Today I had two DICOM knee images (right and left which we will refer to as rightImage.dcm and leftImage.dcm) that were shot separately, but I needed them together on the same image to be consistent with a project I was working on.  Here is how I pulled it off.  The process is rather convoluted but it worked.  I will try to post some pictures and more details later.

This was convoluted but seemed to work.  Follow these steps roughly:
– load the rightImage.dcm DICOM image into Sante and use the ‘Utilities/DICOM Templates/Create from Active File’ option to save the header information (we will use this later after we have merged the images)
– export both two DICOM images we want to merge (rightImage.dcm and leftImage.dcm) as TIFF from Sante (otherwise Photoshop might have issues loading the DICOM images)
– expand the rightImage.dcm canvas double size (image to the left)
– copy leftImage.dcm image and paste into rightImage.dcm as another layer, position the layer and merge
– crop image to desired size
– note image pixel size (width and height) of merged image to use later
– export image as lossless TIFF from Photoshop
– in Sante DICOM use the ‘File/Batch Convert Images To DICOM’ and select the folder where the merged DICOM images (TIFF) file is located and then select the DICOM header template you exported earlier, and set the File Type to TIFF, then use the Edit/View Template option to  modify the 0028,0010 and 0028,0011 DICOM elements to match the pixel size of your merged image (everything else can remain the same from the header template)
– then simply convert
At this point you should have a merged DICOM image with the same annotations and scale bars etc. that matches the rightImage.dcm original image.  Close the merged DICOM file and load it back into Sante to confirm everything looks correct.