Prostate Ultrasound and Biopsy

The Prostate

The prostate is a walnut-sized gland located beneath the bladder and in front of the rectum in men.  The urethra (tube that transports urine and sperm out of the body) passes through the prostate to the bladder neck.  Prostate tissue produces prostate specific antigen (PSA) and prostatic acid phosphatase, enzymes found in seminal fluid ( the milky substance that combines with sperm to form semen).

Prostate Ultrasound

An ultrasound involves using a special device (transducer) that reflects high-frequency sound waves off internal structures to create detailed images called sonograms.  Transrectal ultrasound (TRUS), also called prostate ultrasound, provides images of the prostate and surrounding tissue and allows the physician to examine the gland for abnormalities (enlarged prostate [BPH], prostate cancer).

A TRUS and prostate biopsy are used to diagnose prostate cancer in patients with an abnormal digital rectal exam (DRE) or an elevated PSA level, to assess prostate volume and to detect inflammation of the prostate (prostatitis).


Patients may be instructed to discontinue blood-thinning medications (e.g., aspirin, ibuprofen) for a week prior to undergoing a TRUS and prostate biopsy.  An antibiotic may be prescribed prior to and sometimes for a couple of days following the procedure to help prevent infection.  An enema is usually required to cleanse the bowel.

Transrectal ultrasound, which is performed with patients lying on their side with knees bent, involves a small cylinder-shaped transducer, which is lubricated and inserted into the rectum.  The transducer directs high-frequency sound waves into the body.  As these sound waves are reflected back to the transducer, it records and transmits them to the monitoring device, which creates the images (sonogram).

In the presence of an abnormal PSA and/or DRE a prostate biopsy is sometimes required.  During a biopsy, transrectal ultrasound is used to help the physician properly place a needle to inject anesthetic to numb the prostate.  A tiny needle is projected through the tip of the probe inserted through the rectum along side the prostate.  The biopsy needle is used to extract a tissue sample from several areas of the prostate.  The entire procedure lasts about 5-10 minutes.

The biopsy samples are sent to a pathologist (physician who identifies diseases by studying cells under a microscope) who analyzes the samples for the presence of prostate cancer.  The pathologist examines the tissue samples.  It takes about one week to get the results.

Side Effects and Complications

Transrectal ultrasound usually is not associated with side effects or complications.

Following a prostate biopsy, patients may experience:

  • Blood in the urine (hematuria)
  • Blood in the semen (hematospermia)
  • Blood in the stool
  • A dull ache in the perineum (area between the anus and the scrotum)

These side effects are usually minor and diminish within one to two weeks.  If the patient develops a large number of blood clots, fever over 101° or cannot urinate, the physician should be contacted immediately.  These side effects are very rare.