Association of testicular MRI findings with spermatogenic status and intratesticular sperm in patients with azoospermia or cryptozoospermia

BACKGROUND: The pathophysiology and presence of intratesticular sperm in patients with azoospermia are usually assessed based on clinical findings, hormonal evaluation, and ultrasonography; however, assessment based on these conventional examinations does not always yield an accurate diagnosis. OBJECTIVES: We focused on magnetic resonance imaging (MRI) and aimed to investigate the association between testicular MRI findings, spermatogenic status, and the presence of intratesticular sperm in patients with azoospermia or cryptozoospermia. Methods: Thirty-three patients (45 testes) who underwent preoperative testicular magnetic resonance imaging (MRI) and intraoperative testicular biopsy during varicocelectomy or testicular sperm extraction were included in this study. Associations between the apparent diffusion coefficient (ADC) values of testes and clinical parameters were analyzed. RESULTS: Among the 33 patients (45 testes) included in the analysis, normalized ADC values showed significant positive correlations with serum follicle-stimulating hormone (FSH) (rs = 0.366, p = 0.015) and LH (rs = 0.414, p = 0.006), and a significant negative correlation with Johnsen's score count (JSC) (rs = -0.377, p = 0.0088). No significant correlation was observed between ADC values and total testosterone (TT) concentration or testicular volume (TV). ADC values were significantly higher in testes without intratesticular sperm (p < 0.000005). Receiver-operating characteristic (ROC) analysis yielded an area under the curve (AUC) of 0.667 for predicting the presence of intratesticular sperm, using a cutoff ADC value of 0.382×10-3 mm2/s (sensitivity 0.686, specificity 0.8). CONCLUSIONS: These findings suggest that testicular MRI findings are associated with spermatogenic status and the presence of intratesticular sperm and may provide complementary information when combined with other clinical parameters.