# How to find the largest area of a 3d structure

**URL:** <https://discourse.slicer.org/t/how-to-find-the-largest-area-of-a-3d-structure/20050>\
**Category:** Support\
**Created:** [October 7, 2021, 10:41am UTC](https://discourse.slicer.org/t/how-to-find-the-largest-area-of-a-3d-structure/20050 "2021-10-07T10:41:28Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![hourglassnam](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/hourglassnam/32/11796_2.png) [@hourglassnam](https://discourse.slicer.org/u/hourglassnam)\
**Post date:** [October 7, 2021, 10:41am UTC](https://discourse.slicer.org/t/how-to-find-the-largest-area-of-a-3d-structure/20050/1 "2021-10-07T10:41:28Z")

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Hello!  
I wanted to know if there is any way to find a cross-section image with the largest length or area of a 3d structure, regardless of the orientation.  
I know I can get cross-section areas of segments and find the largest area, however, this means I have to reorientate volume properly in advance.  
Instead, I wanted to find the largest area of the 3d structure, then set that as the axial slice afterward.  
Is this possible?  
I have been looking all over the forum but could not find an answer to this.  
Any advice would be grateful.  
Thank you always.

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**Author:** ![lassoan](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/lassoan/32/13_2.png) [@lassoan](https://discourse.slicer.org/u/lassoan)\
**Post date:** [October 7, 2021, 1:29pm UTC](https://discourse.slicer.org/t/how-to-find-the-largest-area-of-a-3d-structure/20050/2 "2021-10-07T13:29:33Z")

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The most common way of extracting the largest cross-section is to use SlicerVMTK extensions “Extract centerline” module to automatically get a centerline of the object and then use “Cross-section analysis” module to get a plot of the maximum inscribed sphere radius across the structure and in that module you can also get the full cross-sectional area and reslice the image/segmentation, jump to minimum/maximum cross-section, etc.

 ![image](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/1/1/11999dc146f0d4c0329c3392ea22ae619c203a16.jpeg)

This is available for recent Slicer Preview Releases.

If you just want to explore a segment across a straight line then you can use the new [SegmentGeometry extension](https://github.com/jmhuie/Slicer-SegmentGeometry#segment-geometry).

If you need to automatically detect size of a structure then you can get oriented bounding box position, orientation, and size using Segment Statistics module. You can also use [this script](https://slicer.readthedocs.io/en/latest/developer_guide/script_repository.html#markups-roi) to create ROI nodes from them that you can use in Crop volumes module to resample the segmentation.

 ![image](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/e/b/ebca15647d17714a8363864e0990efbed6f283d6.jpeg)