Health Imaging & IT - January 2009 - (Page 19)

RSNA 2008 IN-Depth @ 2007 RSNA360.HealthImaging.com RSNA 2008 In Review pAtIeNt SAFety & CoNtRoLLING RADIAtIoN DoSe Appropriateness criteria for outpatient Ct, mR have room for improvement In evaluating the appropriateness of outpatient CTs and MRIs referred from primary-care clinics at an academic medical center, researchers found that 26 percent do not meet appropriateness criteria, according to Bruce Lehnert, MD, from the University of Washington in Seattle. Researchers reviewed medical records from 462 elective outpatient CT and MR exams: 286 were CT and 176 were MRI. Evidence-based appropriateness criteria from a national radiology benefit company were used to determine if the exam would have met criteria for approval. Of the exams analyzed, “CT of the head stood out the most as considered not appropriate” at 66 percent, Lehnert said. Of the 184 CTs of the chest or abdomen, 17 percent were considered not appropriate. Of the 158 MRI of brain, spine, shoulder and knee, 25 percent were not appropriate, the authors noted. Examples of inappropriate exams include brain CT for chronic headache; lumbar spine MR for acute back pain without radiculopathy; knee or shoulder MRI in patients with obvious osteoarthritis; CT chest to follow pneumonia with a normal chest x-ray; and CT for hematuria during a urinary tract infection. Renal failure is more common in iso-osmolar than low-osmolar contrast media Iso-osmolar contrast media is not the solution to solve the major problem of renal failure after injection, according to a retrospective study presented by Per Liss, MD, PhD, from the Uppsala University in Uppsala, Sweden. They found the incidence of the diagnosis renal failure within 12 months after percutaneous coronary interventions (PCI) was greatest for patients receiving iodixanol (1.4 percent) compared to ioxaglate (0.9 percent). When adjusted for gender, age, diabetes, injected volume of contrast media, previous PCI and previous renal insufficiency and the hazard ratio for iodixanol, Liss said that the treated patients remained significantly higher than that for ioxaglate. affairs manager with American Association of Physicists in Medicine. Physicists, vendors and radiologists are focusing on additional steps to ensure minimum pediatric dose, she said. These include improved dose displays on CT panels, so technologists are aware of the dose associated with each scan, pre-set protocols to streamline the shift from adult to pediatric protocols (and dose) and a stronger focus on radiation dose awareness in vendor applications training programs. Horii made mention of the Alliance for Radiation Safety in Pediatric Imaging “Image Gently” initiative that offers a series of protocols to reduce dose for children and young adults. The Alliance plans to expand its educational campaign to CR/DR, interventional radiology, nuclear medicine and fluoroscopy in the next two years. Interventionalists bone up on radiation dose risks Despite evidence that operator radiation exposure has decreased over time, radiation exposure in the interventional radiology suite is often taken for granted, said John F. Angle, MD, of the University of Virginia Health System in Charlottesville. Three basic concepts that radiation physicists apply to reducing these doses are: time, distance and shielding. All the staff and operators in the room must work to minimize patient and operator exposure. “In a population of 10,000 people, four excess deaths are expected from 10mSv of exposure,” Angle said. He noted, however, that 88 percent of radiologists get exposed to less than 0.5mSv per year, mainly from scatter from the patient during a procedure. Interventional radiologists (IR) must provide practical and accurate consultation to patients prior to procedures, particularly for procedures on young patients or pregnant women. Operators most at risk for radiation exposure are fluoroscopy and digital acquisition interventionalists, and IRs who perform CT-guided procedures. IRs also must be prepared to record patient dosimetry in the future, he said. Reducing Ct radiation dose for the pint-sized set Methods for multidetector CT dose reduction in pediatrics include design and education, said Steven Horii, MD, from the Hospital of the University of Pennsylvania in Philadelphia. He urged increasing awareness among technologists of CT radiation dose; implementing decision support for pediatric CT studies; and developing low-dose protocols when CT is needed. Pediatric radiation dose is a concern for all types of facilities as most pediatric scans are not performed at pediatric hospitals, said Lynne Fairobent, legislative and regulatory HealthImaging.com January 2009 | Health Imaging & IT 19 http://RSNA360.HealthImaging.com http://www.HealthImaging.com

Table of Contents Feed for the Digital Edition of Health Imaging & IT - January 2009

Health Imaging & IT - January 2009 Contents The Enterprise News Update DR Breathes New Life into Radiography Radiology in the Spotlight Educational Sessions Keynote Addresses Tech Trends on the Exhibit Floor Imaging Tools Managing Technology People & Technology Reader's Resource

Health Imaging & IT - January 2009

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