XDS for Imaging (XDS-I) is an extension to the IHE XDS protocol explicitly for imaging, which stores a DICOM Key_Image_Note (aka Key_Object_Selection_Document) as the stored object in the Document Repository which in turn lines to the images in the "Image Source" (normally the original PACS, or perhaps a regional equivalent).

The images can be retrieved using either C-MOVE or more commonly using WADO