Microvascular imaging ultrasound (MicroV) and power Doppler vascularization analysis in a pediatric population with early scrotal pain onset

Introduction: The power Doppler is a useful tool in the evaluation of pediatric acute scrotal pain. Nonetheless, it may have some inherent limitations in scrotal vascularization analysis, potentially causing unnecessary surgery. The microvascular imaging ultrasound (MicroV) is an innovative Doppler technique able to improve the detection of very low flow. This retrospective study aims to compare both power Doppler and MicroV in the evaluation of a pediatric population with early-stage scrotal pain onset, first in testis vascularization analysis, and second in their diagnostic performances. Materials and methods: 69 patients met the following inclusion criteria, age < 18-year-old, a clinical diagnosis of acute scrotal disease, pain onset ≤ 6 h, ultrasound examination (including B-mode, power Doppler, and MicroV), 3-months follow-up. For both power Doppler and MicroV, through a defined vascularization scale, it was evaluated the agreement in vascularization detection, and the sensitivity and specificity in US diagnostic abilities. Results: Retrospective diagnoses were of 8 testicular torsion, 15 orchi-epididymitis, and 46 children with other scrotal conditions. Power Doppler provided inconclusive US evaluation in 37.68% of the cases, while MicroV only in the 1.45% (p < 0.0001). Testicular torsion and orchi-epididymitis were identified, respectively, with MicroV in 100% (sensitivity, specificity, PPV, NPV, and accuracy of 100%) and 80% of patients (80% sensitivity, 100% specificity and PPV, 94.73% NPV, 95.65% accuracy); with power Doppler the identification was, respectively, of 87.5% (87.5% sensitivity, 100% specificity and PPV, 98.38% NPV and accuracy) and of 73.3% (73.33% sensitivity, 98.14% specificity, 91.66% PPV, 92.98% NPV, 92.75% accuracy). Conclusions: Our findings indicate that MicroV is a reliable technique in vascularization detection of pediatric testes, being able also to detect vascularization in healthy testicles with no-flow at power Doppler examination. Moreover, MicroV could be a valuable ally in the US diagnostic of children with early-stage scrotal pain onset.