Trans-rectal ultrasound (TRUS) footage of a guided prostate needle biopsy. This test is used to confirm or exclude the existence of prostate cancer when the tissue samples are examined in the lab. Generated by a rectal probe, this ultrasound shows the needle of the biopsy gun entering the prostate from the bottom right corner. Several samples are extracted in different regions of the prostate so that the extent of any cancer can be determined.