Research applications of ultrasonic imaging in reproductive biology.

In the short time that transrectal ultrasonic imaging of the reproductive tract has been used as a research tool, many discoveries have resulted, some of which would otherwise have escaped detection for many years. Ultrasonography provides a wide array of morphologic information without invading or disturbing the tissues. Examinations can be done repeatedly over many days, or a dynamic event (e.g., ovulation) can be monitored in its entirety by continuous observation (e.g., 30 min). Inclusion of ultrasonic examinations in experimental protocols affords the opportunity to associate changing morphology with hormonal and other functional changes. If experimental testing is expected to involve changing morphology, ultrasonic imaging should be considered. End points can be measured or ranked and therefore data can be statistically analyzed for conventional hypothesis testing. The research potential of this technology and its adaptability for computer-assisted assessment go far beyond simplistic determination of ovulation, luteal formation, and pregnancy diagnosis. It is the authors' opinion that ultrasonic imaging is a revolutionary advance in reproductive research that is destined to rival the impact of other technologic breakthroughs, including radioimmunoassay.