Abstract
PURPOSE: Magnetic resonance imaging (MRI) is the gold standard investigation for lumbosacral degenerative disc disease. However, there is controversy regarding the clinical value of repeating an MRI scan within 12 months when a patient presents with recurring or changing symptoms. This study measures rates of radiological change in a real-world cohort to guide clinicians when deciding to repeat a scan. METHODS: All patients over a 10-year window in one general hospital who underwent two lumbosacral MRI scans for degenerative disc disease within 12 months of each other were included in the study. All MRI reports were manually reviewed. The level of main vertebral pathology was recorded, along with the location of a disc prolapse. Time intervals between the two scans were calculated, and these were collated into 30-day intervals for analysis. The repeat scans were categorized into three groups: no change, radiological improvement, and radiological deterioration. Patients who had clinically significant deterioration in the form of cauda equina compression on MRI scans were recorded. FINDINGS: Four hundred and eighty-one patients were included for analysis. Three hundred and ninety (81%) showed no change in MRI findings, 18 (3.7%) had improvements in their repeat scans, and 73 (15.3%) demonstrated deterioration in their repeat scans. Of the 73 patients with radiological deterioration, three patients (0.62% of the total) required urgent surgical intervention for cauda equina syndrome (CES). CONCLUSIONS: Though there is no alternative to detailed clinical assessment in determining whether a repeat MRI scan is indicated, the findings demonstrate that repeating MRI within 12 months for patients with lumbosacral degenerative disc disease has a low chance of altering the management plan. Over the 10-year period, only three patients required an urgent change to their clinical management. We believe this data can help guide clinical decision-making when considering a repeat scan.