By: zzzzzlll on Feb. 21, 2022, 9:41 a.m.
Dear organizers,
Can you please confirm that the physical unit of the 'SliceThickness' field is the same across the dataset? A concerning case would be patient #4382, where this field has a value of 5 and the scan has 270 slices. If the unit is millimeter (as is likely the case for most other scans), these values would indicate a physical volume that is not consistent with the body parts imaged.
By: LuukBoulogne on Feb. 22, 2022, 8:47 a.m.
Thank you for raising this point. To the best of our knowledge, the physical unit (mm) of SliceThickness is the same across the dataset.
Doing computations with SliceThickness can be confusing, as the slice thickness can be different from the slice increment. The slice increment is the distance moved for scanning the next slice. If the slice thickness is larger than the slice increment, the slices overlap. This is the case for patient 4382: The slice thickness is 5mm, and the slice increment is 1.3mm. To compute the physical size of the CT volume, you could use ElementSpacing.
