Since 2011, the American College of Radiology’s Dose Index Registry (DIR) DIR Logohas helped clinicians and facilities improve the quality of patient care by collecting CT dose indices through automated data transmission and leveraging that data to provide feedback to participants and establish national benchmarks.

The ACR’s largest registry, the DIR has data on more than 50 million exams from more than 2,100 facilities as of April 2018. After anonymization at the site, exam data are transmitted automatically from CT scanners, reducing errors while collecting data daily.

The DIR automatically aggregates data not readily available elsewhere. In addition to CTDIvol and Dose Length Product (DLP) values, the DIR also computes size-specific dose estimate values (SSDE), for body examinations, that more accurately represent the radiation dose actually absorbed by the patient, based on patient size. Exam descriptions are standardized, using RadLex Playbook procedure names, so that data are comparable across facilities and scanners. And, the large volume of data allows the DIR to provide feedback reports segmented by adult and pediatric populations, with pediatric data segmented into five distinct age groups.

The DIR has already helped improve patient care nationally through the ACR’s development of size-specific Diagnostic Reference Levels (DRLs) and Achievable Dose (AD) guidelines for the 10 most common adult CT examinations.  The first such guidance for this population, radiologists can now use DRLs and ADs, based on size, to avoid giving unnecessary radiation exposure to patients. And, because data are collected automatically, updates and new analyses can be completed far faster and more economically than with manual data collection.DIR US DRL and AD for 10 Adult CT Exams

The DIR also provides direct feedback to facilities through quarterly reports that provide peer comparisons of each standardized exam name by

  • facility type (e.g. Freestanding vs. Community hospital)

  • location (Metropolitan, Suburban, or Rural), and

  • geography.

Comparisons allow facilities to identify dose outliers, by exam, so they can focus on reducing radiation exposure while maintaining image quality. DIR Comparison Report Box Plots


Credit and Recognition

The DIR is certified as a Practice Quality Improvement (PQI) project for American Board of Radiology Maintenance of Certification (MOC) Part IV Programs. Because DIR data are collected at the facility level, participation applies to all radiologists and medical physicists at a facility who choose to participate in the project.ACR DICOE Logo

The DIR also helps facilities qualify for designation as an ACR Diagnostic Imaging Center of Excellence (DICOE), allowing radiology practices to communicate their dedication to, and success in, delivering superior diagnostic imaging and patient care.

And, DIR participation meets the Joint Commission dose benchmark requirement.


Ease of Use and Fees

As part of the NRDR suite of registries the DIR utilizes the same Physician and User dictionaries as other NRDR registries so that information need only be entered once, regardless of the number of registries in which a facility participates.

DIR data can be transmitted directly from scanners or your PACS via the ACR’s TRIADTM software. TRIAD works with a wide variety of scanners and has successfully retrieved from more than 900 different models from all major, and some smaller, manufacturers. Participants can install TRIAD on their systems or can work with an ACR-certified software partner. See DIR Data Collection Using TRIAD for more information.

The DIR offers a wide range of reports and tools, including interactive reports using Tableau software, that allow users to quickly identify dose outliers across scanners or exam types.DIR Interactive Reports - Sample Scatterplot 2

The annual participation fee for the DIR is based on the number of physicians practicing at a facility and the number of sites included in that facility. See Registration and Participation Fees for more information.