The Directory Record is based on the specification of Section F.3. It is identified by a Directory Record Type of Value "STUDY." Table F.5-2 lists the set of keys with their associated Types for such a Directory Record Type. The description of these keys may be found in the Modules related to the Study IE of Composite IODs. This Type of Directory Record may reference a Lower-Level Directory Entity that includes one or more Directory Records as defined in Table F.4-1. Only one Study Directory Record per Study Instance UID shall be present in a Basic Directory Instance; this implies that a study belongs to a single patient and shall be referenced only once for that patient.
Table F.5-2STUDY KEYS
|Specific Character Set||(0008,0005)||1C||Required if an extended or replacement character set is used in one of the keys|
|Study Instance UID||(0020,000D)||1C||Required only if (0004,1511) is absent. (See Note)|
|Any other Attribute of the Study IOD or Study IE Modules||3|
Note: The Study Instance UID shall be present as a mandatory key only if no file is referenced by this Directory Record. In the case where this Directory Record references a file, the Directory Record contains in the Referenced SOP Instance UID in File (0004,1511). In this case (0004,1511) may be used as a "pseudo" Directory Record Key (See Table F.3-3) and need not be duplicated.