When a Fast Healthcare Interoperability Resources (FHIR) server finds it convenient to manage the content within the same overall REST framework as the other resources, the Binary resource is generally used as the target in the Attachment data type to reference content via the .url element, such as in the DocumentReference and Media resources. Consequently, the Binary resource can be a target wherever the Attachment data type is used such as in the DocumentReference resource.
The DocumentReference and Media resources allow conveying binary content (via attachment) or pointing to one (as a Binary or non-FHIR URI) along with the metadata around that resource, and as such are searchable. Binary resources do not support ‘search’.
While CDA and PDF documents are conveyed as Binary (because they cannot be expressed natively in FHIR), FHIR Documents do not need to be similarly encoded and can be sent natively in FHIR using Bundle. However, in some situations FHIR Documents may be sent as a Binary if there is a need to treat them the same as other types of documents or binary files.
The Binary resource does not convey context of the file. If the context (information such as author, procedure, technique, etc.) should be conveyed, Media or DocumentReference resources are appropriate. The Binary resource may be used to convey actual binary file content conveyed by those resources. The Media resource is preferred for handling images, but this is not possible when the content is already binary (e.g. in some uses of IHE XDS).
Fast Healthcare Interoperability Resources (FHIR) is a draft standard describing data formats and elements (known as “resources”) and an application programming interface (API) for exchanging electronic health records. The standard was created by the Health Level Seven International (HL7) health-care standards organization.
Its goal is to facilitate interoperation between legacy healthcare systems, to make it easy to provide healthcare information to healthcare providers and individuals on a wide variety of devices from computers to tablets to cell phones, and to allow third-party application developers to provide medical applications which can be easily integrated into existing systems.
FHIR provides an alternative to document-centric approaches by directly exposing discrete data elements as services. For example, basic elements of healthcare like patients, admissions, diagnostic reports and medications can each be retrieved and manipulated via their own resource URLs (Uniform Resource Locators). FHIR was supported at an American Medical Informatics Association meeting by many EHR (Electronic Health Record) vendors which value its open and extensible nature.