# Method-Voxel Analysis comparing the same segment on two scans

**URL:** <https://discourse.slicer.org/t/method-voxel-analysis-comparing-the-same-segment-on-two-scans/42801>\
**Category:** Support\
**Tags:** segmentation, python\
**Created:** [May 5, 2025, 6:37pm UTC](https://discourse.slicer.org/t/method-voxel-analysis-comparing-the-same-segment-on-two-scans/42801 "2025-05-05T18:37:08Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![CSalt](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/csalt/32/79817_2.png) [@CSalt](https://discourse.slicer.org/u/CSalt)\
**Post date:** [May 5, 2025, 6:37pm UTC](https://discourse.slicer.org/t/method-voxel-analysis-comparing-the-same-segment-on-two-scans/42801/1 "2025-05-05T18:37:08Z")

</div>

I am trying to perform voxel analysis for scans taken at different time periods to track tumor uptake at varying time points. I am using registered images. I was able to plot a voxel histogram like the one in this documentation:

> **[Script repository — 3D Slicer documentation](https://slicer.readthedocs.io/en/latest/developer_guide/script_repository.html#get-histogram-of-a-segmented-region)**

I want to find out if anyone has guidance to plot a comparison of the voxels. I would like to do something very similar to figure one in the following paper:

> **[Voxel-by-Voxel Functional Diffusion Mapping for Early Evaluation of Breast...](https://pmc.ncbi.nlm.nih.gov/articles/PMC2804941/)**
>
> Quantitative isotropic diffusion MRI and voxel-based analysis of the apparent diffusion coefficient (ADC) changes have been demonstrated to be able to accurately predict early response of brain tumors to therapy. The ADC value changes measured ...

but I am not certain how to go about it. Please let me know if you have any ideas.

Thanks in advance.