The ACR’s recent introduction of the “cmbX” designation in the Dose Index Registry (DIR) is a meaningful step forward. By separating combination studies, the DIR now allows for more accurate mapping to combination RPIDs—or, when necessary, assignment to RPID88 to remove them from the “unmapped” category. But as many facilities are now discovering, this improvement… Read More
Streamlining cmbX Mapping in the ACR Dose Index Registry
Background On February 17, 2026 the American College of Radiology (ACR) announced an important enhancement to the Dose Index Registry (DIR): the introduction of a “combination study” designation, identified by the cmbX prefix in Study Descriptions. This change represents a meaningful improvement in how the DIR handles multi-part or combined CT exams. The Challenge While… Read More
Important DIR Update – Combination Exam Mapping Changes
To my Dose Registry Clients and Friends, The DIR recently announced changes in how the NRDR maps combination CT studies. In my opinion, this is one of the most significant and welcome changes to the DIR in years. See the link immediately below. https://nrdrsupport.acr.org/support/solutions/articles/11000135515-dir-improves-the-accuracy-of-combination-exams-for-ct The article explains changes to how the DIR records and processes… Read More
Using Pivot Tables to Review Exam Name Mappings
Here is a short video explaining how to use Excel Pivot tables to review your Exam Name Mappings – This is much easier than trying to do it on the Mapping Tool.
CTDIvol vs DLP – a simple explanation
What do they represent? CTDIvol is based on measurements obtained when scanning either a 16cm or 32 cm phantom. Essentially, it represents scanner output. DLP is derived from CTDIvol, but incorporates a scan length component. Both function as reasonable proxies for absorbed dose but do not represent the actual patient dose. In other words, if… Read More
Plan your Dive; Dive Your Plan
A few years ago, I had the pleasure of hearing Andrea Browne, Ph.D speak about the then newly released Joint Commission Dose Incident Identification requirements (PI-02.01.01.A6 standards). Dr. Browne is a Diagnostic Medical Physicist with The Joint Commission and served as one of the primary liaisons between TJC and TJC-accredited organizations as these standards came… Read More
Expanding Your Use of the DIR to Include Fluoroscopy, Nuclear Medicine, and Digital Radiography Doses
Here is an interesting article on the ACR’s Dose Index Registry (DIR). It is titled “Physicist Spotlight: Meet the Chair of the ACR Dose Index Registry Committee.” I encourage you to pay specific attention to the article’s discussion of the DIR’s ability to accept and compare doses, not only from CT scanners, but now also… Read More
Exam Name Mapping Guide – A Useful Tool
Exam Name Mapping in the DIR is one of the most important, yet under-appreciated, duties for those managing their facility’s DIR program. It is important inter-exam mapping is maintained. By that I mean similar studies should be assigned to the same RPID. Sounds easy, but it isn’t for a variety of reasons. First and foremost,… Read More
New Scanner Dose Review – A Unique DoseID Service
Generally speaking, today’s scanners are much more dose efficient than the ones they are replacing. When a site installs a new scanner I like to provide them with an overview of just how their doses changed so they can share their success within the institution. One of my clients installed a new scanner a few… Read More
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Dose Registry Support Services Brochure
Dose Registry Support Services 