IRSA ASM 2024 Abstract

Aim: Radiological interventions are increasingly complex and also increasingly performed on high body mass index (BMI) patients. As such we sought to quantify the radiation dose to the eyes of the operator, the dose area product and skin dose to the patient, as well as variations in cardiac angiographic image quality. Over the range of normal to high BMI's.

Methods: Five thickness of Acrylic 15, 20, 25, 30 and 35 cm were used to simulate increasing patient BMI. The patient dose area product and skin dose were measured from the built-in metering systems of the angiographic system. The simulated operator eye dose was measured using (Rando) tm Phantom and a (Unfors)tm radiation detector at 150–170 cm in 5 cm gradients at the primary operator position. For image quality measurement, a Westmead testing object was used to test high and low contrast range and line pairs per 0.5 mm.

Results: Our study shows that whilst a low-grade linear decrease in image quality and corresponding rise in radiation dose is seen over the standard patient BMI ranges. There is a very large nonlinear drop in image quality and corresponding large rise in radiation dose in the high BMI patient range (over 25) using standard settings. Our secondary aim was proven in the results showing the high effectiveness (over 90%) of the standard lead equivalent acrylic shielding in protecting the operators' eyes. Especially for the very high levels found in the extreme patient size cohort.

Conclusion: These results indicate the important need of the radiographers' role in radiation safety. Selecting the most efficient frame rate/Ma settings possible, positioning of the detector, monitoring of ongoing case dose and that operators are using radiation protection equipment, especially the ceiling acrylic (Pb) shield for the higher BMI patients.