Diagnosis of nonpalpable testes in childhood: comparison of magnetic resonance imaging and laparoscopy in a prospective study.

In a prospective study, the accuracy of magnetic resonance imaging (MRI) and laparoscopy in the diagnosis of nonpalpable testes was evaluated. Advantages and disadvantages of the two procedures were compared. 29 boys with unilateral nonpalpable testis underwent MRI. When MRI failed to demonstrate a testis, laparoscopy with a 1.9 mm mini-laparoscope was performed. All cases were verified by operative exploration of the inguinal region. MRI demonstrated 10 inguinal and 7 abdominal testes. MRI revealed no testis in 12 boys. The false positive rate was 32%, correct negative findings were confirmed in four patients. When laparoscopy was performed, preservable testis could be demonstrated in 8 of 12 patients (1 abdominal, 7 inguinal) which otherwise were not visible on MRI. The correct positive rate was 100%. We encountered no complications with laparoscopy. In summary, laparoscopic evaluation is recommended as the preferable method in pediatric cases of nonpalpable testes.