A.5.1.3 Structured Body (Level 3)

Coded Observations

DICOM Template 2000 specifies that Imaging Report Elements of Value Type Code are contained in sections (row 6 and 8). The Imaging Report Elements are inferred from Basic Diagnostic Imaging Report Observations (Row 9) that consist of image references and measurements (linear, area, volume and numeric). Coded DICOM Imaging Report Elements in this context are mapped to CDA coded observations that are section components and are related to the SopInstance or QuantityMeasurement act classes by the SPRT (Support) act relationship (Figure A.5.1.3-1).

[pic]

Figure A.5.1.3-1: CODED OBSERVATION WITHIN SECTION

Table A.5.1.3-1 shows the mapping of attribute values for DICOM Imaging Report Elements to CDA coded observation. The component act relationship between Section and CodedObservation is encoded as a section entry in CDA; CodedObservation as an observation CDA entry and the support act relationship as entryRelationship.

Table A.5.1.3-1

CODED OBSERVATION (DICOM IMAGING REPORT ELEMENT, VALUE TYPE CODE)

Attribute Data Type Multiplicity Value
classCode CS 1..1 OBS
moodCode CS 1..1 EVN
templateId LIST<II> 1..* Set root portion of II to “2.16.840.1.113883.10.20.6.2.13” (identifies the template that defines constraints on “Code Observation” of CDA Diagnostic Imaging Reports as specified by CDA R2 DIR IG).
code CE 1..1 Concept Name Code Sequence (0040,A043) of CODE Content Item: ): <code value as code property, coding scheme designator as codeSystemName property, code meaning as displayName property>
effectiveTime TS 0..1 Observation DateTime (0040,A032)
languageCode CE 0..1 Not used at entry level.
value CE 1..1 Concept Code Sequence (0040,A168) of CODE Content Item: <code value as code property, coding scheme designator as codeSystemName property, code meaning as displayName property>

Text Observations

DICOM Template 2000 specifies that Imaging Report Elements of Value Type Text are contained in sections (Rows 6 and 10). The Imaging Report Elements are inferred from Basic Diagnostic Imaging Report Observations (Row 11) that consist of image references and measurements (linear, area, volume and numeric). Coded DICOM Imaging Report Elements in this context are mapped to CDA text observations that are section components and are related to the SopInstance or QuantityMeasurement act classes by the SPRT (Support) act relationship (Figure A.5.1.3-2).

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Figure A.5.1.3-2: TEXT OBSERVATION WITHIN SECTION

Table A.5.1.3-2 shows the mapping of attribute values for DICOM Imaging Report Elements to CDA text observation. The component act relationship between Section and TextObservation is encoded as a section entry in CDA; TextObservation as an observation CDA entry and the support act relationship as entryRelationship.

Table A.5.1.3-2

TEXT OBSERVATION

Attribute Data Type Multiplicity Value
classCode CS 1..1 OBS
moodCode CS 1..1 EVN
templateId LIST<II> 1..* Set root portion of II to “2.16.840.1.113883.10.20.6.2.12” (identifies the template that defines constraints on “Text Observation” of CDA Diagnostic Imaging Reports as specified by CDA R2 DIR IG).
code CE 1..1 Concept Name Code Sequence (0040,A043) of TEXT Content Item: ): <code value as code property, coding scheme designator as codeSystemName property, code meaning as displayName property>
effectiveTime TS 0..1 Observation DateTime (0040,A032)
languageCode CE 0..1 Not used at entry level.
value ED 1..1 Text Value (0040,A160) of TEXT Content Item

Image References and Measurements within Section

Image references and measurements (linear, area, volume and numeric) may also be inserted directly within sections (Template 2000, Rows 6 and 12). In this case CDA sections are related to SopInstance and/or QuantityMeasurement act classes via component (COMP) act relationships.

Quantity Measurement + DICOM Composite Object References

For the modeling of DICOM Composite Object References refer to section A.7: Updated pattern based on A_DicomCompositeObjectReference minimal (COCT_RM830120UV). In the context of the CDA, entry act class and actRelationships names shall be used as specified for the CDA mapping.

The mapping of observations (i.e. quantity measurements based on image data) is specified below (structured contents of linear, area, volume and numeric measurements). The updated pattern based on CMET COCT_RM830120 „ReferencedDicomComposite Object“ (refer to section A.7) is reused for the mapping. Instead of starting directly with the SopInstance Act Class, the COCT_RM830120 pattern is applied in the context of Quantity Measurements (refer to Figure A.5.1.3-3 for details).

Quantity Measurement Act Class (Observation)

Table A.5.1.3-3

QUANTITY MEASUREMENT

Attribute Data Type Multiplicity Value
classCode CS 1..1 OBS
moodCode CS 1..1 EVN
templateId LIST<II> 1..* Set root portion of II to “2.16.840.1.113883.10.20.6.2.14” (identifies the template that defines constraints on “Quantity Measurement Observation” of CDA Diagnostic Imaging Reports as specified by CDA R2 DIR IG).
code CE 1..1 If a DICOM code is used in Concept Name Code Sequence (0040,A043) of Numeric Measurement (NUM) Content Item: <code value as code property, "1.2.840.10008.2.16.4" as codeSystem property, "DCM" as codeSystemName property, code meaning as displayName property>. If a SNOMED code is used in Concept Name Code Sequence (0040,A043) of Numeric Measurement (NUM) Content Item: <mapped code value as code property, "2.16.840.1.113883.6.96" as codeSystem property, "SRT" as codeSystemName property, mapped code meaning as displayName property>. Please refer to table 33 for the mapping of linear measurement codes, table 34 for the mapping of area measurement codes and table 35 for the mapping of volume measurement codes.
effectiveTime TS 0..1 Observation DateTime (0040,A032)
languageCode CE 0..1 Not used at entry level.
value PQ 1..1 The Numeric Value (0040,A30A) DICOM decimal string (DS data type) is mapped to the value component of the PQ data type (real number). The contents of the Measurement Units Code Sequence (0040,08EA) macro are mapped to the unit component of the PQ data type (UCUM codes are used for the CS data type): unit of measure code value as code property

Tables A.5.1.3-4 to A.5.1.3-6 list the code value and code meaning of SNOMED codes contained in DICOM context groups 7470 to 7472 and corresponding attribute values of SNOMED observable entity codes for DICOM SR TID 2000 based diagnostic imaging reports. For the latter codes SNOMED Concept IDs are used as code values.

Table A.5.1.3-4 TID 2000 LINEAR MEASUREMENT SNOMED CODE MAPPING FOR DICOM CONTEXT GROUP 7470

Coding Scheme Designator (0008,0102) Code Value (0008,0100) Code Meaning (0008,0104) Code Value of Equivalent Observable Entity Code (Concept ID) Code Meaning of Equivalent Observable Entity Code
SRT G-A22A Length 439932008 Length of structure
SRT G-A220 Width 440357003 Width of structure
SRT G-D785 Depth 439934009 Depth of structure
SRT M-02550 Diameter 439984002 Diameter of structure
SRT G-A185 Long Axis 439933003 Long axis length of structure
SRT G-A186 Short Axis 439428006 Short axis length of structure
SRT G-A193 Major Axis 439982003 Major axis length of structure
SRT G-A194 Minor Axis 439983008 Minor axis length of structure
SRT G-A195 Perpendicular Axis 440356007 Perpendicular axis length of structure
SRT G-A196 Radius 439429003 Radius of structure
SRT G-A197 Perimeter 440433004 Perimeter of non-circular structure
SRT M-02560 Circumference 439747008 Circumference of circular structure
SRT G-A198 Diameter of circumscribed circle 439748003 Diameter of circular structure

Table A.5.1.3-5

TID 2000 AREA MEASUREMENT SNOMED CODE MAPPING FOR DICOM CONTEXT GROUP 7471

Coding Scheme Designator (0008,0102) Code Value (0008,0100) Code Meaning (0008,0104) Code Value of Equivalent Observable Entity Code (Concept ID) Code Meaning of Equivalent Observable Entity Code
SRT G-A166 Area 439746004 Area of structure
SRT G-A16A Area of defined region 439985001 Area of body region

Table A.5.1.3-6

TID 2000 VOLUME MEASUREMENT SNOMED CODE MAPPING FOR DICOM CONTEXT GROUP 7472

Coding Scheme Designator (0008,0102) Code Value (0008,0100) Code Meaning (0008,0104) Code Value of Equivalent Observable Entity Code (Concept ID) Code Meaning of Equivalent Observable Entity Code
SRT G-D705 Volume 439749006 Volume of structure

Subject Act Relationship (QuantityMeasurement to SopInstance)

Equivalent DICOM relationship types of the CDA SUBJ actRelationship in this context are: INFERRED FROM and R-INFERRED. CDA Release 2 does not specify reference relationships. However act class clones that carry a unique identifier only and omit other attribut values of the original act class may be used to that purpose.

The relation of quantity measurements to procedures and acts is specified in section A.5.1.4.2 Procedure Context.

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Figure A.5.1.3-3: QUANTITY MEASUREMENT AND DICOM COMPOSITE OBJECT REFERENCE

The act relationships shown in figure A.5.1.3-3 are encoded as entryRelationships in CDA; the act classes are represented as observations.

DICOM SR numeric measurements (value type NUM) are mapped to the QuantityMeasurement act class.

The QuantityMeasurement act class is associated with one or more SopInstance act classes. SopInstance is associated with zero or one PurposeOfReference act class through the reason entry relationship.

Multi-frame Image References

The DICOM Image Reference Macro (used for SR content items of value type IMAGE) allows for referencing individual frames of a multi-frame image if the reference does not apply to all frames. The individual referenced frames (DICOM attribute “Referenced Frame Number” (0008,1160)) are mapped to the value attribute (list of integers) of the boundary act class. For mapping quantity measurements (applies to SR template 1400, 1401, 1402 and 1404) that are related to frames of a multi-frame image, one ReferencedFrames act class is associated with SopInstance through an entryRelationship of type code component (Figure A.5.1.3-3). The DICOM code 121190 “ReferencedFrames” is assigned to the ReferencedFrames.code attribute. The ReferencedFrames act class is related to one Boundary act class through an entryRelationship of type code component. In the context of mapping DICOM template 2000 the Boundary.value attribute contains the referenced frame number of the frame that is the basis for measurements or coded purpose of reference terms.