By the endMatch each need to the standard whose scope covers it.
Choose the right healthcare standard
DICOM, HL7 Version 2, and FHIR each publish a scope. Match each need in a project to the standard whose scope covers it: imaging information to DICOM, ADT and result messages to HL7 Version 2, and coded content in resources to FHIR.
DICOM
Covers medical imaging information: network protocols, the commands and data exchanged over them, and media storage with a file format.
HL7 Version 2
Covers messages between healthcare applications for admission, discharge, and transfer (ADT) data, orders, results, and clinical observations.
FHIR
Defines all exchangeable content as resources. A StructureDefinition can constrain a resource's cardinality, datatypes, and terminology bindings.
Worked example
Apply the model: Choose the right healthcare standard
A project needs image transfer, an admission event, and a coded laboratory observation.
1
Image transfer
DICOM specifies the network protocols that medical imaging equipment follows and the commands and information exchanged with them, so it covers the image transfer.
2
Admission event
HL7 Version 2 defines interfaces for ADT data, so an ADT message carries the admission event.
3
Coded laboratory observation
HL7 Version 2 observation reporting sends laboratory results as identifiable data elements. In FHIR, a StructureDefinition can bind the observation's coded element to a terminology.
Result: Each need maps to the standard whose published scope covers it: DICOM for the image, HL7 Version 2 for the admission, and HL7 Version 2 or a FHIR resource with a terminology binding for the laboratory observation.
Scope and limits: Choose the right healthcare standard
Each scope statement also names what the standard leaves out.
DICOM
Specifies network protocols, commands, and media storage for medical imaging information.
Does not specify the overall features of a system built by integrating several DICOM-conformant devices.
HL7 Version 2
Defines messages for ADT data, orders, results, and clinical observations.
Is not, by itself, a complete systems integration solution, so each site negotiates the trigger events and data items it uses.
Try it
Check your reasoning: Choose the right healthcare standard
A project needs image transfer, an admission event, and a coded laboratory observation. Which standard covers each need?
Hint: Compare each need with the scope each standard publishes.
DICOM covers the image transfer, and an HL7 Version 2 ADT message covers the admission event. The laboratory observation fits HL7 Version 2 observation reporting, or a FHIR resource whose coded element has a terminology binding set in a StructureDefinition.
02 / Questions
Answer 4 questions
Choose an answer. The explanation appears after you submit.
Check 1 of 4scenario · medium
A project needs image transfer, an admission event, and a coded laboratory observation. Every imaging device claims DICOM conformance, and a manager concludes that the integrated system will work without further checks. What does DICOM PS3.1 say about that conclusion?
DICOM PS3.1 says the Standard facilitates interoperability among conformant systems but does not, by itself, guarantee it. It does not specify the overall features of a system built from conformant devices or a procedure to test conformance. DICOM also does not cover the whole field of medical informatics, and HL7 Version 2 defines the interfaces that carry ADT data such as an admission.
Check 2 of 4recall · hard
An interface team compares HL7 Version 2 with FHIR. Which statement matches how each specification describes itself?
HL7 Version 2 encoding rules group variable-length, separated data fields into segments, and FHIR defines all exchangeable content as resources. FHIR states that resources do not require REST and that FHIR can be used alongside existing standards. HL7 Version 2 covers a superset of trigger events and data, so each site negotiates the subset it uses.
Check 3 of 4recall · easy
A FHIR implementation must control which terminology a coded laboratory element uses. Which kind of rule can a StructureDefinition add for that purpose?
In FHIR, a StructureDefinition provides rules that constrain the optionality, cardinality, terminology bindings, datatypes, and extensions of the resources an implementation uses. A binding on the coded element sets the terminology it uses. A trigger event, a Transfer Syntax, and a presentation context are not among those rules, so none of them controls which codes a FHIR element uses.
Check 4 of 4scenario · medium
A project needs image transfer, an admission event, and a coded laboratory observation. Which standard has a published scope that covers the image transfer?
DICOM is the standard for the communication and management of medical imaging information, so it covers the image transfer. HL7 Version 2 addresses interfaces for ADT data, orders, results, and clinical observations, which fit the admission and the laboratory result. The FHIR Terminology module supports coded meaning, not image transfer.
03 / Recall
Answer without looking back
Without looking back, name the standard that covers imaging information, the standard that covers ADT and result messages, and the FHIR rule that controls which codes an element uses.
DICOM covers imaging information, HL7 Version 2 covers ADT, order, and result messages, and a FHIR StructureDefinition can constrain the terminology bindings on coded elements.