Diagnostic accuracy of plain radiography compared with MRI in adults with non-traumatic low back pain

Abstract

Background. Low back pain (LBP) is among the most prevalent musculoskeletal disorders globally and contributes significantly to disability, reduced productivity, and increased healthcare utilization. In Iraq, the burden of LBP is substantial, and timely and accurate diagnosis is critical for effective management. Despite their limitations in detecting certain pathologies, plain radiographs remain widely used owing to their low cost and accessibility. This study aimed to assess the diagnostic accuracy of plain radiographs compared with magnetic resonance imaging (MRI) in identifying non-traumatic causes of LBP. Methods. A cross-sectional comparative study was conducted at the Radiology Center in Basra, Iraq, involving 244 adult patients with non-traumatic LBP. Each participant underwent plain radiography and MRI. Demographic and clinical data, including age, sex, occupation, work history, comorbidities, and history of spinal disease, were collected. Imaging findings were compared to evaluate the ability of plain radiographs to detect vertebral involvement, using MRI as the reference standard. Results. Plain radiographs demonstrated moderate-to-high sensitivity in identifying gross bony abnormalities, advanced degenerative changes, and vertebral deformities. However, their diagnostic accuracy was limited for detecting intervertebral disc disease, bone marrow edema, and early degenerative or inflammatory changes. MRI was more effective in identifying subtle soft tissue and early spinal pathologies. Conclusion. MRI remains the superior modality for comprehensive assessment of non-traumatic LBP, while plain radiographs offer value as a rapid, cost-effective, and accessible first-line diagnostic tool, particularly in resource-limited settings. Plain radiography may support preliminary evaluation; however, MRI should be prioritized when advanced intervention is anticipated or when early inflammatory, neural, or soft tissue pathology is suspected. Further large-scale studies are warranted to validate these findings and inform diagnostic strategies in similar healthcare contexts.