Comparison of Microvascular Flow Imaging With Other Doppler Methods in Ultrasonography for Assessment of Parenchymal Perfusion in Undescended Testis in Young Children

Background: Cryptorchidism is a common congenital anomaly in male children, where accurate assessment of testicular vascularity is important for imaging evaluation and characterization of intratesticular blood flow. Conventional Doppler techniques have limitations in detecting low-velocity microvascular flow, particularly in small pediatric testes. These limitations may affect the ability to adequately visualize subtle vascular signals using standard ultrasound techniques. Methods: This cross-sectional study was conducted at a tertiary care center over six months and included 40 children aged less than five years with clinically diagnosed undescended testis (UDT). Ultrasonography was performed using a high-frequency (2-14 MHz) linear probe of Samsung V7 (Samsung Medison Co., South Korea). Each patient underwent evaluation with Color Doppler (CD), Power Doppler (PD), and Microvascular Imaging (MVI). Doppler settings were optimized (CD/PD pulse repetition frequency (PRF): 520-1000 Hz, MVI PRF: 210 Hz). Intratesticular vascularity was assessed and graded for each modality. Statistical correlation was done using Wilcoxon signed-rank test and McNemar test. Results: CD detected intratesticular flow in 55% of cases, while PD detected flow in 70%. Both color MVI (cMVI) and monochrome MVI (mMVI) demonstrated significantly higher detection rates (95%). Comparison showed statistically significant superiority of MVI over CD. Although cMVI and mMVI demonstrated similar flow detection rates, mMVI showed a higher proportion of Grade 3 vascularity, indicating superior visualization of intratesticular microvascular flow. Conclusion: In this prospective study, MVI, particularly mMVI, demonstrated significantly higher intratesticular vascularity grades than conventional CD and PD ultrasonography. mMVI consistently yielded the highest perfusion scores across different anatomical locations of UDT, indicating enhanced visualization and grading of intratesticular microvascular flow. These findings suggest that MVI may serve as a valuable adjunct to conventional ultrasonography in the assessment of testicular perfusion in children with UDT.