DICOM Labeling Editor

Overview of the DICOM Labeling Editor interface on Ango Hub

Ango Hub provides a labeling editor with which single-frame and multi-frame DICOM files can be annotated.

This article will exclusively go over Ango Hub's DICOM labeling interface. Features common to all labeling editors are instead explained here.

Overview

Supported File Types

The DICOM labeling editor supports DICOM assets with the following file extensions:

.dcm

Supported Labeling Tools

The DICOM labeling editor supports following labeling tools:

Tools

Bounding Box
Polygon
Polyline
Point
Voxel Brush
Angle

Classifications

Radio
Checkbox
Single-Select Dropdown
Multi-Select Dropdown
Single-Select Tree
Multi-Select Tree
Text

Relations

Single Relation
Group Relation

DICOM Interface Elements

When you open a DICOM asset, Ango Hub displays the DICOM file in a DICOM-specific image editor. Single-frame DICOM files behave like image assets. Multi-frame DICOM files also include frame navigation controls.

If the asset contains multiple DICOM files, Ango Hub displays them in a multi-view grid.

Multi-frame Navigation

For multi-frame DICOM files, use the playback bar at the bottom of the editor to move through frames. You can move one frame at a time, drag the playhead, play through the frames, or enter a frame number.

When multiple DICOM files are displayed at once, frame navigation applies to the active DICOM view. Click a DICOM view to make it active before navigating its frames.

If the active DICOM has more than one frame, a vertical slice navigator is also shown on the left side of that view. Use the slider or the up and down arrows to move through the DICOM's frames.

You may also use the left and right arrow shortcuts to move backward and forward through frames in the active DICOM.

Multi-view Grid

In multi-DICOM assets, each DICOM file appears in its own view. The active view is highlighted. Click a view to make it active, or hover over a view while a tool is selected to annotate in that view.

You can rearrange views by dragging them with the handle in the top-left corner of each view. You can also enlarge a single view with the expand button in the top-right corner of that view, then restore the full grid.

While holding Alt (Option) on your keyboard, click DICOM views to select a smaller set of views. When the selected count matches an available layout, a layout button appears. Click it to show only the selected DICOMs in a compact layout. Click Default to return to the full grid.

The alignment button at the top of the grid lets you align the displayed DICOM views.

DICOM Filenames

By default, the filename of each DICOM is displayed on the bottom-left of each view. You can turn this off from the editor's settings menu by toggling off Show DICOM Filename.

How to Annotate DICOM Files

Annotating DICOMs is similar to annotating images. For multi-frame DICOMs, annotations are created on the current frame of the active DICOM.

The following are the labeling tools supported on DICOMs:

From the Tools panel on the left sidebar, select a supported labeling tool. Then, follow the instructions found on each tool's docs page, linked to above.

If no tools are present in the project, only answer the questions in the Classifications panel.

When done, move forward to the next frame or DICOM and repeat the process until all required frames and DICOMs are labeled.

Nested Questions and Classifications

If the labels have nested questions, right-click on each label and click on the menu item that appears to see and answer the nested questions.

If classification questions are present, you may answer them from the Questions panel on the left sidebar.

Annotating Multiple DICOM Files at Once

For information on how to import multi-DICOM assets, please consult this docs page.

Focusing the Grid

When multiple DICOM files are displayed on screen, you may choose to focus the layout on a smaller number of them.

By default, the filename of each DICOM is displayed on the bottom-left of each view. You can turn this off from the editor's settings menu by toggling off the Show DICOM Filename option.

While holding Alt (Option) on your keyboard, click on the DICOMs you would like to focus on. If the selected number of DICOMs matches an available compact layout, a layout button will appear.

Clicking the layout button will display the selected DICOMs in their own, larger layout.

To return to the full grid, click Default.

Copying and pasting annotations from one DICOM to another

You may select a single annotation, or multiple by holding Shift, then use Control + C (⌘ + C on macOS) to copy the objects to the clipboard, even if the objects are on different slices in the same DICOM. You may then paste the new objects to the other DICOM by clicking on the target DICOM and pressing Control + V (⌘ + V on macOS).

Due to a current limitation, all objects in the clipboard will be pasted on the slice (frame) you are currently viewing, regardless of whether they came from different frames.

Changing Window Levels

Click the Window tool in the toolbar to open windowing options for the active DICOM.

You can adjust the window width and level using the sliders or by entering values. You can also choose from presets such as Abdomen, Bone, Air, Brain, Lung, and Liver, or reset width and level to the DICOM's default values.

Alternatively, right-click and drag on the DICOM view to change the window width and level directly.

Keyboard Shortcuts

A full list of keyboard shortcuts is available by clicking on the Keyboard button on the right side of the top bar: