Questions about Slicer Coordinates

This is the image information I read and printed from DCM images through ITK

Based on the calculation, I found that the physical spatial coordinates should be at (-420, -140, -420, -140, -140,140)

Why is the coordinate information displayed in the 3D slicer not like this

According to the ITK reader, the physical LPS coordinates are in the range:

  • L [-420, -140] = R 140 to R 420
  • P [-420, -140] = A 140 to A 420
  • S [-140, 140] = I 140 to S 140

In Slicer, the G view’s offset (A 297) is in the same range as in ITK, but the yellow view is not (L 285.5). Most likely you have not loaded the image using DICOM module.

If you find the physical coordinates range are still different in ITK and Slicer then please share the image (upload somewhere and post the link here) and I’ll have a look.

I am sure I used the dicom module to read the image

image is delete

WIth both the latest Slicer Stable Release (Slicer-5.2.2) and a recent Slicer Preview Release (Slicer-5.3.0-2023-04-25) the yellow slide range is negative L, which means R, which is correct.

green why not negative ?

The direction code (L, R, A, P, I, S) is chosen so that when you move the slider to the right the numerical value increases.