Working with Segments

Working with Segments

After a method produces results, manage them in the Select segments list.

The Segment List

Each entry in Select segments shows:

• The segment name
• An eye button that toggles the segment’s visibility in the 3D view

Click a segment name to select it. Selecting an entry makes it the active segment for further actions.

Merging Segments

To combine multiple segments into one:

1. Select two or more segments in the list
2. Click Merge selection

The selected segments are merged into a single anatomy.

Store and Simulate

When the segmentation (and optional CleanUp) is ready, save it as a project so it can be used by the lung analysis tools or the engineering simulation workflow.

1. In the Store selection as project section, type a name into the New project input
2. Confirm to create the device/project from the current anatomy

This creates a new project from the segmented anatomy (or adds it to an existing one), bridging the medical and engineering workflows.

Tip: You can also refine the surface in the CleanUp section before storing — see the next tutorial.

Troubleshooting

Auto Segmentation Produces Nothing

• Verify the Target: make sure the chosen anatomy is actually present in the scan
• Check the acquisition: low-contrast or truncated scans reduce AI accuracy
• Lungs: enable Segment airways (TfeNet) only when airways are in range

Region Growing Leaks

• Lower the threshold to tighten the intensity window
• Move the seed away from boundaries and vessels
• Press Backspace to clear the mask and retry

A Segment Is Not Visible in 3D

• Click the eye button next to the segment in Select segments

Best Practices

1. Start with Auto segmentation and refine only when needed
2. Enable airways for lungs when virtual spirometry or surgery planning will follow
3. Merge related segments before storing so the anatomy is a single object
4. Name projects clearly in Store selection as project for easy retrieval