In men, the prostate gland is located directly in front of the rectum, so the ultrasound exam is performed trans-rectally. A protective cover is placed over the transducer, it is lubricated, and then placed into the rectum so the sound need only travel a short distance from the prostate. The images are obtained from different angles to get the best view of the prostate gland. Ultrasound of the prostate is most often performed with the patient lying on his left side with his knees bent up slightly.
If a suspicious lesion is identified with ultrasound or with a rectal examination, an ultrasound-guided biopsy can be performed. This procedure involves advancing a needle into the prostate gland while the radiologist watches the needle placement with ultrasound. A small amount of tissue is taken for microscopic examination. Below is an example of a trans-rectal transducer (probe).
When the examination is complete, the patient may be asked to dress and wait while the ultrasound images are reviewed, either on film or on a monitor. Often the sonographer or radiologist is able to review the ultrasound images in real time as they are acquired, and the patient can be released immediately.