DICOM PS3.3 2020c - Information Object Definitions

C.17.2.2 Identical Documents Sequence

If identical copies of a document are to be included in multiple Studies then the entire document shall be duplicated with appropriate changes for inclusion into the different Studies (i.e., Study Instance UID, Series Instance UID, SOP Instance UID, Identical Documents Sequence etc.). The Identical Documents Sequence Attribute in each SOP Instance shall contain references to all other duplicate SOP Instances.

Note

If a document contains an Identical Documents Sequence then it will not be further duplicated without producing a new complete set of duplicate SOP Instances with re-generated Identical Documents Sequences. This is a consequence of the rules for modification of document content in PS3.4. For example, if there are two identical reports and an application is creating a third identical report, then the first two reports must be re-generated in order that their Identical Documents Sequence will reference the new duplicate document and all other identical documents.

If a new document is created using content from a document that contains an Identical Documents Sequence and is part of the same Requested Procedure, then the new document shall only contain a new Identical Documents Sequence if the new document is duplicated. The Predecessor Documents Sequence in all the new documents shall contain references to the original document and all its duplicates as well as any other documents from which content is included.

Note

It is up to an implementation to decide whether a new document is duplicated across multiple Studies. This may require user input to make the decision.

DICOM PS3.3 2020c - Information Object Definitions