Figure 5. Enhanced colour Doppler in prostatic cancer. Colour Doppler has been advocated as a way to improve the well-known poor sensitivity of ultrasound for detecting prostatic cancer. Only weak colour signals could be obtained on the conventional scan (a) but after administration of the microbubble contrast agent SonoVue, there was marked enhancement in the left side of the prostate (b). Biopsy of this region demonstrated cancer.