According to an investigation published Online First by the Archives of Internal Medicine, one of the JAMA/Archives journals, magnetic resonance imaging (MRI) prior to administration of epidural steroid injections (ESI), does not seem to improve outcomes for individuals with chronic lower back pain or for those with conditions like sciatica, and only has a small effect on the physician’s decision making.

In the report the researchers explain:

“Lower back pain is the number one cause of disability in the world, and one of the top three reasons people seek medical attention.

Despite several studies demonstrating that advanced radiologic testing does not improve outcomes in patients with lower back pain, with or without radicular symptoms [nerve irritation, characterized, for example, by pain radiating down the back of the leg], the use of MRI in this context continues to soar.

The lack of unequivocal guidelines on the use of MRI before ESI is somewhat unexpected, considering that ESI is the most frequently performed procedure in pain clinics throughout the United States.”

A multi-center randomized study was conducted by Steven P. Cohen, M.D., from Johns Hopkins School of Medicine, Baltimore and his team. A total of 132 patients, primarily women (57%) with an average age of 52, were enrolled to participate in the study.

The researchers randomly assigned participants to two groups. In one group the treating physician was blinded to the MRI results, while for group two the physician decided on treatment after reviewing the MRI findings.

For participants in group one, an independent doctor reviewed the MRI findings and recommended a treatment plan, the plan was then compared to the treatment the participant actually received. All participants in group one received ESIs. In group two not all participants received ESIs, if the MRI finding did not support the treatment, at which point the participant discontinued with the investigation. 34% of all participants were taking opioids. Pre-procedure leg pain scores and function showed moderate to severe dysfunction.

The researchers state:

“Slightly lower leg pain scores were noted in group two at one month compared with MRI-blinded patients in group 1. No differences were observed in pain scores or function at three months.

Overall, the proportion of patients who experienced a positive outcome was similar at all time points (35.4 percent at three months in group one vs. 40.7 percent in group two.

For the patients in group one who received a different injection that was proposed by the independent physician, scores for both leg pain (4.8 vs. 2.4) and function (38.7 vs. 28.2) were inferior to patients whose injection correlated with imaging.

Collectively, 6.8 percent of patients did not (group two) or would not have (group one) received an ESI after the MRI was reviewed.”

The team conclude:

“In conclusion, our results suggest that although MRI may have a minor effect on decision making, it is unlikely to avert a procedure, diminish complications, or improve outcomes. Considering how frequently ESIs are performed, not routinely ordering an MRI before a lumbosacral ESI may save significant time and resources.”

In a commentary associated with the report, Janna Friedly, M.D., from the University of Washington, Seattle, and Richard A. Deyo, M.D., M.P.H., from Oregon Health and Science University, Portland, Ore., explain:

“Given the modest benefits of epidural injections themselves, it may not be surprising that the benefit of imaging prior to injection is hard to demonstrate.

Although the overall results of this study were largely negative, they suggest a small benefit to using MRI to guide epidural steroid injection planning in patients with lumbar radiculopathy. Use of MRI may have reduced the total number of injections required and may have improved outcomes in a subset of patients.

Given these potential benefits as well as concerns related to missing important rare contraindications to epidural steroid injection, it seems premature to counsel against guideline recommendations for obtaining MRI prior to consideration of epidural steroid injections.

In the meantime, cost savings and clinical benefit might result from discouraging epidural injections in conditions for which efficacy is unclear, such as spinal stenosis and low back pain without radiculopathy. More prudent patient selection may help offset the costs of obtaining advanced imaging prior to injection for those in whom a treatment benefit is more likely.”

Written by Grace Rattue