# Anyone know how to calculated the lesion on CT corresponding on SPECT images?

**URL:** <https://discourse.slicer.org/t/anyone-know-how-to-calculated-the-lesion-on-ct-corresponding-on-spect-images/21562>\
**Category:** Feature requests\
**Tags:** segmentation, pet\
**Created:** [January 21, 2022, 4:22pm UTC](https://discourse.slicer.org/t/anyone-know-how-to-calculated-the-lesion-on-ct-corresponding-on-spect-images/21562 "2022-01-21T16:22:51Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![akmal871026](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/akmal871026/32/11642_2.png) [@akmal871026](https://discourse.slicer.org/u/akmal871026)\
**Post date:** [January 21, 2022, 4:22pm UTC](https://discourse.slicer.org/t/anyone-know-how-to-calculated-the-lesion-on-ct-corresponding-on-spect-images/21562/1 "2022-01-21T16:22:51Z")

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Hi All, I have SPECT image with lesion 1 and lesion 2. (as attached picture)

I also have CT from the PET machine that also have the same lesion 1 and lesion 2. (as attached picture)

My problem is how to calculate the lesion on the CT image?

Anyone can help me?

 ![2](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/6/b/6b33f0038ee238f7bda6b7ca6d666fa62babc50f.jpeg)

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**Author:** ![pieper](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/pieper/32/8_2.png) [@pieper](https://discourse.slicer.org/u/pieper)\
**Post date:** [January 21, 2022, 5:58pm UTC](https://discourse.slicer.org/t/anyone-know-how-to-calculated-the-lesion-on-ct-corresponding-on-spect-images/21562/2 "2022-01-21T17:58:54Z")

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I’ve never worked with SPECT data so it’s not clear I can help, but could you elaborate on what you mean by “calculate the lesion on the CT image”? It might be that you can create a segmentation with thresholding on the SPECT and then run segment statistics with the CT as the target volume.