Quantification of testicular fat deposition in the evaluation of middle-aged overweight male infertility.

OBJECTIVES

To measure the testicular volume and testicular fat deposition of middle-aged overweight men and to assess the utility of testicular fat deposition and testicular volume in determining and monitoring testicular infertility.

MATERIALS AND

METHODS

Pelvic MRI with thin slice T2WI, T1WI and mDIXON Quant was performed on 30 middle-aged overweight patients in the treatment group and 30 middle-aged overweight men in the control group. Testicular volume and testicular fat deposition were measured separately based on thin slice T2WI and the fat fraction (FF) map of mDIXON Quant, and the testicular fat deposition observed with T1WI was used as a reference for qualitative diagnosis. Testicular volume and testicular fat deposition in middle-aged overweight individuals were compared using a t test with Bonferroni correction and receiver operating characteristic (ROC) curve.

RESULTS

The testicular volumes (10.6-17.9 cm3) of individuals in the treatment group were smaller than those (12.6-19.0 cm3) of individuals in the control group (p < 0.05), and the average FF value (2.2-4.6%) of the testes in the treatment group was higher than that (1.5-3.1%) in the control group (p < 0.05). The ROC analysis showed that the area under the curve (AUC) of testicular fat deposition (0.899) was higher than that of testicular volume (0.777), and biopsy and sperm count were used as references to diagnose infertility. The diagnostic sensitivity (90.00%) of testicular fat deposition of the mDIXON Quant sequence was higher than that (50.00%) of the T1W sequence (p < 0.05). Testicular fat deposition was decreased after 6 months of active treatment with exercise weight loss and drug treatment, and no significant change in testicular volume was observed 6 months later.

CONCLUSION

The findings suggest that the proton density fat fraction (mDIXON Quant sequence in this study) approach is a novel tool for the quantitative and objective evaluation of testicular fat deposition. Testicular fat deposition measurement is more specific than testicular volume measurement in the diagnosis of male infertility, and the mDIXON Quant is more sensitive than T1WI in the diagnosis of testicular fat deposition. Furthermore, our findings may facilitate a more accurate diagnosis and monitoring of testicular infertility, therapeutic effect, and prognosis by measuring testicular fat deposition.