Quantification of testicular fat content: the value of evaluating testicular function after cryptorchidism surgery

To investigate the correlation between testicular fat content (TFC) and sex hormone levels in patients with cryptorchidism and its value in assessing postsurgical testicular function. Pelvic MRI with the mDIXON Quant sequence was performed on 23 cryptorchidism patients and 15 normal controls. The TFC before and after surgery was measured and compared. The correlations between cryptorchid TFC and testosterone (TSTO), follicle-stimulating hormone (FSH), and estradiol (E2) levels were analyzed, as was the specificity of TFC and each hormone for assessing testicular function after surgery. The preoperative cryptorchid TFC (3.06% ± 0.74) was higher than that of the normal controls (1.36% ± 0.49). TSTO was negatively correlated with the cryptorchid TFC (r = -0.698), while FSH and E2 were positively associated with the cryptorchid TFC (r = 0.658, 0.676). Cryptorchid TFC after surgery (2.01% ± 0.55) was lower than the preoperative TFC, but hormone levels were not significantly different. The TFC after surgery (0.864) had a larger AUC value than did TSTO (0.639), FSH (0.597), and E2 (0.586). Noninvasive quantification of cryptorchid TFC using the mDIXON Quant sequence is more specific than hormone levels for assessing postsurgical changes in testicular function. The cryptorchid testicular fat content is significantly higher than the normal testicular fat content. Cryptorchid testicular fat content is negatively correlated with presurgical serum TSTO levels and positively correlated with presurgical FSH and E2 levels. Pre- and postoperative changes in cryptorchid testicular fat content change are more sensitive than changes in TSTO, FSH, or E2 levels. Noninvasive cryptorchid testicular fat content quantified by the mDIXON Quant sequence is more specific than serum TSTO, FSH, and E2 levels for assessing changes in testicular function after cryptorchidism surgery.