Value of superb microvascular imaging ultrasonography in the diagnosis of carpal tunnel syndrome: Compared with color Doppler and power Doppler

The aim of this study was to compare the value of superb microvascular imaging (SMI) in carpal tunnel syndrome (CTS) with that of color Doppler ultrasonography (CDUS) and power Doppler ultrasonography (PDUS). Fifty patients with symptomatic CTS and 25 healthy volunteers were enrolled. The cross-sectional area (CSA), CDUS score, PDUS score, and SMI score of the median nerve (MN) at the carpal tunnel were recorded. The value of different ultrasonography (US) diagnostic strategies was calculated. The blood flow display ratio in the MN of the healthy volunteers had no statistical difference between CDUS, PDUS, and SMI (20%, 32%, and 48%, respectively, P >.05). The blood flow display ratio for SMI in patients was significantly higher than that of CDUS and PDUS (90%, 52%, and 60%, respectively, P <.005). The accuracy of SMI score ≥2 (79%) was much higher than that of CDUS and PDUS (61% and 63%, respectively, P <.05). Comprehensive consideration of SMI and CSA, CSA≥10.5 mm(2), and/or SMI score ≥2 has the highest accuracy (83%), significantly higher than that of CSA combination with CDUS or PDUS (68% and 69%, respectively, P <.05). SMI is more sensitive to display the blood flow in the MN with CTS than CDUS and PDUS. It might significantly improve the diagnosis value for CTS.