# NHDR Format direction

**URL:** <https://discourse.slicer.org/t/nhdr-format-direction/26241>\
**Category:** Support\
**Created:** [November 15, 2022, 6:36am UTC](https://discourse.slicer.org/t/nhdr-format-direction/26241 "2022-11-15T06:36:14Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![seyang](https://avatars.discourse-cdn.com/v4/letter/s/b38774/32.png) [@seyang](https://discourse.slicer.org/u/seyang)\
**Post date:** [November 15, 2022, 6:36am UTC](https://discourse.slicer.org/t/nhdr-format-direction/26241/1 "2022-11-15T06:36:15Z")

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Someone can help me to set the direction for NHDR Format?  
This is a micro CT image (360 degrees). when I import the NGDR format after making it, it displayed the wrong position.

 ![image](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/c/0/c09aa588d56c368270200021642cdef055466e84.png)  
 ![image](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/5/4/54b154823f3c9da61c3b32d75769b5d7e7c80bbe.png)

I want to crop x-y-z like this.

 ![image](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/1/d/1dee03aed7a31a95ea06b620642aeae41128ec9d.jpeg)  
 ![image](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/b/c/bcc92523b31ef8b1c76e9e15f6db7afeefefa9be.jpeg)

NRRD0004  
type: unsigned short  
dimension: 3  
space: LPS  
sizes: 2000 1718 361  
space directions: (0.027,0,0) (0,0.027,0) (0,0,0.027)  
endian: little  
encoding: raw  
datafile: projection%04d.raw 0 360 1

Is it any require additional item?  
Thanks to the 3d slicer development team, I am using this program well.

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**Author:** ![muratmaga](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/muratmaga/32/3622_2.png) [@muratmaga](https://discourse.slicer.org/u/muratmaga)\
**Post date:** [November 15, 2022, 6:41am UTC](https://discourse.slicer.org/t/nhdr-format-direction/26241/2 "2022-11-15T06:41:09Z")

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What you have in the first set of pictures (white background) are the shadow (projection) images. Those are X-rays collected in the scanner by changing the samples orientation by small rotations. By themselves they are not useful for anything. From them, cross-sectional slices of the object are “reconstructed” using an algorithm (typically Feldcamp backprojection).

It is these cross-sectional slices (second set of pictures with dark background) that is usable by Slicer. You can virtually reconstruct the 3D object using visualization techniques. Or segment parts of it.

You can’t do any of that on projection images.

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**Author:** ![seyang](https://avatars.discourse-cdn.com/v4/letter/s/b38774/32.png) [@seyang](https://discourse.slicer.org/u/seyang)\
**Post date:** [November 15, 2022, 7:10am UTC](https://discourse.slicer.org/t/nhdr-format-direction/26241/3 "2022-11-15T07:10:35Z")

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Ok got it. Currently, it can’t use in the 3d slicer software.  
Thanks a lot.

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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:** [November 15, 2022, 12:07pm UTC](https://discourse.slicer.org/t/nhdr-format-direction/26241/4 "2022-11-15T12:07:49Z")

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You should be able to reconstruct a 3D Cartesian volume in your scanner software (or reconstruct yourself using [RTK](https://www.openrtk.org/)) and that image will be usable in Slicer.