reasonable to conclude that the radiation dose patients receive from CT exams
does pose a small, but real, risk. For a single scan, or even a small number of ...
by
O
ver the past 25 years, Computed Tomography scans (CT scans) have become one of the most powerful diagnostic imaging tests in health care. The expanding indications for and utilization of CT scans has significantly improved our ability to diagnose and treat a myriad of diseases efficiently and effectively. Their increased use, however, has also significantly increased the exposure of patients to higher levels of ionizing radiation. While this trend has been a concern to radiologists and other physicians for many years, several recent news articles have also highlighted the potential health risks from radiation exposure associated with CT. Understanding of the risks that CT exams may pose will help patients make informed decisions about their own health. Two recent studies published in the Archives of Internal Medicine have brought the issue of CT radiation dose into mainstream media coverage. One of these studies analyzed doses of the CT exams performed in the United States in 2007 and projected that meaningful number of new cancers could be induced by these exams alone. A second study documents the wide variation in radiation doses for common CT exams. Media reports also highlight occasional instances of patients receiving significant radiation overexposures, which occurred due to operator or equipment errors. These studies highlight an issue that concerns both health professionals and patients. By some estimates, 72 million CT scans were performed in the US in 2007. A significant number of those scans were performed on patients who have had a CT scan previously in their lifetime. Radiation dose received in the body is cumulative. However, when CT exams are performed only for appropriate reasons and using the lowest doses possible, the risks posed to each person can be kept quite low. One of the difficult aspects of studying the increased risk of cancer caused by CT exams is the high baseline rate of malignancy present in the US population. It has been estimated that 42 out of every 100 individuals in this country will be diagnosed with some type of malignancy in their lifetime. Therefore, a large number of patients will develop cancer whether or not they have
Thomas L. Presson, M.D.
a CT scan. The dose received from CT scans effects patients by the same mechanisms as the dose they receive by living on earth (cosmic radiation, radon exposure, air travel). Thus assigning risk to each source individually is imprecise at best. Using a broad variety of sources, including long-term studies of exposures resulting from atomic-bomb survivors, health professionals have begun to draw conclusions about risks from one or several CT exams. Statistically, an individual’s increased risk of cancer from one CT, or even several CT exams, remains quite low, on the order of less than one percent. The increased risk is real, however, and is believed to likely increase with each additional exam. And, while overuse and overexposure are always concerns, this data must be weighed against what may happen to a patient if they do not have a CT scan. Cancers induced by radiation would likely take decades to develop, versus diseases that may harm patients much sooner. The challenge for health care providers, therefore, is to use CT most appropriately while minimizing the risk imposed to patients. This challenge may be addressed by providers and others at multiple points in the care of individual patients as well as populations at large. First, physicians/providers should order diagnostic exams using evidence based/outcome criteria appropriate for each patient. These diagnostic protocols will guide physicians to the best test to request for most patients. Many disease entities may be imaged using a variety of modalities so CT may not be necessary or even best in many cases. If questions or exceptions arise, consulting a radiologist will help make sure that only the most appropriate exam is done. Second, imaging providers should employ stringent dose reduction guidelines for all CT exams. Exam protocols should be established and maintained by knowledgeable radiologists, who are best able to tailor the exams to balance resolution required with the radiation dose delivered. The newest CT scanners employ advanced dose reduction algorithms to keep doses at a minimum. Breast and thyroid shielding may help minimize the dose to these areas.
Third, in response to calls for national standards in imaging, the American College of Radiology (ACR) has developed certification criteria for imaging centers and hospitals. These criteria assure that each certified center meets high standards for quality of imaging instruments, training of personnel, radiation dose and physician oversight. ACR certification for a location can be quite challenging to meet; however, several certified locations should be available in your area. Lastly, it is critical that children do not receive adult radiation doses. All efforts should be made to utilize alternative imaging methods; however, if a CT exam is necessary, only modified CT protocols should be used to image pediatric patients. Overall, based on current evidence, it is reasonable to conclude that the radiation dose patients receive from CT exams does pose a small, but real, risk. For a single scan, or even a small number of scans over a lifetime, this risk is likely no greater than from normal environmental sources. However, the risk will slightly increase with each additional scan. Using methods described above, and with care taken at every level, the dose received can be minimized.
Perimenopausal Estrogen Replacement Therapy Study
You may qualify for research study providing up to $1275 in compensation. We’re Looking for Women Who: 1) are between 45 and 55 years old 2) are in the menopause transition (irregular/absent menstrual cycles or hot flashes) 3) are medically healthy 4) had 2 or more experiences with depression in the past, but are not currently depressed 5) or never experienced depression
This study is conducted by David Rubinow, M.D. and Susan Girdler, Ph.D., UNC Center for Women’s Mood Disorders.
If interested, please contact Karin at 919-966-8963
Wake Radiology serves the Triangle area with 17 convenient locations and 55 board-certified radiologists with imaging subspecialties available at each location. For more information visit wakeradiology.com.
1214 Vaughn Road, Burlington, NC 27217
Dr. Presson, a vascular and interventional radiologist, is certified in diagnostic radiology by the American Board of Radiology. In addition to serving as director of Radiation Safety Programs for Wake Radiology, Dr. Presson serves as radiation safety officer at WakeMed Raleigh and WakeMed Cary Hospitals. His clinical areas of interest include arterial and venous interventions, vertebroplasty, hepatic brachytherapy, and uterine fibroid embolization. He is a member of the American College of Radiology and the Society of Interventional Radiology.
Piedmont Health SeniorCare offers services that enable elderly individuals to age in place and remain at home for as long as possible. Care is individualized and coordinated by a team based on the needs of the participant and his/her family.
References: Berrington de González A, Mahesh M, Kim K-P, et al. Projected cancer risks from computed tomographic scans performed in the United States in 2007. Arch Intern Med. 2009; 169(22): 2071-2077. Smith-Bindman R, Lipson J, Marcus R, et al. Radiation dose associated with common computed tomography examinations and the associated lifetime attributable risk of cancer. Arch Intern Med. 2009; 169(22): 2078-2086.
Now accepting participants!
For more information or to visit our facility, call our Intake Coordinator, Donna Gilchrist, at (336) 532-0000.
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CT Scans: What are the Real Risks?
Women Between 45 - 55 Needed for Research Study
21 live well
Patient Safety Awareness Month
