High-resolution sonography of the undescended testis in childhood: an analysis of 45 cases.

: A prospective study correlating the ultrasound and operative findings was carried out in 45 consecutive pediatric patients with undescended testes. Thirty-six of 37 (97%) palpable testes were located preoperatively by ultrasound. Six of eight impalpable testes (75%) were correctly localized by ultrasound. The three testes missed by the ultrasound examination were found to be atrophic at surgery. Three intra-abdominal (palpable) testes were found at surgery just proximal to the internal ring; all three had been identified by ultrasound preoperatively. The main contribution of ultrasound was the preoperative detection of impalpable testes (six of eight), which modified the consequent surgical approach. Ultrasound also helped in providing objective support to the clinical diagnosis in 36 of 37 children with palpable undescended testes. The ultrasound examination is noninvasive, nonionizing, readily available and of low cost. It is therefore suitable as the initial routine procedure for the evaluation of undescended testis.