Emerging Magnetic Resonance Imaging Technologies for Musculoskeletal Imaging Under Loading Stress: Scope of the Literature

Imaging under loading stress is hypothesized to improve the diag-nostic value of magnetic resonancel imaging (MRI) for musculo-skeletal conditions. This article reviews 57 studies about MRI under physiologic loading stress performed in an upright or sitting position or under axial loading by using a compression device. The most commonly imaged regions were the spine (33 studies) and knee (13 studies). Most studies had a cross-sectional (n 37) or case– control (n 13) design and reported on anatomical measurements rather than patient-relevant end points. Studies were generally small: The median (25th, 75th percentile) number of case patients was 26 (17, 45), and the median (25th, 75th percentile) number of control participants was 13 (12, 20 for case–control studies). Fif-teen of 57 studies used at least 2 imaging tests and reported on diagnostic or patient-relevant outcomes but did not report mean-ingful information on the relative performance of the tests. In 10 studies that included information on adverse effects, 5 % to 15 % of participants reported new-onset or worsening pain and neuropathy during MRI under loading stress. Overall, evidence is insufficient to support the clinical utility of MRI under loading stress for muscu-loskeletal conditions. Ann Intern Med. 2011;155:616-624. www.annals.or