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Coronary angiography (CAG) is a commonly performed procedure in cardiology, resulting in patients being exposed to radiation. Patients with high body mass index (BMI) are at increased risk of coronary artery disease. Catheter laboratory intensifiers use automatic exposure control (AEC) which adjusts radiation dose aiming to provide optimal quality images. Factors shown to be responsible for dose variability are complexity of the procedure, operator experience, their level of training in radiation protection, type and performance of x-ray equipment. The objective of present study was to evaluate if radiation dose received by patients correlated with BMI.
Retrospective data for 3678 CAG performed from Sep-07 to Mar-10 from a single centre, were analysed. Radiation dose was calculated as Dose Area Product (DAP) in mGym2.
Mean radiation dose during the procedure was 4339 ± 286 mGym2. Mean BMI, contrast volume used and screening time were 29.22 ± 0.08 kg/m2, 125 ± 10.0 ml and 5.2 ± 0.1 minutes respectively. BMI was positively correlated with increasing radiation dose during CAG (graph-1 & 2). Patients with increased BMI did not require prolonged procedure or increased contrast volume. There was no significant inter-operator variability. Even Ten degree increase in angulation (oblique, cranial or caudal) increased radiation dose significantly.
Patients with increased BMI receive a significantly higher radiation dose during CAG, affecting not only the patient, but every one present in the catheter laboratory. This has to be recognized by the operator when undertaking procedures in patients with a high BMI.
- 2013 American College of Cardiology Foundation