COLOR DOPPLER SONOGRAPHY OF THE PROSTATE

Digital rectal examination, prostate-specific antigen and transrectal sonography (TRS) are the main diagnostic tools for evaluating men at r isk for carcinoma of the prostate (PCa). PCa has a hypoechoic echo pat tern via TRS in 60-85% of cases. Hypoechoic areas are observed, howeve r, in benign prostatic hyperplasia (BPH) as well. For this reason, TRS yields a low specificity and sensitivity in detecting PCa in screenin g programs. Additional data, independent of the grey scale information available via TRS, can be obtained by using the innovative technology of color Doppler sonography. This imaging modality allows simultaneou s real-time sonographic visualization and evaluation of vascular struc tures. The present study analyzes to what extent the analysis of blood flow perfusion of prostatic parenchyma can provide further informatio n concerning the pathologic alterations occurring in abnormal prostate tissue. Blood flow phenomena were reproducibly demonstrated in the pr ostate and in the periprostatic tissue with the color-coded Doppler so nography (CD-TRS). 31 patients with the diagnosis of BPH could be sepa rated into two different groups according to the findings with TRS and CD-TRS. In contrast, patients with histologically proven PCa (n = 16) had subjectively increased perfusion rates. Blood flow phenomena were analyzed using computer-calculated resistive index and pulsatility in dex as evaluations of flow and frequency. A preliminary analysis of th e wave-form characteristics shows that flow in the prostate gland is a ssociated with a high resistive index in both PCa and BPH. The mean fr equency demonstrated in the pulsatility index appears to be high in PC a, but low in BPH cases. Further studies are needed to verify the desc ribed factors' abilities to differentiate prostate tissue as either PC a or BPH.