The impact of preoperative ultrasound on correct diagnosis of urachal remnants in children

BackgroundUltrasound is a noninvasive imaging method used widely in urachal diagnostics. This study investigated the effectiveness of ultrasonography in correctly depicting urachal anomalies in children.MethodsPreoperative ultrasound findings of all patients who were operated on for suspected urachal anomalies between 1990 and 2008 were retrospectively compared with the final diagnosis.ResultsFifty-three patients (31 female, 22 male; ∼2.6 years; range, 0-17 years) were reviewed. In 37 patients, the final diagnosis of an urachal anomaly matched the ultrasound findings. In 7 patients, there was a false-positive ultrasound finding, and in 9 patients, there was a false-negative ultrasound finding. Three of 4 patients with urachal cysts, 23 of 29 patients with urachal fistulas, and 8 of 10 patients with urachal sinuses were correctly identified by ultrasonography. In 10 patients, no urachal rests were found intraoperatively: in 7 of these patients, urachal rests were falsely suspected by ultrasound. The positive predictive value for ultrasound is 83%, whereas the negative predictive value is 25%. The sensitivity for this diagnostic method is 79% and the specificity 30%.ConclusionsUltrasound helps to identify urachal anomalies in case of their presence but is not helpful to rule out a nonexisting urachal anomaly.