Diagnostic Accuracy of Magnetic Resonance Imaging for Localizing Testes in Cases of Cryptorchidism

Aim: To determine the diagnostic accuracy of MRI for localizing undescended testes in clinically detected cases of cryptorchidism taking surgical findings as gold standard. Study design: Cross-sectional survey Methods: It was a cross-sectional survey. Patients were recruited by non probability purposive sampling technique. One hundred and seventy clinically and ultrasonically (superficial linear 7.5 MHZ transducer with AU5 Harmonic EZAOTI) diagnosed cases of non palpable undescended testes having age ranged between 0-16 years were selected from the Department of Diagnostic Radiology, The Children's Hospital and Institute of Child Health, Lahore during the period of six months from 03-08-2007 to 02-08-2009. Children having ambiguous genitalia on clinical examination and Boys not fit for anesthesia or surgery were excluded from study. MRI of all cases using 1.5 Tesla MR System was performed. Results: The age of the patients ranged between 0-16 years. Mean age of the patients was 5.1 +/- 2.3 years. According to the side affected, there were 49 cases (28.8%) on right side, 93 cases (54.7%) on left side and 28 cases (16.5%) bilateral. Comparison of the results of MRI with surgical findings showed that there were 127 true positive cases, 3 false positive cases, 27 false negative cases and 13 true negative cases. Statistical analysis of the study revealed sensitivity 82.4%, specificity 81.2%, diagnostic accuracy 82.3%, positive predictive value 97.6%, and negative predictive value 32.5% of MRI for localizing undescended testes in clinically detected cases of cryptorchidism taking surgical findings as gold standard. Conclusion: It is concluded that magnetic resonance imaging (MRI) offered a new promising imaging modality for localization of the undescended testis because it has better resolution, multiplanar capability, different sequences and is also non-hazardous and safe.