Assessing the vascular-stromal coefficient in patients with benign prostatic hyperplasia or prostate cancer using transrectal ultrasonography and power Doppler analysis.

OBJECTIVES: To assess a coefficient of the prostatic blood supply in patients with prostate cancer or benign prostatic hyperplasia (BPH), and thus improve the diagnostic and prognostic variables needed to evaluate patients with prostate cancer. PATIENTS AND METHODS: The vascular-stromal coefficient was defined as the ratio of the blood vessel surface area and the surface area of the prostate, using power Doppler functions and transrectal ultrasonography. The index was calculated for the plane of the prostatic surface from the apex to the widest points of the peripheral zone, and for the plane across the highest density of blood vessels in the transition zone. A micobubble contrast agent was used to intensify the acoustic signals from prostatic vessels. The images were reconstructed in three dimensions. In all, 61 patients with BPH and 32 with confirmed prostate cancer were examined, and compared with a control group of young men. RESULTS: In the horizontal plane crossing the apex of the prostate, the vascular-stromal coefficient was 0.0054 for the controls, 0.0072 for BPH and 0.0067 for cancer. At the level of the highest density of blood vessels the respective values were 0.0083, 0.038 and 0.029. The respective values for the first plane after using the contrast agent were 0.025, 0.092 and 0.0365, and in the second level 0.04, 0.15 and 0.14. CONCLUSION: The vascular-stromal coefficient measured at both levels was higher in patients with BPH than in those with cancer or than in the controls. The prostatic vascular system can be computer-reconstructed in three dimensions, allowing an evaluation of asymmetry and other vascular abnormalities. The contrast agent effectively increases the vascular acoustic signals from the prostate, enhancing by a factor of five the visualization of blood vessels when using the power Doppler option.

Vascular angiographic asymmetry on three-dimensional transrectal power Doppler ultrasonography in patients with organ-confined prostate cancer.

OBJECTIVE: To assess whether organ-confined prostate cancer not detected on routine transrectal ultrasonography (TRUS) can be detected using three-dimensional (3-D) power Doppler methods. PATIENTS AND METHODS: A preliminary trial of the use of TRUS with 3-D power Doppler image reconstruction was conducted in 116 patients being evaluated for lower urinary tract symptoms. Using a microbubble enhancing agent, an adequate horizontal plane allowed the simultaneous visualization and assessment of the symmetry of echogenicity and vascularization of the peripheral area of both prostate lobes, which is not possible in standard TRUS. The peripheral zone vascular asymmetry in the horizontal plane was also assessed retrospectively in those patients with pT2a,b prostate carcinoma. RESULTS: Stage pT2a,b prostate carcinoma was confirmed in 26 patients; in this group, two independent investigators confirmed the vascular asymmetry between the left and right peripheral zone, in the horizontal plane, in 22 patients, giving a sensitivity of 85%. CONCLUSIONS: Vascular asymmetry allows guided biopsy in lesions that are invisible using standard TRUS. Microbubble agents are an effective method of increasing the acoustic signals from small vessels of the prostate.