Seeing the Unseen: Evaluating Testicular Vascularity in Neonates by Using the Superb Microvascular Imaging Ultrasound Technique

Objectives To evaluate testicular vascularity in neonates by using the novel Superb Microvascular Imaging (SMI; Toshiba Medical Systems Corporation, Tokyo, Japan) ultrasound (US) technique and to compare this technique to conventional Doppler US techniques. Methods A total of 140 healthy neonates between 2 and 60 days old who were admitted for routine screening were included in the study. However, in 9 cases, the Doppler study could not be completed. In the remaining 131 cases, color Doppler imaging (CDI), power Doppler imaging (PDI), Advanced Dynamic Flow (ADF; Toshiba Medical Systems), and monochrome SMI (mSMI) techniques were performed on a single representative testicle. Real-time cine images were captured for 5 to 10 seconds for each technique by using a high-frequency (7.2-14-MHz) linear transducer. The images were evaluated by 3 observers using a grading system to quantify the degree of vascularity and artifact interference. Results A total of 131 testicles (74 right and 57 left) were evaluated, and vascularity was shown in 110 (84%) testicles with CDI, 109 (83%) with PDI, 94 (72%) with ADF, and 128 (98%) with mSMI by the consensus of all observers. The Doppler techniques were ranked from highest to lowest in the following order based on the degree of vascularity detected: mSMI > PDI > CDI > ADF (P < .001). Based on the presence of artifacts, the Doppler techniques were ranked as follows from high to low: ADF > CDI > PDI > mSMI (P < .001). Conclusions Superb Microvascular Imaging is a promising US technique that appears to detect testis vascularity better than conventional Doppler US techniques; however, further research is needed to support the results of this study.