Search

CMS has adopted a new CT quality measure seeking to discourage excessive radiation dose while preserving image quality. The measure score is expressed as the percentage of qualifying studies that exceed predetermined thresholds indicating inadequate image quality (based on image noise) or excessive radiation dose. The measure has been incorporated into the major CMS quality-based payment programs, impacting hospitals and clinician payments; measure reporting began in January 2025. Following measure development, practitioners identified a spectrum of concerns and impediments, prompting the American Association of Physicists in Medicine to convene a multidisciplinary expert panel to provide further guidance. The panel identified 20 issues and ambiguities in the measure specifications, stemming from metrology concerns, unconventional terminology, and inconsistencies with practice standards or norms, while relating to themes of applicability, categories and metrics, informatics, performance expectations, and meta considerations. In this article, the panel presents these issues and ambiguities with associated recommendations to promote the measure's intentions. These recommendations include greater data access (e.g., to the measure's source data and to reporting elements for audit support) and a more holistic treatment of image quality. The panel ultimately urges a shift toward open-source, open-access, consensus-based, and community-owned strategies to ensure CT quality and safety.

Objective: The U.S. Centers for Medicare & Medicaid Services (CMS) recently approved the use of low-dose CT for lung cancer screening and described volumetric CT dose index (CTDI vol ) requirements. These were based on the National Lung Screening Trial, which used only fixed-tube-current techniques. The aim of this study was to evaluate dose index data from a lung cancer screening program using automatic exposure control (AEC) techniques to ensure compliance with requirements and to correlate dose index values with patient size., Materials and Methods: CTDI vol , dose-length product (DLP), and body mass index (BMI) data were collected for 563 lung cancer screening examinations performed with AEC between January 1, 2014, through August 31, 2015. CTDI vol and DLP were analyzed according to the patient's BMI classification. Results were compared with the CMS requirement that the CTDI vol for a standard-sized patient (height, 170 cm; weight, 70 kg) be 3.0 mGy or less, with adjustments for patients of different sizes. For a subset of patients, the average water-equivalent diameter and size-specific dose estimate were estimated., Results: The average CTDI vol for a standard-sized patient was 1.8 mGy, which meets CMS requirements. CTDI vol values were lower for smaller patients and higher for larger patients. Overall, the mean CTDI vol and DLP were 2.1 mGy and 74 mGy⋅cm, respectively. The size-specific dose estimate for the average water-equivalent diameter (27.5 cm) of the patient subset was 2.6 mGy., Conclusion: The screening protocols using AEC resulted in CTDI vol values that were compliant with CMS requirements. CTDI vol values greater than 3.0 mGy were only observed for overweight or obese patients.

Objective: The Multi-Ethnic Study of Atherosclerosis is a longitudinal study evaluating determinants of future cardiac events and progression of atherosclerosis. Emerging data are showing that coronary artery calcification (CAC) is a robust independent predictor of future cardiac events and that measurement of progression depends on reproducibility of the measure. Reproducibility previously was reported on baseline scans obtained with both electron-beam tomography (EBT) and MDCT. The aim of this study was to compare the interscan variability for both Agatston and volume scores derived with newer (16- and 64-MDCT) scanners with that derived with older scanners in the Multi-Ethnic Study of Atherosclerosis., Subjects and Methods: The participants in this study were 4,054 persons who underwent dual scanning with EBT (n = 1,716), 4-MDCT (n = 370), 16-MDCT (n = 1,245), or 64-MDCT (n = 723). Agreement on the presence or absence of CAC was assessed with logistic regression models adjusted for age, sex, body mass index, and scanner type. Among participants with CAC, the log-transformed interscan difference was regressed on log-transformed amount of CAC, age, sex, and body mass index., Results: The percentage agreement for the presence or absence of CAC was high and similar across scanner groups (EBT, 16-MDCT, and 64-MDCT). The greatest adjusted average absolute CAC differences between scans were found with the Aquilion 64 (24%; 95% CI, 20.9-27.6) and LightSpeed Pro 16 (19%; 95% CI, 17.4-21.0) scanners, both differences being significantly greater than with the EBT scanner (16%; 95% CI, 15.4-17.5) (p < 0.05). No differences were found between the EBT, Sensation 16, and Sensation 64 scanners. For volume score, the Aquilion 64 was the only scanner with significantly greater average absolute interscan differences than the EBT scanner (p < 0.001). Volume scoring resulted in lower rescan differences for all scanners., Conclusion: For CAC scoring, interscan variability with newer-generation MDCT scanners was similar to but not superior to that with the EBT scanner.