Cryptorchidism. Evaluation with MR imaging

Aim: Evaluation of magnetic resonance imaging (MRI) for localisation of nonpalpable testes. Materials and methods: 17 boys aged 11 months - 9 years with 20 undescended testes were included in this study. MR imaging was performed on a 1.0-T system (Magnetom Expert, Siemens, Erlangen). Localizations were divided in: intraabdominal testis, high inguinal testis,lower inguinal testis. Definitive localization was obtained by laparoscopy or open surgery in all patients. Results: Surgically localized undescended testes and anorchia (1 pat.) were previously identified with MR imaging in 16 of 20 nonpalpable testes (80%). 2 undescended testes could not be localized with MRI. In two cases of unilateral absence, an inguinal lymph node was mistaken for a testis. Summary: 1. MRI has an accuracy of 80% in localization-diagnosis of nonpalpable testis. 2. MRI is not able to differentiate sufficiently between an anorchidism and a cryptorchidism. Endoscopic diagnostic techniques can not be replaced by MRI. 3. If an endoscopic procedure is intended in a routine case, MRI is not necessary for preoparative diagnosis.