The role of magnetic resonance imaging in the investigation of undescended testes.

The location of undescended impalpable testes is important because of the greatly increased risk of malignancy. Various imaging methods have been used in the past with only partial success. In many cases an exploratory laparotomy has been performed although even this has not proved completely successful. We describe the use of magnetic resonance imaging (MRI) in six adults with eight undescended testes. We were able to detect the position of six of the eight testes by this method. MRI does not use ionising radiation and is a useful method of locating these radiosensitive organs.