In vivo human testicular function assessed with P-31 MR spectroscopy

The clinical feasibility of assessing testicular metabolic integrity with phosphorus-31 magnetic resonance (MR) spectroscopy was investigated in six healthy volunteers and 23 patients with azoospermia. MR spectroscopic findings were compared with sperm count and motility in all patients and with findings at testicular biopsy in 23 patients. Significant differences (P less than .05) were found between the P-31 spectra of normal and azoospermic testicles in the following peak area ratios: phosphomonoester (PM)/beta-adenosine triphosphate, PM/phosphodiester, and inorganic phosphate/PM. In the patients with azoospermia, there were significant differences in these same peak area ratios between patients with primary testicular failure and those with chronic tubular obstruction. Although the differences between these two groups were statistically significant, there was a large overlap in numbers, and therefore a study with a larger patient population will be required. P-31 MR spectroscopy is a sensitive tool for assessment of testicular metabolic integrity and differentiation of normal testicles from those with markedly decreased spermatogenesis.