Andrew Karellas, PhD University of Massachusetts Medical School, Worcester, MA
Sarwat Hussain, MD University of Massachusetts Memorial Medical Center, Worcester, MA

The American College of Radiology Appropriateness Criteria® are designed to help referring physicians use radiology services effectively [1]. These criteria guide providers to select the radiological study that best addresses a clinical question. With the increased contribution of imaging procedures to the population radiation dose, knowledge of the radiation dose delivered by an imaging procedure has grown in importance [2]. With the rapid growth of multi-detector computed tomography (MDCT) in the past few years, image quality and new applications have received greater attention than has radiation dose.

However, the great benefits of MDCT come with a price, namely a dramatic increase in radiation dose to the population, with part of the increase attributed to overutilization [3-6]. This problem in CT and other imaging procedures has resulted in the inclusion of radiation dose information in the ACR Appropriateness Criteria. The inclusion of dose information uses the concept of relative radiation level (RRL), a simple coding of effective doses from various tests on a relative scale [7]. This coding system assigns a radiation rating for the most common imaging procedures based on the typical effective dose to the patient that is associated with each procedure. A single radiation symbol "☢" is used as a radiation level code for procedures that are associated with an effective dose of less than 0.03 mSv such as hand and chest radiographs. Five symbols "☢☢☢☢☢" are used for procedures that deliver the highest dose, from 10-30 mSv for complex interventional procedures that involve long fluoroscopic time.

Computed tomography, with an effective dose from 3-10 mSv, is assigned a level of three radiation symbols "☢☢☢☢☢”, while ultrasound and MRI that are not associated with ionizing radiation are assigned a "0" [7]. An imaging procedure high on the appropriateness rating scale and with a low RRL rating is a good choice by the referring physician. Avoiding imaging procedures that are not indicated, and using ultrasound or MRI when appropriate, result in no radiation exposure to the patient, and should always be considered.

It is important to correct decisions by the referring physician and by radiologists that lead to excessive radiation dose to the individual patient and the overall population. Some of the problems and suggested solutions are listed below.

Problem 1: Referring physicians who lack knowledge of ACR Appropriateness Criteria

Solution: Incorporate appropriateness criteria into medical practice guidelines and facility-wide decision support systems [8]. Conduct discussions at clinical-radiological conferences, present appropriateness information in structured educational modules, provide posters for clinics

Problem 2: Inadequate understanding by referring physicians of radiation dose, absorbed dose concepts, and risks [9, 10]

Solution: Educate referring physicians about appropriateness criteria with inclusion of radiation dose. Suggest alternative tests with no radiation when applicable. Establish a clinically relevant radiation protection program.

Problem 3: Overutilization of imaging caused by self-referral [6]

Solution: Support the reduction of self-referral practices that lead to overutilization of imaging.

Problem 4: Radiologist time constraints prevent review of high-dose imaging requisitions

Solution: Develop and apply dose-reduction strategies for high-dose imaging protocols; multiphase CT studies are a good example. Educate residents, fellows, and technologists to apply these strategies, and consult the attending radiologist when necessary.

Problem 5: Inappropriate prescribing habits for imaging tests by referring physicians and their surrogates, and inability to change an approved study in Medicare patients

Solution: Educational campaign through pamphlets, computer screen savers, posters, grand rounds, and in-service education.

Problem 6: Difficulties in contacting referring physicians to discuss indications, appropriateness, and alternate imaging methods

Solution: Alert administration about the problem. If needed, update policies on radiology requisitions and effective communication between the radiologist and the ordering physician.

Problem 7: Unavailability of previous imaging studies at the time a study is requested

Solution: Implement online protocoling, or have a printout of the imaging history available to the protocoling radiologist.

Problem 8: Unavailability of alternative tests after-hours; e.g., ultrasound technologist or access to MRI not available

Solution: Appropriateness in staffing. Explore shared staffing with other facilities.

Problem 9: Technologists lack motivation or education to adjust technique factors with regard to patients’ age, gender, body region, and previous imaging history

Solution: In-service training and periodic audit of technique factors and imaging protocols. Identify patients with chronic conditions who have had many imaging tests.

Problem 10: Lack of interest in developing or adopting new protocols and fostering dose-reduction techniques.

Solution: Promote innovation though research. Provide incentives to radiologists, technologists, and medical physicists who develop new concepts and strategies for radiation dose reduction.

As physicians with extensive training in radiation, radiologists are the best gatekeepers for limiting the radiation dose from medical procedures. However, many imaging tests are performed at facilities (clinics, imaging centers, physician offices) where physicians other than radiologists are in charge. Appropriate reductions in radiation dose can only be achieved by full participation by all physicians using imaging. An accreditation program patterned after the mammography accreditation initiative could be very effective in ensuring good radiation practices.

References

1. ACR Appropriateness Criteria®, The American College of Radiology. Available at:
   http://www.acr.org/secondarymainmenucategories/quality_safety/app_criteria.aspx. Accessed September 8, 2010.
2. Mettler F.A. Jr, Huda W., Yoshizumi T.T., Mahesh M., “Effective Doses in Radiology and Diagnostic Nuclear Medicine: A Catalog,” Radiology, July 2008.
3. Brenner D.J., Hall E.J., “Computed Tomography — An Increasing Source of Radiation Exposure,” New England Journal of Medicine, November 29, 2007.
4. Fazel R., Krumholz H.M., Wang Y., et al., ”Exposure to Low-Dose Ionizing Radiation From Medical Imaging Procedures,” New England Journal of Medicine, August 27, 2009.
5. Initiative to Reduce Unnecessary Radiation Exposure From Medical Imaging, Center for Devices and Radiological Health, U.S. Food and Drug Administration, February 2010. Available at:
   http://www.fda.gov/downloads/Radiation- EmittingProducts/RadiationSafety/RadiationDoseReduction/UCM200087.pdf. Accessed September 8, 2010.
6. Hendee W.R., Becker G.J., Borgstede J.P., et al., “Addressing Overutilization in Medical Imaging,” Radiology, October 2010.
7. ACR Appropriateness Criteria®, Radiation Dose Assessment Introduction, American College of Radiology. Available at:
   http://www.acr.org/secondarymainmenucategories/quality_safety/app_criteria/rrlinformation.aspx. Accessed September 8, 2010.
8. Sistrom C.L., Dang P.A., Weilburg J.B., et al., “Effect of Computerized Order Entry With Integrated Decision Support on the Growth of Outpatient Procedure Volumes: Seven-Year Time Series Analysis,” Radiology, April 2009.
9. Schueler B.A., “Incorporating Radiation Dose Assessments Into the ACR Appropriateness Criteria®,” Journal of the American College of Radiology, June 2008.
10. Lee C.I., Haims A.H., Monico E.P., et al, “Diagnostic CT Scans: Assessment of Patient, Physician, and Radiologist Awareness of Radiation Dose and Possible Risks,” Radiology, May 2004.