The imaging psoas sign is an MRI finding specific for spondylodiscitis and is seen as T2 hyperintensity in the psoas major muscle. The sign has a high sensitivity (92%) and specificity (92%) for spondylodiscitis and in the clinical context of a suspected infective process of the spine supports confidence in diagnosing spondylodiscitis 1.
History and etymology
The imaging psoas sign was first described in 2016 by Luke Ledbetter, an American neuroradiologist and colleagues 1.
1. Ledbetter LN, Salzman KL, Shah LM. Imaging Psoas Sign in Lumbar Spinal Infections: Evaluation of Diagnostic Accuracy and Comparison with Established Imaging Characteristics. (2016) AJNR. American journal of neuroradiology. 37 (4): 736-41. doi:10.3174/ajnr.A4571 - Pubmed