Navigation Links
Experts recommend closer scrutiny of radiation exposure from CT scans

(SACRAMENTO, Calif.) Amid increasing fear of overexposure to radiation from CT scans, a panel of experts has recommended more research on the health effects of medical imaging and ways to reduce unnecessary CT tests, as well as industry standardization of CT machines.

The recommendations, published in the November 2012 issue of Radiology, were developed at the Radiation Dose Summit, organized by the National Institute of Biomedical Imaging and Bioengineering (NIBIB). The summit included more than 100 medical physicists, radiologists, cardiologists, engineers, industry representatives and patient advocates. The proceedings, held in Bethesda, MD in early 2011, covered currently understood risks of radiation exposure from CT scans, set priorities for future research, and called for changes to industry practices.

"The number of CT exams in the U.S. has increased by about 10 percent each year over the past decade," said John Boone, UC Davis professor of radiology and lead author of the Radiology article. "This trend underscores the importance of developing a better understanding of the health risks of radiation exposure versus the benefits of enhanced diagnosis."

The experts conceded that despite widespread public concern about radiation risks, the biologic effects from medical imaging tests are not entirely understood. Most direct evidence comes from the effects of instantaneous, high-dose, whole-body exposures due to industrial accidents and from survivors of the atomic bombs in Hiroshima and Nagasaki, Japan. Whether these findings can be extrapolated to people exposed to occasional and much smaller dosages applied to only parts of the body is uncertain.

"The standards regarding 'safe levels' of radiation were designed for workplace safety and are very conservative," said Boone. "We don't know whether the established thresholds are really meaningful for exposure from medical testing."

The experts pointed out that because there is a high background incidence of cancer worldwide, the small incremental increase in cancer that may be attributable to low doses of radiation from medical imaging is extremely difficult to ascertain. They stated that national and international registries that track cancers and patient exposures to medical radiation may one day make it possible to conduct large epidemiological studies that could help make such associations.

"In reaction to media coverage of radiation overexposure cases, some patients refuse to undergo medical imaging procedures," said Boone. "Yet for almost all patients, the risks of foregoing a needed medical procedure far outweigh any potential radiation-associated risks."

Even accurately recording patient exposures of radiation from medical imaging is extremely difficult, according to the authors. Although it is easy to ascertain how much radiation a machine administers during an imaging study, the amount actually received by a patient depends on various factors including body size. For example, because of differences in body mass, children and small adults can receive a dose of radiation two to three times that of larger people, even when the dose administered is the same.

Other factors, such as whether the patient lies on a moving or stationary table, also affect the radiation dose received. Federally sponsored research is needed to develop methods to more accurately measure patient exposures from different types of CT scans, the authors suggested.

Summit participants also discussed the role of human error in CT scanning, which has resulted in widely publicized instances of radiation overexposure. They point out that CT operators frequently are responsible for several machines made by different manufacturers, each of which may utilize dissimilar nomenclature and control consoles, thereby increasing the chance for error.

"For some scanners, you turn a dial to the right to get a larger dose, and for others, turning it the same way gives a smaller dose," said Boone. "There are so many differences in current CT scanners, it can be like driving a car with the brake pedal on the left in the morning, then with the brake on the right in the afternoon."

CT scans should be built more like cars, he argued, which may have different exteriors, dashboards and seat coverings but are standardized across the industry so that they are driven the same way, making driving errors unlikely to occur when switching from one kind of car to another.

The experts call for academic and professional radiology societies, as well as industry trade organizations, to exert pressure on CT manufacturers to standardize nomenclature and control consoles to help avoid mistakes.

The experts also considered "wasteful imaging" -- tests that have little impact on patient diagnoses or outcomes -- resulting in unnecessary radiation exposures. Wasteful imaging can arise if physicians are unaware of a patient's prior tests or don't really know whether a scan will benefit a patient with certain signs and symptoms. In addition, physicians may order tests they know are only marginally useful to avoid accusations of negligence in a possible future lawsuit. The experts recommend use of information technology to develop national imaging and radiation exposure registries, as well as standardized protocols that guide physicians on the use of optimal imaging modalities for different clinical problems.

The University of California recently provided grants to all five of its medical schools to develop methods for more accurate measures of radiation exposure from CT scans and to build protocols that improve diagnostic information and reduce radiation risks. According to Boone, the tools under development are very powerful and will move the UC system toward achieving the goals outlined during the Radiation Dose Summit.


Contact: Dorsey Griffith
University of California - Davis Health System

Related medicine news :

1. Resolving conflicts over end-of-life care: Mayo experts offer tips
2. Diabetes Prevention: Start Small, Experts Say
3. CHOP experts describe research in pediatric heart disease
4. Health Risks Will Rise in Sandys Wake, Experts Warn
5. Is Sex Addiction Real? Some Experts Say So
6. Get Ready for Hurricane Sandy, Experts Warn
7. Experts call for increased neonatal inclusion in pediatric drug trials
8. Experts convene to address major cause of childhood illness and death
9. 4,000 analytics experts come to Phoenix for INFORMS Annual Meeting
10. Swallowed Toothpicks Can Lead to Big Trouble, Experts Warn
11. Lights off? International experts call attention to dangers of exposure to light at night
Post Your Comments:
(Date:11/27/2015)... ... November 27, 2015 , ... Intellitec Solutions announced today that ... (MSDSLUG). Recognized as Microsoft’s official group for end users of Dynamics SL ERP ... partners, industry experts and representatives. Intellitec Solutions’ membership status demonstrates their ongoing commitment ...
(Date:11/27/2015)... , ... November 27, 2015 , ... ... Secura Consultants has prided itself for not only fulfilling the needs of advisers ... solutions at an affordable price and providing top-tier customer service. However, there's always ...
(Date:11/27/2015)... Angeles, CA (PRWEB) , ... November 27, 2015 , ... ... Commission on Accreditation of Allied Health Education Programs (CAAHEP) awarded accreditation to its Diagnostic ... list of CAAHEP accredited colleges, as only one of twelve colleges and universities in ...
(Date:11/27/2015)... (PRWEB) , ... November 27, 2015 , ... Dr. ... Medical Associates, Inc. and Dr. Tucker Bierbaum with Emergency Medicine at St., ... observed that both STEMI and Sepsis conditions present in similar ways and require time-critical ...
(Date:11/27/2015)... , ... November 27, 2015 , ... ... center software Q-Suite, announces the incorporation of Asterisk 11 LTS (Long Term Support) ... supported Asterisk 11 LTS brings Q-Suite 5.10 up-to-date with a version of Asterisk ...
Breaking Medicine News(10 mins):
(Date:11/29/2015)... and NUREMBERG, Germany , ... meeting, innovation leader Ziehm Imaging invites attendees to experience ... on the market. The highlight on display is Ziehm ... flat-panel technology that provides a 16 cm edge length ... Vision RFD Hybrid Edition, the first fully motorized mobile ...
(Date:11/27/2015)... 2015 --> ... online. The potential to save costs, improve treatment quality ... from fully exploited as yet. Here, particular emphasis is ... via mobile tablet or directly at the patients, bedside. ... ) -->      (Photo: ...
(Date:11/26/2015)... PUNE, India , November ... --> ... / personal emergency response system ... grow steadily for 5 years ... growing region expected to see ...
Breaking Medicine Technology: