[Preoperative magnetic resonance imaging in the management of the nonpalpable testis]

We evaluated the efficacy of magnetic resonance imaging (MRI) as the preoperative study in the management of the nonpalpable testis. From 1997 to 2005, a total of 41 MRI was performed for the patients with nonpalpable testis and 42 testes were evaluated. The MRI showed 19 testes from 18 patients in the inguinal region. Eighteen testes were found in the inguinal region and one was intraabdominal during groin exploration. Six testes were pointed out to be intra-abdominal by MRI. Five testes were identified in the abdomen and one was disclosed to be vanishing testis. Seventeen testes could not be detected by MRI and they underwent laparoscopic or groin exploration. Four abdominal testes were identified. Thirteen patients had a diagnosis of vanishing testis. The sensitivity and the specificity of our MRI studies in predicting the presence of nonpalpable testis were 85.7% and 92.9%, respectively. Enlarged lymph node could be misdiagnosed as abdominal testis. Inguinal undescended testes can be diagnosed accurately with MRI. MRI is informative regarding the testis location and useful for limiting the area of surgical exploration.