DICOM sort method

I have a question about DICOM.

I am dealing with MR images. At this time, I try to use the Instance Number when aligning the DICOM. When I look at the Type of Instance Number Tag, it says “Required, Empty if Unknown (2)”, but it sounds like there are cases where it doesn’t exist. What should I do in this case?

Hello @Hu-nie,

This is a DICOM specific question and not a ITK/SimpleITK one. A more appropriate forum is the comp.protocols.dicom google group.

The question was also asked and answered on the Slicer forum:

The role of instance number has been discussed there a few times, for example:

In short: instance number is not intended for spatial sorting.

I didn’t know, thanks for the good info

Thanks for the info, I’ll read it