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 1.0.6: the complete viewer that every plan includes, 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. 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.

To update, run the newer package. It replaces the application in place. 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 ticked on the last page and click Finish.

Afterwards you start OmniDICOM from the Start menu. To remove it, use Start menu ▸ OmniDICOM ▸ Uninstall OmniDICOM, or Windows Settings ▸ Apps.

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….

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

Connect to the internet once to start your free 14-day Professional trial.

The viewer works normally in the meantime; only the Professional features stay locked. OmniDICOM tries again on the next launch.

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.

The trial, sessions and subscriptions

Five-minute sessions

After the trial ends, 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.

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 explains that the 5-minute session has ended and offers two buttons: Enter licence… and Close OmniDICOM. 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 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 paid license, Basic or Professional, exports without the banner and saves 3D models.

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 "You are subscribed to Basic — 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.

Entering your license key

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

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 status bar says "Licence activated — thank you."

You can also enter the key from the Enter license… button in any locked-feature dialog, and from the Enter licence… button 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. 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 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.

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.

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 ▸ OmniDICOM Help (F1) opens this manual.
• Help ▸ About OmniDICOM (Ctrl+F1) shows the version and build. Its ... button offers Copy information, which is useful to paste into a support request.
• 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.

The Open button

A plain click on Open shows a short menu with the three everyday choices: Open DICOM files, Open DICOM folder and Open ZIP archive....

The small arrow next to the button opens the full Open / Add menu. It contains the same three items plus Open DICOM CD/DVD, the Add DICOM images submenu, and the window commands New window (Ctrl+N), Duplicate window (Ctrl+Shift+N), Close window (Alt+F4) and Exit (Ctrl+Alt+F4), and Export... (Ctrl+E).

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.

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

On a Mac, insert the disc and wait 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.

On Windows, open a disc with Open DICOM folder and choose the disc drive.

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.

Selecting and browsing

• Click a card to display that series in the active panel. Enter or Space on the highlighted card does the same.
• 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.

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.

The » button

When the window is narrower than the row, the buttons that do not fit move behind a » 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 trackpad, pinch to zoom. Two-finger scrolling works like the mouse wheel. A three-finger drag adjusts the window.

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.

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.

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.
• Splitting a series into volumes (Ctrl+F5) 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."

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.

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 trackpad, pinch to zoom, scroll with two fingers to move through the images (the same as the wheel), and drag with three fingers to adjust the window. In the 3D Volume Rendering window, a rotate gesture rolls the volume.

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 are not written into the DICOM files. They live in the viewer for as long as the study is open. To keep a picture of them, export or copy the image: an export with annotations switched on includes the measurements drawn on it.

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.

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.

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.

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.

• 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 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", "License expired", or, on a Basic subscription, "You are subscribed to Basic — Professional features are not included". Enter license… 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.

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, Copy data or Copy all copies the numbers as tab-separated text, and Save CSV… writes them to a file for a spreadsheet.

#### 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; Save CSV… saves them.

#### 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 lesion is most intense along the stack.

#### 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.

#### ROI manager

One table for every measurement on the series: #, Image, Type, Mean, SD, Min, Max, Area, Angle (°) and Length. Lengths are in mm, or px where an image is uncalibrated. 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.

#### 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 lesion 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.

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. The DICOM files on disk are never modified.

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.

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, Discard and Cancel. 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.

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

Pinch to zoom, drag with two fingers to pan, drag with three fingers to change the window, and drag with 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

Pinch to zoom, drag with two fingers to pan, rotate with two fingers to roll, and drag with three fingers to change the window. 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, 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.

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.

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

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

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.

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 are drawn unless Annotations is set to Disabled.

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).

Basic (anonymous) 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. Use a separately validated de-identification workflow before sharing patient images.

How the files are named

Series subfolders are named after the series number and the end of its identifier, for example S3_… .

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. Nothing is written into the original files.

On a trial or expired copy, 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".

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
• 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.

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

Copying to the clipboard

The status bar confirms with "Panel image copied to clipboard", "N panel(s) copied to clipboard" or "Measurement copied".

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.

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.

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.

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. On a trial or expired copy they carry the trial banner in their pixels and are marked as containing burned-in annotation; the original files of an unprocessed series 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
• 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 toolbar holds Folder, CD/DVD (shown only while a DICOM disc is inserted), PACS, Export, 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.

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.

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.

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 de-identified one, 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 exactly one kind of connection to OmniDICOM: the license service.

The underlying hardware identifier never leaves your computer; only the salted hash does. No email address is sent from the application.

Everything else stays local:

• PACS and DICOMweb connections go only to the servers you configured yourself.
• 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