Ejaculation in men: a dynamic endorectal ultrasonographical study.Br J Urol. 1994 Apr; 73(4):442-8.BJ
To study the ejaculatory mechanisms in men using a dynamic endorectal ultrasonographical approach.
SUBJECTS AND METHODS
Seven recordings were made of a young healthy volunteer during ejaculation, scanning the longitudinal plane from the bladder neck to the bulbous urethra.
The study demonstrated the existence of a pre-ejaculatory phase characterized by a notable decrease in echogenicity of the inner prostate gland, due to the contraction of the pre-prostatic sphincter 13-25 s before ejaculation. Several stages were recorded including an ejaculatory stage with an initial prostatic emission phase lasting 2-20 s and a posterior emission phase through the ejaculatory ducts lasting 3-14 s, with a seminal stoppage of 3-8 s, and finally a urethro-vesical reflux of a minimal fraction of the ejaculate over 5-9 s. The bladder neck and inner gland returned to their resting configuration between 10 and 90 s after ejaculation.
Endorectal ultrasonographical imaging during ejaculation, a recently developed diagnostic procedure, may provide a new approach to ejaculation-related problems.