Hi -

I have been trying to understand when and how I would need to use the
mapping from pixel location to the reference coordinate system (RCS)
as described in section c. of Part 3. The calculation uses
the Image Orientation (0020,0037), the Image Position (0020,0032) and
the Pixel Spacing (0028,0030).

I understand that the Image Orientation gives the unit vectors for the
row and column of the image matrix. When the Orientation is all 0s
and 1s, it is clear to me, but when it is not, I have trouble
understanding how I should use it. For example, one MR dataset I'm
using has the values:
-0.32\0.95\-0.03\0.08\0.00\-1.00. I know this tells me that the
images are mostly in the sagittal orientation, but rotated somewhat.

I am trying to interpolate the MR data onto an isovox grid in
preparation for registering the patient's PET images to the MR images,
and I'm not sure if I need to take the Patient Orientation into
account, and if so, how. The header says that the slice thickness is
1.0 mm, but because the images are rotated, if I look at the Image
Position (0020,0032) of successive slices is less than 1.0 (ie the
difference between the Image Position of successive planes is 0.94).

Any help in understanding this would be appreciated!