Ultrasound Microflow Imaging Technology for Diagnosis of Adhesive Capsulitis of the Shoulder

Abstract

Objectives To assess the diagnostic accuracy of Superb Microvascular Imaging (SMI; Canon Medical Systems, Otawara, Japan) at the subcoracoid triangle for adhesive capsulitis of the shoulder, to compare the diagnostic value of SMI with that of conventional ultrasound (US) and power Doppler ultrasound (PDUS) findings, and to investigate the correlation between vascular flow on SMI with clinical features. Methods Our study included 39 patients with a diagnosis of adhesive capsulitis and 35 healthy patients as a control group. The echogenicity in the rotator interval and coracohumeral ligament thickness were assessed with conventional US. Vascular flow in the subcoracoid fat triangle was evaluated with SMI and PDUS (SMI and PDUS areas). A receiver operating characteristic curve analysis was performed to evaluate diagnostic accuracy. The correlation between US findings and the range of motion, pain intensity, and duration of symptoms was also evaluated. Results The SMI area was higher in the adhesive capsulitis group than in the control group (2.95 versus 0 mm(2); P < .01). The visualization of vascular flow at the subcoracoid fat triangle was superior with SMI compared with PDUS (P < .01). In the receiver operating characteristic analysis, the SMI area showed higher diagnostic performance, with an area under the curve of 0.90 compared with other US findings. The area of SMI vascular flow was also negatively correlated with external rotation and forward flexion (P < .05) in the adhesive capsulitis group. Conclusions Measurement of vascular flow at the subcoracoid fat triangle using SMI facilitated the diagnosis of adhesive capsulitis. Superb Microvascular Imaging was superior to PDUS in diagnostic performance. Vascular flow was negatively correlated with the range of motion of external rotation and forward flexion.