The majority of interventional spine physicians reported using magnetic resonance imaging (MRI) ahead of lumbar epidural steroid injections (ESIs) to correlate with the physical examination, among other reasons, and to change clinical management decisions regarding the planning and delivery of lumbar ESIs, based on MRI findings, according to a report published in the Spine Journal.
Although MRI is the gold standard for evaluation of lumbar spine structural pathology, there remains uncertainty regarding its necessity and utility before spinal interventions such as ESI, with few studies examining how often advanced imaging affects treatment decisions.
Researchers conducted 3 separate studies examining the data of patients who presented with leg or back pain and were candidates for spinal intervention: a physician survey (n=2960), a retrospective chart review (n=235; mean age, 58.1 years), and a prospective analysis (n=100; 58.0% women). For the survey, physicians were asked to answer a questionnaire regarding their rates of and reasons for ordering MRIs ahead of planned ESIs. The retrospective review was a comparative assessment of the initial injection plan and the actual procedure performed after examining MRI scans. The prospective study compared pre- and post-MRI injection plans.
A total of 249 (8.4%) spine physicians responded to the survey, a majority of whom were anesthesiologists and physiatrists (86%). Prelumbar injection MRI was ordered in 33% of cases compared with 64% and 54% for cervical and thoracic pathologies, respectively. When ordered, MRIs were used for physical exam correlation (91%) and detection of synovial cysts (68%). Identification of infection or tumor (93%) was the most frequent reason for altering injection plans; other common reasons included finding different spinal levels (61.4%) or nerve roots (47.0%) affected than initially suspected.
The procedure carried out after viewing MRIs matched the initial injection planned in 49.8% of cases (n=117), according to the retrospective analysis. In 15.3% (n=36) of cases, specialists performed a different procedure than initially planned, and in 34.9% of cases (n=82), the original injection plan was altered (ie, on a different level, 67.1%; on an additional side, 34.1%).
In the prospective study, 43% of performed injections were found to differ from the initial clinical management decision after viewing MRI results, with 24.0% and 19.0% resulting in different and altered procedures, respectively. Transforaminal ESI (67%) was most frequently planned injection before MRI, and the most common rationales for changing the injection plan were facet pathology (22%) and different levels (36%) or nerve roots (16%) being affected.
Study limitations include a low response rate, selection bias, lack of follow-up, retrospective design, lack of consistent documentation regarding injection plan alterations, lack of evaluation of injection outcomes, and possible confounding by symptom change.
“This study demonstrates that MRI results do frequently alter injection plan, most commonly due to different spinal level affected, presence of synovial cysts or other facet pathology, or the absence of pathology,” noted the authors.
Akuthota V, Meron AJ, Singh JR, et al. The utility of magnetic resonance imaging results in physician decision-making before initial lumbar spinal injection [published online April 19, 2019]. Spine J. doi:10.1016/j.spinee.2019.04.016