Constrained DICOM SR documents based on Imaging Report templates can be mapped to HL7 CDA Release 2 Imaging Reports based on Template 1.2.840.10008.9.1, as specified in Section 7.1. The SR report templates to which this transformation applies include:
SR instances based on other templates may also be able to be mapped using the transformations in this Annex.
SR documents can be thought of as consisting of a document header and a document body, corresponding to a CDA document header and body. The header includes the modules related to the Patient, Study, Series, and Equipment Information Entities, plus the SR Document General Module, as specified in PS3.3. The SR Document Content Module contains the content tree (structured content) of the document body. Note, however, that DICOM SR considers the root content item, including the coded report title, and some context-setting content items as part of the document body content tree, but these constitute part of the CDA header. See Figure C-1.
This Annex defines the transformation of an Enhanced SR SOP Instance to a CDA instance. The following constraints apply to such SOP Instances:
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Observation Context: The mapping does not support changing the observation context for the report as a whole from its default context, as specified in the Patient, Study, and Document Information Entities (see PS3.3 Section C.17.5 “Observation Context Encoding”)
Note
TID 2000, TID 2005 and TID 2006 specify inclusion of TID 1001 Observation Context as Mandatory, but TID 1001 has no content if all aspects of context are inherited, as under this constraint.
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Subject Context: The mapping does not support the subject of any of the report sections to be a specimen TID 1009), a device (TID 1010), or a non-human subject. Only a fetus subject context is supported for a Findings section.
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Procedure Context: The mapping allows identification of a different procedure than the procedure identified in the SR Study IE only as context for a Prior Procedure Descriptions section.
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De-identified Documents: There is no CDA implementation guidance from HL7 for de-identified documents, other than general rules for using the MSK null flavor (see Section 5.3.2). There is no CDA capability equivalent to the Encrypted Attributes Sequence (see PS3.3 Section C.12.1.1.4.1 “Encrypted Attributes Sequence”) for carrying encrypted re-identification data.
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Patient Study Module: Medical or clinical characteristics of the patient specified in the Patient Study Module are not mapped (see PS3.3 Section C.17.5 “Observation Context Encoding”)
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Clinical Trials: Template 1.2.840.10008.9.1 does not define attributes for clinical trials equivalent to those of the Patient, Study, and Series IEs (Clinical Trial Subject Module, Clinical Trial Study Module, Clinical Trial Series Module).
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Spatial Coordinates: The mapping does not support SCOORD observations. As CDA documents are principally for human reading, detailed ROI data is presumed to reside in the DICOM SOP Instances of the study, or in images ready for rendering with a Presentation State, not in the CDA report. Template 1.2.840.10008.9.1 does not support the CDA Region of Interest Overlay entry class (see Section 9.1.2.4).
