• RadLex

  • What is RadLex?

    As images, imaging reports and medical records move online, radiologists need a unified language to organize and retrieve them. Radiologists currently use a variety of terminologies and standards, but no single lexicon serves all of their needs.

    Enter RadLex, a comprehensive lexicon—a unified language of radiology terms—for standardized indexing and retrieval of radiology information resources. With more than 68,000 terms, RadLex satisfies the needs of software developers, system vendors and radiology users by adopting the best features of existing terminology systems while producing new terms to fill critical gaps. RadLex also provides a comprehensive and technology-friendly replacement for the ACR Index for Radiological Diagnoses. It unifies and supplements other lexicons and standards, such as SNOMED-CT and DICOM. RadLex development has received support from both the National Institute of Biomedical Imaging and Bioengineering (NIBIB) and the cancer Biomedical Informatics Grid (caBIG) project.

    RSNA has developed a term browser (radlex.org) to give potential users a convenient way to view RadLex's structure and content. RadLex is available for download via the National Center for Biomedical Computing’s Bioportal.

    In 2005, RSNA formed six RadLex organ system committees. Representatives of more than 30 radiology professional and standards organizations, including the American College of Radiology (ACR), DICOM, and IHE, participated in the process. In November 2006, they publicly released an initial set of more than 7,500 anatomic and pathologic terms. The lexicon has grown over the succeeding years through the continual work of RadLex committees and the addition of terminology drawn from other resources such as the University of Washington's Functional Model of Anatomy.


    Providing consistent procedure names for radiology procedures was an important priority of the RadLex initiative. Six additional committees, each focusing on a specific imaging modality, were recruited in 2007 to develop the RadLex Playbook which provides terms to describe the devices, imaging exams, and procedure steps performed in radiology. Beginning in 2008, RSNA has worked with research centers, radiology sites, government agencies and standards bodies to establish Playbook as a standardized "chargemaster" of radiology orderables and procedure steps. A first release of the Playbook was published in 2012. It has subsequently been refined using chargemaster data from several care sites and input from radiology specialty organizations. The first comprehensive release of Playbook for clinical use was published in 2014.

    Playbook is designed for sites to use in implementing or updating their orderables. They can map existing orderables to Playbook and gain the value of consistent coded values for procedure names to facilitate ordering, reporting and analysis of the data in imaging records. Users can review the structure of Playbook terms using the term browser (playbook.radlex.org) developed for that purpose.

    RadLex and RadLex Playbook are released under an open license that allows for their free use. Click here to review the RadLex license and download RadLex and Playbook.

  • Resources

  • RsnaProgram7

    Bioportal Download

    Download the latest RadLex ontology and review additional details, metrics, versions and projects that use RadLex.


    RadLex License

    This RadLex® License permits use of RadLex® and PlaybookTM without charge.


    Release Notes

    Stay up to date on the latest additions and amendments to RadLex terms, preferred names and synonyms.