# Combine 2 ct volumes into one

**URL:** <https://discourse.slicer.org/t/combine-2-ct-volumes-into-one/32580>\
**Category:** Support\
**Created:** [November 3, 2023, 12:02pm UTC](https://discourse.slicer.org/t/combine-2-ct-volumes-into-one/32580 "2023-11-03T12:02:15Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![mijelsan](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/mijelsan/32/66442_2.png) [@mijelsan](https://discourse.slicer.org/u/mijelsan)\
**Post date:** [November 3, 2023, 12:02pm UTC](https://discourse.slicer.org/t/combine-2-ct-volumes-into-one/32580/1 "2023-11-03T12:02:15Z")

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I have 2 ct of same patient of 2 half bodys overlapping, one from head to pelvis and second from pelvis to feet.

I want to combine them into one, i’m going with this workflow:

first i enlarge body section to body\_extended volume using crop volume module setting -1000 to the fill value and linear as interpòlator.

Nexti register two images body\_extended and legs manually with transform module then with brains general registration ok.

now i have to combine two cts into one, i think a tool that can compare boxel by boxel and select maximun value would do the job but i cant find that tool.

I try to use add scalar volumes module but in the legs section the hu value isnt correct as it shows good value for bones (1000) but bad for muscle (-xxx) i think thats because it is linearly scalinf from body\_extended (-1000) to leg values (say 100) and then it outputs something in range -xxx…

please may any help with this issue

thank you,

Miguel

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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:** [November 3, 2023, 12:05pm UTC](https://discourse.slicer.org/t/combine-2-ct-volumes-into-one/32580/2 "2023-11-03T12:05:31Z")

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This material should help:

> **[GitHub - PerkLab/SlicerSandbox: Collection of utilities that are not polished...](https://github.com/PerkLab/SlicerSandbox#stitch-volumes)**
>
> Collection of utilities that are not polished implementations but can be useful to users - GitHub - PerkLab/SlicerSandbox: Collection of utilities that are not polished implementations but can be u...

> [@Multiple partial volumes reconstruction](https://discourse.slicer.org/t/multiple-partial-volumes-reconstruction/25786):
>
> Hi there, I’m trying to synthesize one full volume from multiple partial volumes(smaller FOV) of the same objects. I wonder if anyone else has explored this topic, and happy to hear any thoughts on what would be the best approach to this. I appreciate any ideas and advice on things to do or not to do.

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**Author:** ![mijelsan](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/mijelsan/32/66442_2.png) [@mijelsan](https://discourse.slicer.org/u/mijelsan)\
**Post date:** [November 3, 2023, 5:09pm UTC](https://discourse.slicer.org/t/combine-2-ct-volumes-into-one/32580/3 "2023-11-03T17:09:20Z")

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Very much thank you for your answer, i’ve managed to get the job done with the tool you posted. nevertheless i would like to dig into the details and know if this can be done manually with the tools included default

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**Author:** ![mijelsan](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/mijelsan/32/66442_2.png) [@mijelsan](https://discourse.slicer.org/u/mijelsan)\
**Post date:** [November 3, 2023, 7:31pm UTC](https://discourse.slicer.org/t/combine-2-ct-volumes-into-one/32580/4 "2023-11-03T19:31:44Z")

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after play a little more with the modules i have reproduced what is done by the stitch script:

1. use module resample image brains, image to warp is the smallest image in my case the legs, and reference image the bigger in my case body\_extended. i have to use pixel tipe as short and linear interpolation with default value=-1000

2. go to the simple filters module named “maximunimagefilter” put the two volumes and then you get the combined ct

problem is solved after this thank you!!! any correction or improvement would be apreciated!!