Diagnostic Value of an Additional Sequence (Large-Field Coronal Stir) in a Routine Lumbar Spine MR Imaging Protocol to Investigate Lumbar Radiculopathy

Abstract

Objective. Lumbar radiculopathy mainly originates in the spine (lumbar disc herniation or spine osteoarthritis) but can sometimes be explained by extra-spinal nerve compression or confused with referred pain mimicking radiculopathy. Our main objective was to demonstrate the clinical benefit of the large-field coronal STIR (coroSTIR) sequence in the etiological assessment of lumbar radiculopathy with a duration of more than six weeks. Materials and methods. Six hundred consecutive lumbar MRI scans performed using the same protocol were retrospectively reviewed. Two musculoskeletal radiologists independently assessed the coroSTIR sequence for the presence of extra-spinal anomalies (ESA) that could explain or contribute to the lumbar radiculopathy. The presence of an ESA was then correlated with sex, age, topography and lateralization of radiculopathy, history of vertebral surgery, as well as the presence of a spinal cause explaining the symptoms. Extra-spinal incidentalomas (ESI) with potential clinical impact visible only on the coroSTIR sequence were also systematically reported. Results. An extra-spinal cause was detected on the coroSTIR sequence in 68 cases (11.3%), mainly gluteal tendinobursitis (30.9%), congestive hip osteoarthritis (25%), degenerative sacroiliac arthropathy (14.7%), or inflammatory sacroilitis (7.3%). Their prevalence was significantly correlated in multivariate regression with age (58 years vs. 53 years, p = 0.01), but not with the type of radiating pain (sciatica or cruralgia). The presence of ESI was also frequent (70 cases, 11.7%), including some potentially severe diagnoses (38% of tumor or pseudo-tumor mass requiring further assessment or monitoring). Conclusions. Considering its acceptable acquisition time, the detection of a significant number of potentially symptom-related extra-spinal anomalies, and the discovery of a non-negligible number of extra-spinal incidentalomas with potential clinical impact, the coronal STIR should be performed systematically in routine MRI for lumbar radiculopathy.