Effect of Low-Frame Invasive Coronary Angiography on Radiation and Image Quality

Invasive coronary angiography (ICA) uses harmful x-ray energy. To date, there are no studies evaluating the effect of performing ICA at lower than the standard 15 frames per second (f/s) on radiation dose and image quality. In this study, we investigated the effect of performing ICAs at 7.5 f/s as opposed to the standard 15 f/s on radiation exposure and image quality. Thirty-nine patients referred for ICA for clinical indications were assigned to have their ICA performed at 7.5 f/s or 15 f/s in a 2:1 ratio, respectively. All studies were performed by one experienced operator in the same laboratory. Magnification, table height, collimation, number of images, and specific angles for image acquisition were kept constant to account for these variables that also effect radiation. Studies performed at 7.5 f/s had significantly less radiation exposure than those performed at 15 f/s (252.2 mGy vs 433.7 mGy, p <0.01). In addition, radiation per unit time was also significantly reduced in the 7.5 f/s versus the 15 f/s group (140.0 mGy/min vs 254.7 mGy/min, p <0.01). Image quality was evaluated by an experienced operator blinded to the goals of the study; allstudies were graded as good to excellent. In conclusion, performing ICA at 7.5 f/s versus 15 f/s significantly reduces x-ray exposure without compromising image quality. The results of this single-center study warrant a larger randomized clinical trial.