An appraisal and comparative analysis of superb microvascular imaging with conventional ultrasound and MRI for greater trochanteric pain syndrome management

Abstract

Greater trochanteric pain syndrome (GTPS) is a common cause of hip pain and is often associated with chronic lower back pain and lower extremity osteoarthritis. Its diagnosis is clinical; however, imaging has been shown to aid in the differential diagnosis of challenging cases. Superb microvascular imaging (SMI) is a new technique that may be more effective than power Doppler ultrasonography (PDUS) in the detection of inflammation-related vascularity in patients. In this study, we aimed to compare the diagnostic accuracies of SMI and PDUS in patients with GTPS and evaluate the usefulness of these techniques in clinical practice. We recruited 37 GTPS patients and 15 healthy volunteers for participation in this study. PDUS and SMI examinations were performed and we retrospectively reviewed the magnetic resonance imaging scans for tendinosis, tears, and edema. The PDUS and SMI were positive in 19 and 31 hips, respectively. Both techniques had low sensitivity but high specificity and positive predictive values, with SMI being slightly better. PDUS and SMI had accuracies of 75% and 82.7%, respectively, with a grade 1 vascularization threshold. Moreover, magnetic resonance imaging detected peritendinous edema with an accuracy of 60.5%, including tendinosis and partial tears but not complete tendon tears. Our study showed that PDUS is an underutilized modality in the diagnosis of GTPS and that SMI may further improve diagnostic accuracy. However, the low sensitivity of both techniques suggests that a clinical diagnosis remains essential.