Quantifying Patient Positioning Errors and Radiation Dose Variation in Cardiac Computed Tomography Angiography.

Objectives: Accurate patient centring at the computed tomography (CT) scanner isocentre is essential for optimising radiation dose. This study aimed to quantify positioning errors, assess their relationship with radiation dose, and estimate the potential dose reduction achievable with optimal centring. Methods: ) and dose length product (DLP), were extracted from DICOM dose reports. Statistical analyses comprised descriptive statistics, correlation analysis, multivariable regression, and simulation of potential dose reductions with ideal centring. Results: by approximately 12%, with a similar reduction in DLP. Conclusion: Patient off-centring was highly prevalent in cardiac CT examinations. No independent association between off-centring and radiation dose was observed when adjusting for BMI, age, and sex. Literature-based scenario modelling suggests that meaningful radiation dose reductions may be achievable with optimum centring, although this requires prospective confirmation.