Identifying High-Dose Views and Modes in the Catheterization Laboratory: A Run-Level Mixed-Effects Analysis

Radiation exposure in the catheterization laboratory is influenced not only by fluoroscopy time but also by acquisition mode, frame rate, and projection geometry. This study aimed to identify high-exposure imaging modes and projection angles using a run-level analysis of catheterization laboratory procedures.

This single-center retrospective study included 331 consecutive patients who underwent hemodynamic or interventional procedures. System-generated dose reports from a flat-panel angiography system were used to analyze 4753 angiographic runs. Runs were categorized according to five imaging modes and nine projection angles. The primary outcome was the log-transformed run-level dose-area product [log(DAP)]. A linear mixed-effects model with a patient-level random intercept was used to account for within-patient clustering.

The mean age was 60.6+-11.2 years, and 64.7% of the patients were men. The mean fluoroscopy time was 690.7+-758.8 s and was correlated with cumulative air kerma and cumulative DAP. In the mixed-effects model, log(DAP) differed significantly according to imaging mode and projection angle, whereas the mode×angle interaction was not significant. Cerebral 2 FPS and peripheral 3 FPS acquisitions had the highest adjusted log(DAP) values, corresponding to approximately fivefold higher geometric mean DAP values than fluoroscopy. Among the projection angles, AP had the lowest adjusted log(DAP), whereas RAO and right caudal projections had significantly higher values. The highest estimable mode-angle combination was peripheral 3 FPS in the AP-caudal projection.

Run-level radiation exposure varies significantly according to acquisition mode and projection angle. Local auditing of high-exposure modes and views may support protocol optimization and targeted operator training in the catheterization laboratory.