# Why does the shape of the image change?

**URL:** <https://discourse.slicer.org/t/why-does-the-shape-of-the-image-change/4192>\
**Category:** Support\
**Created:** [September 26, 2018, 11:05am UTC](https://discourse.slicer.org/t/why-does-the-shape-of-the-image-change/4192 "2018-09-26T11:05:42Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![zgk110](https://avatars.discourse-cdn.com/v4/letter/z/ed8c4c/32.png) [@zgk110](https://discourse.slicer.org/u/zgk110)\
**Post date:** [September 26, 2018, 11:05am UTC](https://discourse.slicer.org/t/why-does-the-shape-of-the-image-change/4192/1 "2018-09-26T11:05:42Z")

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Hi, I read a MRI series image by Simpleitk and the shape of it is (168L, 640L, 640L).  
However, when i use the 3D slicer to read the same image, the shape of the image is changed to (24L, 640L, 640L), meanwhile, I find that the image read by the Simpleitk just have many same slices (7 times repeated for each slice ).  
I don’t know whether the 3D slicer does some pre-processing to merge the repeated slices to one or some else operations, so can anyone give any advice?

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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:** [September 26, 2018, 2:23pm UTC](https://discourse.slicer.org/t/why-does-the-shape-of-the-image-change/4192/2 "2018-09-26T14:23:12Z")

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Slicer’s DICOM reader uses the same reader as ITK (SimpleITK) at the lowest level, but it does a lot of additional pre-processing (determine how to group and order slices) and post-processing (apply necessary warping to correct any geometrical issues).