The Writing on the Wall: Scientific Posters

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Advanced viz tool development aids whole-breast ultrasound efforts

Whole-breast ultrasound offers the potential for CT-like clarity in breast imaging without the load of ionizing radiation while the volume of images from these exams poses a throughput issue for interpreting clinician workflow. Advanced visualization tools can assist with the deployment of whole-breast ultrasound in clinical practice because fatigue from interpreting a large volume of breast ultrasound images can contribute to oversights of masses, according to a team of scientists from Chunichi Hospital and the Nagoya Medical Center in Nagoya, Dokkyo Medical University in Mibu, and Gifu University in Gifu.

They discovered that if an automated recognition system could extract skin, nipple, rib, fat, pectoralis and mammary gland from whole-breast ultrasound images, the results could be applied to a computer-assisted detection system and a computerized registration of other modality images. Their preliminary work proposed methods for extraction of skin and nipples from whole-breast ultrasound images.

High-use flat-panel displays require conscientious QC

“To prevent medical malpractice, quality control (QC) for luminance of high-quality medical displays at PACS terminals is very important,” according to a team of researchers from Nagoya City University Hospital, Kanazawa University School of Health Sciences and Fujita Health University in Japan.

The team investigated the correlation between the frequency of use and luminance degradation in heavily used displays for image interpretation in the department of radiology and the less-frequently-used displays at other departments.

The displays were divided into two groups: the displays at the PACS workstations used for a considerable time each day in the radiology department; and display monitors that were used less frequently.

The average cumulative hours of use for radiology displays were 144,880 hours, while those for other department displays were 2,192 hours.

They observed that when the highest luminance became 350 candelas per meter squared (cd/m2) or less, luminance hardly recovered, even though calibration was carried out. The team’s research found that after about 20,000 hours of cumulative use, luminance had degraded to approximately 400 cd/m2.


THE BUSINESS OF IMAGING

CT: Doing more but getting less; Rads recommend fewer procedures over time

Despite continuing technical advances and increased use of CT in clinical practice, the diagnostic yield of CT exams has actually decreased over the past decade, according to data from a Natural Language Processing program, Leximer, developed at Massachusetts General Hospital in Boston, that was used to analyze reports of all CT exams performed at the institution from 1996 to 2005. Pragya Dang, MBBS, reported that the group found there was a 14 percent growth in volume of CT exams, which outpaced the increase in recommendation rates for further imaging studies in the radiologist’s report (13.6 percent to 19.6 percent, increasing by 0.5 percent per year). “Over this time, the rate of findings in radiology reports changed from 79.5 percent to 75.4 percent, decreasing at a rate of 0.6 percent per year,” Dang said. The researchers found that recommendation rates increased for all radiology specialties; however, finding rates decreased for all radiology sub-specialties, except neuroradiology.

Using the same system, researchers also found that the longer a radiologist is in practice, the lower his or her rate of requests for additional diagnostic imaging procedures. A decrease in recommendation rates was observed with an increase in years of experience of radiologists in abdominal imaging, neuroradiology, thoracic and musculoskeletal radiology.

CPOE and strategies for taming the CT growth beast

Massachusetts General Hospital (MGH) in Boston has contained growth in outpatient CT imaging volume by basing its CT-diet regimen on computerized radiology order entry with decision support. “Computerized radiology order entry with decision support is an effective way to reduce the image intensity creep,” said Dang (see reference above).

MGH introduced web-based computer order entry in 2001 and rolled the system out across the entire outpatient physician population over the next two years. The hospital launched decision support in 2004, requiring ordering physicians to enter indications and demographics for imaging studies. Dang reported a decrease in CT volume growth and the growth rate after implementing decision support. The quarterly CT growth rate declined from 3.1 percent to 0.2 percent. She attributed the results to two factors: the gatekeeper effect and the educational effect.

On the (far) horizon: Pay for performance at a glance

“Pay for performance (P4P) is here for the long haul,” commented Kimberly Applegate, MD, from Indiana University Riley Hospital for Children in Indianapolis. “The good news for radiologists is that the specialty is not yet in the crosshairs, which gives the profession time to prepare.”

Only a handful of the approved metrics apply to radiology. Consequently, radiologists face a slightly different mandate than their clinical colleagues. P4P will drive better integration with clinical colleagues, resulting in “IT infrastructure for better reporting,” predicted Applegate.

She highlighted upcoming priorities on the P4P agenda, including coordination of care, transition, communication and planning. Smart facilities will invest in systems and processes that tackle target metrics and related objectives like communication and clinical coordination.

Early studies hint at some troubling outcomes. Surveys of peer-reviewed studies show mixed results, said Bibb Allen, MD, chair of the American College of Radiology’s commission on economics. Studies have not yet established a link between P4P and improved patient outcomes, and some indicate that P4P could limit access to care. In addition to producing less than stellar clinical outcomes, P4P has not yet benefitted participating physicians. “Nearly half of all overall eligible bonus funds are left on the table,” Allen noted. Next year could see better results for radiologists as two more measures are reportable, and the Medicare bonus will increase from 1.5 to 2 percent. 


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.

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 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.