X.3.5 Structured Entries

The Current Requested Procedure Evidence Sequence (0040,A375) of the KO instance lists all the SOP Instances referenced in the IMAGE content items in their hierarchical Study/Series/Instance context. It is recommended that this list be transcoded to CDA Entries in a Section with Section.Title “DICOM Object Catalog” and a Section.Code of 121181 from the DICOM Controlled Terminology (see PS3.16).

Notes: 1. Structured Entries are not defined in CDA Release 1.

2. Since the image hypertext links in the Section narrative may refer to both an image and a softcopy presentation state, as well as possibly being constrained to specific frame numbers, in general there is not a simple mapping from the <linkHtml> to an entry. Therefore it is not expected that there would be ID reference links between the <linkHtml> and related entries.

The purpose of the Structured Entries is to allow DICOM-aware applications to access the referenced images in their hierarchical context.

The encoding of the DICOM Object References in CDA Entries is shown in Figure X.3-1 and Tables X.3-2 through X.3-6. All of the mandatory data elements for the Entries are available in the Current Requested Procedure Evidence Sequence; optional elements (e.g., instance datetimes) may also be included if known by the encoding application.

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Figure X.3-1 CDA Section with DICOM Object References

Note: The format of Figure X.3-1 follows the conventions of HL7 v3 Reference Information Model diagrams.

Table X.3-2 DICOM Study Reference in an HL7 v3 Act (CDA Act Entry)

Attribute Data Type Multiplicity Value
classCode CS 1..1 ACT
moodCode CS 1..1 EVN
id II 1..1 <Study Instance UID (0020,000D) as root property with no extension property>
code CD 1..1 <113014 as code property, 1.2.840.10008.2.16.4 as codeSystem property, DCM as codeSystemName property, “DICOM Study” as displayName property>
text ST 0..1 <Study Description (0008,1030)>
effectiveTime TS 0..1 <Study Date (0008,0020) and Study Time (0008,0030)>

Table X.3-3 DICOM Series Reference in an HL7 v3 Act (CDA Act Entry)

Attribute Data Type Multiplicity Value
classCode CS 1..1 ACT
moodCode CS 1..1 EVN
id II 1..1 <Series Instance UID (0020,000E) as root property with no extension property>
code CD 0..1 <113015 as code property, 1.2.840.10008.2.16.4 as codeSystem property, DCM as codeSystemName property, “DICOM Series” as displayName property, Modality as qualifier property (see text and Table X.3-4)>
text ST 0..1 <Series Description (0008,103E)>
effectiveTime TS 0..1 <Series Date (0008,0021) and Series Time (0008,0031)>

The code for the Act representing a Series uses a qualifier property to indicate the modality. The qualifier property is a list of coded name/value pairs. For this use, only a single list entry is used, as described in Table X.3-4.

Table X.3-4 Modality Qualifier for the Series Act.Code

Property Data Type Value
name CV <121139 as code property, 1.2.840.10008.2.16.4 as codeSystem property, DCM as codeSystemName property, “Modality” as displayName property>
value CD <Modality (0008,0060) as code property, 1.2.840.10008.2.16.4 as codeSystem property, DCM as codeSystemName property, Modality code meaning (from PS3.16) as displayName property>

Table X.3-5 DICOM Composite Object Reference in an HL7 v3 Act (CDA Observation Entry)

Attribute Data Type Multiplicity Value
classCode CS 1..1 DGIMG
moodCode CS 1..1 EVN
id II 1..1 <SOP Instance UID (0008,0018) as root property with no extension property>
code CD 1..1 <SOP Class UID (0008,0016) as code property, 1.2.840.10008.2.6.1 as codeSystem property, DCMUID as codeSystemName property, SOP Class UID Name (from PS3.6) as displayName property>
text ED 0..1 <application/DICOM as mediaType property, WADO reference (see Table X.3-6) as reference property>
effectiveTime TS 0..1 <Content Date (0008,0023) and Content Time (0008,0033)>

Notes: 1. The DGIMG class is used to reference all DICOM Composite Instances, not just diagnostic images.

2. The Observation.Text reference property may alternatively use a DICOM protocol based URI, rather than WADO, should such a URI be defined.

Table X.3-6 WADO Reference in an HL7 DGIMG Observation.Text

WADO Component Source
<scheme>://<authority>/<path> Configuration setting, used by the conversion process, identifying the WADO server
?requestType=WADO Fixed
&studyUID=<uid> Study Instance UID for referenced instance
&seriesUID=<uid> Series Instance UID for referenced instance
&objectUID=<uid> SOP Instance UID for referenced instance
&contentType=application/DICOM Fixed