A novel parameter by EFOV US for the quantification and the distinction of physiological amount of scrotal fluid and hydrocele:Ratio of testis volume/scrotum volume

摘要

Objective: To determine the limits for the amount of tunical fluid enough to be termed as hydrocele by using extended-field of view US technology and to define hydrocele for the first time with standard numerical criteria.Methods: A total of 60 patients were evaluated in this prospective study. Group 1 consisted of 20 patients with unilateral clinical hydrocele. Group 2 included 20 patients referred for scrotal US for reasons other than hydrocele.Group 3 comprised 20 male controls with no scrotal complaints.Testis volume (V_t), scrotum volume (Vs) and V_t/V_s ratio were calculated for each subject by dimensions measured in longitudinal and tranverseplanes.Results: Mean Vt/V,ratio was 0.28+-0.17 (range, 0.07-0.57),0.69+-0.08 (range,0.53-0.80) and 0.71 +-0.07 (range, 0.61-0.85) for groups 1,2 and 3,respectively.Mean V_t/V_s for group 1 was significantly lower than those for groups 2 and 3, respectively (p< 0.001 for each).Based on theROC curve analysis, 0.55 for V_t/V_s ratio was determined as the optimal cut-off point below which the US diagnosis of hydrocele could be made(sensitivity 95.0percent and specificity 97.5percent).Conclusions: We propose a novel US parameter of V_t/V_s ratio below 0.55 for a standard distinction between hydrocele and physiological amountof scrotal fluid.