Ultrasonography of the prostate and testes.

The first application of ultrasound in medical diagnosis occurred in 1942 when Karl Dussik placed transducers on patients’ craniums and recorded the throughtransmission of the sound beam in an attempt to localize a brain tumor.1 In 1949, the first successful pulse echo system, which could record echoes from tissue interfaces, was developed by Douglas Howry and W. Roderic Bliss at the University of Colorado School of Medicine.2 In 1951, Wild and Neal3 of St Martin’s Hospital reported that Amode display sonography was capable of showing differences between normal and abnormal tissues, and the following year, Wild and Reid4 published the first twodimensional echograms of biological tissues (kidney cortex and myoblastoma of the thigh). In 1963, Takahashi and Ouchi5 were the first investigators to report the use of ultrasound to image the prostate via an abdominal approach, but, unfortunately, these A-mode display images were difficult to interpret and not clinically useful. A year later, these investigators successfully obtained tomographic pictures of the prostate with the use of a transrectal probe equipped with a radical scanning device. Although resolution improved, the images also were of poor quality and thought to be of no clinical value.6 Watanabe and associates,7 using a chair device, are credited with obtaining the first clinically useful transrectal ultrasonographic images of the prostate in 1967 (Fig. 1). Remarkable improvement in ultrasonography of the prostate was obtained with the use of a transrectal radial probe with a special concave 3.5-MHz transducer covered with a water-filled balloon.8 A B-mode display was used, and reproducible transverse prostate images were visualized on a black-and-white screen. It is important to recognize that transrectal ultrasound scanning was also evaluated by VonMicsky,9 a gynecologist who developed an ultrasound scanning device in conjunction with a sigmoidoscope to visualize the pelvic structures. The first reports of investigators in the United States using transrectal ultrasound for evaluation of the prostate came in 1972, and the images shown in the cathode ray tube (CRT) were recorded with a Polaroid camera (Fig. 2).10,11 These initial reports were the culmination of a number of experiments that were conducted beginning in 1968 at the Bowman Gray School of Medicine under the direction of William H. Boyce, who described these early developments.12–14 Initially studies were carried out with skincoupled B-mode transducers through the perineum and other portals before the final decision was made to use an intrarectal balloon-coupled rotational array transducer.