- Imaging Psoas Sign in Lumbar Spinal Infections: Evaluation of Diagnostic Accuracy and Comparison with Established Imaging Characteristics
In this retrospective case-control study, the authors evaluated lumbar spine MR imagings during a 30-month period that were requested for the evaluation of discitis-osteomyelitis. Fifty age-matched control patients were compared with 51 biopsy-proved or clinically diagnosed patients with discitis-osteomyelitis. The investigators assessed the randomly organized MR imaging examinations for abnormalities of the psoas musculature, vertebral bodies, discs, and epidural space. Psoas T2 hyperintensity demonstrated high sensitivity (92%), specificity (92%), and positive likelihood ratio (11.5). They conclude that psoas T2 hyperintensity, the imaging psoas sign, is highly correlated with discitis-osteomyelitis.