A 55-year-old male patient has an abnormal digital rectal examination (DRE) with

1 -- Transrectal ultrasonography (TRUS) may be used when the digital rectal examination (DRE) is abnormal or if the PSA ( prostate-specific antigen) level is elevated. In the TRUS test, a small probe is inserted in the rectum. The probe gives off sound waves that make a picture of the prostate on a video screen. Guided by this picture, the physician inserts a narrow needle through the rectal wall into the prostate gland, and the needle removes a sample of tissue for examination. The bone scan, MRI, or CT scan may be performed at a later date to determine the presence of tumor metastasis.