How Safe Are CT Scans? A Guide to Radiation Exposure Risks
A CT (computed tomography) scan is a type of imaging test. Like an x-ray, it shows structures inside your body. To get these images, a CT machine takes X-ray pictures as it revolves around you. Healthcare providers use CT scans to see things that regular X-rays can’t show. A CT shows the details of each of your organs for a clearer and more precise view. CT scans help healthcare providers detect various injuries and diseases, including certain types of cancer and benign tumours, fractures, heart disease, blood clots, kidney stones, brain injuries, spinal cord injuries, bowel disorders and internal bleeding.
Since its introduction in the 1970s, computed tomography has revolutionized diagnostic decision-making. Over the last few decades, there has been a dramatic increase in the availability and application of tests that use ionizing radiation to take images of the body. These tests include computed tomography, or CT, scans and nuclear medicine exams that use small amounts of radioactive material such as nuclear stress tests, bone scans, and PET scans.
Physicians use these tests to help diagnose disease, as well as to make treatment decisions and monitor a patient’s response to therapy. However, some media reports have suggested that doctors may be overusing these types of tests, especially CT scans, and exposing patients to unneeded radiation. One of the major concerns associated with the widespread use of CT is the associated increased radiation exposure incurred by patients.
Dr Hrushikesh Vaidya, Medical Director and Chairman, Horizon Group of Hospitals said “The low doses of radiation used in CT scans have not been shown to cause long-term harm. But for repeated scans, there may be a small increase in the lifetime risk of cancer. This can affect children more than adults. CT scans have many benefits that outweigh any small risk. Advances in technology and medical physics practice have helped to reduce the dose of radiation that patients receive from tests like CT. Radiation exposure is measured in units called millisieverts, or mSv. The effective dose from a diagnostic CT procedure depends on the area of the body being imaged as well as the size of the patient and typically ranges from about 1 to 10 mSv.”
Explaining further Dr Hrushikesh Vaidya said “For the average person, a CT scan may be associated with a very small potential theoretical risk — perhaps less than about .05 percent, or less than one in 2,000 — of possibly developing a future cancer. If we’re trying to figure out whether you have cancer or how best we should treat an existing cancer, such a small potential theoretical risk is far outweighed by the clinical benefit, which could save your life. CT scans renders a much lower dose of radiation compared with the kind of CT scans we use to look at a suspected lung cancer in someone with symptoms or to make treatment decisions. Because those scans require a greater amount of information about the image, the dose is appropriately higher.”
Dr Ria Vaidya, CEO, Horizon Group of Hospitals said “There are differences in organ sensitivity to radiation. For example, the breasts, thyroid, lungs, and bone marrow are more sensitive to radiation because the cells in those areas divide rapidly. Less-sensitive organs include the brain, where cells don’t divide as quickly. Children are more sensitive to radiation than adults as their cells divide rapidly. Hence, when doing imaging for children, we emphasize justification and implement child specific protocols to minimize the overall exposure.”
Every day, patients reach the hospitals for imaging tests, such as CT scans and X-rays. Occasionally, patients are concerned because they’ve heard that these types of tests expose them to radiation. Imaging tests do expose patients to a small amount of radiation. There is a potential, small risk that being exposed to radiation can induce cancer in a patient. But in most cases, the benefits of imaging tests far outweigh the risks from radiation exposure. Mammograms also involve radiation, but it’s a very small dose. Imaging tests have helped revolutionize the practice of medicine. Fifty years ago, physicians didn’t have a way to see the internal organs very well. So if there was a problem with a patient’s liver or kidneys, doctors didn’t have a way to identify it. Often, many medical problems weren’t diagnosed until they were very advanced, and sometimes doctors had to resort to exploratory surgery to find the source of the problem. With X-rays and CT scans, we can now essentially take a picture of the internal organs. Today, we can see even more detail by using contrast agents that patients drink or that we deliver through an IV. These scans help us detect many types of cancer and organ injuries, and seeing what’s wrong helps determine the next step of treatment. For example, if a patient comes in with abdominal pain, we can do a CT scan to determine whether the patient has appendicitis and needs an emergency operation.
The Final Takeaway
Often when people hear the word “radiation,” they think of scary things like an atomic bomb or a meltdown at a nuclear power facility. But the radiation used for medical purposes isn’t that scary. These tests can help identify acute problems and different types of cancer. In many cases, a CT scan can help a surgeon plan a surgery, and sometimes can help patients avoid unnecessary surgery. However, radiation exposure certainly isn’t trivial, so we make every reasonable effort to minimize a patient’s exposure to radiation.
At Horizon Prime Hospital, our goal when we turn on the imaging machine is for the radiation to go to good use. We want it to go into the patient to give us a good picture of the bones or organs. That’s why we ask anyone who attends an appointment with a patient to stay outside the room during the test. The amount of radiation associated with an imaging test is small, but we also want to avoid unnecessary radiation exposure to anyone who isn’t getting the test.
People who have cancer often need CT scans every few months to determine if their treatment is working. Some patients worry that repeated CT scans will give them cancer again in the future. Horizon Group of Hospitals through this article, we are trying to reassure these patients that while there is theoretically a small risk of getting a new cancer in many years from radiation exposure, the risk of having a complication from their existing cancer is much larger. We don’t want to frighten anyone, so it’s important to maintain some perspective.
