Reliability of Evaluating Lumbar Paraspinal Muscles Using Magnetic Resonance and Computed Tomography Imaging in Adults With and Without Low Back Pain: A Systematic Review and Meta-Analysis

OBJECTIVE: To evaluate the reliability of magnetic resonance imaging (MRI) and computed tomography (CT) for assessing lumbar paraspinal muscles (LPMs) in adults with and without low back pain (LBP). DESIGN: Systematic review and meta-analysis following PRISMA of Diagnostic Test Accuracy. LITERATURE SEARCH: Searches of Medline, Embase, PubMed Central, Science Citation Index Expanded, Emerging Sources Citation Index, Social Sciences Citation Index, and the KCI-Korean Journal Database were conducted in 2022 and updated in 2024, without date restrictions. STUDY SELECTION CRITERIA: Studies reporting the reliability of MRI and/or CT for assessing the size and/or quality of the erector spinae, multifidi, quadratus lumborum, and/or psoas in adults, with/without LBP, were included. Two reviewers independently selected the studies. DATA SYNTHESIS: Studies reporting intraclass correlation coefficients (ICCs) were included in random-effects meta-analyses. All LPMs were analyzed in adults with and without LBP, followed by muscle-specific analyses regardless of LBP status. RESULTS: Seventy-three MRI and thirteen CT studies were included. Most studies assessed the erector spinae and multifidi at lower lumbar levels and underreported reliability methods. Fifty-seven MRI and nine CT studies were included in meta-analyses. MRI demonstrated excellent reliability for evaluating LPM size and quality in adults with/without LBP (ICCs: 0.922–0.983). CT assessments showed good-to-excellent reliability (ICCs: 0.839–0.994), based on ≤4 studies. Muscle-specific meta-analyses confirmed excellent reliability for MRI (ICCs: 0.931–0.977) and CT (ICCs: 0.929–0.970). CONCLUSION: LPM assessments using MRI and CT demonstrate excellent reliability regardless of LBP status. However, limited CT evidence and underreported methodology highlight the need for additional research and improved reliability.