Radiologists See Opportunity in Overuse of Back Imaging

A recently published metaanalysis that questions the value of lumbar spine imaging on some patients presents an opportunity for radiology to strengthen its role as imaging gatekeepers for referring physicians and patients.

Roger Chou, M.D. Oregon Health & Science University

Taking responsibility for telling a physician or patient "no" or recommending other courses of action isn't always easy, said Michelle S. Barr, M.D., chair of the musculoskeletal subcommittee of the RSNA Scientific Program Committee. "A lot of education needs to be done with referring physicians and patients who may not understand," said Dr. Barr, an associate professor of radiology and chief of musculoskeletal interventional radiology at the University of Virginia in Charlottesville.

The study, "Imaging Strategies for Low-Back Pain: Systematic Review and Meta-Analysis," published in the February 7, 2009, issue of The Lancet, shows lumbar imaging on patients who do not have serious underlying conditions will not improve clinical outcomes and can unnecessarily raise lifetime radiation dose.

Lead researcher Roger Chou, M.D., and colleagues analyzed six controlled trials that compared the results of immediate lumbar imaging and results of typical clinical care without an immediate radiograph, MR or CT scan for low-back pain. Dr. Chou, an associate professor in the School of Medicine at the Oregon Health & Science University in Portland, and director of clinical guideline development for the American Pain Society, said he came up with the idea for the study after being asked repeatedly about imaging and low back pain during interviews.

"2007 Guidelines from the American College of Physicians and the American Pain Society say doctors should not routinely image patients with lower back pain," Dr. Chou said. Despite those guidelines, physicians have continued to order imaging, he said.

Excerpts from the American College of Radiology Appropriateness Criteria® for Low Back Pain

Reprinted with permission from the American College of Radiology (ACR). No other representation of this material is authorized without expressed, written permission from ACR. Refer to the ACR Web site at www.acr.org/ac for the most current and complete version of the ACR Appropriateness Criteria®.

Researchers looked at the diagnostic accuracy of the imaging tests and found slightly worse, but not statistically significant, outcomes for those who were imaged. Looking at pain and function outcomes and anxiety outcomes for patients who might receive psychiatric benefits by getting lumbar images, Dr. Chou and colleagues were surprised to see no benefit. In terms of patient satisfaction, there were mixed results.

"We went in with open minds, but we confirmed there is no important benefit from routine imaging for patients who do not have serious underlying conditions," he said.

Another problem, researchers discovered, was that ordering doctors blame back pain symptoms on what they see in imaging studies—degenerative discs, bulging discs and arthritis; however, said Dr. Chou, these symptoms may not be the true cause of the back pain. "Fifty percent of patients over the age of 50 have degenerating discs," he said.

Dr. Barr praised Dr. Chou's extensive literature review. "Many jump to imaging," she said. "I hope this discourages doctors from ordering imaging immediately."

Published Criteria Provide Direction

Since clinicians haven't policed themselves, radiologists must become the gatekeepers, said Drs. Chou and Barr. "Radiologists need to help clinicians better understand which back pain symptoms require diagnostic imaging and which symptoms are likely to improve with or without imaging," said Dr. Chou. "Radiologists need to ask if the patient really needs an imaging study."

The best way to evaluate the necessity of an imaging test, said Dr. Barr, is to use the American College of Radiology (ACR) Appropriateness Criteria^®. The criteria offer standards for the use of imaging based on medical conditions. (See sidebar for ACR Appropriateness Criteria for low-back pain).

"The criteria are used at my hospital," said Dr. Barr. "They should go to every hospital and every insurance company."

Ten so-called "red flags" in the ACR criteria that indicate the need for lumbar imaging studies are:

• Recent, significant trauma, or milder trauma for those older than 50

• Unexplained weight loss

• Unexplained fever

• Immunosuppression

• History of cancer

• IV drug use

• Prolonged use of corticosteroids and/or osteoporosis

• Age over 70

• Focal neurologic deficit with progressive or disabling symptoms

• Symptoms with duration longer than six weeks

Dr. Barr acknowledged that while finding the information to help make a decision may be easy, playing the role of gatekeeper often is not. She likened a back pain patient's desire for imaging to a patient who is sick and wants antibiotics. Even though antibiotics will help only those patients with bacterial infections—and imaging helps only those patients with serious underlying conditions—patients can be hard to persuade, said Dr. Barr.

Patient Education Needed

Patients themselves should question imaging tests, said Dr. Chou. "Patients want to know the cause of pain but imaging tests can be misleading and may lead to unnecessary procedures," he said, noting a strong correlation between rates of MR and rates of surgery.

For patients who demand an imaging study, Drs. Chou and Barr said clinicians must efficiently explain how imaging can help or harm them. Even still, there is a risk of litigation. "Four of the studies we analyzed followed 1,100 patients who did not get an imaging study, to see if any of them developed cancer. Not a single cancer was missed," Dr. Chou said.

In a separate commentary published in the same issue of The Lancet, Michael M. Kochen, M.P.H., F.R.C.G.P., and co-authors noted, "Over the past decade there has been a broad consensus among different scientific organizations worldwide on the benign self-limiting nature of unspecific low-back pain and hence the need for education of patients—to reassure patients and encourage them to continue with normal activities.

"Although most patients with back pain never undergo any radiologic tests because they do not seek medical attention, there remains a large group who seeks the dubious promise of imaging procedures despite contrary recommendations in evidence-based guidelines," Dr. Kochen and colleagues concluded.

While pleased with the 2,000 patients analyzed in his study, Dr. Chou said he would have liked to have seen greater numbers of patients and imaging studies. "Additional data always give you more confidence in the results," he said. For future studies, Dr. Chou said he'd like to determine when it is appropriate to get an imaging study, especially for patients with chronic low back pain or with sciatica.