Findings of fat-suppressed T2-weighted and diffusion-weighted magnetic resonance imaging in the diagnosis of non-palpable testes

What's known on the subject? and What does the study add? Both conventional magnetic resonance imaging (MRI) and ultrasonography (US) have been used for children with non-palpable testes to facilitate a preoperative diagnosis, but the accuracy of these examinations was not satisfactory. In the present study, to improve the diagnostic accuracy of non-palpable testes by MRI examination, we employed fat-suppressed T2-weighted imaging and DWI, as well as conventional MRI. Additional MRI assessments are useful methods to improve the accuracy of diagnosing non-palpable testes. OBJECTIVE To evaluate the magnetic resonance imaging (MRI) findings, diagnostic accuracy and clinical usefulness of fat-suppressed T2-weighted and diffusion-weighted imaging (DWI) in the management of non-palpable testes. PATIENTS AND METHODS In all, 56 children (63 non-palpable testes) aged 8 months-11 years (mean 24.7 months) with non-palpable testes were enrolled. T1- and T2-weighted imaging, as well as fat-suppressed T2-weighted imaging and DWI were performed during MRI examination, and the imaging results were compared with surgical findings. RESULTS In the 63 non-palpable testes, MRI identified 22% (14/63) as intra-abdominal, 20% (13/63) as intra-canalicular, 29% (18/63) as testicular nubbins, and 29% (18/63) as unidentifiable. Although it was difficult to confirm their presence in the abdominal cavity using T1- and T2-weighted imaging alone, additional assessment, including fat-suppressed T2-weighted imaging and DWI facilitated the detection of intra-abdominal testes more easily because they were imaged at a markedly higher signal intensity. The sensitivity, specificity and positive and negative predictive values for the MRI vs the operative findings were 100, 97.3, 96.3, and 100%, respectively. The overall prediction accuracy was 98.4%. CONCLUSION Additional MRI assessments, fat-suppressed T2-weighted imaging and DWI are useful examinations to improve the preoperative diagnostic accuracy of non-palpable testes.