MRI for Lumbar Spine Often Unnecessary

Most orders for MRIs of the lumbar spine are unnecessary, according to a study reported in a research letter published online today in JAMA Internal Medicine.

Canadian researchers sought to determine the appropriateness of MRIs for both the lumbar spine and the head for complaints of headache. They collected data from 500 lumbar spine requisitions and 500 head for headache requisitions from the University of Alberta Hospital in Edmonton, Alberta, and The Ottawa Hospital in Ottawa, Ontario. Each case was matched to an appropriate clinical scenario.

The requisitions were reviewed by expert panels and the appropriateness of the orders were rated on a scale from 1 to 9: 1 – 3, inappropriate; 4 – 6, uncertain; and 7 – 9, appropriate.

The researchers found that fewer than half of the requests for lumbar spine MRI were appropriate (443 out of 1,000). A total of 285 were inappropriately ordered and 272 were uncertain. Only post-operative leg or back pain was associated with an almost certain appropriate rating (160 of 167), but these orders comprised only 16.7 percent of the total requisitions.

Family physicians had the lowest rate of appropriate MRI orders of the lumbar spine. Only 33.9 percent of their scans were deemed appropriate, compared with 58.1 percent ordered by other specialists. Within the specialties, neurosurgeons had the highest rate of appropriate orders at 75.7 percent versus neurologists (48.2 percent were appropriate) and orthopedic surgeons (49.3 percent were appropriate).

On the other hand, 82.8 percent of head MRIs for headaches were deemed appropriate by the expert panel. Nine percent were considered to be inappropriate and 8.2 percent were uncertain. Family physicians ordered appropriate MRIs 78.5 percent of the time, neurologists or neurosurgeons 87 percent, and other physicians 89.1 percent.

The study authors noted that most patients who were complaining of headaches had already undergone CT imaging, which could explain the higher rate of appropriate MRI orders. 

The authors cautioned against generalizing these findings: “Since rates of appropriateness vary with indication and part of the body being imaged, we cannot assure there are universally high rates of inappropriateness,” they wrote. However, overuse of medical tests drive healthcare costs and can result in adverse outcomes. “Solutions will require strict adherence to appropriate guidelines and better education of patients.”