FHIR uses several DICOM-derived value sets:

http://build.fhir.org/valueset-instance-availability.html

http://build.fhir.org/valueset-dicom-cid29.html

http://build.fhir.org/valueset-audit-event-type.html

http://build.fhir.org/valueset-audit-event-sub-type.html

http://build.fhir.org/valueset-dicm-405-mediatype.html

Only CID-29 states that the offical value set definition is from DICOM, all other state that they are "a value set defined by FHIR." If it is the intent that the value sets be defined by FHIR, so that they can diverge from what DICOM has defined, then that is appropriate, although it would probably be good to point back to the DICOM-defined value set they were derived from. On the other hand, if they are intended to match the DICOM-defined value sets, then FHIR should point to the DICOM definitions as official, similar to what is done with CID-29.

For reference, the relevant DICOM value sets are defined at:

Instance availability: http://dicom.nema.org/medical/dicom/current/output/chtml/part16/sect_CID_50.html

Media availability: http://dicom.nema.org/medical/dicom/current/output/chtml/part16/sect_CID_405.html

Audit event type: http://dicom.nema.org/medical/dicom/current/output/chtml/part16/sect_CID_400.html

Audit event subtype: http://dicom.nema.org/medical/dicom/current/output/chtml/part16/sect_CID_401.html

It also might be good if the value set names had some consistency.

(DICOM-derived http://build.fhir.org/valueset-kos-title.html is intended to be a subset of CID 7010, so I didn't include it in the above list, however, it could be update to indicate that it is a subset of the value set defined at http://dicom.nema.org/medical/dicom/current/output/chtml/part16/sect_CID_7010.html.)