Virtual Colonoscopy CT Colonography Reporting and Data System : A Consensus Proposal 1

Computed tomographic (CT) colonography continues to evolve rapidly. Advances in scanning and display technologies, encouraging performance data, and increased utilization necessitate clarification and standardization of results reporting in CT colonography. There are several reasons for this. First and most important, standardized reporting can better assist patients and referring physicians in making management decisions on the basis of the results of CT colonography. The precedent of the mammography Breast Imaging Reporting and Data System, or BI-RADS, schema is a strong incentive to provide a similar structure for CT colonography. Second, as more examinations are performed, the likelihood increases that radiologists interpreting results of a CT colonography examination performed at one center will require comparison to examination results and reports generated at other sites. As has been seen with mammography, a common set of terms facilitates this kind of assessment (1). Third, as utilization of CT colonography increases, our colleagues in other medical specialties, the various third-party payers, and the general public will insist on larger-scale evaluations of examination performance, examination quality, patient outcome, and cost. Here again, a common approach to interpretation will assist us in meeting these demands. Finally, a common scheme for reporting facilitates structured reporting. The purpose of this communication is to facilitate clear and consistent communication of CT colonography results. The authors—an ad hoc group of investigators active in the area of CT colonography—have collaborated to develop a reporting scheme that is coupled to recommendations for follow-up. Our group, the Working Group on Virtual Colonoscopy, includes members of the American College of Radiology Colon Cancer Committee. On the basis of our collective experience and a review of the relevant literature, we present a practical guide to the interpretation of CT colonography results: the CT Colonography Reporting and Data System, or “C-RADS. ” Future multidisciplinary collaboration and longitudinal data may lead to a refinement of the terms and concepts we present here; our effort is a starting point in which we attempt to address the needs of current practice. Adequate training and rigorous quality control of examination performance are essential elements for maximizing the potential of CT colonography; however, these related topics will not be discussed here. Instead, we will focus on the interpretation and follow-up of CT colonography results in three parts: first, a description of terms useful for reporting the size, morphologic features, and location of polyps and masses; second, a description of a classification scheme for colonic lesions and suggestions for follow-up; Published online 10.1148/radiol.2361041926 Radiology 2005; 236:3–9 1 From the Division of Abdominal Imaging and Intervention, Department of Radiology/ White 270, Massachusetts General Hospital, Boston, MA 02114 (M.E.Z.). The complete list of author affiliations is at the end of this article. Received November 12, 2004; accepted November 15. Address correspondence to M.E. Z. (e-mail: mzalis@partners.org).