The Role of Cross-sectional Imaging in Male Infertility: A Pictorial Review

Ultrasound of the Normal and Abnormal Vas Deferens

ABSTRACT

The extrapelvic portion of the vas deferens is readily visible with ultrasound but often overlooked. Several publications have described the scanning technique and the normal anatomy of the vas deferens. Sonographic evaluation of the vas deferens provides critical information in the workup of male infertility. Obstruction, inflammatory conditions, and neoplasms of the vas deferens can also be diagnosed with ultrasound. Knowledge of the normal and abnormal appearance of the vas deferens improves scans of the scrotum and expands the conditions that can be recognized and accurately diagnosed with ultrasound.

When to ask for an MRI of the scrotum

Background

Multiparametric MRI (mpMRI) of the scrotum has been established as a useful second‐line diagnostic tool for the investigation of scrotal diseases. Recently, recommendations on clinical indications for scrotal MRI were issued by the Scrotal and Penile Imaging Working Group of the European Society of Urogenital Radiology.

Objective

To update current research on when to ask for an MRI of the scrotum.

Methods

PubMed database was searched for original articles and reviews published during 2010–2021.

Results

Eighty‐three articles fulfilled the search criteria. Scrotal MRI is mainly recommended after inconclusive US findings or inconsistent with the clinical examination and should be asked in the following cases: differentiation between intratesticular and paratesticular lesions (in rare cases of uncertain US findings), characterization of paratesticular and intratesticular lesions (when US findings are indeterminate), discrimination between germ cell and sex cord‐stromal testicular tumors, local staging of testicular malignancies (in patients planned for testis‐sparing surgery), differentiation between seminomas and non‐seminomatous tumors (when immediate chemotherapy is planned and orchiectomy is delayed), assessment of acute scrotum and scrotal trauma (rarely needed, in cases of non‐diagnostic US findings) and detection and localization of undescended testes (in cases of inconlusive US findings). Although preliminary data show promising results in the evaluation of male infertility, no established role for mpMRI still exists.

Conclusion

Multiparametric MRI of the scrotum, by assessing morphologic and functional data represents a valuable problem‐solving tool, helping to improve our understanding on the nature of scrotal pathology and the process of spermatogenesis. The technique may improve patient care and reduce the number of unnecessary surgical procedures.

MRI findings of obstructive azoospermia: lesions in and out of pelvic cavity

Obstructive azoospermia (OA) is caused by excurrent duct obstruction, which can occur anywhere along the course of the male reproductive tract and is classically characterized by normal spermatogenesis. To be familiar with the imaging anatomy of normal and abnormal male genital ducts is essential to the diagnosis of OA. In some circumstances, OA can also be related to some specific syndromes; thus, making an accurate diagnosis may require an integral view of the whole abdomen and pelvis. MR is a great complementary imaging modality either for the detection of obstructive factors, especially for characterization of those indeterminate features on ultrasound, or for the identification of specific syndromes related to OA. In this article, a series of patients with OA caused by different kinds of lesions in and out of the pelvic cavity (abdomen) shown on MR imaging were included, and some cases of specific syndromes related to OA were also reviewed.

Vas deferens sonographic appearances of tuberculosis lesions of 19 cases of male genital systemic tuberculosis

To investigate the sonographic findings of the vas deferens in male genital tuberculosis.The ultrasonographic findings of the vas deferens of 19 cases of genital tuberculosis were retrospectively analyzed.According to the pathological and ultrasound findings, the ultrasonographic appearances of the vas deferens tuberculosis could be divided into 4 groups, 1 of normal sonograms, 3 of abnormal sonograms. The abnormal ultrasonographic appearances of the vas deferens tuberculosis were considered 3 categories as follows: diffusely thickening of vas deferens, nodular thickening of vas deferens, and space-occupying lesions adjacent to the vas deferens.The ultrasound manifestations of vas deferens in tuberculosis of the male genital system have certain characteristics. Combination of clinical manifestations, history of tuberculosis, experimental antituberculosis treatment, and ultrasound examination of vas deferens can suggest tuberculosis of vas deferens. Furthermore, it can provide objective basis for the comprehensive and noninvasive evaluation of the impact of genital tuberculosis on the reproductive ability for further treatments.

Imaging in male-factor obstructive infertility

The main purpose of imaging evaluation in male infertility is to identify and treat correctable causes of infertility, such as obstruction of the seminal tract. Various imaging modalities are available to evaluate men with obstructive infertility including scrotal ultrasonography, transrectal ultrasound (TRUS), vasography, magnetic resonance imaging, seminal vesicle aspiration, seminal tract washout, and seminal vesiculography. To date the most reliable and accurate diagnostic technique for obstructive infertility is unclear. In this review article, we report the role of these modalities in diagnosis of obstructive infertility. Scrotal sonography is the initial modality, and if patient results indicate non obstructive azoospermia as varicocele or testicular pathology they will be treated according to standard protocols for management of these pathologies. If the patient findings indicate proximal obstructive azoospermia, they can be managed by vasoepididymostomy. If the scrotal ultrasound is normal, TRUS is the second imaging modality. Accordingly, they are classified into patients with criteria of obstructive infertility without urogenital cysts where TRUS-guided aspiration and seminal vesiculography can be performed and transurethral resection of the ejaculatory ducts (TURED) will be the management of choice. In patients with urogenital cyst, TRUS-guided cyst aspiration and opacification are performed. If the cyst is communicating with the seminal tract, management will be transurethral incision of the cyst. If the cyst is not in communication, the obstruction may be relieved after cyst aspiration. If the obstruction is not relieved, TURED will be the management of choice. Sperm harvested during aspiration may be stored and used in assisted reproduction techniques. If the results of TRUS are inconclusive or doubtful, endorectal magnetic resonance imaging should be performed to serve as a “detailed map” for guiding corrective operative interventions.