[Insight-users] Transforming image to world coordinates with negative z axis

[John Drescher]

I am loading a dicom CT series in image # order

The first slice is:
0020|0032 Image Position (Patient) = -164.300\-169.500\-24.750
0020|0037 Image Orientation (Patient) =
1.000000\0.000000\0.000000\0.000000\1.000000\0.000000

And the last slice is:
0020|0032 Image Position (Patient) = -164.300\-169.500\-359.750
0020|0037 Image Orientation (Patient) =
1.000000\0.000000\0.000000\0.000000\1.000000\0.000000

The problem I am having is that TransformIndexToPhysicalPoint is
returning Z values that are positive which is impossible because the z
range is from -24.750 to -359.750. I thought it was the same problem
as

http://www.nabble.com/itk::Image-vs.-itk::OrientedImage-td19899159.html

but my direction vector (examined while debugging) looks wrong to me:
1 0 0
0 1 0
0 0 1

Any ideas how to fix this so that I get the correct world coordinates?
Or am I misunderstanding something? I am quite new at itk and vtk.

I am using itk version is 3.10.2, and vtk-5.2.1.

Thanks,
John M. Drescher