Quantitative MRI for Functional Imaging of the Testis: A New Methodology for Evaluation of the Infertile Male

Overview

Infertility-the inability to conceive despite one year of properly timed unprotected intercourse-is a common problem. Of all types of male factor infertility, non-obstructive azoospermia may be the most difficult for couples. Importantly, patients with non-obstructive azoospermia are asked to make difficult decisions in terms of reproductive choice; surgical attempts at identifying sperm (microdissection testicular sperm extraction) are often offered to these patients without a guarantee of being able to identify sperm. New methodologies in terms of evaluation of azoospermic males PRIOR to the couple embarking upon IVF are needed urgently. The other potential benefit of non-invasive determination of testis function and spermatogenesis would be the potential targeting of sperm extraction procedures. We hypothesize that quantitative MRI employing advanced functional metrics will be sensitive to functional and metabolic differences between subsets of azoospermic cases and will improve upon current characterization of patients with this condition. Moreover, it is believed that these techniques will provide complementary information, such that they may be combined in a synergistic fashion for targeted extraction methodologies.

Of all types of male factor infertility, non-obstructive azoospermia may be the most difficult for couples. Azoospermia (both obstructive and non-obstructive) occurs in approximately 10-20% of all infertile males with non-obstructive azoospermia encompassing the majority of cases. In this study, quantitative MRI will be investigated by employing advanced functional metrics for addressing these challenges. Specifically, diffusion-weighted imaging will be assessed, multi-echo T2 mapping, arterial-spin labeling, and spectroscopy. No intravenous contrast will be administered for purposes of this study. It is hypothesized that these techniques will be sensitive to functional and metabolic differences between subsets of azoospermic cases and will improve upon current characterization of patients with this condition. Moreover, it is believed that these techniques will provide complementary information, such that they may be combined in a synergistic fashion for targeted extraction methodologies. The goal of this exploratory study is to investigate whether associations exist between quantitative MRI metrics and the previously noted features of testis architecture.