Initial experience with contrast-enhanced sonography of the prostate

OBJECTIVE: We investigated the usefulness of contrast-enhanced sonography to depict vascularity in the prostate and improve the detection of prostatic cancer. SUBJECTS AND METHODS: Twenty-six patients with an elevated prostate-specific antigen level (≥ 4 ng/ml) or an abnormal digital rectal examination were enrolled in a phase II study of an IV injected sonographic contrast agent. Continuous gray-scale, intermittent gray-scale, phase inversion gray-scale, and power Doppler sonography of the prostate were performed. Sonographic findings were correlated with sextant biopsy results. RESULTS: After the administration of contrast material, gray-scale and Doppler images revealed visible enhancement (p < 0.05). Using intermittent imaging, we found focal enhancement in two isoechoic tumors that were not visible on baseline images. No definite focal area of enhancement was identified in any patient without cancer. Contrast-enhanced images revealed transient hemorrhage in the biopsy tracts of three patients. CONCLUSION: Enhancement of the prostate can be seen on gray-scale and Doppler sonographic images after the administration of an IV contrast agent. Contrast-enhanced intermittent sonography of the prostate may be useful for the selective enhancement of malignant prostatic tissue.