Recently published research and media reports have raised public concern about the risks of radiation exposure from diagnostic tests, especially CT scans.
"A CT scan, also known as computed tomography, is a noninvasive test that gives doctors a 3-D view inside the body," said Dr. Peter Apicella, Board Certified Radiologist and Chairman of Medical Imaging at Salem Community Hospital."An individual's risk of developing cancer as a result of the radiation exposure from CT scans is very low, especially when compared to the risks associated with the medical condition that a CT scan may help identify."
How a CT Scanner Works
"CT scanning combines special x-ray equipment with sophisticated computers to produce 3-D images or pictures of the structures inside the body in just a few seconds of time," Dr. Apicella stated. "The number of CT procedures performed in the United States has increased tremendously in the past decade because of improvements in CT scanner speed, image quality, and three-dimensional imaging."
"CT scans are used to help diagnose strokes, cancers, pneumonias, blood clots, kidney stones, blood flow in the body, and a host of other diseases. This advanced form of medical imaging can identify medical problems at an early stage and provide the possibility for early treatment and cure."
X-rays used in medical imaging are a form of radiation-like light or radio waves-that can be directed at the body. Any amount of radiation exposure has a small risk of future cancer.
"Every day, we are all exposed to natural forms of radiation, such as from radon gas in the ground or from cosmic rays in space," Dr. Apicella advised. "This natural radiation exposure is above the low doses used in medical imaging for most tests including mammograms; x-rays of the chest, abdomen, arms, and legs; and CT scans of the head.
Some CT scans, like chest and abdominal studies, require more radiation to have clear images but still much less than doses known to cause damage to cells of the body," said Dr. Apicella.
Risk vs. Benefit
The U.S. Food and Drug Administration (FDA) considers the risk of absorbed X- rays from CT scans to be very small, and has stated on its website that, "For a patient with a medical need, the benefit of a diagnostic or therapeutic CT procedure recommended by a physician normally far exceeds the small cancer risk associated with a CT procedure."
The Alliance of Radiation Safety in Pediatric Imaging has another way of describing the relative risk of having an abdominal CT scan and compares it to the risk of a person being involved in an automobile accident if he or she were to drive 7,500 miles.
Patients should not let the recent studies about CT risks cause them to worry about getting a diagnostic study when it is needed. Many experts, including the American College of Radiology (ACR), disagree with the recent study's use of this type of model as a fair comparison for estimating the number of cancer cases that may be related to CT scans. According to the ACR, no published studies show that radiation from imaging exams causes cancer, and most CT scans are performed in controlled settings with limited radiation exposure to a small portion of the body.
"Patients and physicians may have concerns about repeated CT scan exposure over time, however, when medically indicated, the benefits of the procedures outweigh the small future risks," added Dr. Apicella.
ACR Facility Certification
Researchers have noted significant variations in the amount of radiation used by various institutions for similar medical imaging examinations including CT scans. This information has been used to prompt patients to inquire if their medical imaging test is performed in a facility that is ACR accredited to ensure that:
1. The physician interpreting scans has met stringent education and training standards;
2. The technologists operating the equipment are certified by the appropriate body; and,
3. The imaging equipment is surveyed regularly by a medical physicist to make sure that it isfunctioning properly and is taking optimal images at the lowest possible doses.
"The good news is that as an ACR Certified Facility, Salem Community Hospital has physicists, radiologists, and staff working together to use the lowest possible radiation dose for optimal imaging," concluded Dr. Apicella. "Participation in the ACR accreditation program means that our staff has been specially trained to use the proper amount of radiation necessary to obtain high quality results."
"Your physician considers the benefits and risks when prescribing any form of treatment ranging from prescribing a medication to ordering a diagnostic test, such as a CT scan. If you have a question or concern about your care, talk with your doctor."
Peter L. Apicella, M.D. is the chairman of the Department of Medical Imaging and a board certified radiologist at Salem Community Hospital.