# Circular ROI on PET

**URL:** <https://discourse.slicer.org/t/circular-roi-on-pet/32141>\
**Category:** Support\
**Tags:** segmentation, petct\
**Created:** [October 10, 2023, 8:26pm UTC](https://discourse.slicer.org/t/circular-roi-on-pet/32141 "2023-10-10T20:26:23Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![tugba\_kissa](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/tugba_kissa/32/67810_2.png) [@tugba\_kissa](https://discourse.slicer.org/u/tugba_kissa)\
**Post date:** [October 10, 2023, 8:26pm UTC](https://discourse.slicer.org/t/circular-roi-on-pet/32141/1 "2023-10-10T20:26:23Z")

</div>

I am trying to do segmentation from PET/CT fusion image. But I cannot get circular ROI. When I can get circular ROI, when I select the source volume as pet, the image is distorted and pixel-by-pixel squares are seen as I presented in the attachment. what can I do to solve this problem?