The classic candidate for a transrectal ultrasonography (TRUS) evaluation has semen analysis findings consistent with complete distal ejaculatory obstruction, including low ejaculate volume (usually less than 1.5 ml), azoospermia, low pH (less than7), and absence of fructose. In most cases, TRUS can be performed as an outpatient procedure without the need for anesthesia. In order to understand the normal and pathological appearance of the ejaculatory structures on TRUS, it is important to appreciate their anatomic relationships and embryological origins. Traditionally, vasography after vasopuncture was used to evaluate the patency of the ejaculatory ducts. The types of pathologies found on a TRUS evaluation include agenesis or hypoplasia of urogenital structures, cysts, dilatations, calcifications, and stones. Distal ejaculatory duct obstruction (EDO) is strongly suspected in case of azoospermia in which TRUS reveals dilated seminal vesicles with an anteroposterior length greater than 15 mm, or ejaculatory ducts with diameter greater than 2.3 mm.

This chapter summarizes various imaging modalities in the workup of male infertility with emphasis on indications and outcome interpretation. The conditions outlined in this chapter are commonly identified causes for oligospermia and azoospermia, and are the usual targets for imaging investigations. Color Doppler ultrasound (CDUS) has become the most frequently used imaging modality for varicocele detection. Ultrasound studies of spermatic veins have suggested that the presence of multiple large veins. In CBAVD the diagnosis is established clinically by the absence of the two vasa deferentia on palpation. Intratesticular cysts include cysts of the tunica albuginea, tubular ectasia of the rete testis, and testicular cysts. Testicular microlithiasis (TM) is characterized by the presence of numerous punctate calcifications within the testis. Transrectal ultrasound (TRUS)-guided echo-enhanced seminal vesiculography in combination with transurethral resection of the ejaculatory duct (TURED) is considered the best imaging method when treating ejaculatory duct obstruction (EDO).

This chapter offers a discussion of basic normal ejaculatory duct embryology, anatomy, and physiology to lay a foundation for an understanding of the clinical findings and treatment of obstruction. In the male the mesonephric duct continues to develop into the epididymis, vas deferens, seminal vesicle, and ejaculatory duct. The remnant Müllerian structures in the male are the prostatic utricle and appendix testis, and in some men remnant Müllerian duct structures can be found in the midline of the prostate as Müllerian duct cysts. The ultrasonographic diagnosis of ejaculatory duct obstruction is based upon the finding of dilation of the seminal vesicles and abnormalities in the region of the ejaculatory ducts. Stricturing of the resected ejaculatory ducts may represent the most significant complication in regard to fertility, and may occur immediately or in a delayed fashion.