dcm and .dicom by default; switch to All files for DICOM files without an extension. Only the selected files are opened, not the whole folder.

Opening from Finder or Explorer

The installed app registers .dcm and .dicom as supported file types. Installation leaves your existing default viewer alone. Choose Open With ▸ OmniDICOM DICOM Viewer to open a file once, or use the operating system's default-app setting to make double-clicks open OmniDICOM.

On a Mac, select a DICOM file, choose Get Info, expand Open with, select OmniDICOM DICOM Viewer, then use Change All… if you want that choice for all files of the same type. Finder and Dock file requests also work while OmniDICOM is already running. Files selected together are opened together; an existing study stays in its own viewer window.

On Windows, choose Open with ▸ Choose another app, select OmniDICOM DICOM Viewer, and choose Always if you want it as the default. Explorer opens each selected file in its own viewer. To open a whole CT/MR stack or many files together, use Open DICOM folder or the app's multi-file picker instead.

Extensionless DICOM files and a DICOMDIR disc index can still be opened through the app's folder or CD/DVD commands.

ZIP archives

OmniDICOM opens ZIP archives directly, including password-protected ones. For an encrypted archive it asks for the password in a dialog titled Encrypted ZIP archive; a wrong password brings the prompt back with "Wrong password." The contents are unpacked into a temporary folder that OmniDICOM cleans up itself. The ZIP file is not changed.

DICOM CDs and DVDs

Insert the disc and wait for it to be read (on a Mac, for it to mount). As soon as a disc with a DICOMDIR or a DICOM folder is present, Open DICOM CD/DVD becomes available. If several discs are mounted, a dialog asks you to choose one. Without a disc the command is grayed out and the status bar says "No DICOM CD/DVD disc detected".

A CD/DVD toolbar button exists as well. It is not on the default toolbar; you can add it with Customize toolbar… (see Toolbar, layout and settings), and it then appears only while a DICOM disc is inserted.

Open DICOM folder with the disc drive chosen works as well.

Adding to what is open

Use the Add DICOM images submenu, or File ▸ Add Folder to Study… and Add File(s) to Study…, when you want a second study next to the first, or when a study arrived in several folders. The new series are sorted into the list under their own patient and study header.

Drag and drop

Drag one or more files, folders or ZIP archives onto the window. A blue dashed overlay reading "Drop DICOM files or folders to open" appears while you hold them over the window. Release to open them. This replaces the current series list, like the Open command.

Inside OmniDICOM you can also drag a series card from the list onto any panel of the image area to show that series there. Empty panels in a multi-panel layout show the hint "Drop a series here".

The Local archive as a source

The Archive button (F8) opens a window titled Local archive followed by the name of the database, a searchable catalog of studies on this computer. The default database is created automatically in your Documents folder, under DicomViewerDB.

Import studies into it with the Folder button or the Import DICOM files... and Import ZIP files... commands, then find them by patient, study, date or modality. To open a study from the archive, double-click it, or right-click it and choose:

The arrow next to the Archive button holds three shortcuts: Import to database (imports the study you are looking at; a dialog asks whether the files should be copied into the database or only linked), New archive database... (Ctrl+F8) and Open archive database... (Shift+F8). Local Archive and PACS describes the archive window in full.

The series list

The column on the left is the series list, also called the series preview bar. Hide or show it with Panels ▸ Series preview bar (Ctrl+Alt+F2). Drag the divider between the list and the image area to change its width; the maximum width is a setting (see Toolbar, layout and settings).

Study headers

Every study starts with a header block:

• the patient's name in capitals, with the date of birth underneath;
• the study date and time followed by the study description;
• the modality and the number of series, for example "CT: 3 series", or "Mixed: 5 series" when a study holds more than one modality.

Studies are ordered by patient name, then date of birth, then study date. Hide patient data (Shift+F12) blanks the identifying lines in the headers as well as on the images.

Series cards

Each series is a card with a thumbnail on the left and text on the right:

The workflow state is one of:

Click Done on a card to mark the series done; the status bar confirms "Series marked done" and the button changes to Reopen. Click Reopen to take the mark off again. Done and Review marks are remembered between sessions.

Series comments

You can add a comment to a series, or to one cine run of an X-ray study. Comments work the same in Basic and Professional.

Select a series and click the speech bubble on its thumbnail, or right-click ▸ Add comment…. N and Edit ▸ Series Comment… open the comment of the highlighted series while the series list has the focus, otherwise of the series in the active panel. A small window titled Comment opens beside the series list. Type the comment, up to 1000 characters; a counter appears near the limit, and text pasted past the limit is shortened. Enter saves, Shift+Enter starts a new line, and Esc closes the window without saving. Tab moves to the buttons in the order Cancel, Save, Remove, and Shift+Tab from the text goes back to Save; Enter or Space then presses the highlighted one. Remove deletes the comment, and so does saving an empty one.

The corner line is not shown on a panel while its cine plays, with annotations off (F12), while patient data is hidden (Shift+F12), or in panels too small for it, such as the 3×3 and 4×3 layouts; the bubble on the card still marks the comment there. While patient data is hidden, pointing at the thumbnail says that the comment is hidden instead of showing it, the Comment window does not open, and the Local archive's Comment column shows "Hidden".

Sometimes several cine runs of one series share a single card, for example when you add a run to a study that already holds another run of the same series. Each run still keeps its own comment. The bubble marks the card when any run has a comment, pointing at the thumbnail lists each run's comment by run number and time, the corner line shows the comment of the run on screen, and the Comment window edits the run on screen (its second line names the run). When no panel shows the card, the bubble, the right-click menu and N open the first run that has a comment. Single images of such a series that are not cine runs share one comment, the series' own, however the folder lists them.

A comment is kept on this computer only, in a folder of its own that is not copied to other computers with a Windows roaming profile. It is not written into the DICOM files, and it is left out of exports, Copy, Send and de-identified copies. It stays when you remove the series from the list, close all studies or quit, and it comes back when you open the same series again, from a folder, a disc, a ZIP archive or the Local archive. A comment never changes the Done or Review state of the series. Delete files from disk… deletes the comments together with the files, every run's on a card that holds several, and the confirmation says so. Deleting a study or series in the Local archive that was imported as copies deletes its comments too.

Selecting and browsing

• Click a card to display that series in the active panel. Enter or Space on the highlighted card does the same.
• For an SR, PDF or video card, Enter also opens its report or player. Ctrl+Enter (Command+Return on Mac) opens an SR in the browser.
• While the list has the keyboard focus: ← and → step through the images of the current series, ↑ and ↓ move to the previous or next series, Home and End jump to the first or last series.
• Ctrl-click (⌘-click on a Mac) adds a card to the selection; Shift-click selects a range. A multi-selection is what Export selected..., Send selected... and the removal commands act on.
• Drag a card onto a panel to show the series in that panel.

The right-click menu

Right-click a series card:

Right-clicking a study header offers the same menu for the whole study: Remove study from list and Delete study files from disk….

Removing and deleting series

"Delete" can mean two different things, and OmniDICOM keeps them apart.

Remove from list forgets the series for this session only. Nothing on disk changes. Use it to tidy the list.

Delete files from disk… erases the DICOM files of the selected series from the disk. A warning dialog titled Delete files states how many series, images and files are affected and which folders they are in, and reminds you: "They are not moved to the Trash and this cannot be undone." Click Delete files to proceed. Cancel is the default button, so pressing Return or Esc never deletes anything.

Pressing the Delete key (or Backspace) with series selected opens the dialog Delete series, which asks which of the two you mean. It offers Remove from list, Delete files and Cancel; again, Cancel is the default.

Some files are refused rather than deleted:

• files that another loaded series still uses;
• files that the Local archive copied into its own store. Delete those from the archive window instead ("managed by the Local archive — delete it there");
• series computed inside OmniDICOM, such as MPR reconstructions, which have no files on disk.

Neither command touches the Local archive database.

Closing everything

File ▸ Close All Studies, or Close all studies in the list's right-click menu, empties the series list and every panel. A dialog asks "Close all N loaded series? The files stay on disk." with No as the default. This is different from Panels ▸ Close all panels (Shift+F4), which only clears the image area and keeps the list.

Reports, documents and videos

A study may contain items that are not images. OmniDICOM opens DICOM structured reports in its own viewer (press Enter on the series; Ctrl+Enter opens the report in your browser instead), shows encapsulated PDF documents, and plays MPEG-2 and MPEG-4 video objects when you press Enter. A presentation state (such as the one Send images adds for text you typed, see Text on images) has no image of its own and shows as a card that says so.

See also

• Local Archive and PACS — importing, searching and downloading studies
• Toolbar, layout and settings — panels, layouts and the series list width
• Viewing images — what to do once a series is on screen
• Troubleshooting and Support — when a file does not open

Toolbar, layout and settings

The toolbar

The toolbar is one row of buttons along the top of the window. This is the default row, from left to right. Point at any button to see its tooltip; the same text appears in the status bar. On a Mac, press ⌘ where a shortcut says Ctrl.

The tool buttons switch on and off

Window, Zoom, Pan and Measure are the mouse tools. Only one is lit at a time, and the lit one is what a left drag does. Clicking the lit button turns it off. With no tool lit, a left drag scrolls: through the slices of a CT or MR series, or through the frames of a cine run such as angiography or ultrasound, exactly like the mouse wheel. The status bar's readout then says "No tool · drag scrolls". The B key also returns to this state.

Measure draws straight lines only. If another shape is armed (chosen in the Analyze panel, from the right-click menu, from Tools ▸ Measurements or with its letter key), the button stays lit; the first click on it brings the straight line back, and the next click turns the tool off.

The toolbar buttons bind the tool to the left mouse button. To put a tool on the middle, right, back or forward button, use Customize keyboard... ▸ Mouse buttons.

Buttons you can add

These buttons are not on the default row. Add any of them with Customize toolbar…; until then their commands are still reachable through the More menu, the menu bar and their shortcuts.

More toolbar buttons (…)

When the window is narrower than the row, the buttons that do not fit move behind an … button at the right end of the toolbar. Click it to get them as a menu; the tooltip reads "More toolbar buttons — the ones that do not fit at this width". When everything fits, the menu only says "Every toolbar button fits".

Customizing the toolbar

Right-click anywhere on the toolbar:

While the bar is unlocked, you can also drag a button sideways to another place in the row. A short click still runs the button's command.

The Customize Toolbar dialog lists every available button with a checkbox. A blue tick means the button is on the row; an empty box hides it. Each entry names its group: File & PACS, View, Playback, Workflow, Inspect & 3D, and Window & Settings. Type in the Search toolbar tools… box to filter the list, drag entries to change their order, and read the count at the bottom, for example "Showing 16 of 31 available tools" on a fresh install. Reset puts the list back to the default, OK applies your changes. The dialog is also under Edit ▸ Customize toolbar… in the menu bar and in the More menu.

Your toolbar layout, position and lock state are saved and restored the next time you start OmniDICOM.

The More menu

The More button at the right end of the row opens a menu that reaches every viewer function, including the ones whose buttons are not on the bar.

Layouts and panels

The image area is divided into panels. Each panel shows one series.

Choosing a grid

Click Layout and move the pointer across the grid picker; the cells light up to show the layout you are about to choose. Click to apply it. Any grid up to 5 columns by 4 rows is possible, and the status bar confirms, for example, "Panel layout: 2 × 2". The View ▸ Layout menu in the menu bar offers the common grids directly: 1 × 1, 1 × 2, 2 × 1, 2 × 2, 3 × 2, 3 × 3 and 4 × 3.

Filling the panels

• Click a series card to show it in the active panel, or drag a card onto any panel.
• Panels ▸ Open multiple series... (F4) opens the dialog Open multiple series, which lists every loaded series with its thumbnail. Ctrl-click the ones you want (⌘-click on a Mac), or type in the filter box, then click OK to place them in the panels in one go.
• Press Tab or Shift+Tab to make the next or previous panel active.

One panel at a time

Double-click a panel, or press Ctrl+M, to maximize it; do the same to restore the grid. Close panel (Ctrl+F4) removes the active panel, Clear panel empties it, and Close all panels (Shift+F4) empties the whole image area while the series stay in the list.

Right-clicking a panel opens a menu of the commands that apply to the image in it. If you prefer the right button free for a tool, turn the menu off with Panels ▸ Enable panel context menu.

The Panels menu

The Panels button on the toolbar opens the window menu. Its entries are also in the More ▸ View options ▸ Window and panels submenu.

Full screen and distraction-free mode

Press F to fill the screen with the OmniDICOM window; press F again to leave. Double-clicking an empty part of the toolbar does the same, and the Full screen button (if you added it) changes to Exit full screen while you are in full screen. The status bar reminds you: "Full screen — press F to exit".

Distraction-free mode (Shift+Alt+Return) hides the toolbar, the status bar, the series list and the metadata panel at once, leaving only the images. Press the same keys again to bring everything back as it was.

Ctrl+Alt+F3 hides only the toolbar and the status bar; all keyboard shortcuts keep working while they are hidden.

The menu bar

Everything on the toolbar is also in the menu bar, together with a few commands that are only there.

The Settings dialog

Click Settings on the toolbar, or choose Edit ▸ Settings… or More ▸ Viewer settings, to open Viewer Settings. Changes take effect when you click OK and are kept between sessions.

Keyboard shortcuts and the tool on each mouse button are not in this dialog. They are set in Customize keyboard..., reached from the Help menu, from Edit ▸ Customize Keyboard… or from More ▸ Help. That dialog can reassign every command, bind tools to the middle, right, back and forward mouse buttons, and restore the defaults in one step.

The window title and the status bar

The title bar shows "OmniDICOM" followed by the patient name, modality and study date of the series in the active panel, for example "OmniDICOM — DOE JANE · CT · 2026-03-14". While Hide patient data is on, the title shows only "OmniDICOM".

The status bar along the bottom shows progress while a study loads, confirmations such as "Panel layout: 2 × 2", license and trial messages, and, on the right, a readout of the current tool and image for the active panel.

See also

• Viewing images — the tools, presets and synchronization in use
• Keyboard and mouse — every shortcut and the Customize keyboard dialog
• Opening studies — the Open / Add menu and the series list

Viewing images

This chapter covers everyday viewing: moving through a series, adjusting brightness and contrast, zooming, rotating, reading the on-screen text, playing cine runs, keeping panels in step, and looking at the DICOM header.

Most commands act on the active panel. Click a panel to make it active. In a multi-panel layout, Tab and Shift+Tab move the active panel to the next or previous one.

On a Mac, read Ctrl as the Command key and Alt as the Option key throughout this chapter. See Keyboard and mouse for the full shortcut list.

Moving through images and series

With the mouse wheel

Roll the wheel over a panel to move through the images of the series (slices of a CT or MR stack, or frames of a cine run). Roll up for the previous image and down for the next.

Hold Ctrl while you roll to zoom instead. Zooming is centered on the pointer unless you turn that off in Viewer Settings.

A sideways wheel (or a two-finger sideways scroll on a trackpad) moves to the previous or next series. Both wheel directions can be reassigned in Viewer Settings; see Mouse wheel options.

By default the series wraps around: rolling past the last image returns to the first. Turn off "Wrap around when scrolling past first/last image" in Viewer Settings to stop at the ends.

With the keyboard

The same keys work while the series list on the left has the focus.

With a left drag (no tool selected)

When none of the tool buttons on the toolbar is lit, the left mouse button scrolls the stack. Drag down to move forward through the images and up to move back, exactly as the wheel does. The pointer turns into an up-down arrow over the image to show that a drag will scroll.

To get into this state, click the tool button that is currently lit (clicking a lit button turns it off) or press B. The status bar confirms: "No tool selected — a left drag scrolls the images, the same as the wheel (the 3D view turns instead)".

In the 2×2 MPR layout the same drag scrolls a reslice plane, while on the 3D quadrant it rotates the volume (see MPR and 3D).

Scrolling by wheel or by drag while a cine run is playing pauses the run.

The Window, Zoom, and Pan tools

The toolbar has four tool buttons: Window, Zoom, Pan, and Measure. A tool button assigns that tool to the left mouse button. Only one is lit at a time. Click the lit button again to turn it off and return to the no-tool state described above.

The Window and Zoom buttons have a small arrow on their right side. The arrow opens a menu of presets (see below). The main part of the button toggles the tool.

Modifier drags and other buttons

You can reach Window, Pan, and Zoom from any tool without touching the toolbar. These are the defaults; all of them can be changed in Help ▸ Customize keyboard... (see Mouse buttons).

On a Mac, either Command or Control works for the Ctrl drags.

Trackpad gestures

On a Mac trackpad, pinch to zoom. Two-finger scrolling works like the mouse wheel; small movements accumulate smoothly instead of counting as full wheel notches. Resting or moving a third finger on the trackpad does not change the window. On a touchscreen, the three-finger window gesture remains available.

Zoom presets and keyboard zoom

The Zoom button's arrow, the right-click menu, and the View ▸ Zoom menu offer fixed zoom levels.

Reset View in the panel's right-click menu puts zoom and pan back to their defaults. It does not change the window.

Zoom by rectangle

Turn on "Zoom by dragging a rectangle (zoom-to-region)" in Viewer Settings to make the Zoom tool work differently: drag a rectangle over the region you want, and the panel zooms to it. The rectangle must be at least a few pixels tall and wide, so a slight slip of the mouse does not zoom.

Windowing direction

If you are used to a viewer that moves the window the other way, open Viewer Settings and use the "Windowing mouse direction" group: "Switch WL / WW axes", "Reverse vertical direction", and "Reverse horizontal direction".

Window presets

Press a number key, or open the arrow next to the Window button, to apply a preset. The bottom-left annotation shows the current values as "WL: … WW: …" with the preset name in brackets.

For PET series the keys 2 to 9 work differently. Each sets the top of the window to a percentage of the series maximum: 0.5%, 1%, 2.5%, 5%, 10%, 25%, 50%, and 100%.

In the 2×2 MPR layout, setting the window on one reslice plane applies it to all three planes.

Negative

Press F11, or choose "Negative" from the Window menu, to invert the grayscale. The annotation shows "[Negative]" while it is on. Press F11 again to turn it off.

Custom window

Press Ctrl+F11, or choose "Custom window..." from the Window menu, to type exact values. The "Custom window" dialog has an "Adjust" selector with three modes:

Click Presets in the same dialog to save your own presets. Each has a Name, an optional Shortcut, and a Modality ("(all modalities)" or one modality). Use Add and Delete to manage the list. Saved presets appear at the bottom of the Window menu. A preset bound to a number key replaces the built-in preset on that key for its modality.

Rotate and flip

The rotate and flip commands are in the panel's right-click menu under Rotate / Flip, in More ▸ Transform image, and on the keyboard.

A Rotate button can be added to the toolbar with Customize toolbar…. Its left half rotates counterclockwise, its right half clockwise, and its arrow opens the full menu.

The top-right annotation shows "Rotated 90°", "Flipped horizontally", or "Flipped vertically" while a transformation is applied.

Annotations

Annotations are the text in the corners of each panel, the orientation letters (A/P, L/R, H/F) at the edges, and the scale rulers. Press F12 to hide or show them. The Annotations command is also in More ▸ View options and in the View menu.

Static information (patient, study, series) is drawn in pale yellow. Values that change as you work (image number, window, zoom state, cursor readout) are drawn in salmon.

While a cine run is playing, the active panel hides its annotations so the image is clean.

Measurements, cross-reference lines, the 3D cursor, and the DSA readout stay visible when annotations are off. To hide measurements in the active panel, use Hide measurements (Alt+F12) in Edit measurements.

Hiding patient data

Press Shift+F12 (or choose "Hide patient data" in the Panels menu) to blank the patient's name, ID, birth date, institution, and comment lines. The series list headers and the window title are blanked as well. This is meant for demonstrations and screenshots. It lasts for the current session only.

Structured reports can contain identifying details in their titles and free text. While Hide patient data is on, the entire report is replaced by a hidden-report notice in its preview, report window, thumbnail and copied or exported pictures. Turn the option off to view the report again. A duplicated viewer window inherits the current privacy choice.

DICOM overlays

Some files carry overlay planes (graphics or text stored inside the DICOM file). They are drawn over the image, and unlike annotations they stay visible during cine playback. Press Ctrl+Shift+F12 (or choose "Hide DICOM overlay" in the Panels menu) to hide them.

Cine playback

Any series with more than one image can be played as a movie: multi-frame runs (angiography, ultrasound clips) as well as ordinary stacks.

Starting and stopping

Press Space to play or pause. More ▸ Playback has "Play / pause", "Previous image", and "Next image". For multi-frame and dynamic series the right-click menu also offers "Play Cine" / "Pause Cine". Play, Prev, Next, and Speed buttons can be added to the toolbar with Customize toolbar….

In the series list, Space shows the highlighted series. If that series is already showing, Space plays or pauses it.

Every run loops. In a multi-panel layout every playable panel plays at the same time, each at its own frame rate and each looping on its own length.

The transport bar

Once a panel is in cine mode (playing or paused), a transport bar appears over the image whenever the pointer is over that panel. From left to right:

The frame rate typed in the transport bar applies to that series only. Hover over the field to see the rate recorded in the file ("DICOM cine rate").

Frame rate

The Speed menu (toolbar Speed button or More ▸ Playback ▸ Playback speed) offers 5, 10, 15, 20, 25, 30, 40, and 60 fps and applies to every run. "Playback FPS" in Viewer Settings sets the default rate.

Automatic playback

Ultrasound, IVUS, angiography, and fluoroscopy series (US, IVUS, XA, RF) start playing by themselves when you open them, at the frame rate recorded in the file. Playback waits until the whole run has been decoded. Turn this off with "Auto-play dynamic series (US/IVUS/XA/RF) in cine mode on load" in Viewer Settings.

Scrubbing

Rolling the wheel or dragging with no tool selected while a run plays pauses it and steps through the frames. The transport bar stays available, so you can resume with the play button or Space.

Synchronizing panels

Series synchronization is a simple ON/OFF switch. Press F5, click the Sync button on the toolbar, or choose More ▸ Series synchronization ▸ Synchronize panels. The button's body toggles the switch and its arrow opens the menu.

The switch is available when at least two images are open, including images in other viewer windows. With only one image it is disabled; the chosen mode is remembered for when a second image opens.

When you turn it ON, the app records where every panel is at that moment: its slice or frame, its zoom, and its pan. From then on, moving one panel moves all the others by the same amount, keeping the offsets you set up. The status bar says "Sync on — panels move together from where they were when you turned it on." To take a fresh reference from new positions, turn it off and on again.

Some details:

• Series with position data (CT, MR) follow by patient position. Planes must be roughly parallel; a coronal stack does not follow an axial one, and the reslices of the 2×2 MPR layout do not drive each other.
• Series without position data (angiography, ultrasound, radiographs) follow by frame number.
• Synchronization works across studies and across viewer windows. A series you open after turning sync on joins from where it is.
• Reaching a stack's end gathers the linked stacks at that end. Scrolling back then moves them together from those positions.
• Pan follows physical distance when both panels have patient geometry, and otherwise follows the same screen distance. Maximizing a panel, changing layouts or resizing preserves the linked zoom relationship.
• Window settings follow only when the proposed range overlaps the target frame's displayed values. This avoids blanking an X-ray with incompatible CT values while allowing lung and bone windows on CT.
• Splitting a series into volumes (Ctrl+F5, or Shift+Command+F5 on a Mac) turns sync on so the parts stay aligned.

Turn it OFF with F5 again: "Sync off — each panel scrolls, zooms and pans on its own."

Matching panels

Right-click the panel the others should look like and choose Match Other Panels to This One. Every other panel in the window that shows an image then:

• Gets the same size on screen. One millimetre of the patient takes the same number of screen pixels in every panel, so the rulers are the same length. The size comes from a manual calibration if there is one, otherwise from the image's pixel size. A panel whose image has no pixel size keeps its own zoom.
• Is centred on the same place. Series of the same scan (the same frame of reference, MPR reslices included) are lined up by patient position and move to the slice through the centre of the panel you right-clicked, even in another plane. A series from another scan keeps its slice and is centred the same number of millimetres from the middle of its image.

Sync then turns on, so the panels stay matched while you scroll, zoom and pan. The status bar says how many panels were matched, for example "Matched 3 panels to this one. Sync is on."

The window settings stay as they are, so the panels can be compared at different windows. Tick Also Match Window in the same menu to copy the window too; the choice is remembered. A window that would show nothing on another series is not copied. With Window settings on in the Sync menu (the default), changing the window afterwards changes it in the other panels as well.

Time-intensity curves, document and video cards, and the 3D quadrant are left as they are. A panel in a different plane is matched once; like any perpendicular plane, it does not follow later scrolling.

Cross-reference lines

Cross-reference lines are separate from synchronization. Press Ctrl+F12, or choose "Cross-reference lines" in the same menu, to draw a line on the other panels showing where the active panel's image cuts through them. Lines appear only on panels showing a different plane of the same study (an axial line on a sagittal series, for example). They work across viewer windows and are hidden while the 3D cursor is showing.

3D cursor

Press Q, or hold Ctrl+Shift and drag from any tool, to mark a point on the image. Every other panel showing the same anatomy jumps to the slice nearest that point. See Measuring for details.

The DICOM Meta panel

Click Metadata on the toolbar (or More ▸ View options ▸ DICOM metadata) to open the DICOM Meta panel on the right side of the window. Click the button again, or the X in the panel header, to close it. Drag the divider to resize the panel; the width is remembered.

The panel lists the header of the selected series as a table with three columns: Tag, Name, and Value. Type in the "Filter tag/name/value..." box to show only matching rows. Long values are cut off on the right; hover over a cell to read the whole value.

If you select several series from different patients, the panel shows "mixed patients selected" and no rows.

Right-click a row for Copy value, Copy selected item, Copy all items, Save RAW value..., and Reveal file in Finder. The same actions are in the separate DICOM tags window (Ctrl+Alt+T).

Editing values

Double-click a value to edit it, then press Enter. Edited values are not written until you click Save Changes at the bottom of the panel. The button stays disabled until you change a value; it then turns blue and shows how many values you changed, for example Save Changes (2), and the changed values are shown in bold blue. Your changes stay in the table while the series keeps loading in the background. If you select another series before saving, OmniDICOM asks whether to save the changes first.

Save Changes writes every edited value into every file of the selected series, in place. No backup copy is made. Work on a copy of the data if you may need the originals.

Sequences (shown as "[Sequence: n items]") and binary values such as pixel data are read-only. So are the values inside a sequence: they are listed in grey right after the sequence's row, and Save Changes writes only top-level values. The status bar reports the result, for example "Saved 3 value updates across 60 file(s)."

See also

• Keyboard and mouse — the full shortcut list, mouse buttons and wheel options
• Toolbar, layout and settings — the toolbar, panel layouts and the Settings dialog
• Measuring — measurements and the 3D cursor
• MPR and 3D — the 2×2 layout and the 3D windows
• DSA subtraction — playing and subtracting angiographic runs

Keyboard and mouse

This chapter lists every keyboard shortcut, explains how to change them, and shows how to assign tools to the mouse buttons and the wheel.

On a Mac, read Ctrl as the Command key and Alt as the Option key. Enter and Return are the same key. Shortcuts written as "Ctrl++" mean Ctrl with the plus key; "Ctrl+=" does the same.

Every shortcut below is the default. Any of them can be changed; see Customizing the keyboard.

Keyboard shortcuts

Opening files and windows

Moving through images

Tools

Window and zoom

Rotate, flip, and filters

Layout and display

Measurements

Synchronization, MPR, 3D, fusion

3D quadrant of the 2×2 layout

DSA

Archive and PACS

DICOM tags window

These keys work inside the window opened with Ctrl+Alt+T.

Customizing the keyboard

Open Help ▸ Customize keyboard... (the Help button on the toolbar, or the Edit or Help menu in the menu bar). The "Customize keyboard" dialog lists every command with its current shortcut in a two-column table, Command and Shortcut.

To change a shortcut:

1. Type part of the command's name in the "Filter commands..." box to find it.
2. Click the row.
3. Click in the "Press new shortcut:" field and press the key combination you want.
4. Click Assign.

If the combination already belongs to another command, a "Shortcut in use" prompt names that command and asks whether to move the shortcut. Click Remove to take the shortcut away from a command without giving it a new one.

Changes apply at once in every open viewer window and are remembered between sessions. Reset all defaults restores every command, and the mouse buttons, to the defaults after asking you to confirm.

A key you gave a command stays with it when a later version gives that key to a new command by default. For example, if you had put Pan on T, Pan keeps T and the Text tool has no key; the status bar says so once at start-up. Give the Text tool a key here, or move Pan to another key and T goes back to Text.

The navigation keys are fixed and cannot be reassigned: the arrow keys, Page Up/Down, Home/End, Space, Enter, Esc, Tab, and Delete for measurements.

Mouse buttons

The lower part of the Customize keyboard dialog has a Mouse buttons group with one selector for each of the five buttons: Left, Middle, Right, Back, and Forward. Each can hold one tool:

• Browse series (a drag scrolls through the images)
• Window (brightness/contrast)
• Pan
• Zoom
• Measure tools

The toolbar tool buttons (Window, Zoom, Pan, Measure) change the left button only. Clicking the lit tool button sets the left button back to "Browse series". Tools placed on the other buttons here stay until you change them.

A right click without dragging opens the panel menu; a right drag runs the tool bound to the right button.

Modifier + left button

The Modifier + left button group assigns a tool to four combinations: Ctrl + Left, Shift + Left, Alt + Left, and Ctrl + Shift + Left. Choose "(none)" to leave a combination unused, in which case the plain left-button tool applies.

These combinations work whatever tool is lit on the toolbar, and they work the same way in the 2D panels, the 3D MPR window, and the 3D Volume Rendering window.

Notes for Mac users: macOS turns a Control+click into a right click. OmniDICOM recognizes this, so a Control+drag still runs the "Ctrl + Left" tool. A Command+drag does the same.

Mouse wheel options

Open Viewer Settings (the Settings button on the toolbar) to change what the wheel does.

Ctrl+wheel always zooms, whichever choice you make for the vertical wheel.

Two other mouse-related settings live in the same dialog:

Trackpad gestures

On a Mac trackpad, pinch to zoom and scroll with two fingers to move through images. Holding Ctrl (Command on Mac) while scrolling zooms smoothly. Resting extra fingers on the trackpad does not adjust the window. In the 3D Volume Rendering window, a rotate gesture rolls the volume. On a touchscreen, two-finger pan and three-finger window/level gestures remain available.

See also

• Toolbar, layout and settings — the toolbar buttons behind these keys
• Viewing images — tools, window presets and cine playback in use
• Measuring — how each measurement shape is drawn
• DSA subtraction — the DSA keys explained
• MPR and 3D — the keys of the 3D MPR and 3D Volume Rendering windows

Measuring

OmniDICOM draws measurements over the image: distances, areas with pixel statistics, angles, arrows and freehand marks. Every measurement belongs to the image it was drawn on. Scroll to another slice and it stays behind; scroll back and it is still there.

Measurements and text are not written into the DICOM files. Measurements stay in the viewer while the study is open; to keep them, export or copy the image with annotations switched on. Text you type on an image is kept on this computer and comes back when you open the series again (see Text on images). For a note about the whole series, use its comment.

All measurement tools are part of the Basic viewer. Only the Analyze panel, which adds statistics and plots on top of them, needs a Professional subscription (see Analyze and Process).

The Measure button

The toolbar button Measure turns on the straight-line distance tool. Drag across the image to draw a line. The label shows the length in millimeters, or in pixels when the image carries no calibration.

The button toggles:

• Click Measure once: the left mouse button draws distances.
• Click it again: the tool turns off. With no tool lit, a left drag scrolls through the images, just like the mouse wheel.
• If another shape is armed (chosen from the Analyze panel, the right-click menu or the Tools menu), the button is lit with that shape. The first click brings the straight line back; the click after that turns the tool off.

Hold Shift while drawing to keep the line exactly horizontal or vertical.

The other shapes

Measure only draws straight lines. The other shapes are reached in four ways:

To put a measurement tool on the middle, right, back or forward mouse button instead, use Customize keyboard... ▸ Mouse buttons (see Keyboard and mouse).

The status bar names the tool you just armed and reminds you of the gesture for the multi-step shapes.

The 3D Cursor needs image position tags in the series (CT, MR). It does not work while cine playback is running. From any other tool, Ctrl+Shift+drag does the same thing.

Press Esc while drawing to throw the shape away.

Text on images

Press T or click Text on the toolbar, click the image and type. The text keeps the same size on screen when you zoom, and moves with the image when you pan, rotate or flip. Drag it to move it, double-click it to change it, select it and press Del to remove it. Change its size with − and + under the text while typing, or right-click it ▸ Text size. The size and color you last chose are used for the next text. Turn on All images to show one text on every frame of a cine run or every slice of a series.

While you type, the bar under the text sets its size (8 to 72 px; Ctrl+Shift+= and Ctrl+Shift+- step it too), its color (white, yellow, green, red or cyan) and All images. Text on an X-ray or ultrasound cine run starts with All images on, so it does not flash by for a single frame; on a CT or MR series it goes on the one slice. Clicking the image while a run plays stops the playback first.

The text is finished when you press Enter, click anywhere else, scroll, or change the view; Esc throws a new text away and puts a changed one back as it was. A text you empty and finish is deleted.

The arrow beside the Text button sets the size, the color and the background box for new text. On a narrow window the button moves into the ••• menu as Text on image; T always works.

Right-clicking a text offers:

Where text is kept

Text is kept on this computer only, in a small file beside the series' comment, in a folder that is not copied to other computers with a Windows roaming profile, and comes back when you open the series again, after a restart too. It belongs to the image it was typed on (by the image's DICOM identity), so it stays on that image when slices are added or the folder is moved. It is never written into the DICOM files. Delete files from disk also deletes the text on the images whose files were deleted; text on a file that could not be deleted stays.

With the same series open in two windows (or a duplicated window), text typed, changed or deleted in one shows in the other at once, and neither window's saving ever removes the other's text. Changing a text never moves it, even when it runs past the edge of the panel.

Exported pictures and movies show the text unless Annotations is set to Disabled; Basic (anonymous) keeps it, so do not type patient details on an image you will share. Send images takes the text along as a DICOM presentation state (see Export and Sharing). Measurements are not sent.

Alt+F12 hides text together with the measurements.

Selecting a measurement

Click on a measurement to select it. The outline turns yellow-olive and its label chip turns red. Only one measurement is selected at a time, across all panels. Click on empty image, or press Esc, to deselect.

Measurements that are hidden (see Hide measurements below) cannot be clicked.

The Analyze panel, when open, shows what is selected. Statistics, Histogram and the other Analyze tools measure inside the selected ellipse or closed polygon.

Editing a measurement

If you press Del with nothing selected, the status bar says: "Click a measurement to select it, then press Del".

Right-click on a measurement

Right-clicking a measurement selects it and opens a menu. What it offers depends on the shape:

Arrow properties

The Arrow properties dialog sets Arrow style (Filled, Open, Thin, Double ended), Line width, Head size, Arrow color, Opacity, Text, Text size and Text color.

Under Presets you can name the current style (Add), pick a saved preset from the list or Delete one. Set current style as default for new arrows makes every arrow you draw from now on use this style. Presets never carry the text; the text belongs to the one arrow.

Arrow colors and Restyle All Arrows

Each arrow keeps its own color. The Color row of the arrow's right-click menu recolors that one arrow; More… opens a color picker for any other color. If the arrow's text had the arrow's color, the text follows; a text with a color of its own keeps it.

Restyle All Arrows… gives every arrow one look in one step:

• Apply to: All arrows, or only the arrows of the right-clicked arrow's color (for example Only red arrows). Arrows of other colors are left as they are.
• Color, Thickness (0.5 to 10) and Head size (4 to 60). The dialog starts from the arrow you right-clicked, so Apply without changing a value keeps that value.

It changes every arrow on the open series and images of the window. Mark numbers, texts, arrow styles and opacity stay as they are, and so do your presets and the default style for new arrows. The status bar says how many arrows changed.

Mark numbers

Number Marks numbers your arrows and measurements 1, 2, 3… in the order you draw them, so a slide or a table can refer to "Mark 2". It is off until you turn it on, and the choice is remembered. It is in the right-click menu of every arrow and measurement and in the Edit measurements dropdown.

• Numbers count per patient: every open series of one patient shares one sequence, so a prior and a current line up. Another patient starts again at 1.
• Turning it on numbers the arrows and measurements you already drew, in the order you drew them. New ones get the next number.
• A measurement shows its number at the start of its label ("3 · Mean=…"). An arrow shows its number just beyond its tail; the arrow's own text is unchanged.
• Mark Number ▸ gives the mark another number (two marks may share one), Next Free Number, or No Number, which stays even when you turn Number Marks off and on again.
• Copies keep the number: Paste, Duplicate in other panels and Duplicate in all images of the series give the copy its original's number, so an arrow repeated on every image of a series is the same mark on each.
• Show Numbers on Picture hides the numbers on the image while keeping them on the marks.
• The ROI manager has a Mark column while Number Marks is on, and its saved Excel and CSV files carry the numbers (see Analyze and Process). With Number Marks off, the Mark column of a saved file is empty.
• Turning Number Marks off hides the numbers everywhere. The marks keep them, and they come back when you turn it on again. Deleting a mark never renumbers the others.

Text and freehand (pencil) marks are not numbered. Copied pictures (Copy Image, Copy Layout) and exported pictures show the numbers as the screen does.

Copying, duplicating, deleting and hiding

These commands live in the Analyze panel under the Edit measurements dropdown. Their keys work whether or not the panel is open.

Copied measurements go to a clipboard inside OmniDICOM, not to the system clipboard. Copying a text also puts its words on the system clipboard, ready to paste into a report. A text shown on all images is already on every image, so Duplicate in all images of the series leaves it as it is.

Calibration

A distance can only be reported in millimeters when the viewer knows how large a pixel is. The color of the label chip tells you where that knowledge came from:

Ultrasound images can contain several calibrated regions (for example a B-mode image and a Doppler trace). A Length drawn inside a region is reported in that region's units, such as cm, s or cm/s.

Manual calibration

If a series has no calibration, or you do not trust it, calibrate it yourself:

1. Draw a Length over something whose true size you know, such as a ruler or a catheter.
2. Right-click the line and choose Calibration....
3. Enter the True distance and pick the Units: millimeters, inches or French (1 Fr = 1/3 mm).
4. Click OK.

The dialog shows the measured segment in pixels. The new scale applies to every measurement in that series, and their chips turn green. The status bar reports the scale in mm/px.

To go back to the file's own calibration, open Calibration... again and click Reset calibration.

Units and precision

These settings are global: they apply to every measurement in every panel and are remembered between sessions. Distances, polygon areas and perimeters, and angles follow them. Uncalibrated measurements are always shown in px or px².

Ellipse statistics have their own fixed format. On CT the values are Hounsfield units and carry no suffix. On PET they show the units stored in the file, or SUVbw when SUV is switched on.

See also

• Analyze and Process — statistics, histograms and profiles over a measured region
• Viewing images — annotations, the 3D cursor and copying images
• Keyboard and mouse — the measurement keys and mouse-button assignment
• Export and Sharing — exporting pictures with measurements drawn on them

Analyze and Process

Analyze and Process are the two Professional workspaces. Both open as a column beside the images from a toolbar button of the same name. Denoise, also Professional, is a toolbar button of its own and a row in the Process panel.

• Denoise reduces the noise of CT, MR and X-ray series.
• Process decides how the image looks: a chain of filters, or a thresholded region, applied to a series without touching the files.
• Analyze measures the image: statistics and plots over a region, particle counts, projections, image arithmetic and time-intensity curves.

They are used one after the other, not side by side. Opening one closes the other.

Basic, Professional and the trial

Basic is the complete viewer. Professional adds Denoise, the Process panel with every image filter, and the Analyze panel with all of its tools, including TIC. The 14-day trial, the 5-minute sessions after it, the two plans and license keys are described in Getting started.

When you open a Professional feature without a license for it, a dialog explains the situation instead of opening the feature. Its status line reads "Trial expired", "Licence expired", or, on a Basic subscription, "Basic licence on this computer — Professional features are not included". Enter licence… reveals a box for a key of the form OMNI-XXXX-XXXX-XXXX-XXXX and an Activate button; if the key unlocks the feature, the feature opens right away. On a Basic subscription, Upgrade to Professional moves your existing key to Professional when you pay; see "Upgrading from Basic to Professional" in Getting started.

Switching a filter off is never locked. If a trial runs out while a filter is on, you can still remove it.

The watermark

While OmniDICOM is on a trial or has no valid license, every exported picture or movie and every image copied to the clipboard carries the banner "OmniDICOM trial — not licensed for publication" along its bottom edge. Basic and Professional subscriptions export without it. See Export and Sharing.

The Analyze panel

Click Analyze on the toolbar to open the panel; click it again, or the close button in its header, to close it. Keep open in the header opens Analyze automatically when the viewer starts.

The top of the panel describes the active panel: the image number and zoom, the window (WL and WW), how many measurements are on this image, which tool is armed, and which measurement is selected.

Measurements

Four buttons arm a drawing tool on the left mouse button: Length, Ellipse, Polygon (a closed polygon) and Angle. The lit button is the one currently armed. The other shapes have letter keys; see Measuring.

Edit measurements is a dropdown with copy, paste, duplicate, delete and hide commands and their keys. Measuring lists them.

Which pixels are measured

Every Quantify tool works on the image shown in the active panel and on one region of it:

1. If an ellipse or closed polygon is selected, that region.
2. Otherwise, the whole image.

Only one measurement can be selected at a time. Length and angle measurements bound no area, so they do not count as a region.

Values come from the stored pixels, not from the picture on screen. Changing the window does not change a result. Display filters from the Process panel do not change the numbers either. DSA subtraction does, because it changes the data: the result's title then says which source it was measured on.

Units follow the modality: HU on CT, SUVbw on PET when the file carries the tags for it, none otherwise. Derived images (3D renderings, Z projections, calculator results) are reported without a unit.

Each result dialog is titled with the series, the image number and the region, for example "Series 3 — image 42/120 · Ellipse 1".

Quantify tools

Buttons that cannot run are greyed out; hover over one to read the reason.

Every plot and table dialog has the same way out: Copy plot copies the picture (on a trial, with the banner on a strip below it), Copy data or Copy all copies the numbers as tab-separated text, and Save as Excel… and Save as CSV… write them to a file.

Saving numbers (Excel and CSV)

Save as Excel… writes an Excel workbook (.xlsx); Save as CSV… writes a CSV file. Both hold the same columns. The workbook has three sheets:

A CSV holds the first sheet only. It is UTF-8 with a byte-order mark, so Excel reads Korean text and the mm²/° units correctly.

Every row says where its number came from: Series, Series description, Image, Slice location (mm), Plane (Axial, Coronal, Sagittal or Oblique), the Region measured, the Pixel source (Original, Denoised, Subtracted or Fusion overlay) and the Calibration (Pixel spacing, Detector plane, Estimated magnification, Ultrasound region, Manual or None). The slice location is the image's DICOM Slice Location, or its position along the stack when the image has none.

• Numbers are saved as numbers at full precision; Excel shows them with the decimals used on screen. A large value such as 1234567 is saved as 1234567.
• Units are in a Unit column (Measurements, Statistics) or in the column heading (the plots, Particles and the TIC).
• The tables, the files and an ellipse's on-image label all use the sample standard deviation (n − 1).
• The files hold no patient name, patient ID, study or birth date, time of day or DICOM UID. Series are named by their number and description.
• Text that starts with =, +, -, @, a tab or a line break is saved so that Excel never runs it as a formula.

The suggested name is the table's name and the time, for example Measurements 2026-10-13 1530.xlsx. The suggested name is always free. If you choose a name that exists, the save dialog asks whether to replace it, on the Mac and on Windows: Replace overwrites that file, Cancel keeps it. Saving starts in Documents and remembers the folder of the last successful save. If the file cannot be written, for example because it is open in Excel or the folder is read-only, a message says so and the previous folder is kept.

Select region

Opens the Threshold & morphology — Process dialog. It selects an intensity range and refines the detected region; the source image is not changed.

Click Apply. The region becomes part of the series' processing: it appears in the Process panel's "Applied:" line and is removed by Reset to default or Tools ▸ Process ▸ Reset processing.

Histogram

A bar chart of pixel values. Bins sets the number of bars; the default is one bin per unit on integer data such as CT, and the value you choose is kept for the session. Log scale makes the tissue range readable when a CT histogram is dominated by air.

Under the plot: Pixels, Mean, Std dev, Min, Max, Median, Area (when calibrated), Mode and Bin width.

Statistics

A dialog named Measure listing:

On a color series the values are measured as (R+G+B)/3 and the dialog adds a mean for each channel, so a red and a blue structure of equal brightness are not mistaken for each other.

Copy copies the rows as they read on screen. Save as Excel… and Save as CSV… save them as numbers: one row per value, with Measure, Value and Unit columns after the columns that say where the values came from. Std dev is saved as SD, and 5th–95th pct as two rows, 5th percentile and 95th percentile.

Plot profile

Graphs the pixel values along a Length measurement. Draw a Length across the structure first. If one line is selected, that line is used; otherwise the most recently drawn line is used and the status bar says so. With no line on the image, a message explains what to draw.

The x axis is the distance along the line in mm (or px when uncalibrated). Under the plot: the statistics of the sampled values, the line length and the number of samples.

Z profile

Takes the region drawn on the current image and reports its mean on every image of the series, plotted against the image number. Under the plot: the statistics of those means, the number of images, and the image where the mean peaks. Use it to find where a region's values peak along the stack.

The means are measured on the panel's own series, in its unit: on PET they are in SUVbw like every other PET statistic. On a fused panel they still come from the panel's own series, not from the overlay. The saved file has one row per image, each with that image's number and slice location.

Z project

Combines a range of slices into one image. Choose the Projection (Max intensity, Min intensity, Average intensity, Sum slices, Standard deviation, Median) and the Slices range (from … to), then click OK.

The result opens as a new series in a new panel. The original is untouched. The projection keeps the in-plane calibration of its source, so measurements on it are in millimeters. Like every derived series it can be exported as an image but not as DICOM.

Particles

Groups the pixels inside a value range into connected objects and measures each one.

The Analyze particles dialog has a Value range (it starts at the brightest 5 % of the image), a Particle size range in px (an upper limit of 0 means "no limit"), Exclude particles touching the image edge (on by default, because a particle running off the image has an unknown size) and Fill holes inside particles. While you adjust the values, the matching particles are outlined on the image and the dialog counts them.

Click OK for the results table:

Click a column header to sort. Double-click a row to zoom to that particle and highlight it. The summary line gives the count and the total area. The outlines disappear when the table closes; they are a result, not an annotation. To keep a picture of them, click Copy Image in the table: it copies the active panel with its outlines, as Copy Image does (see Export and sharing). Each column shows the decimals it always did; Copy all and the saved files keep every digit.

ROI manager

One table for every measurement: #, Image, Tool, Mean, SD, Min, Max, Area, Angle (°) and Length. Show at the top switches between This series and All open series; with All open series a Series column gives each row's series number. When only other open series have measurements, the table opens on All open series. While Number Marks is on (see Measuring), a Mark column gives each measurement's number.

Lengths are in mm, or px where an image is uncalibrated. Areas are in the unit of the on-image label: cm² for an ellipse, mm² or cm² for a polygon, px where an image is uncalibrated. On PET an ellipse's values are in SUVbw when its label is, and in the PET's own unit (for example Bq/ml) when SUV is turned off for that ellipse; polygons follow the series. A column whose rows have different units shows the unit in each cell. The table shows the decimals of the on-image labels; Copy all and the saved files keep every digit.

Double-click a row to jump to the image that measurement lives on, which is the practical way to find a measurement again in a long series. A row of a series that is not on screen opens that series in the active panel.

Save as Excel… and Save as CSV… save the Measurements sheet of what Show lists: one row per value, with the columns Mark, Series, Series description, Image, Slice location (mm), Plane, Tool, Measure, Value, Unit, Pixel source and Calibration. Units follow the on-image labels, so an ellipse's area is in cm² and a polygon's in mm² or cm². The Calibration is each measurement's own: a length inside a calibrated ultrasound region reads Ultrasound region. The Mark column is filled only while Number Marks is on. An arrow is saved with its length; its typed text is never saved. Text and pencil strokes measure nothing and have no rows.

Calculator

The Image calculator combines two images of the same size into a new series.

A preview updates as you change anything. Subtracting a mask frame from a contrast frame of the same run is manual subtraction angiography.

TIC (time-intensity curve)

A TIC plots the mean of one ellipse across the phases of a dynamic study. It is reached from the TIC button, from Tools ▸ Time-Intensity Curve, or with Ctrl+Shift+E.

1. Draw an Ellipse over the region on one series of the study. If several ellipses exist, select the one you want; otherwise the most recent is used.
2. Start TIC. The Time-intensity curve dialog lists every loaded series with its acquisition time. Series of the same study with matching geometry are already ticked. Tick at least two and click OK.
3. A new panel opens with the curve: mean intensity against time (acquisition time from the files, or the timepoint number when the files carry no times), with a small windowed capture of the region from each series along the bottom.

The ellipse is scaled into each series' matrix, and the image nearest to the source position is used. The result panel behaves like any other: double-click it to maximise, copy it with Ctrl+C or Copy Image, or export it as a picture. It cannot be exported as DICOM.

Right-click the curve panel for Save as Excel… and Save as CSV…: one row per series, in the curve's order, with Mark, Series, Series description, Image, Slice location (mm), Time (s), Mean, Pixel source and Calibration. Time is counted in seconds from the first series that has a time; times of day are not saved. The mean is measured on the stored pixels, as the curve is, so the Pixel source is Original. Like TIC itself, saving needs Professional or the trial.

Denoise

Denoise reduces the noise of CT, MR and X-ray images: grainy areas become smooth while edges and fine structures are kept. It is computed on this computer, and no image leaves it. On a Mac with macOS 15 or later it runs on the graphics processor; on macOS 14 it runs on the processor. Either way it typically takes well under a tenth of a second per slice. On Windows it uses the graphics card where there is one; otherwise it uses the processor, which takes longer.

Denoise works on CT and MR series and on X-ray images (CR, DX, DR and RG). For any other modality, mammography included, the Denoise button is greyed out and says so. On an X-ray series the menu, the status bar and the image corner say image instead of slice. On a Mac, Denoise needs macOS 14 or later; on macOS 13 it says so when you press it.

From the toolbar

In the Process panel

The DENOISE row at the top of the Process panel is the same Denoise, over the whole series. Tick it and press Apply or Save & Apply like any filter. It runs before the filters below it.

Saving

Denoise is processing like any other. Until it is saved, leaving the series or opening another study asks "Save the processing applied to …?" (Save, Don't Save — Discard on Windows — and Cancel). A saved Denoise runs again by itself the next time the series is opened. The DICOM files are never changed.

On a denoised series, measurements, Statistics and Histogram read the denoised values, and their results say "denoised image". Hold to compare in the Process panel shows the original while it is held.

The Process panel

Click Process on the toolbar (or choose Tools ▸ Process ▸ Process panel) to open it. Keep open in the header opens it at every start.

Processing belongs to the series, not to the panel. It is remembered for the series and comes back whenever that series is shown again, and exports and Send carry it. Processing never modifies the DICOM files on disk.

Under the header, Applied: names what is on the image right now ("Original" when nothing is), and Not saved appears while an applied preset has not been saved.

PRESET

FILTERS

One row per filter. Tick a filter to switch it on and type its numbers. Ticked filters run in the order shown, top to bottom; a numbered badge shows each one's position. Drag the ≡ handle to change the order. Up to 8 filters can run at once.

Order matters: blur then sharpen is not the same image as sharpen then blur.

The two sharpenings sit together. Sharpen (3×3) is the quick fixed kernel with one strength, as on the Image filters menu. Sharpen – unsharp mask sets the size of the detail (Radius) and how much of it is added (Amount); Threshold leaves differences smaller than that many grey levels alone, so fine noise is not sharpened with the edges.

On an angiogram, vessels, catheters and guidewires are darker than what surrounds them. Choose Dark for Small-structure enhance and Vessel enhance, and Light background for Subtract background; the defaults suit bright structures on a dark background, as on CT. Auto lets Vessel enhance decide on every frame, which can change between frames of a cine run; Dark or Bright holds it. Tiles sets how many regions CLAHE balances across the image: more tiles, more local.

Apply, Save and compare

Apply is for trying things. Save & Apply is for finishing. A saved combination comes back the next time the series is opened; it is stored in OmniDICOM's own data folder, not in the DICOM files.

If you switch to another series, or close the panel, while something is applied but not saved, the Unsaved processing dialog asks "Save the processing applied to …?" with Save, Don't Save (Discard on Windows) and Cancel. Don't Save puts the series back to its last saved processing; Cancel keeps you where you are.

Filters change what you see, not what is measured: Statistics, Histogram and measurement labels read the stored pixel values. Denoise is the exception (see "Denoise" above).

The Image filters menu

Tools ▸ Process ▸ Image filters offers ready-made presets that apply immediately to the active panel and are saved for the series:

The same presets are behind the toolbar's Image filters button, which is not on the default toolbar; right-click the toolbar and use Customize toolbar to add it. A preset chosen from a menu shows up as ticked rows in the Process panel, except Emboss and Equalize histogram, which have no adjustable numbers.

Tools ▸ Process ▸ Reset processing removes the filter and any region from the active series.

Fine-tune & combine

Tools ▸ Process ▸ Image filters ▸ Fine-tune & combine… (Ctrl+Shift+U) is a dialog for building a filter chain by typing exact numbers, with the image updating as you type.

1. Pick a Filter and set its values. The image already shows the effect.
2. Click Add to sequence to keep it as a step and start the next one.
3. Select a step in the Sequence list to edit its numbers, or use Move up, Move down and Remove.
4. Clear all returns to the original image.
5. OK keeps exactly what the panel is showing, including the step you are still composing. Cancel restores the image as it was.

The Process panel and this dialog edit the same chain; whichever you use, the result is what the series shows.

See also

• Measuring — drawing the regions the Analyze tools measure
• Getting started — the trial, the plans and entering a license key
• Export and Sharing — exporting processed series and the watermark
• DSA subtraction — subtraction of angiographic runs

MPR and 3D

OmniDICOM can rebuild a stack of slices into a volume and show it in several ways: as new slices cut along another plane (MPR), as three linked oblique planes in the 3D MPR window, and as a rendered volume (3D VR), either in a quadrant of the main window or in its own window. It can also fuse two series, such as PET over CT. All of this is included on every plan, including Basic.

On a Mac, read Ctrl as the Command key and Alt as the Option key; the app's own tooltips use the Mac names on a Mac.

Which series can be reconstructed

The volume tools need a stack of parallel, evenly spaced slices with position and orientation information. When a series does not qualify, the MPR and 3D VR buttons are grayed and their tooltip names the reason.

If the slices are unevenly spaced but otherwise usable, the volume is still built and the missing slices are interpolated. A dialog titled "MPR — uneven slice spacing" warns you once per series, and the 3D windows show "Interpolated slices" or "Uneven slice spacing — interpolated" while you work.

Where the 3D commands are

The More menu (the last toolbar button) also holds an MPR submenu and the 3D Volume Rendering entry. A Fusion button can be added to the toolbar with Customize toolbar; it is not in the default row.

Every command works on the series in the active panel. With no series loaded you get a status message such as "Load a series first to open the 3D MPR window".

Reslices in a panel (2D MPR)

Press Ctrl+Alt+1 (Coronal), Ctrl+Alt+2 (Sagittal) or Ctrl+Alt+3 (Axial), or pick the plane from the MPR button. The app cuts the volume along that plane and shows the result in the active panel as a new series named, for example, "Coronal MPR". It opens on the middle slice. The plane the panel already shows is checked and grayed in the menu.

The reslice behaves like any other series: scroll it, window it, measure on it. It is a reconstruction held in memory, not a new set of DICOM files.

The MPR 2×2 layout

Press Ctrl+Alt+M. The main window switches to a 2×2 grid: Axial, Coronal and Sagittal reslices in three quadrants and a live 3D rendering of the same volume in the fourth. Each plane opens on its middle slice. A crosshair marks the same point in all three planes, starting at the center of the volume.

The status bar shows "MPR 2×2 — rendering VR..." while the 3D quadrant is prepared; the three planes are usable immediately.

The three planes

The planes follow the toolbar exactly as ordinary panels do.

The mouse wheel always scrolls the slices. Ctrl+wheel zooms.

The crosshair

The crosshair is a handle. Move the pointer onto one of its lines: the pointer becomes a move cursor. Drag there and the crosshair moves; the other two planes jump to the slices that pass through the new point. This works whatever tool is lit. The crosshair keeps its position when you release the mouse.

Scrolling a plane slides the crosshair onto the slice you are now looking at, so the other planes keep cross-locating the point you are examining.

To place the crosshair somewhere else in one step, select the 3D Cursor measurement tool (press Q, or choose it under Tools ▸ Measurements) and click the point, or hold Ctrl+Shift and drag on any plane.

The 3D quadrant

The fourth quadrant is a rendered volume. Its behavior also follows the toolbar:

Whatever is lit, the modifier drags still work: Ctrl+drag adjusts the threshold, Shift+drag pans, Alt+drag or a right-button drag zooms, and a middle-button drag pans. Ctrl+wheel zooms. When you click into the quadrant, the status bar says what a plain drag will do right now and adds "turn the tool off to rotate" while a tool is lit.

An orientation cube sits in the lower right corner of the quadrant. Click one of its faces (A, P, L, R, S, I) to look straight at the volume from that side.

A CT opens in the "Bones and skin 1" preset; every other modality opens as a MIP.

The 3D tools strip

While a quadrant of the layout is active, a vertical strip appears at the right edge of the window. From top to bottom:

The strip serves the whole layout. On a plane, the 3D-only buttons are grayed rather than hidden, so the strip does not change shape as you move between quadrants.

Right-click menu of the 3D quadrant

Shading adds a light-and-shadow effect to the composited presets. It has no effect on the MIP presets. The status bar confirms "3D shading: on" or "3D shading: off".

Cutting with the scalpel in the layout

1. Turn the scalpel on with the Scalpel button on the strip or the right-click menu. The status bar says "Scalpel: drag an area on the 3D view, then cut inside or outside".
2. Drag a free-hand outline. You can draw it on the 3D quadrant, or on one of the three planes. Drawing on a plane is often more precise: you outline anatomy you can see in cross-section, and the cut goes straight through that plane.
3. Press Del (or the Cut inside button) to remove what is inside the outline, or Enter (Cut outside) to keep only what is inside. Esc clears the outline without cutting.
4. Ctrl+Z undoes the last cut, Ctrl+Shift+Z redoes it, and Restore volume brings the whole volume back.

While the scalpel is on, a plain drag on the 3D quadrant draws the outline instead of rotating. Clicking a face of the orientation cube still turns the volume, so you can change the view between cuts. Turning the scalpel off clears any outline you have drawn.

Leaving the layout

While the layout is on screen, clicking another series in the series list rebuilds all four quadrants for that series. If the new series cannot be reconstructed, the layout collapses to a single panel and the series opens there. Choosing any other layout from the Layout button also ends the 2×2 arrangement.

The 3D MPR window (F2)

Press F2, or choose MPR ▸ 3D MPR (window). A separate window titled "3D MPR — " followed by the series description opens with three viewports: Sagittal (blue chip), Axial (yellow chip) and Coronal (pink chip). The colored square in the top right corner of each viewport identifies it; the axes drawn in the other viewports use the same colors.

Unlike the 2×2 layout, the planes here can be tilted freely (oblique reslicing), and each plane can show a slab rather than a single slice. The window opens with the tool the main window's left button uses, and the status bar reminds you of the keys: "3D MPR ready — B browse, R rotate, T roll, H thickness".

Toolbar

Progressive rendering sets how coarse the picture is while you drag; the full-resolution image is drawn a moment after you stop.

Auto centering decides what happens to a viewport when the crossing point is moved from another viewport: Always re-centers the image on the new point; Only hidden re-centers only when the point would otherwise be outside the visible area; Never leaves the image where it is. Center all re-centers every viewport at once.

Mouse

A plain left drag runs the selected tool. Holding a modifier overrides the tool for one drag:

The mouse wheel moves through the volume; Ctrl+wheel zooms. Double-click a viewport, or press Enter, to maximize it; do it again to restore the three views.

Axes, center and slab thickness

The colored axes in each viewport are the other two planes seen edge-on.

• Drag the crossing point of the axes to move the center of the reconstruction. All three viewports follow.
• Drag an axis line away from the crossing to rotate the two other planes around the line of sight. This is how you make an oblique plane.
• Small square handles sit on the slab boundary lines. Drag a handle to change the slab thickness of the plane it belongs to.
• The label in the top left corner of a viewport reads "MPR" for a single slice, or the mode and thickness, such as "MIP 12.0mm", for a slab. Click the label to cycle through MIP, MinIP and Avg. F2 does the same.

The window readout is in the bottom left corner ("WL: … WW: …", with "[Negative]" when inverted). Orientation letters are drawn at the edges.

Keys

Measurements in this window are the same shapes as in the 2D viewer and can be dragged by their handles after drawing.

Trackpad

On a Mac trackpad, pinch to zoom; extra resting fingers do not change the window or slab thickness. The mouse tools and modifier drags above remain available. On a touchscreen, pinch to zoom, drag with two fingers to pan, three fingers to change the window, and four fingers to change the slab thickness.

The 3D Volume Rendering window (F3)

Press F3, or click the 3D VR toolbar button. A window titled "3D Volume Rendering — " followed by the series description opens. The status bar notes "CPU renderer": the picture is computed on the processor, so it is drawn coarsely while you interact and refined when you pause. The window opens with the 3D rotate tool selected and reminds you: "3D VR ready — R rotate, T roll, Z zoom, M pan, W window, S scalpel, K snapshot, F2 rotation movie".

A CT opens in the "Bones and skin 1" preset; every other modality opens as "MIP B/W".

Toolbar

Opening the menu of a tool button also selects that tool.

Mouse and keys

A plain left drag runs the selected tool. The same overrides as in the main window apply: Ctrl+drag adjusts the window, Shift+drag pans, Alt+drag zooms, and a right-button drag zooms. Ctrl+Alt+drag rolls. The mouse wheel zooms. Click a face of the orientation cube to look at the volume from that side; the status bar confirms, for example, "View: Anterior".

While this window is in front, its keys take priority over the main window's (for example, F2 makes a movie here rather than opening the 3D MPR window).

Presets, window and shading

The MIP presets show the brightest value along each line of sight, in black and white or inverted. The other presets are color transfer functions: they decide which values are transparent, which are solid, and what color they take. They are approximations tuned for CT.

The Window tool moves the range those presets work on. Dragging with the window tool shifts and stretches the opacity ramp, which is how you make skin disappear or bone stand out. The status bar shows the current "WL … / WW …". Press 0 to return to the default window.

Shading (Ctrl+S) lights the surfaces of a composited preset. It does nothing to the MIP presets.

Scalpel

1. Select Scalpel (S).
2. Drag a free-hand outline on the volume. When you release, a bar appears at the bottom of the picture with three choices: Cut inside (Del), Cut outside (Enter), Clear area (Esc). The status bar says the same.
3. Click a choice or press its key.

Ctrl+Z and Ctrl+Y step back and forward through your cuts (up to 32 steps). Clear scalpel history forgets the undo steps without changing the picture. Restore volume (Ctrl+Alt+0) puts everything back. A pen on a graphics tablet draws the scalpel outline directly.

Measurements

Length (L) and Arrow (Y) are drawn on the picture in the viewing plane; depth is ignored, so a length is only correct for structures lying in the plane of the screen. Hold Shift while drawing a length to keep it horizontal or vertical. With Length or Arrow selected, drag an end, the line or its label to adjust a measurement, or click it to select it and press Delete to remove it; Esc deselects.

Snapshots

A snapshot stores the whole state of the view: rotation, zoom, pan, window, preset, shading and any scalpel cuts, with a thumbnail. Press K to take one. The 3D snapshots panel (F3, or the toolbar button) lists them; click one to restore it, or use ] and [ to step through them. The panel has Add, Delete, Load and Save buttons and a Movie settings button.

Save writes the snapshots to a file; Load reads one back. You can also drop a snapshots file onto the window. Snapshots loaded onto a different volume are restored without their scalpel cuts.

Rotation movies

Quick movie (F2) renders the current view turning through 360° or 180° and saves it as an MP4, using the current preset, shading, window, zoom and scalpel cuts. Create from 3D snapshots (Ctrl+F2) needs at least two snapshots and moves smoothly from one to the next instead. On a trial or expired copy, every frame of either movie carries the trial watermark, as do the 3D and MPR windows' JPEG exports and clipboard copies. Both dialogs are described under "Rotation movie" in Export and Sharing.

Saving a 3D model (STL)

Export ▸ Save 3D model as STL... (Ctrl+Shift+E), or the same command in the right-click menu of the 3D quadrant in the 2×2 layout, writes the visible surface as a triangle mesh for 3D-printing or CAD software. The lower edge of the current window decides what counts as solid, and scalpel cuts are respected. Saving a model needs a Basic or Professional subscription: a trial or expired copy shows a dialog explaining this and saves nothing, because a model cannot carry the trial watermark. The resolution choices and the messages you may see are under "Save 3D model as STL" in Export and Sharing.

Trackpad and pen

On a Mac trackpad, pinch to zoom and use a rotate gesture to roll; extra resting fingers do not change the window. On a touchscreen, two-finger pan and three-finger window gestures remain available. A pen on a tablet draws the scalpel outline.

Image fusion (PET-CT)

Fusion shows one series in color on top of another, resampled by patient position. PET over CT is the usual case, but any two registered series work.

1. Open the base series (for example the CT) in one panel and the overlay (for example the PET) in another.
2. Click the base panel to make it active.
3. Press Ctrl+Alt+F, or choose Tools ▸ Image Fusion (PET-CT), Layout ▸ Fusion, or More ▸ Fusion.

The overlay is taken from another panel: a PET or nuclear medicine series is preferred; otherwise the other panel's series is used. Both series must carry position and orientation information and must share a Frame of Reference, that is, they must come from the same registered acquisition. The status bar confirms with the overlay's series description, for example "Fusion on — PET over the active panel (click the color bar to change the scale, drag it for opacity)".

A color bar appears at the left edge of the fused panel:

• The percentage above the bar is the overlay opacity. Drag the bar up to make the overlay more opaque and down to make it more transparent. It starts at 50%.
• Click the bar without dragging to pick the color scale: Hot iron (the default), Rainbow, PET, Jet or Gray.
• The numbers to the right of the bar are the overlay's window range. For PET, they are shown in SUVbw when the series carries the data for it, and the unit is printed under the bar.

The overlay takes its window from the panel that shows the overlay series on its own. Change the window there and the fused colors follow. The base image keeps its own window in the fused panel.

Press Ctrl+Alt+F again to turn fusion off.

See also

• Viewing images — the toolbar tools, window presets and synchronization
• Export and Sharing — rotation movies, STL models and exporting from the 3D windows
• Measuring — the 3D cursor and the measurement shapes
• Keyboard and mouse — the full shortcut list

DSA subtraction

Digital subtraction angiography removes the static background from an angiographic run so that only the contrast-filled vessels remain. OmniDICOM subtracts a mask frame from every frame of the run and lets you correct for patient movement between the two.

Subtraction is available for angiography and fluoroscopy series (modalities XA, XRF and RF). It is included on every plan.

On a Mac, read Ctrl as the Command key.

Turning subtraction on and off

Press / (slash) with the run in the active panel. The same switch is available as:

• Tools ▸ DSA subtraction
• The right-click menu of the panel: DSA Subtraction, or Turn Off DSA while it is on
• The top button of the DSA strip (see below)
• A "DSA subtraction" toolbar button, which you can add with Customize toolbar (it is not in the default row)

A run that was stored as a subtraction study opens with subtraction already on. Your choice for a series is remembered: if you turn it off, it stays off when you come back to that series.

Subtracted images use their own default window (WL −100, WW 600). You can window the subtracted image as usual, and Default (the 0 key) returns to the subtraction default while DSA is on. The app keeps separate windows for the subtracted and the unsubtracted view of a series, so switching back and forth does not lose either.

The DSA strip

While a subtraction-capable run is active, a vertical strip of buttons appears at the right edge of the window. It shows for runs stored as subtraction studies and for any run on which you have turned subtraction on. The mask and pixel-shift tools are enabled only while subtraction is on.

Ctrl+M is shared with Maximize / restore panel. While the DSA strip is showing it selects Auto pixel shift; otherwise it maximizes the panel.

Reading the overlay

The bottom left corner of the panel shows the current DSA state:

Choosing the mask frame

By default the mask is the frame named in the DICOM mask information of the run, or, when there is none, the second image of the series.

To use another frame, move to it and press Shift+/ or click Use current image as mask. The status bar confirms "DSA mask set to image 7". Choosing a new mask discards any Magic Mask result, because the registration was computed against the old mask.

Reset mask (Ctrl+Shift+/) returns to the default mask and clears every pixel shift.

Manual pixel shift

When the patient moved between the mask and the run, the background does not cancel and you see doubled edges. Manual pixel shift moves the mask under the run until the edges disappear.

1. Press Shift+M or click Manual pixel shift. The status bar says "Manual pixel shift — drag the image; Shift+Arrows 1 px, Ctrl+Shift+Arrows 0.1 px".
2. Drag the image with the left button. The mask moves with the drag; the subtraction updates as you go.
3. For fine control, use the keys:

Press Shift+M again to turn the tool off ("Pixel-shift tool off"). The shift stays applied; only the drag is released back to the normal tools. The arrow-key nudges work whenever subtraction is on, even with no shift tool selected.

Auto pixel shift

1. Press Ctrl+M (while the strip is showing) or click Auto pixel shift. A yellow square follows the pointer over the image.
2. Put the square over an area of static anatomy, such as bone, and click. The app searches for the shift that best cancels the anatomy inside the square and applies it. The status bar reports the result, for example "Auto pixel shift: X +1.25 px, Y −0.50 px — tracks each frame".

The alignment is tied to the point you clicked. While the auto tool stays selected, the app repeats the search for every frame you move to, so the correction follows the motion through the run instead of freezing at one frame. Click again elsewhere to change the reference point.

If the status bar says "Auto pixel shift: no mask applies to this frame", the run's own mask information marks that frame as not subtracted, so there is nothing to align on it. Move to a subtracted frame and click again.

Split mask

When the two sides of the image moved differently, one shift cannot fix both. Split mask gives each half of the mask its own shift.

1. Press Ctrl+Alt+/ or click Split mask. Both halves start from the current shift, and Manual pixel shift is selected for you ("Split mask on — drag the left or right half to align each side").
2. Drag on the left half to shift the left half of the mask, or on the right half to shift the right. Auto pixel shift works per half too: click in the half you want to align.
3. The arrow-key nudges go to the half you last dragged or clicked. Before you have touched either half, they move both.

The two halves are blended across a narrow seam in the middle. The overlay shows "Shift L:" and "Shift R:" while split is on.

Press Ctrl+Alt+/ again to turn split off. The two shifts are merged into one (their average) and the mask is whole again.

Magic Mask

Magic Mask corrects movement that a rigid shift cannot: it warps the mask to fit each frame of the run separately. It is a one-shot command, not a mode.

1. Press . (period) or click Magic Mask. The status bar and the panel overlay show "Magic Mask: computing…" with a percentage, and a progress indicator appears. The button is disabled while the computation runs.
2. When it finishes, the result is applied to every frame and the overlay shows "Magic Mask". The status bar reports "Magic Mask applied (30 frames) — straight lines may be slightly distorted": the warp can bend rigid structures slightly, which is expected.

Pressing Magic Mask again computes it afresh; the old result is dropped first. There is no separate "off": Reset mask (Ctrl+Shift+/) clears the result, and it also cancels a computation that is still running. Choosing a new mask frame clears the result too.

Magic Mask needs the whole run decoded. If you press it while the run is still loading, the status bar says "Magic Mask: waiting for the full series decode…"; wait for the loading to finish and press it again.

Manual and auto pixel shifts can be combined with a Magic Mask result: the shift is applied on top of the warped mask.

Resetting

Reset mask (Ctrl+Shift+/) puts everything back at once: the default mask frame, no pixel shift, split off, and any Magic Mask result cleared or cancelled. The status bar confirms "DSA mask reset to default; pixel shifts cleared". To stop subtracting altogether, press / again.

Keys at a glance

These are the DSA keys only; Keyboard and mouse has the full list.

See also

• Viewing images — cine playback and windowing
• Analyze and Process — the Image calculator for manual subtraction of any two images
• Keyboard and mouse — the full shortcut list
• Export and Sharing — exporting subtracted runs as pictures or movies

Export and Sharing

This chapter covers everything that leaves the viewer: picture and movie files, copies of the original DICOM files, NIfTI volumes, the clipboard, 3D movies and models, and sending images to a PACS.

Ways to get an image out

Opening the Export dialog

The dialog is called "Export images". You can open it from several places.

Opening it from the series list preselects the "Selected series" scope.

File ▸ Export as NIfTI… opens the same dialog with NIfTI (volume) already chosen, in a scope that holds a volume (see "Exporting NIfTI volumes" below). It has no shortcut.

Only one export runs at a time. If one is still running, the status bar says "An export is already running".

Choosing what to export

The top row of the dialog is the scope.

Reconstructions the viewer computed itself (MPR planes, fusion, TIC) can be exported as pictures or movies, but not as DICOM.

Choosing the file format

The movie formats are grayed out while the chosen scope holds only a single image. The dialog then explains: "This holds a single image, so a movie would be a still picture." Choose a wider scope, or use Rotation movie for a turning 3D view.

WMV is grayed out when the built-in encoder cannot produce it. If a WMV export fails at encoding time, the viewer writes an MP4 instead and tells you in the results.

More options

Click "More options" at the bottom left to show two extra groups. While they are shown the button reads "Fewer options".

Export location

If you click Export without a folder, the viewer asks you to choose one first. The folder you use is remembered for next time.

File settings

Corner annotations stay in separate areas. Long labels and extra lines are shortened with an ellipsis when they do not fit; the chosen image dimensions are preserved. Choose Full HD or 4K to keep labels readable on a small source image, or disable annotations when you need only the pixels.

When the format is DICOM, the size, annotation and quality settings are disabled because the files are copied, not rendered.

When the format is NIfTI (volume), File settings shows a single row, Values: Original values (HU for CT), the default, or Denoised values (HU for CT) (see "Exporting NIfTI volumes" below). Neither the format nor this choice is remembered for the next export.

If "Hide patient data" (Shift+F12) is on in the viewer, exported pictures blank the patient fields too, whatever the Annotations setting.

Running the export

Click Export. The Close button leaves without exporting.

The status area shows progress. When everything succeeded, the status bar says "Exported N item(s)." If anything failed, an "Export finished" dialog lists the first errors. A NIfTI export counts slices instead of files, and reports its own way (see "Exporting NIfTI volumes" below).

What the pictures contain

Exported pictures and movie frames show the image as you see it: the current window, inversion, image filter, rotation and flip, DSA subtraction, fusion overlay, region processing and crop are all applied. Measurements and the text you typed are drawn unless Annotations is set to Disabled; both grow with the picture, so they stay readable on a Full HD or 4K export.

The whole image is exported, not only the part visible in the panel, and pan never affects the file. Zoom affects only the pixel size, and only with Image size set to Current size (as rendered).

The Basic annotation setting is not de-identification. It leaves only the fields listed above out of the corner text; other details stay, and so does any text burned into the image pixels. To share DICOM files without the patient's details in their headers, make a copy with De-identify in the Local archive; see De-identify a copy.

How the files are named

Series subfolders are named after the series number and the end of its identifier, for example S3_… . A processed series has a new identifier each time it is exported, so each processed export gets a new subfolder, for example S3_…_processed, and never replaces the original files or an earlier processed export.

Exporting DICOM files

Choose the DICOM format to copy the source files. The copies are byte-for-byte identical to the originals; only the file names change.

There is one exception. A series that carries processing that is not in the file on disk (an image filter or a region operation) is written as new DICOM objects instead. These carry what you see: the windowed 8-bit pixels, new instance and series identifiers, and the description with "(processed)" added. They go into their own _processed subfolder. Nothing is written into the original files.

A DICOM export never writes over the files being exported. If you open a series from an earlier export and export it again, without processing, to the same folder, its subfolder is the folder it was opened from. That series is then not exported: nothing in the folder changes, and the export summary gives the reason. Choose another folder and export again.

Reapplying saved processing for export requires Professional access or an active Professional trial. If access has ended, reset processing to export original images; previously saved DICOM files remain available. During the active trial, those processed images carry the trial banner burned into the pixels of every image and every frame, and they are marked as containing burned-in annotation (see "The watermark" below). Original files are exported unchanged on every copy.

DICOM export is not offered for reconstructions. The option's tooltip says "DICOM export is unavailable for derived (MPR/fusion/TIC) series".

Exporting NIfTI volumes

Choose the NIfTI (volume) format to save each series as one compressed NIfTI-1 file (.nii.gz) for research and segmentation tools. The file holds the original values, after rescale slope and intercept: Hounsfield units for CT, the scanner's own units for MR, and for PET the units in the file, often Bq/mL (not SUV). Window, inversion, filters, rotation, flip, crop, fusion and measurements are not applied. Its orientation matrix places every voxel in patient space in millimeters, so other tools show the anatomy the right way round. The values are read from the files themselves, so a long thin-slice series is exported whole.

When NIfTI is chosen, the dialog changes:

• Current image is grayed out, because a NIfTI file always holds a whole series; the scope moves to Current series.
• A note under the format says what the file holds and what is not applied.
• The rendering settings (image size, annotations, quality, frame rate) are hidden; File settings shows only Values.
• The NIfTI format is grayed out, with the tooltip "NIfTI needs an original series of 3 or more parallel slices", while the chosen scope holds no such series.

Only original series of 3 or more parallel slices, and volumes made with Split series, can be saved; MPR planes, 3D views and other results computed in the viewer cannot. A series that holds several volumes, such as several phases or echoes, must be split first: Layout ▸ Split series (Ctrl+F5, or Shift+Command+F5 on a Mac).

Uneven slice spacing

A series whose slices are not evenly spaced, usually because a slice is missing, is not exported unless you tick Resample to even spacing. That box appears under the NIfTI format, together with a line naming the series, whenever the scope holds such a series. When nothing else in the scope could be exported, the line says so and Export stays unavailable until you tick the box or choose another scope. With the box ticked, the series is resampled onto an even grid at the spacing it was acquired with, the missing slices are filled in by linear interpolation, and the file name ends in _resampled.

Small differences in the recorded positions count as even: every slice may sit up to 5% of the slice spacing off an even grid, and at least 0.05 mm, which covers positions recorded to a tenth of a millimeter (0.6 and 0.7 mm gaps between 0.625 mm slices, or 0.2 and 0.3 mm gaps between 0.25 mm slices). For slices at an angle to the patient axes the allowance grows to as much as 0.09 mm, because rounding all three coordinates moves a slice further. A larger difference is uneven, for example one 5.9 mm gap among 5 mm slices.

Denoised values

Denoised values (HU for CT) is available on Professional, and during the trial, once Denoise has finished every slice of a series in the export. Those series are saved with their denoised values, as floating-point numbers, and their file names end in _denoised. Series without Denoise are saved with their original values. A series whose Denoise has not finished every slice is not exported; choose Original values or wait for Denoise to finish. A series with Denoise on some slices only (Denoise this slice) is not exported either; use Denoise all slices first, or choose Original values.

On CT, Denoise works on values from -1024 to 3071 HU. Values outside that range, such as the padding outside the scanned field or metal, are not changed by Denoise, so the file keeps their original values. Denoise also works only on the part of a series the viewer holds at once, about 384 slices of 512 × 512; a longer series cannot be saved with denoised values.

What is not exported, and why

A series that cannot be saved as one volume is left out of the export, and the rest are still saved. The results give one line per series, for example:

Series with fewer than 3 images, and results made in the viewer, are left out without counting as failures.

Results

While the export runs, the status bar shows "Exporting NIfTI volumes..." and then the slices left. When every series was saved and there is nothing to report, the status bar says, for example, "Exported 3 NIfTI volumes." Otherwise an Export finished dialog gives the counts (exported, not exported, left out) and up to five lines of detail: first the series that were not exported and why, then the resampled series, then what was left out.

An earlier export of the same series to the same folder is replaced. A different file of the same name, such as the volume of another series with the same number and identifier ending, is kept, and the new file's name ends in _2. The file is written under a hidden temporary name first (.omnidicom-….nii.gz.part) and renamed only when it is complete, so an interrupted export never leaves a half-written volume under the final name. Closing OmniDICOM during an export stops it and deletes its temporary file. A temporary file left by a crash is deleted the next time OmniDICOM starts, or by a later NIfTI export to the same folder.

A NIfTI file carries no patient name or ID, but it is not de-identified: a head scan can be reconstructed into a face, and the file name holds the end of the series identifier.

The NIfTI files

The watermark

During the 14-day trial, and after the trial ends until a subscription key is activated, every exported picture and every frame of every movie carries a banner along its bottom edge: "OmniDICOM trial — not licensed for publication". That covers every way a picture leaves OmniDICOM:

• the Export dialog, from the viewer or from the Local archive
• pictures copied to the clipboard, from the viewer, the MPR window or the 3D window (every copy gets the banner on a strip added below the picture)
• the MPR window's Export active viewport and Export all viewports (one banner along the bottom of the combined picture)
• the 3D window's Export JPEG, Quick movie and Create from 3D snapshots, including a Rotation movie started from the 3D quadrant
• processed images exported or sent as DICOM (a series with an image filter or a region operation)

The banner is a dark strip with white text below the image area. It never covers the image itself, so it cannot hide or imitate a finding. On an image too narrow for the whole sentence, such as a 128 × 128 slice, the banner uses fewer words ("OmniDICOM trial — not for publication", "OmniDICOM trial" or "Trial") so that no word is cut off.

In processed DICOM images the banner is burned into the pixels themselves, in every image and every frame. Each file is also marked as containing burned-in annotation: Burned In Annotation is YES, Image Type starts with DERIVED, and Derivation Description ends with "trial watermark burned in".

Original DICOM files never get the banner. A DICOM export of an unprocessed series copies the original files byte for byte, and sending one sends the original files. Saving changes in the DICOM Meta panel changes only the tags you edited. This is the same on every copy, paid or not.

A 3D model has no picture to carry the banner, so a trial or expired copy cannot save one. See "Save 3D model as STL" below.

A NIfTI volume has no picture to carry the banner either. During the 14-day trial you can still save one. After the trial, or when a subscription has lapsed, the dialog Export as NIfTI — Needs a subscription opens instead, with the same buttons as for a 3D model, and nothing is written. Choosing NIfTI in the Export dialog on such a copy also shows the line "Needs a Basic or Professional subscription: a NIfTI volume has no picture to carry the watermark." From File ▸ Export as NIfTI… the dialog opens before any option. If you close it from the Export dialog, NIfTI stays chosen and you can pick another format instead.

Both Basic and Professional subscriptions export and send without the banner, and can save 3D models and NIfTI volumes.

Copying to the clipboard

Copy Image and Copy Layout do not photograph the screen. Each panel is drawn again at a fixed size, so a copy comes out the same on a Retina Mac, a laptop or a large monitor, whatever the size of the window:

• The picture is 2400 pixels on its long side (Slide, the default) or 3600 pixels (Large).
• In Copy Layout every panel gets the same size and the panels are laid out as on screen; a panel that fills the rest of a row on screen does so in the copy too. A white line (the default), a black line or no line runs between panels.
• Kept: the image as shown (window, zoom, rotation and flips, filters, Denoise, DSA, fusion with its colour bar), measurements, arrows, typed text, label and particle overlays, the DICOM overlays as displayed, and the rulers and orientation letters.
• Left out: the cursor readout, the crosshair and the 3D cursor, cross-reference lines, selection handles and colours (a selected arrow is copied in its own colour), scrollbars, a text box still being typed (it is finished first) and the series comment.

Copy Options

Copy Options… sets what both copies hold. Your choices stay until you change them.

The preview on the right is exactly what Shift+C copies with these settings, the trial banner included. OK keeps the settings; Cancel leaves them as they were.

A copy never shows more than the screen. With the annotations off (F12) it has no corner text, and the rulers and orientation letters follow F12 as on screen, whatever Corner text is set to. Hide Patient Data (Shift+F12) always leaves the patient identifiers out, and series comments are never copied.

The cards of SR documents, PDF documents and videos are copied the same way. On an SR card, the patient's name, ID and birth date, the referring physician, the study date and the study are copied only when their Corner text field is ticked: Patient name, Patient ID, Birth date and sex, Hospital (for the referring physician), and Study date and time (for the study date and the study). Names of people in the SR's content follow Patient name. A card never copies the file name it shows on screen.

While a copy would include patient identifiers, the status bar shows an orange badge, for example "Copies include: Name, ID". Click it to open Copy Options. It goes away when you untick the identifiers, turn on Hide Patient Data or turn the annotations off.

The status bar confirms each copy with the size of the picture, for example "Layout copied: 2400 × 2008 px", "Image copied: 2400 × 1400 px" or "Measurement copied". On a trial or expired copy the banner is on a strip added below the picture, so the size includes it.

In the MPR window, Ctrl+C copies the active viewport and Shift+C copies all viewports. In the 3D window, Ctrl+C copies the rendering. These copies follow Copy Options like the viewer's: they are made at the chosen size with the lines between the viewports, and Shift+C letters the viewports when panel labels are on. What each viewport shows, crosshair included, is copied as it is on screen. On a trial or expired copy their banner is on a strip added below the picture too.

Saving as PowerPoint slides

Save as PowerPoint (.pptx)… saves what is on screen as a PowerPoint file in one step. It is in the File menu, the toolbar Export menu and the image panel's right-click menu. Choose where to save; the suggested name is "OmniDICOM slides" followed by the date and time.

• One image on screen: one slide.
• Several panels: a first slide with the whole layout as one picture, then one slide per panel, the active panel first.

Each image slide holds the picture on the left and, on the right:

• the series number and description;
• the modality and the image number ("Image 34 of 120");
• the window ("W 400 · L 40");
• "Pixels: Denoised" or another pixel source when the image is not the original;
• a table of the measurements on that image, numbered as on screen when Number Marks is on, with the units and decimals of their labels. A long list shows the first 12 and then "+N more".

The speaker notes repeat the series, image and window lines as text, with the plane and the calibration where they are known; the measurements are in the table. The slides are 16:9 with a black background, and every text box and table can be edited in PowerPoint.

The pictures are the ones Copy Image and Copy Layout make: the same size and Copy Options, and the same privacy. Patient details appear on a slide only if Copy Options would put them on a copied picture; the slide text and the file properties carry no patient name, ID, date or DICOM UID. While OmniDICOM is on a trial or has no valid license, each picture carries the trial banner below it, as copied pictures do.

Exporting from the MPR window

The MPR window has its own Export button.

Exporting from the 3D window

The 3D window's Export button offers the following.

The 3D save dialogs start in your Documents folder, or your home folder if Documents is unavailable. After a successful JPEG, movie, STL or snapshot-file save, the next 3D save dialog starts in that folder. Cancelling a dialog or a failed export keeps the previous location. A JPEG that cannot be written shows an error instead of a saved message.

Rotation movie

In the 2×2 MPR layout, right-click the 3D quadrant and choose "Rotation movie…". This opens the 3D window's "Quick movie" dialog. Inside the 3D window itself, press F2.

Below the settings the dialog tells you how many frames will be rendered, how long the movie will play, and an estimate of the rendering time. Every frame is rendered at the full chosen resolution, so larger frames and smaller angle steps take proportionally longer. If the estimate is very long, the dialog suggests a coarser step or a smaller frame.

Click "Export movie" and choose a file name; the default is vr-movie.mp4. An "Exporting movie" window shows a preview, a progress bar and a Cancel button. The movie uses the current preset, shading, window, zoom and scalpel cuts.

To make a movie that moves between chosen views instead of a plain rotation, take at least two 3D snapshots in the 3D window (press K), then choose "Create from 3D snapshots..." (Ctrl+F2). In that dialog, set a Step duration for the selected snapshot, or type a Total length and click Set to scale every step. Loop movie ends the movie back at the first snapshot. Rotation, zoom, pan and window are interpolated between snapshots; the preset, shading and scalpel cuts switch at each step. Resolution and frames per second are as above; Bitrate is 2000, 4000, 8000 or 16000 kbps.

Save 3D model as STL

An STL file is a triangle mesh of the surface of the visible volume. It can be opened in 3D-printing and CAD software.

Right-click the 3D quadrant of the 2×2 MPR layout and choose "Save 3D model as STL…", or in the 3D window use Export ▸ Save 3D model as STL... (Ctrl+Shift+E).

Saving a 3D model needs a Basic or Professional subscription. A trial or expired copy can still view, rotate and cut the volume, but an STL model has no picture to carry the trial watermark, so instead of the steps below a dialog titled Save 3D model as STL — Needs a subscription opens and nothing is saved. Its buttons:

On a subscription, choose the "Model resolution":

The surface follows what is visible on screen: the lower edge of the current window (where the rendering becomes opaque) sets the threshold, and scalpel cuts are respected. The mesh is scaled to millimeters using the voxel spacing of the series.

Click Save and choose a file name; the default is vr-model.stl. The status bar reports "Saved 3D model (N triangles) to …".

If the status bar says "STL export produced an empty mesh — adjust the window / preset first", nothing was visible at the current threshold. Pick a different 3D preset or adjust the window on the 3D view, then try again.

Sending images to a PACS

Sending transmits DICOM files to a server you have configured. Open the "Send images" dialog from any of these places.

Choose a Destination and a Scope, then click Send.

Text you typed on the images goes along. For each series with text, the dialog also sends a DICOM presentation state (series "OmniDICOM text", a Grayscale Softcopy Presentation State in the same study) that names every image carrying text, and says "Typed text goes along as a presentation state." under the Scope. A series whose images are stored with different rescale values (some PET series), or two runs of a series shown turned or windowed differently, get one presentation state each, in the same "OmniDICOM text" series. The images themselves are sent unchanged; a viewer or PACS that shows presentation states draws the text over them. The presentation state is made for the send and removed from this computer afterwards. Measurements are not sent; export the images as JPEG or PNG to share them. A DICOM export never carries the text.

The file counts in the dialog are the images of the scope; a clean send ends with "Sent N files to (destination), with the typed text". Clicking Send again after a failure sends the same presentation state again, never a second copy of it. A destination that does not accept presentation states still receives every image; the dialog then says "The typed text was not sent" with the reason, and stays open until you close it.

When a processed series is sent, its text is placed on the processed copies: on the same anatomy, after the crop, rotation and flip that are part of those copies' pixels.

The dialog never defaults to the widest scope. A series with processing applied is sent as new DICOM objects marked "(processed)", exactly as DICOM export writes them, so the receiving system does not mistake them for the originals. An active trial stamps the derived copies with the trial banner and marks them as containing burned-in annotation. Without Professional access, reset saved processing before sending original files; original files are sent unchanged. Reconstructions have no files and are not sent.

Configuration of destinations, and what happens on the receiving side, are described in Local Archive and PACS.

Copying metadata as text

The DICOM Meta panel on the right of the viewer (see Viewing images) offers the same copy actions. To copy tag values from the separate window instead, open the DICOM tags window with Ctrl+Alt+T (also File ▸ DICOM Tags…, or the toolbar Help button ▸ DICOM tags window). The window shows the Tag, Name and Value of the file behind the current image, with a filter box at the top. Right-click a row for these actions.

Press Ctrl+Alt+T again to close the window.

See also

• Local Archive and PACS — configuring the servers you send to
• MPR and 3D — the 3D views the movies and STL models are made from, and Split series for series that hold several volumes
• Getting started — the plans and why an export is watermarked
• Viewing images — the DICOM Meta panel

Local Archive and PACS

The local archive is a study database kept on your own computer. PACS networking lets you search, download, send and receive studies over the network. Both are described here.

The local archive

What it is

The archive is a database of studies with a search box, keywords, and one-click opening in the viewer. Studies are either copied into the database's own data folder or linked to where they already are.

The default database is created the first time you open the archive. It lives in your Documents folder, under DicomViewerDB, as archive.db. Copied files are stored next to it in a folder with the same name and the ending .data.

You can keep several databases and switch between them.

Opening the archive

The arrow next to the Archive button opens a small menu.

The archive window

The title bar shows "Local archive — " followed by the database name. At the top left a summary reads "Studies: N Images: N Size: …". At the top right is the search box.

Below are up to three panes: studies, the series of the selected study, and the images of the selected series. Press F2 to cycle between the Studies, Series and Images views, or choose one under Database ▸ Advanced ▸ View.

The study list has these columns: Patient name, Patient ID, Birth date, Sex, Study date, Time, Description, Accession, Modality, Series, Images, Size, Keywords. Right-click a column header to hide columns or to "Restore default columns".

The series list has the columns No., Description, Modality, Images and Comment. Comment shows the series comment added in the viewer (see Series comments); a series with several commented runs or planes reads "2 comments: …", and pointing at the cell lists each one, labelled with the run's number and time. The column is read-only and is not searched: open the series to edit its comment. While patient data is hidden in a viewer window (Shift+F12), the column shows "Hidden" instead of the comment.

The toolbar holds Folder, CD/DVD (shown only while a DICOM disc is inserted), PACS, Export, De-identify, Delete and Database.

Importing studies

Click Folder to import a folder, or use the arrow next to it for "Import ZIP files..." and "Import DICOM files...". You can also drag folders, files or ZIP archives onto the window.

When you import a folder, the viewer asks "How should the DICOM files be imported?"

Copy files is the default. Individual files and ZIP archives are always copied.

Encrypted ZIP archives ask for their password. Files that are not DICOM are skipped.

Import runs in the background. The status bar shows how many files are done, the data volume, the speed and the remaining time. Studies appear in the list as soon as they are read, and you can open them while the rest is still importing. When it finishes, the status bar reports, for example, "Import finished: 120 DICOM files (3 non-DICOM skipped)".

To import the study you are looking at in the viewer, click the arrow next to the toolbar Archive button and choose "Import to database". You get the same Copy files / Add links choice.

Studies downloaded from a PACS can be imported automatically; see "Import to database" in the PACS section below.

Searching

Type in the search box at the top right. The list filters as you type. The search looks at the patient name, patient ID, birth date, study date, description, accession number, modality and keywords.

Opening studies in the viewer

Double-click a study, or select it and press Enter, to open it in the active viewer window. Right-click for the other options.

In the series pane, double-click a series or choose "Open series" to open only that series.

Linked files that have been moved or deleted cannot be opened. The status bar then says "No image files found for the selection".

Keywords

Keywords tag studies so you can find them again with the search box.

Select one or more studies and press K, or right-click and choose "Add keyword". Type a new keyword or pick an existing one. To remove one, right-click and open "Remove keyword"; it lists the keywords on the selected studies and offers "Remove all".

Exporting and sending from the archive

Select studies or series, then click Export (Ctrl+E) or right-click and choose Export ▸ Export images... . This opens the same "Export images" dialog described in Export and Sharing, with the selection preselected. Choosing "All opened series" there exports every study currently listed, so an active search filter limits what "All" means.

Export ▸ Export to CSV... writes the study list (the selected studies, or every listed study when nothing is selected) to a spreadsheet file.

"Send images..." in the right-click menu sends the selected studies or series to a PACS. Text typed on those images in the viewer goes along as a presentation state, as it does from the viewer.

De-identify a copy

De-identify makes a copy of the selected studies or series with the patient's details removed from the DICOM header and new DICOM identifiers. Your original files are not changed. It lives in the Local archive only: the viewer window has no De-identify entry.

Select studies in the study list, or series in the series pane, then click De-identify on the archive toolbar, or right-click and choose "De-identify..." (studies) or "De-identify series..." (series). De-identify works on a Basic or Professional subscription and during the 14-day trial. After the trial, or once a licence has lapsed, the window explains that it needs a subscription and offers Subscribe and Enter licence… .

Text burned into the images is not removed. Only the DICOM header is changed. Names, dates or ID numbers drawn into the pixels stay in the copy, so open the copy and look through every series before you share it. Faces can be rebuilt in 3D from head CT and MR, and they are not removed either.

The line under the options states what the copy applies, for example "Applies the DICOM PS3.15 Basic Application Level Confidentiality Profile with the Retain Longitudinal Temporal Information with Modified Dates Option".

For PET, SUV on the copy needs the dates shifted or kept and the patient's weight: a hint says what is still missing.

Click De-identify. The progress bar counts the files. Stop finishes the file being written, then removes the unfinished copy; closing the window or quitting OmniDICOM during a run does the same. If the disk fills up, the folder disappears or OmniDICOM can no longer write to it, the run ends and the unfinished copy is removed. When it cannot be removed (the permission was lost, or the drive was disconnected), the window names it so you can delete it yourself, and OmniDICOM tries again when it quits. On a small screen the window keeps its buttons in view: once the copy is running, "Also keep" folds away (the line under it still names every option), and the patient table may show fewer rows. When the copy is made, the window reports how many files were de-identified and lists anything left out or any file that could not be copied, and stays open. "Open the copy" opens the copy in the viewer beside what is open (it appears as a patient of its own, because its identifiers are new); "Open output folder" shows it in Finder or File Explorer.

The copy is laid out from new values only, never from the original file or folder names:

No DICOMDIR is written.

What De-identify does to a copy

This is OmniDICOM's statement of conformance to DICOM PS3.15 Annex E (section E.1.3) for De-identify a copy.

Profile. The Basic Application Level Confidentiality Profile, as listed in Table E.1-1 of the 2026d edition, applied to every attribute it lists wherever it occurs, including inside sequences. Attributes the table does not list, such as slice thickness or the manufacturer, are kept.

Options supported. Retain Longitudinal Temporal Information with Modified Dates Option (Dates: Shift), Retain Longitudinal Temporal Information with Full Dates Option (Dates: Keep unchanged), Retain Patient Characteristics Option, Retain Institution Identity Option, Retain Device Identity Option, and Clean Descriptors Option. Not supported: Clean Pixel Data, Clean Recognizable Visual Features, Clean Graphics, Clean Structured Content, Retain UIDs and Retain Safe Private.

Removed. Every attribute whose action is X. Always removed as well: private (odd-group) attributes and their creators, attributes that are not in this version's DICOM dictionary (what they hold cannot be told), whole overlay groups (60xx), curves (50xx), group 0004, group lengths, the Encrypted Attributes Sequence, icon images, the Original Attributes Sequence and digital signatures. Beyond the table, wherever they occur: the issuers of the IDs and numbers the profile removes (Issuer of Accession Number Sequence, Issuer of Patient ID Qualifiers Sequence, Order Placer and Order Filler Identifier Sequences, Assigning Facility, Jurisdiction and Agency Sequences, and Local Namespace Entity ID, Universal Entity ID and Universal Entity ID Type), web addresses (UR attributes such as Retrieve URL and Retrieve URI), and Patient's Birth Date and Death Date in Alternative Calendar with the calendar's name. A sequence whose action is D in an image (Content Sequence, Graphic Annotation Sequence, Verifying Observer Sequence) is outside the image's definition and is removed.

Emptied. Every attribute whose action is Z is given an empty value, except Patient's Name, which gets the new patient ID.

Replaced with a dummy. Every attribute whose action is D gets a fixed value, the same in every file: text "REMOVED", date 19000101, time 000000, date-time 19000101000000, numbers 0. Patient ID and Clinical Trial Subject ID get the new patient ID.

Combined actions. X/Z is emptied. X/D, Z/D and X/Z/D get a dummy when the attribute has a value and are emptied when it is empty. X/Z/U* sequences (Referenced Image Sequence, Source Image Sequence) are kept and cleaned inside, with their UIDs replaced.

UIDs. Every UID the table marks U, at any depth and in every value of a multi-valued attribute, including Media Storage SOP Instance UID, is replaced with a new 2.25 UID made from a random UUID. So is every other UID of an object that the table does not list, such as the SOP Instance UID of a concatenation source, the multi-frame source, table and volume frames of reference and radiopharmaceutical administration events. Within one copy the same original UID always gets the same new UID, so references between the copied files still match. The mapping is held in memory only, so another run gives different UIDs, and series of one study de-identified separately no longer line up. Never replaced: UIDs that name a definition (SOP classes, private ones included, transfer syntaxes, coding schemes and context groups) and the UIDs the DICOM Standard registers, such as the well-known frames of reference. A UID that a device merely made under the Standard's root 1.2.840.10008 is replaced. Device UID is kept with Scanner identity.

Dates. With Shift, each patient gets one random whole number of days, from 1 to 10 years, and every date and date-time of that patient moves back by it, so intervals are kept. Times of day, fractions of seconds and time-zone offsets inside date-times are unchanged, which keeps PET decay correction and time-intensity curves working. The number is held in memory only. Partial, invalid or range values are emptied. Timezone Offset From UTC is removed. With Remove, the dates the table lists take their Basic Profile action and every other date is emptied. With Keep unchanged, dates are kept. Patient's Birth Date is always emptied, and birth and death dates in an alternative calendar are removed. Scanner identity would keep the eleven calibration, installation and manufacture dates and times; the Dates choice decides them instead, so they are shifted with Shift, take their Basic Profile action with Remove and are kept only with Keep unchanged.

Patient characteristics. With "Age, sex, height and weight", the attributes the option retains are kept: sex, age, size, weight, ethnic group, smoking and pregnancy status. Allergies, patient state, pre-medication, special needs and the sex parameters comment are cleaned by removal.

Institution and scanner. With the institution option, institution name and address, department and clinical-trial site names are kept. The issuers of IDs are removed even then, as Issuer of Patient ID is in the table. With Scanner identity, station name, serial numbers, detector and gantry IDs and Device UID are kept; network (AE) titles are cleaned by taking the Basic Profile's action (removal, or the dummy where the table asks for a value).

Descriptions. With "Study and series descriptions, after review", Study Description, Series Description and Protocol Name are kept as you reviewed them, and a cleared one is removed. Every other description and comment is cleaned by taking the Basic Profile's action: removal, or the dummy where the table asks for a value. Without the option, all of them take that action.

Inserted. Patient Identity Removed = YES. De-identification Method names the profile, each option and "OmniDICOM version; PS3.15 2026d; pixel text not removed". De-identification Method Code Sequence holds the CID 7050 codes 113100 and one code per option (113105 only when the descriptions were reviewed). Longitudinal Temporal Information Modified is MODIFIED, UNMODIFIED or REMOVED. Burned In Annotation and Recognizable Visual Features are left as they were.

File meta. Replaced: a zero preamble, OmniDICOM's own implementation class UID and version name, and the source's transfer syntax. No source, sending or receiving AE titles are kept.

Pixels. Copied exactly as stored, compressed or not, and never decoded. Saved processing and Denoise are not applied. Text a scanner stored inside the compressed data itself, such as a JPEG comment, is copied with it; the report says so.

Not copied. Structured reports and key object selections, encapsulated documents, presentation states, RT objects, raw data, registrations, segmentations, surfaces, waveforms and video, whether a whole series or one file inside an image series.

Not created. No Encrypted Attributes Data Set, and no record anywhere of which new identifier belongs to which patient.

Check the copy before you share it. Using a profile does not guarantee that every piece of identifying information is gone, and whether the copy counts as de-identified under the rules that apply to you is for you to decide.

Deleting

Select studies or series and click Delete, press Del or Backspace, or right-click and choose "Delete studies" or "Delete series".

The viewer asks for confirmation and explains: "Copied files are removed from disk; linked files are only unlinked." No is the default answer. There is no undo, and removed copies do not go to the Trash. A series whose copies are removed loses its comment and the text typed on its images too, unless it is open in a viewer window.

Managing databases

The Database button opens this menu.

Archive keys

PACS networking

What is supported

OmniDICOM talks to two kinds of server.

The viewer can also receive studies pushed to it from another system.

Where to find the PACS functions

Two toolbar buttons, "PACS search / download" and "Send to PACS", are not on the default toolbar. Right-click the toolbar and choose Customize toolbar to add them.

The first time you search or send with nothing configured, the viewer asks "No PACS locations are configured yet. Open the PACS configuration to add one?"

PACS configuration

The "PACS configuration" dialog has three parts: this computer's own identity, the list of servers, and a few options.

This computer

The "Receiving" line tells you whether this computer can currently accept images, for example "ON — other systems can send to OMNIDICOM @ 192.168.1.20:11112". Click "Copy send-to address" to copy the AE title, IP and port for the PACS administrator.

Servers

The table lists every configured location with its Status, Description, AE title, Host, Port, Protocol, Transfer syntax and Max DL (maximum simultaneous downloads).

Options

Click OK to save. The listener starts when OK is clicked with "Accept pushed studies" on.

Adding a server

Click Add... . The "Type" field switches between the two kinds of server and shows only the fields that apply.

DIMSE (C-FIND / C-MOVE / C-GET)

DICOMweb (QIDO / WADO / STOW-RS)

Press Enter or click OK to save the location.

C-MOVE or C-GET

With C-GET the images come back over the same connection the viewer opened. Nothing else is needed.

With C-MOVE the server opens a new connection back to your computer. For this to work the viewer starts its listener on the Listener port, and the PACS administrator must have registered your AE title, IP address and port on their side. Use "Copy send-to address" to pass these on. If the listener cannot start, the download fails with "Cannot start C-STORE listener".

DICOMweb needs only the URL and credentials.

Searching a PACS

Press Ctrl+F. The window is titled "PACS — search and download studies".

The top row sets what you search for: choose a field, type a value, and press Enter or click Search.

"Auto wildcards" adds wildcards around what you type, so a partial name matches. "Search settings" holds "Replace spaces with carets" (for servers that store names as LAST^FIRST) and "Character set...". Clear resets the filters.

The second row narrows the search.

Results show Patient name, Patient ID, Birth date, Study date, Description, Modalities, Series, Images, Accession and Source (which server answered). The status line at the bottom reports how many studies were found.

The arrow next to Search keeps search presets. "Save search preset..." stores the current fields, optionally with the selected locations, and can give the preset a key from F2 to F12.

Downloading

Select one or more studies (or series, with the series table open) and choose how to open them.

Series appear in the viewer as they arrive. The status bar of the search window shows progress. "Statistics (Ctrl+L)" opens the transfer window and "Configuration (Ctrl+O)" the configuration dialog.

Transfer statistics

The "PACS transfer statistics" window lists every transfer with Status, Description, Host, Protocol, Files, Size, Elapsed and Speed. A failed job shows its error when you hover over the status. "Clear finished" removes completed rows; "Stop all (Ctrl+Del)" cancels everything still running.

Receiving pushed studies

Turn on "Accept pushed studies" in the configuration and give the sender your AE title, IP and port. A pushed study is either shown in the viewer at once or imported into the default archive, depending on "Display pushed studies immediately".

Sending

Open the "Send images" dialog (see Export and Sharing for every route). Choose the Destination, choose the Scope, and click Send.

A progress bar shows "Sending... 3 of 40". When every file arrives, the dialog reports "Sent 40 files to …" and closes by itself. If some files were refused, the dialog stays open and lists each file with its error so you can retry.

Some servers refuse compressed transfer syntaxes. When that happens, the viewer decompresses the file and sends it again, so the server receives the same pixels uncompressed.

DICOMweb locations receive the files through STOW-RS.

See also

• Opening studies — opening from the archive and the Open / Add menu
• Export and Sharing — the Export images and Send images dialogs
• Troubleshooting and Support — PACS error messages

Troubleshooting and Support

This chapter lists the messages you may see when something does not open or transmit, where the log file is, what to send to support, and what the application does and does not send over the internet.

When a DICOM file does not open

The viewer reads any file that is valid DICOM, whatever its name or extension. It also opens folders (searched recursively), DICOMDIR discs, and ZIP archives.

"No readable DICOM series were found in that location."

The scan finished without finding an image series. Check the following.

• The files are DICOM. Screenshots, JPEGs, PDF printouts and reports exported by another program are not.
• You opened the right folder. Studies from a disc or a download often sit several folders deep; the scan searches every subfolder, so opening the top folder is enough.
• The disc or drive is still mounted and readable.

If the status bar shows "Scan failed:" followed by a reason, the folder could not be read at all. The reason names the problem, for example a permission error.

Encrypted ZIP archives

A password-protected ZIP asks "The archive is encrypted. Enter password for …". If the password is refused, the prompt says "Wrong password." A ZIP that cannot be unpacked shows "Could not extract the archive."

"Load failed — The pixel data could not be read."

The file was recognized as DICOM but its images could not be decoded. The dialog shows the technical error underneath. Most often this means the file is truncated, was written incorrectly by the source system, or uses an encoding the viewer does not support (see the next section). Copy the error text; it is what support needs.

While a series is being decoded in the background, the status bar may briefly say "Decode failed:" with the same kind of reason.

Special files

Structured Reports, encapsulated PDF documents and MPEG video files are DICOM too, but they are not image stacks. They open in their own way (press Enter on the series) and are described in Opening studies.

Reconstructions that will not open

MPR, 3D and fusion need the whole series decoded first. The status bar says "The series is still loading" if you ask too early. Wait a moment and try again; the 2×2 MPR layout opens by itself once the series is ready.

Compressed transfer syntaxes

A DICOM file stores its pixels either uncompressed or with one of several compression schemes, called transfer syntaxes. The application ships with decoders for the common ones.

Files that use a rare or very new encoding may fail with the "Load failed" message. Ask the source system to export the study uncompressed or in one of the encodings above.

When you send to a PACS that refuses compressed files, the viewer decompresses them and sends them again by itself. When you download, the "Preferred transfer syntax" of the location lets you ask the server for a particular encoding.

PACS problems

License messages

These come from the license service. Getting started explains the trial, keys and activation in full.

The log file

The application keeps a small log so that a report from you carries evidence. It records the application's own warnings, unexpected errors, and the decisions made when playing cine runs and decoding series.

On macOS, ~ is your home folder; in Finder use Go ▸ Go to Folder and paste the path. On Windows, paste the path into the File Explorer address bar.

The log is capped at 2 MB. When it fills up, it is renamed with the ending .1, .2 or .3 and a fresh file is started, so there are at most four files.

The log contains no pixel data and no patient identifiers. Series identifiers are shortened to their last eight characters, enough to follow one series through the file and useless for identifying anyone. The log is never uploaded by itself; you decide whether to send it.

What to send to support

Write to contact@omnidicom.com. One person reads the mailbox and aims to answer within one business day. For a feature request, Help ▸ Request a Feature… opens the email with the version and system already filled in.

Include:

• The application version. Open Help ▸ About OmniDICOM (Ctrl+F1); the version is on the first line.
• Your operating system and version.
• What you did, step by step, and what you expected to happen.
• The exact text of any message, or a screenshot of it.
• The log file from the location above, taken right after the problem occurred.
• Your license key or purchase email when the question concerns a license.

Before sending, remove patient information, image data and private file paths from anything you attach. Do not send patient studies. If a sample file is needed to reproduce a problem, send a copy made with De-identify in the Local archive (see De-identify a copy) after checking its images for text, or tell us the modality, the manufacturer and the transfer syntax shown in the DICOM tags window instead.

Privacy summary

Studies are opened, decoded, rendered and processed entirely on your computer. There is no upload step and no cloud processing. No image, file name, study description or patient detail is ever sent to OmniDICOM, under any setting.

The application makes two kinds of connection to OmniDICOM: the license service and the update check.

The application version travels in every license request (its User-Agent). For a trial computer the license service keeps the days it checked in and the version it last reported, to see whether people keep using the trial. The underlying hardware identifier never leaves your computer; only the salted hash does. No email address is sent from the application. Help ▸ Request a Feature… and Ask for a Longer Trial… send nothing themselves: you see the whole email first, and it goes from your own mail app. The longer-trial email includes the same salted hash, shown as "Computer ID", so we can find the trial. It does not contain the hardware identifier, but anyone who already knows that identifier, and how OmniDICOM makes the hash, can tell that the two belong to the same computer.

Everything else stays local:

• PACS and DICOMweb connections go only to the servers you configured yourself.
• An update is downloaded only after you click Update now, from OmniDICOM's public release page on GitHub.
• The user manual (F1) opens from the files installed with the application.
• Crash reports and the log file are never uploaded automatically.

The website, checkout and license emails are handled outside the application; the privacy policy at omnidicom.com describes them.

See also

• Getting started — installing, the trial and license keys
• Opening studies — every way of opening a study
• Local Archive and PACS — PACS configuration and transfers