Abstract Background: Low back pain (LBP) is a paramount global cause of disability. While magnetic resonance imaging (MRI) is pivotal for excluding serious pathology, the high prevalence of age-related degenerative findings in asymptomatic populations complicates its interpretation. Data on the specific distribution and yield of MRI findings in Middle Eastern clinical cohorts are limited. The objective was to quantify the prevalence and distribution of lumbosacral MRI abnormalities in a Saudi cohort with chronic LBP and to examine variations across referral sources and age. Methods: A retrospective, cross-sectional analysis was conducted on 1,574 consecutive adults with chronic LBP referred for lumbosacral MRI. MRI reports were classified as "positive" (any abnormality) or "negative." Prevalence rates and 95% confidence intervals were calculated. Age differences were analyzed using t-tests. Results: The overall positivity rate was 84% (1,318/1,574). Positivity was highest in orthopaedics (86.6%) and neurosurgery (86.9%) and lowest in the chronic pain clinic (72.2%). Patients with positive findings were significantly older than those with negative findings (mean age 51.8 vs. 37.8 years; p<0.001), a trend consistent across all referral sources. Degenerative disc disease was the predominant finding, comprising 78% of all abnormal scans. Conclusion: In this Saudi cohort, MRI abnormalities were highly prevalent, strongly associated with increasing age, and most frequently identified in surgical specialties. These findings underscore the necessity of guideline-adherent, selective imaging and age-aware interpretation to optimize clinical utility and resource allocation.
Keywords: low back pain; magnetic resonance imaging; degenerative disc disease; prevalence; diagnostic yield; Saudi Arabia