How to calculate space between dicom slices for MPR?

Question

Due to showing MPR view based on Dicoms. I\'ve made a 3D array from series of dicom files. And I show it from Coronal and Sagittal sides.

Answer 1

As discussed in the previous answers, it is not straightforward how to calculate space between DICOM slices. Let's phrase the question differently: How to store DICOM slices in a 3D volume, i.e. a list of equally spaced slices for rendering (guess you want to upload into a 3D texture).

This is because the actual position that a CT slice is captured might not be identical to the position selected by the radiologist. A dataset might have been configured to capture 1 mm slices, but the CT returns slices at position 0.0 mm, 0.997 mm, 2.010 mm, ...

If you use an attribute such as Spacing Between Slices to calculate the size of the 3D volume, you will obtain subtle rounding errors easily. Don't go there.

Rather it is essential to use Image Position (Patient) (0020, 0032) and then perform an optimization to figure our how the slices could be fit into an grid.

Typical problems in practice to consider:

• Missing slices (interpolate? Gap?)
• Out of step slices (hardware defect? data defect?)