# How to get metrics for centerline pieces?

**URL:** <https://discourse.slicer.org/t/how-to-get-metrics-for-centerline-pieces/44252>\
**Category:** VMTK\
**Created:** [August 29, 2025, 2:34pm UTC](https://discourse.slicer.org/t/how-to-get-metrics-for-centerline-pieces/44252 "2025-08-29T14:34:55Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![abitrolly](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/abitrolly/32/80922_2.png) [@abitrolly](https://discourse.slicer.org/u/abitrolly)\
**Post date:** [August 29, 2025, 2:34pm UTC](https://discourse.slicer.org/t/how-to-get-metrics-for-centerline-pieces/44252/1 "2025-08-29T14:34:55Z")

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How to split [extracted centerline](https://github.com/vmtk/SlicerExtension-VMTK/blob/master/Docs/ExtractCenterline.md) into pieces to get curvature, torsion and tortuosity for each piece?

I feel like I miss something obvious, but after hours of trying I haven’t found how to do this through UI. If it is impossible, maybe somebody can point me to the right Python calls? I have coordinates of points where to split the centerlines written down manually from CT scan.

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**Author:** ![chir.set](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/chir.set/32/66982_2.png) [@chir.set](https://discourse.slicer.org/u/chir.set)\
**Post date:** [August 29, 2025, 3:04pm UTC](https://discourse.slicer.org/t/how-to-get-metrics-for-centerline-pieces/44252/2 "2025-08-29T15:04:48Z")

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To split a _bifurcated_ centerline _model_, you can consider the [Centerline disassembly](https://github.com/vmtk/SlicerExtension-VMTK/blob/master/Docs/CenterlineDisassembly.md) module.

The `ExtractCenterline` module provides metrics also.

You can get an overview [here](https://github.com/vmtk/SlicerExtension-VMTK/blob/7708b85902571082ab813bf0833e13ed85e84d09/ExtractCenterline/ExtractCenterline.py#L619) to calculate metrics in Python.

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**Author:** ![abitrolly](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/abitrolly/32/80922_2.png) [@abitrolly](https://discourse.slicer.org/u/abitrolly)\
**Post date:** [August 29, 2025, 5:05pm UTC](https://discourse.slicer.org/t/how-to-get-metrics-for-centerline-pieces/44252/3 "2025-08-29T17:05:26Z")

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Thanks for the pointers. There is a need to split _centerline_ that is _not bifurcated_ into subsequent pieces. On the CT scan there are places where the vein goes through different bones, and I’d like to manually split the _centerline_ into pieces that correspond to these bones to measure the parameters.

The [centerline disassembly](https://github.com/vmtk/SlicerExtension-VMTK/blob/master/Docs/CenterlineDisassembly.md) module mentions branches as “_centerline_ parts that exclude the bifurcations”, but how to I place a point to split one continuous _centerline_ into these branches?

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**Author:** ![mikebind](https://avatars.discourse-cdn.com/v4/letter/m/71e660/32.png) [@mikebind](https://discourse.slicer.org/u/mikebind)\
**Post date:** [August 29, 2025, 6:17pm UTC](https://discourse.slicer.org/t/how-to-get-metrics-for-centerline-pieces/44252/4 "2025-08-29T18:17:07Z")

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You can manually place the endpoints for each section and run extract centerline for each section. Then you will have separate centerlines to take the measurements from. If you are concerned about exactly placing the endpoint in each section in the center of the vessel, you can first extract the centerline for the whole vessel, then place your segment endpoints along the extracted full centerline.

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**Author:** ![chir.set](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/chir.set/32/66982_2.png) [@chir.set](https://discourse.slicer.org/u/chir.set)\
**Post date:** [August 29, 2025, 6:31pm UTC](https://discourse.slicer.org/t/how-to-get-metrics-for-centerline-pieces/44252/5 "2025-08-29T18:31:40Z")

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Ok, so it’s not splitting at bifurcations.

@mikebind 's suggestion is probably the best thing to do.

If you really need to cut your centerline, the `Dynamic modeler` module allows to cut any model with a plane or a ROI for example.

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**Author:** ![abitrolly](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/abitrolly/32/80922_2.png) [@abitrolly](https://discourse.slicer.org/u/abitrolly)\
**Post date:** [August 31, 2025, 1:56pm UTC](https://discourse.slicer.org/t/how-to-get-metrics-for-centerline-pieces/44252/6 "2025-08-31T13:56:37Z")

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> [@mikebind](#):
>
> extract the centerline for the whole vessel, then place your segment endpoints along the extracted full centerline

Thanks. I will try to find out how to place endpoints there, which view and buttons I need to press.

> [@chir.set](#):
>
> the `Dynamic modeler` module allows to cut any model with a plane or a ROI for example

I am going to try this as well. Thanks.