Reporting of Facet Joint Inflammation in Lumbar Spine MRI Studies in Patients With low Back Pain.

STUDY DESIGN:Retrospective. OBJECTIVE:We aimed to assess the frequency of facet joint inflammatory features noted in routine radiology reports of lumbar spine Magnetic Resonance Imaging (MRI) studies among patients with chronic low back pain. SUMMARY OF BACKGROUND DATA:Facet joint arthropathy is one of the most common causes of chronic low back pain. It may encompass various inflammatory imaging characteristics, such as facet joint effusion, bone marrow edema, and soft tissue edema. The extent to which radiology reports mention inflammatory features of the lumbar facet joints and the accuracy of these reports has not been investigated. METHODS:We performed a chart review on 49 subjects with previous facet-related interventions (i.e., medial branch blocks or intra-articular facet joint injection) and MRI available in the medical record. One senior musculoskeletal radiologist and a musculoskeletal radiology fellow graded the inflammatory features using a published facet joint inflammation grading system (gold standard). We identified the inflammatory markers mentioned in the radiology reports and calculated the sensitivity and positive predictive value of the radiology reports compared with gold standard readings. RESULTS:Compared with the gold standard, the sensitivity of radiology reports for facet joint effusion, bone marrow, and soft tissue edema ranged from 6% to 22%, and the positive predictive value ranged from 25% to 100%. L4/5 had the highest number of cases with inflammatory features noted on the reports. CONCLUSION:Inflammatory findings, such as facet joint effusion, bone marrow edema, and soft tissue edema, are not commonly identified in radiology reports. Further investigations are needed to determine the clinical importance of MRI-detected lumbar facet joint inflammatory features as a potential mechanism of nociception and as a predictor of outcomes following injections or other therapies.