MRI has limited accuracy in diagnosing complex regional pain syndrome Type 1 - a systematic review of the literature

Objectives To review the current body of research on the diagnostic accuracy of magnetic resonance imaging (MRI) in Complex Regional Pain Syndrome (CRPS) Type 1.Material And Methods A systematic search was conducted across MEDLINE, Embase, Cochrane, Scopus, and Web of Science from their inception to September 2023, following PRISMA guidelines. Risk of bias was assessed for all included studies, sensitivity and specificity values were extracted from studies with comparative data.Results Fifteen studies published between 1991 and 2022, involving 562 patients (353 with CRPS Type 1 and 209 controls), were included in the qualitative synthesis. Four comparative studies provided sufficient data to calculate diagnostic performance. Reported sensitivity ranged from 6 % to 91 %, and specificity from 50 % to 100 %, demonstrating substantial heterogeneity. Bone marrow edema was the most frequently reported MRI feature, particularly in early disease stages. Most studies had a high risk of bias due to inconsistent diagnostic criteria, non-standardized imaging protocols, and incomplete clinical and demographic reporting. Comparative studies showed inconsistent diagnostic performance, while non-comparative studies revealed variable MRI findings across different CRPS Type 1 presentations.Conclusion MRI is not accurate in diagnosing CRPS Type 1, with a lack of consistent findings across studies. While it may assist in differential diagnosis, its utility as a standalone diagnostic tool is very limited.Clinical Relevance Statement MRI can be used as an adjunct to clinical assessment for CRPS Type 1 to exclude alternative diagnoses and guide management but lacks the diagnostic accuracy to diagnose CRPS Type 1.