DICOM (Digital Imaging and Communications in Medicine) is the global standard for medical image information; a position it has held for over 20 years. It is pervasive throughout the medical imaging community, and nearly every medical imaging device supports some aspect of the standard. DICOM models the image acquisition process and information objects related to imaging, and it specifies how the image data, the metadata, and related objects are represented in a binary format. For example, DICOM models patients as both clinical and clinical trial subjects, imaging studies that consist of series of images as well as all of the technical parameters of imaging modalities. Despite its size and complexity, DICOM lacks a Reference Information Model of the imaging domain. A reference information model is a formal description of a domain that enables users to share consistent meaning and establish semantic interoperability beyond a local context.
There is a pressing need for an information model of imaging based on DICOM to enable the community to create intelligent imaging-based applications that are interoperable. We are developing the DICOM Ontology (DO), an ontology that will be a single common reference information model for the imaging domain. The DO will be analogous to the Gene Ontology (GO) and serve a similar role in radiology that GO serves in biology. The DO will unify and make explicit all the key entities and relations in DICOM in a human-usable and machine-processable format. The DO will ultimately become a reference ontology—one that comprehensively represents knowledge about the medical imaging domain independent from specific objectives or applications, guided by a theory of the imaging domain and by robust ontology design principles that encourages reuse.