Color Doppler imaging of the prostate: important adjunct to endorectal ultrasound of the prostate in the diagnosis of prostate cancer.

The purpose of this article is to evaluate color Doppler imaging (CDI) as an adjunctive tool to gray-scale ultrasound (US) in the diagnosis of prostate cancer and to correlate CDI-positive lesions to cancer grade. We retrospectively analyzed 619 consecutive patients who underwent prostate US, CDI, and biopsy because of abnormal digital rectal examination results or prostate-specific antigen levels. All had directed (into a specific lesion) biopsies or directed biopsies along with systematic four-quadrant or sextant biopsies, or systematic biopsy alone. Color Doppler imaging was compared with gray-scale findings and histologic results. There were 222 (35.9%) biopsy-proven cancers (n = 197) or prostatic intraepithelial neoplasia (n = 25). Of these, 106 (47.7%) had color-flow abnormalities. Of these 106 patients, 26 (24.5%), or 11.7% of all cancer patients, had relatively normal gray-scale US findings but had focal CDI abnormalities as the method of identification. Overall, 76.9% of these were moderate to high Gleason grades and were considered clinically significant lesions. Color Doppler imaging can identify a large number (11.7%) of clinically significant prostate cancers that are poorly seen by gray-scale US. Positive lesions on CDI are of clinical importance because 76.9% are histologically, moderately, or poorly differentiated. We recommend that CDI be used in all diagnostic and biopsy-guided US examinations of the prostate.