DICOM and HL7

DICOM and HL7 messages can be transformed between each format.

This table shows the similarities between DICOM and HL7 messages:

DICOM HL7 Notes
1 Hierarchical & LDL Hierarchical
2 Commands Trigger Events
3 Command Group/DIMSE SH Segment / Message Type Message header. Subfields form TrxID
4 DICOM Information Object (IOD) Message type specific segments Data for the message
5 Service-Object Pairs SOP(= DIMSE + IOD) Specific message, for example, ORU, ADT Message header + data
6 Elements Fields Both have types
7 Elements types (called VR) Field Types
8 Request/Response possible Request/Response possible

This table shows the differences between DICOM and HL7 messages:

DICOM HL7 Notes
1 Upper level protocol/PDU None Items form TrxID also
2 Text and Binary Text Encoding depends on the field type
3 Elements are length delimited Fields, components, sub-components, and segments are character delimited
4 Elements can be grouped within a sequence (SQ element) Grouping is well-defined. Messages contain segments, which contain fields, and so on.