# Registering whole body CT with a SPECT/CT

**URL:** <https://discourse.slicer.org/t/registering-whole-body-ct-with-a-spect-ct/11317>\
**Category:** Support\
**Tags:** registration\
**Created:** [April 27, 2020, 4:04pm UTC](https://discourse.slicer.org/t/registering-whole-body-ct-with-a-spect-ct/11317 "2020-04-27T16:04:10Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Gunjan\_Kayal](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/gunjan_kayal/32/6712_2.png) [@Gunjan\_Kayal](https://discourse.slicer.org/u/Gunjan_Kayal)\
**Post date:** [April 27, 2020, 4:04pm UTC](https://discourse.slicer.org/t/registering-whole-body-ct-with-a-spect-ct/11317/1 "2020-04-27T16:04:10Z")

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Hi,

When we try to perform the elastic registration (using Elastix), the whole body model is cropped to the size of the real SPECT/CT. We need to preserve the whole body and resample this whole body as per the real SPECT/CT.  
Could someone help me with the registration of a whole body CT model with a real SPECT/CT?  
I attach a screenshot of the whole body model with SPECT/CT for better understanding.

Thank you.

 ![Screenshot 2020-04-27 at 17.40.31 (2)](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/9/0/905ad546942618e0593e3943dcc04e635a43a820.jpeg)

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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:** [April 27, 2020, 4:25pm UTC](https://discourse.slicer.org/t/registering-whole-body-ct-with-a-spect-ct/11317/2 "2020-04-27T16:25:01Z")

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Elastix cannot extrapolate the segmentation, but Slicer can. Instead of asking Elastix to create a resampled output image, apply the computed transform to the whole body CT using Transforms module.