February 22, 2013 — Since its launch, less than two years ago, more than 5 million computed tomography (CT) scans, and nearly 3 million exams, have been added to the American College of Radiology (ACR) Dose Index Registry (DIR) — bringing the ACR closer to establishing national benchmarks for CT dose indices, which will help ensure patients receive safe, quality imaging care.
The DIR is a radiology data registry that provides standardized, size-adjusted CT dose indices that facilitate meaningful comparisons — allowing imaging facilities to compare their CT dose indices to regional and national values. Information related to dose indices for all CT exams is collected, anonymized, transmitted to the ACR and stored in a database. Institutions are then provided with periodic feedback reports comparing their results by body part and exam type to aggregate results. A sample report containing actual aggregated data from a participating facility is available here: http://bit.ly/127WGpk.
Currently, the DIR has over 600 registered facilities, including private practices, hospital-based facilities and academic centers. Participation in the DIR is voluntary and will help radiologists meet the requirements for a Physician Quality Reporting System registry starting in 2014.
“As our early success demonstrates, patient safety and CT dose optimization is of utmost importance to radiology professionals, including radiologists, medical physicists and radiologic technologists. As we get closer to establishing national benchmarks for CT dose indices, I hope more imaging facilities will consider participating in the DIR. Having the ability to track dose reduction efforts over time and ultimately lower the radiation dose that Americans receive from medical imaging scans is invaluable,” said Richard Morin, Ph.D., chair of the ACR Dose Index Registry.
The DIR is part of the overall ACR approach to medical radiation reduction, which includes mandatory accreditation of all medical imaging providers and greater adoption of computerized decision support/imaging ordering systems based on ACR appropriateness criteria.
For additional information about the ACR Dose Index Registry: http://bit.ly/VPNTXm
November 12, 2025 
