Credit or Blame? CT Propels Imaging in the ED
EDs are feeling the strain—more patients, fewer resources and ubiquitous closures—and matters are only getting worse. Expanded coverage under the Patient Protection and Affordable Care Act of 2010 and continued spending cuts, the weak economy and lack of insurance coverage will more than likely increase patient demand. On the imaging end, emergency physicians are in the crosshairs, derided as some of the most profligate utilizers of imaging.

For many ED physicians, these figures signify distraction more than doomsday. They point out that increasing volume and decreasing resources have become the baseline, a norm dating back a decade of emergency medicine, if not longer. "The trend is not a major problem because [the shortage of resources] drives quality and efficiency in high-volume EDs," remarks Martin Gunn, MD, an assistant professor of body imaging and emergency radiology at the University of Washington School of Medicine in Seattle.

The medical, economic and political pressures that have shaped ED imaging in the last quarter century are subtle; the result is not. "There is no question that CT is the workhorse of the ED. Combined with ultrasound, it accounts for roughly 90 percent of advanced emergency imaging, and it's likely to stay that way for some time," says John Thomas, MD, a radiologist at the University of Alabama at Birmingham who authored a comprehensive survey of ED practices in the last five years. Statistics cry out that emergency medicine is in need of critical care, but as ED physicians are quick to point out, the data belie the startling advancement of emergency medicine, with CT at the center.

ED imaging: A brief history

Annual ED visits have surged 23 percent over the last 15 years (Centers for Disease Control and Prevention). During that same time, the number of urban EDs fell by more than one-quarter, while the total number of EDs in the U.S. fell by more than 12 percent (CDC; JAMA, 2011). Radiology has played a critical role in keeping up with growing demand: CT utilization in the ED spiked 330 percent from 1996 to 2007, according to a study published in the September issue of Annals of Emergency Medicine. The surge in CT studies grew 11 times faster than the rate of ER visits. Just 3.2 percent of ED patients received CT scan in 1996—13.9 percent of patients had one in 2007 (that's one of every seven patients and also means that one quater of all CT exams are done in the ED).

Neuroimaging accounts for about half of this growth, while abdominal and cardiac CT exams are also on the rise. "We were surprised at the number of EDs performing triple-rule-out scans," a single CT to rule out coronary artery disease, pulmonary embolism and aortic dissection, which was about one-fifth of EDs, according to Thomas' 2008 study. Meanwhile, MRI is performed in less than 1 percent of ED visits, with an equally negligible rate of growth.

Critics have attacked the growth of CT in the ED from a variety of angles. An October 2010 study in Journal of the American Medical Association questioned why the 250 percent growth in CT was accompanied by the diagnosis of only 15 percent more life-threatening conditions, and why abdominal CT is on the rise despite no change in the prevalence of significant abdominal conditions. With a parallel uptake in scrutiny over costs and radiation exposure in the last decade, ED physicians are having to answer to medical, political and public interrogation.

"What often gets forgotten in these debates—the reason we have these issues over CT utilization—is that it's such a tremendously useful tool and so greatly improved our ability to to diagnose and treat our patients," says Aaron Sodickson, MD, PhD, director of emergency radiology at Brigham and Women's Hospital in Boston. The September Annals study pointed to a 50 percent drop in hospital admissions following a CT scan in the ED from 1996 to 2007. Sodickson sees CT ordering as having a low threshold; physicians have become dependent on it.

From the perspective of the clinician, this dependence is in many ways understandable. As emergency physicians become forced to think about patient care in the scale of seconds, CT enables accurate diagnoses, fast. "If a patient comes into the ED with abdominal pain, it could be one of 50 diagnoses. CT is often used because it casts a broad net to see what's going on," Sodickson continues.

Thomas points out, "A good portion of tests ordered by ED physicians are requested by the specialists they consult."

In CT's defense According to half of ED physicians, the fear of lawsuits also factors into their decision to image or clinically observe a patient. A survey of nearly 1,800 emergency physicians published this year by the American College of Emergency Physicians (ACEP) found that 54 percent of respondents conduct the number of tests for which they are so often criticized because they are afraid of being sued. Forty-four percent affirmed that lawsuits present the biggest challenge to cutting costs in the ED.

Many physicians question these findings, though. "I think defensive medicine is way overpublicized," offers Jeffrey G. Graff, MD, head of emergency medicine at NorthShore University HealthSystem in Evanston, Ill., and previous president of the American Board of Emergency Medicine. "We [emergency physicians] have been pictured as this group who is paranoid about malpractice; I don't think that's true. Do I do some testing so that I can tell people you don't have this or that? Yes. But it's not because I'm afraid of getting sued, it's because I don't want to miss anything."

On the other end of the debate are patients. Most recently tempered by well-publicized but minimally understood risks of radiation, patients commonly come to the gurney demanding a CT. As Graff admits, "There are times when we end up doing them because it's easier than trying to spend the time explaining away the CT because of anxiety in patients or parents." Saying no to a patient may be tough in itself, but whether it would convince a jury biased by hindsight is even more dubious, offers Otha Linton, MSJ, from the National Council on Radiation Protection and Measurements with the International Society of Radiology in Bethesda, Md.

Who rules the rules?

In many ways, the pressures of resource paucity, public demands and malpractice attorneys tie ED physicians' hands nearly to ischemia. Curiously, though, when it comes to imaging, ED physicians hold onto a fading freedom among specialists: clinical judgment. Where much of the discretion over imaging tests is being usurped by radiology benefits managers (RBMs) and clinical decision support (CDS), emergency medicine still lacks a unified set of appropriateness criteria.

"There are few systematic meta-analyses looking at appropriate imaging techniques in the ED, and that's a significant shortcoming," Gunn asserts. Linton authored a paper in the Journal of the American College of Radiology this spring, and although the paper drew collaboration from groups as diverse as ACEP, the U.S. Environmental Protection Agency (EPA), the CDC and the American College of Radiology, the list of recommendations is brief. The nine recommendations include developing ED imaging guidelines and addressing overutilization.

Some stakeholders doubt the utility of imaging guidelines in the ED. "[Appropriateness] guidelines couldn't take into account the context of what's going on in the ED," Graff argues. And while Sodickson agrees that emergency patients cannot be lumped into one bucket of appropriateness criteria, Gunn and Thomas question the implicit premise that ED patients present more complicated scenarios than those falling into other specialties. "Whenever anybody sees a patient, he or she is an individual patient with specific needs and quirks, but that doesn't mean you can't apply a guideline," Gunn maintains.

What is to be done?

What is unanimous is the existence of at least some misuse of CT. "It's a very complicated story, lots of gray [areas] about it. But generally, should we limit CT scans? Absolutely," Graff exclaims. The differences often lie in what changes should be made. Graff places a fair portion of the liability on younger physicians, who, he says, are trained with a different outlook on diagnosis than older physicians—an outlook either guided or blinded by CT, depending on one's perspective.

However, many from the CT-dependent generation in emergency imaging are also the ones most creatively ensuring the modality's appropriate use. At Brigham and Women's Hospital, Sodickson and colleagues cut down subsequent imaging of patients transferred from other hospitals by 15 percent after implementing an effective program for importing transfer patients' images from CDs. Meanwhile, Gunn and colleagues at the University of Washington saved an average of nearly $250 per patient, plus lowered radiation exposure, by creating a VPN to instantly share ED images with other Seattle-area emergency rooms.

"The drive now is to CDS. The technology could really help in guiding the right test," Gunn adds. Although many individual institutions are implementing CDS with their own appropriateness criteria, the lack of evidence-based consensus guidelines for ED imaging is anomalous, and for many, a challenge.

Gunn stresses the involved role radiologists are able to play in patient care in EDs with 24-hour attending radiologists, not the  least of which is working with ED physicians to order the right test. He also highlights the important roles that voice recognition, EHRs and structured reporting are playing in improving the efficiency of ED imaging as cost-cutting pressures and patient demand continue to climb. Likewise, Sodickson and researchers at other institutions are acquiring troves of data to inform the creation of evidence-based appropriateness algorithms.

Most physicians acknowledge the dangers facing EDs; but they are quick to point out that these issues, such as overutilization of CT, are only taking place because technology has advanced emergency care at such a rapid pace. "I'm a firm believer in CT and the value it brings. I also believe in controlling our resources and costs, and those need to be balanced," Sodickson reflects. Just as researchers used technology to revolutionize radiology in the ED setting, they are now employing it to check its profligacy and advance care still further, with or without cuts, lawsuits and ubiquitous ED closures.