Contrast-Enhanced Ultrasonography in Patients with Adhesive Capsulitis: Preliminary Experience

Abstract

Background: Imaging findings of adhesive capsulitis (AC) have been reported widely with the use of magnetic resonance imaging (MRI) and ultrasonography (US), although diagnosing AC is still based on clinical finding. However, the use of contrast-enhanced ultrasonography (CEUS) has not yet been reported in patients with AC. Objectives: To validate the application of CEUS in patients with AC, and to compare CEUS findings with those of MRI. Patients and Methods: Both shoulders of five patients with unilateral AC, who underwent MRI on the affected shoulder, were examined using CEUS (2 men, 3 women; mean age, 54.2 +/- 8 years). CEUS was performed after bolus administration of the contrast agent, SonoVue (Bracco, Milan, Italy), followed by a saline flush. Enhancement of the rotator interval was evaluated using a visual enhancement score (0 to 2) and compared with the contrast-enhanced MRI findings. For quantitative analysis, an region of interest was established for each rotator interval, and time-intensity curves were analyzed with parameters including time-to-peak and peak intensity. The difference of peak intensity between the affected and unaffected shoulders was compared. Results: Contrast enhancement of the rotator interval was notable in all CEUS of affected shoulders, whereas no evident enhancement was detected in all asymptomatic shoulders. The mean visual enhancement score of affected shoulders was 1.4 in CEUS and 2.0 in contrast-enhanced MRI. In quantitative analysis, the mean peak intensity was 5.45 +/- 2.80 dB (mean time to peak, 30.6 +/- 5.39 seconds) in affected shoulders, and 0.72 +/- 0.91 dB in unaffected shoulders (P < 0.05). Conclusion: CEUS was capable of demonstrating capsular inflammation in patients with AC, and this was comparable to MRI. CEUS could be a feasible imaging tool for evaluating patients with AC.