FIG 2.

Simplified data model illustrating the linkages between various data types and the organization of data as collections. Subjects are identified consistently within a collection, and all data for that subject are properly linked. Because data are de-identified before leaving the submitting site, it is possible for the same subject to appear in multiple collections, with different subject identifiers. Because the collections have limited overlap, this probability is considered to be low. DICOM, Digital Imaging and Communications in Medicine.