RadLex Radiology Lexicon

 We recognize the benefits that come from radiologists using common language to communicate diagnostic results. For this reason, RSNA produced RadLex®, a comprehensive set of radiology terms for use in radiology reporting, decision support, data mining, data registries, education and research. 

RadLex provides the foundation for vital data resources used in radiology:

The development of RadLex has been supported by the National Institute of Biomedical Imaging and Bioengineering (NIBIB) and the cancer Biomedical Informatics Grid (caBIG) project.

RadLex is licensed freely for commercial and non-commercial users. Review and download the license.

RadLex is now available on GitHub, providing a transparent, collaborative platform for accessing and managing the RSNA radiology ontology. By leveraging GitHub, users can easily explore updates, track changes, submit feedback, and contribute to the ongoing development of this comprehensive radiology terminology resource. Review RadLex on GitHub. 

RadLex has been released in a HL7 FHIR format designed to make it easier to incorporate systems and electronic patient records. This FHIR version allows Radlex to be a terminology binding for other FHIR resources, such as observations, using the standard FHIR format enabling coded values.  Review RadLex FHIR information. 

Have a suggestion? We welcome your input to improve RadLex! Use this form to enter your recommended changes or suggestions for new terms. Or visit the RadLex GitHub and add your request. 

Visit RadLex.org
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Standardized Exam Names: LOINC/RSNA Radiology Playbook

The wide variation in the way radiology procedures are named in radiology departments makes ordering and protocoling less efficient and radiology records difficult to aggregate or compare across sites. The LOINC/RSNA Radiology Playbook was created to address this critical problem. Building on RadLex, RSNA developed names for nearly 1,000 commonly performed radiology procedures. Playbook provides a standard system for naming radiology procedures, based on the elements that define an imaging exam such as modality and body part. By providing standard names and codes for radiologic studies, Playbook supports operational and quality improvement efforts, including workflow optimization, chargemaster management, radiation dose tracking, enterprise integration and image exchange.

The need

Today radiology facilities generally make up their own codes and names for radiology exams. The LOINC-RSNA Radiology Playbook offers an agreed set of names for radiology procedures to enhance information sharing and data analysis.

Features and benefits

Each Playbook exam name includes a unique numerical code (LOINC-RSNA Radiology Playbook Identifier) and a set of procedure names of varying length and readability for use in different applications. The Playbook can support your practice by:

  • Promoting interoperability of imaging exams
  • Facilitating quality improvement, outcomes research and data analysis
  • Enabling integration of radiology with enterprise systems
  • Simplifying participation in data registries
  • Offering optimization to workflow, billing management and radiation dose tracking
  • LOINC/RSNA Radiology Playbook
    • Please note: You'll need to create a free login to access the LOINC/RSNA Radiology Playbook. Once logged in, navigate to "loinc.org/search" and enter "class:rad" to search the playbook.
    • Download the LOINC/RSNA Radiology Playbook (2025-10-03)

Standardizing Acquisition Protocol Names: RadLex Protocol Playbook 

Standardizing Acquisition Protocol Names: RadLex Protocol Playbook

Since 2018, we have had standard radiology exam names in the form of the LOINC-RSNA Radiology Playbook. This standard set of names and codes have lived in the back end of EMRs and image exchange systems. However, as our field became more complex, exam names were no longer enough to communicate the detailed information about each exam. This information tends to be captured in the Acquisition Protocol.  

Each acquisition protocol is typically created to answer either a specific clinical question or investigate a particular focus of anatomy for pathology. Which protocol is used in acquisition will then influence which hanging protocol is used within the PACS to view the images, and which reporting template is used to dictate the findings. Unfortunately, between 2018 and now, this protocol information has not been handed off to downstream system for automation. Thus, organizations have tried to solve this problem by creating protocol specific exam names (orderables), which leads to exam name bloat.  

Through discussion with EMR vendors, modality vendors, PACS vendors and reporting platforms, this needed workflfow is being constructed to allow EMRs to formally model the protocol information and hand it off to downstream systems, which opens the door for setting up automation, and real-time savings across the radiology lifecycle.  

While the first step is to lay the technical workflow foundation and hand off the protocol information institutions are using today, the end goal is to create a group of standardized protocol names/elements for EMRs to hand off to downstream systems to make the process organization and vendor neutral and enabling full interoperability. 

RadLex, in collaboration with SNOMED CT, is in the process of collecting protocol naming information across organizations and countries to identify patterns in the elements captured in exam names and protocol names. They will then work to create clinical buckets of protocol names to hand off standard protocol information using the system infrastructure that exists today, and to partner with RISes to develop a way to model the data in the future so that the elements from the exam name and protocol name can all be captured and handed off as a continuation of detail regarding the same event. Join the SNOMED CT workgroup.

We are looking for a breadth of protocol names from all types of organizations. If you would like to contribute your protocol names, please add them. 

RadLex Playbook Series 

The RadLex Playbook Series establishes standardized, vendor-neutral names for imaging series, helping streamline radiology workflows and improve imaging data analysis. Visit the RadLex Playbook Series page to test our interactive tool and learn more about how standardized imaging series naming can improve consistency across radiology.  

FAQs

An ontology consists of a standardized set of concepts or terms and the relationships between those concepts. RadLex is an ontology focused on the domain of radiology.
RadLex contains individual terms and concepts related to medical imaging that can be used in a variety of applications, including radiology reporting, data mining and research. RadLex Playbook combines RadLex terms, using a consistent syntax, to provide a standard set of exam names and codes.
RadLex Playbook has now been fully incorporated into the Logical Observation Identifiers Names and Codes (LOINC) terminology for clinical observations. RSNA worked with the Regenstrief Institute, the publishers of LOINC, to harmonize the two terminologies, under a project funded by the National Institute of Biomedical Imaging and Bioengineering (NIBIB) and the Department of Defense (DoD). This work was completed in September 2017. The full set of LOINC codes, including the LOINC/RSNA Radiology Playbook, is available rel="noopener noreferrer" for download on the LOINC website.
The comprehensive RadLex terminology is currently only available in English but a full translation of RadLex into German has been completed by the German Radiology Society or Deutsche Röntgengesellschaft (DRG). It will be incorporated into the published version of RadLex in early 2018. A Portuguese translation of RadLex is also currently in development.
Facilities can incorporate RadLex in their reporting process by implementing reporting templates that incorporate RadLex terms and codes. A library of such templates is available at RadReport.org. The LOINC/RSNA Radiology Playbook can be incorporated into a facility's electronic systems in order to facilitate enterprise integration and registry participation. Playbook is used to create consistent procedure names for data submitted to the American College of Radiology’s CT Dose Index Registry. It has also been incorporated into Epic Corporation’s Foundation System, which provides customers up-to-date features and content.
Comments, questions and suggestions for new or revised terms can be submitted to radlexfeedback@lists.rsna.org.
The task of implementing standard codes and procedure names in departmental systems will vary depending on local configurations and practice needs, but is generally a process which is likely to require collaboration between clinical leaders, vendors, and IT staff or consultants with knowledge of system capabilities. You can browse RadLex Playbook by using the term browser. Also on the site is a free, downloadable version of RadLex Playbook in spreadsheet format as well as a User Guide, licensing terms and other information resources. Visit the LOINC website to download LOINC table files, which incorporate the LOINC/RSNA Radiology Playbook.
RSNA partnered with LOINC's publisher, Regenstrief Institute, to harmonize the two terminologies, under a project funded by the National Institute of Biomedical Imaging and Bioengineering (NIBIB) and the Department of Defense (DoD). This work was completed in September 2017. The full set of LOINC codes, including the LOINC/RSNA Radiology Playbook, is available for download on the LOINC website.
RadLex Playbook is currently available only in English.
Playbook is used to create consistent procedure names for data submitted to the American College of Radiology’s CT Dose Index Registry. It has also been incorporated into Epic Corporation’s Foundation System, which provides customers up-to-date features and content.
New code requests may be submitted to the joint Regenstrief–RSNA Governance Committee via the LOINC submissions page.

Please email radlex-feedback@lists.rsna.org with any comments or questions.

RadLex Committee members:

Audrey R. Verde, MD, PhD, Chair 
Michael Hood, MD, Vice Chair 
Mariam S. Aboian, MD, PhD 
Tarik Alkasab, MD, PhD 
William Auffermann, MD, PhD 
Leonid Chepelev, MD, PhD 
Beverly Collins, PhD 
Ethan Cohen, MD 
Jessica G. Fried, MD 
Scott Henneman, MD 
Monica L. Huang, MD 
Gloria Hwang, MD 
Charles E. Kahn, Jr., MD, MS  
Marc Kaemmerer, MD 
Geunwon Kim, MD, PhD 
Jeff Lerman, PhD 
Stacy D. O'Connor, MD, MPH 
Nancy Pham, MD 
Dogan Polat, MD 
Babak Saboury, MD 
Tubo Shi, MBChB 
Nanda Deepa Thimmappa, MD 
Ryan Tierney, MD 
Kenneth C. Wang, MD, PhD 

RadLex license
This RadLex license permits use of RadLex® and RadLex® Playbook without charge (PDF).
Release notes
Stay up to date on the latest additions and amendments to RadLex terms, preferred names and synonyms.
RadLex discussion forum
Post comments and questions about RadLex and RadLex Playbook.
Access LOINC

View and download LOINC components, including the Radiology Playbook under the SearchLOINC.

Access the latest SNOMED CT information
Search and view SNOMED CT.