# How to find Pixel Size/ Voxel Depth on 3D slicer? 

**URL:** <https://discourse.slicer.org/t/how-to-find-pixel-size-voxel-depth-on-3d-slicer/16541>\
**Category:** Support\
**Created:** [March 15, 2021, 3:26am UTC](https://discourse.slicer.org/t/how-to-find-pixel-size-voxel-depth-on-3d-slicer/16541 "2021-03-15T03:26:16Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![simple](https://avatars.discourse-cdn.com/v4/letter/s/e36b37/32.png) [@simple](https://discourse.slicer.org/u/simple)\
**Post date:** [March 15, 2021, 3:26am UTC](https://discourse.slicer.org/t/how-to-find-pixel-size-voxel-depth-on-3d-slicer/16541/1 "2021-03-15T03:26:16Z")

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Hello,  
I was hoping someone can help me find the CT scans parameters. Specifically, I know that this CT scan has an acquisition matrix of 512 x 512 pixels. However, how do I find the pixel size and voxel depth of this CT scan?

 ![Screen Shot 2021-03-14 at 8.54.44 PM](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/e/f/efbdedc19ee27c02392b71e9b0dece2912794536.jpeg)

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**Author:** ![JanWitowski](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/janwitowski/32/4512_2.png) [@JanWitowski](https://discourse.slicer.org/u/JanWitowski)\
**Post date:** [March 15, 2021, 3:33am UTC](https://discourse.slicer.org/t/how-to-find-pixel-size-voxel-depth-on-3d-slicer/16541/2 "2021-03-15T03:33:00Z")

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What do you mean by pixel size and voxel depth? If I understand correctly, you are looking for values that are displayed in the Image Spacing field: (0.46875,0.46875,0.5). You might find [SimpleITK’s Fundamental Concepts page](https://simpleitk.readthedocs.io/en/master/fundamentalConcepts.html) as well as 3D Slicer’s [coordinate systems wiki page](https://www.slicer.org/wiki/Coordinate_systems) helpful with regards to pixel spacing.

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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:** [March 15, 2021, 4:57am UTC](https://discourse.slicer.org/t/how-to-find-pixel-size-voxel-depth-on-3d-slicer/16541/3 "2021-03-15T04:57:14Z")

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Bit depth for original (not-postprocessed) CT images is almost always 16 bits. This is true for this image, too, since scalar type is `short`, which means “short integer” = 16 bits.