You’ve been complaining about the pain in your abdomen that just won’t go away and your doctor lines you up for a cat scan. You lie on the narrow table that slides in and out of the overhead tunnel, whilst x-ray beams rotate and produce sliced images of your very interior.
Such commonplace imaging should not be taken lightly or performed as often as it does, with recent research revealing that radiation from CT scans can cause cancer decades after patient exposure. The research, published in the Archives of Internal Medicine states that the doses delivered by the CT scanners were higher than previously thought, and were in fact extremely variable lacking the rigors of standardization across the industry.
This is of increasing concern due to the escalating use of computed tomography both in symptomatic patients and more recently in the screening of asymptomatic patients. The popularity of this diagnostic procedure has increased over the past few decades, with the number of annual CT procedures performed in the United States rising from 3 million in 1980, to approximately 70 million in 2007.
Computed tomography, commonly referred to as a CT scan, plays a vital part in modern medicine, transforming medical imaging by providing three-dimensional views of the body. However, it does so by delivering extremely large doses of radiation with a CT scan of the chest bombarding the body with more than 100 times the radiation than a routine chest x-ray. Delivering even more radiation, is the CT coronary angiogram which is capable of submitting the patient to the equivalent of 309 chest X-rays leading to the conclusion that one 40-year-old woman out of 270 who underwent a CT scan of coronary arteries would develop cancer as a result of the test.
The authors of the study criticize the increasing use of CT screening for healthy patients and suggest that the risk of carcinogenesis outweighs any diagnostic value. The risks of CT scanning are greatest for the young because they are naturally more radiosensitive, and because they have more remaining years of life during which a radiation-induced cancer could develop.
The increase in CT scanning is driven by many factors, including the ever growing availability of the scanners, and the technology’s expanding detection qualities. Also contributing to the increase in CT usage is the rise in defensive medicine, resulting in physicians ordering unnecessary imaging to avoid expensive lawsuits.
It is estimated that about one-third of all CT scans are not needed. The authors of the study into the risks associated with CT scanning, claim that there is growing consensus that the risks to patients from radiation via cat scans need to be reduced. They argue for the levels of radiation to be standardized across the industry and for a reduction in the number of scans performed. Another method of curtailing the abuse would be the introduction of an electronic tracking system to record the radiation dosage of individual cat scans.
The CT imaging of your abdomen is now over. You are relieved and glad that it was quick and painless. You are soon on your way, ready to carry on your day’s activities. Let’s hope the risk was worth it!