DICOM PS3.4 2019a - Service Class Specifications

C.3 Standard Query/Retrieve Information Models

Three standard Query/Retrieve Information Models are defined in this Annex. Each Query/Retrieve Information Model is associated with a number of SOP Classes. The following three hierarchical Query/Retrieve Information Models are defined:

C.3.1 Patient Root Query/Retrieve Information Model

The Patient Root Query/Retrieve Information Model is based upon a four level hierarchy:

  • Patient

  • Study

  • Series

  • Composite Object Instance

The patient level is the top level and contains Attributes associated with the Patient Information Entity (IE) of the Composite IODs as defined in PS3.3. Patients IEs are modality independent.

The study level is below the patient level and contains Attributes associated with the Study IE of the Composite IODs as defined in PS3.3. A study belongs to a single patient. A single patient may have multiple studies. Study IEs are modality independent.

The series level is below the study level and contains Attributes associated with the Series, Frame of Reference and Equipment IEs of the Composite IODs as defined in PS3.3. A series belongs to a single study. A single study may have multiple series. Series IEs are modality dependent. To accommodate this modality dependence, the set of Optional Keys at the series level includes all Attributes defined at the series level from any Composite IOD defined in PS3.3.

The lowest level is the Composite Object Instance level and contains Attributes associated with the Composite object IE of the Composite IODs as defined in PS3.3. A Composite Object Instance belongs to a single series. A single series may contain multiple Composite Object Instances. Most composite object IEs are modality dependent. To accommodate this potential modality dependence, the set of Optional Keys at the Composite Object Instance level includes all Attributes defined at the Composite Object Instance level from any Composite IOD defined in PS3.3.

DICOM PS3.4 2019a - Service Class Specifications