LAUSR

To the Editor I want to congratulate Shimizu and colleagues for their important contribution on the reduction in radiation exposure that can be achieved by switching the fluoroscopy pulse rate from 7.5 to 4 pulses/second during carotid artery stenting procedures. Low pulse rate fluoroscopy is one the simplest, most easily implemented, and most cost-effective method angiographers can use to decrease radiation exposure to endovascular teams and their patients. It is therefore disconcerting that high pulse rate fluoroscopy remains widely used for diagnostic angiography in adults and—more distressingly—in children. I had the privilege to learn neuroangiography in the 1990s in Geneva, Switzerland, from an exceptional physician, who—besides being equipped with unmatched technical skills—paid utmost attention to radiation protection. During my training years, using 7.5 pulses/second for a cerebral angiogram was not an option. This education has served me well for the last 23 years. I conduct all diagnostic and interventional neuroangiographic procedures, including intracranial and spinal microwire/microcatheter manipulations, at a rate of 3 pulses/second, with two exceptions: N-butyl cyanoacrylate is injected under a negative roadmap technique at 7.5 pulses/ second while diagnostic selective spinal angiograms are performed at 2 pulses/second. Transmitting this practice to our fellows has been seamless: rather than feeling disadvantaged when using low pulse rates, most of them become dizzy—like I do—when the pulse rate is mistakenly set at 7.5 pulses/second. Angiographers should also keep in mind that decreasing the dose per pulse is another powerful method to limit radiation exposure from fluoroscopy. I occasionally question colleagues about their attraction for high fluoroscopy pulse rates. The answer is generally a classic “because that’s how I was trained” or “because the image looks better”. Some acknowledge that a lack of education in medical physics or radioprotection prevents them to consider the impact radiation may have on themselves or their patients. While none ever raised safety concerns, the belief that higher pulse rates are safer could represent an obstacle to the adoption of low dose protocols. Shimizu and colleagues showed that reducing the fluoroscopy pulse rate during a commonly performed procedure did not impact safety. This is an important step, which I hope will stimulate further investigations about the role radioprotective techniques can play in fostering a safer environment for neuroangiography teams and their patients.