Dicom stack metadata - retaining original stack information

I have read in a stack of DICOM images that have then been modified and need writing out again. The problem is that some of the data in the header is missed when written out.

The main property that I want to maintain is the association to other images in the stack, and its slice position. I can see several people have had similar difficulties but rarely there is a solution.

At worst, how should I define the dictionary such that:

- it knows it is part of a stack

- i can give its position in the stack

It is fine to define the image matrices such that each element is a 1x1 pixel, and each image is 1 pixel thick.

Thanks