There is no question that CT scans save lives. But because CT exams involve radiation, they must be performed only by qualified individuals who are properly educated to minimize dose in every possible way.
Albuquerque, NM (Vocus) December 18, 2009
Two recent studies examining radiation doses delivered during computed tomography examinations underscore the important role that competent, educated CT technologists play in minimizing dose and protecting patients, according to the American Society of Radiologic Technologists (https://www.asrt.org).
The studies were published in the Dec. 14 issue of the Archives of Internal Medicine. One found a wide variability in the amount of radiation dose delivered for identical types of exams, resulting in up to a 13-fold difference in radiation dose from institution to institution or even from machine to machine. The second study estimated that approximately 29,000 future cases of cancer could be related to CT scans performed in the United States in 2007.
“These studies clearly point out that additional dose reduction efforts are needed,” said ASRT President Diane Mayo. “Fortunately, radiologic technologists who are certified in CT know how to make the proper adjustments to reduce the total dose delivered to the patient.”
The ASRT, which represents more than 133,000 radiologic technologists, is committed to ensuring radiation dose is as low as possible for all types of medical imaging examinations. “Radiologic technologists, along with radiologists and medical physicists, are members of the team responsible for ensuring that the lowest possible dose is used in order to obtain a diagnostically useful image,” said Ms. Mayo.
To reduce dose delivered during CT scans, the ASRT recommends:
- Technologists responsible for performing CT scans should be certified in computed tomography by the American Registry of Radiologic Technologists. To become certified, technologists must meet specific clinical requirements and pass a national test covering subjects such as patient assessment, radiation safety, CT systems and image processing, as well as knowledge of specific imaging procedures. They also must complete continuing education to remain registered. “One of the best ways to minimize dose is to ensure that only qualified personnel perform CT scans,” said Ms. Mayo.
- Educational and certification requirements for personnel who perform medical imaging examinations should be standardized nationwide. Currently, there is wide variation from state to state in the requirements for personnel who perform these examinations. The Consistency, Accuracy, Responsibility and Excellence in Medical Imaging and Radiation Therapy bill (CARE bill), introduced in the House of Representatives in September as H.R. 3652, would establish minimum national standards. The ASRT has lobbied for passage of the CARE bill for more than 10 years as an important way to ensure the safety of patients undergoing medical imaging examinations.
- Facilities that perform CT should participate in a CT accreditation program such as the ones offered by the American College of Radiology and the Intersocietal Commission for the Accreditation of Computed Tomography Laboratories. These programs evaluate qualifications of personnel, equipment performance, effectiveness of quality control measures and quality of CT images. In addition, the ICACTL accreditation program specifically requires personnel certification in CT, which ASRT supports.
- CT scans should be performed only when there is a clear medical reason. CT scans are a valuable diagnostic tool and often are the only method of obtaining important diagnostic information, but they should be used only when medically necessary. The authors of one of the Archives of Internal Medicine articles estimate that as many as 30 percent of CT scans are not medically necessary.
- Institutions should establish protocols to reduce and standardize CT dose. For example, multiphase scans should not be routinely ordered or performed, dose should be adjusted based on the patient’s size and weight, and only the indicated area should be scanned. The Image Gently campaign, which focuses on reducing dose to children undergoing CT and others types of medical imaging examinations, offers sample CT protocols at its Web site at http://www.imagegently.org. The ASRT is a founding member of the Image Gently campaign, and worked with content experts to design educational modules for technologists related to decreasing pediatric exposure in CT. These modules are currently available on the Image Gently Web site.
The ASRT has a long history of providing educational materials to assist radiologic technologists in minimizing radiation dose during medical imaging examinations. To help radiologic technologists perform quality CT examinations, the ASRT is producing a 10-module course on the basics of CT. The first five modules, including one on patient safety, are already available. The patient safety module demonstrates the methods used to measure patient dose and increase patient safety, including information about technical factor selection, positioning and shielding.
“There is no question that CT scans save lives,” said Ms. Mayo. “More than 70 million CT scans are performed each year in the United States. In the vast majority of these cases, the benefits gained through the medical information obtained far outweigh the small risks involved. But because CT exams involve radiation, they must be performed only by qualified individuals who are properly educated to minimize dose in every possible way. Those individuals are certified CT technologists.”
The ASRT, based in Albuquerque, N.M., represents more than 133,000 members who perform medical imaging procedures or plan and deliver radiation therapy. The Society is the largest radiologic science association in the world. Its mission is to provide radiologic technologists with the knowledge, resources and support they need to improve patient care.
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