Contrast-enhanced power Doppler imaging of normal and decreased blood flow in canine prostates

The purpose of this study was to investigate if Sonazoid, a new ultrasound (US) contrast agent, can improve the delineation of areas with normal and decreased blood flow in the prostate. Sonazoid was administered in the dose range of 0.00625-0.0375 microL microbubbles/kg into five anaesthetised mongrel adult male dogs. Transrectal power Doppler imaging of the prostate was performed in 2-D and 3-D with a C9-5 end-fire probe, using an HDI 3000 scanner. An area of decreased blood flow was created by inducing tissue ablation with a CL60 laser system, to mimic an avascular lesion. A subjective assessment of the intraprostatic vessels and the prostate vascular architecture was performed, with and without Sonazoid, before and after inducing the abnormal site. Visibility of the prostate blood flow improved following Sonazoid injection (p < 0.001). A symmetric, radial vascular pattern was identified in the normal prostate prior to tissue ablation, but only on the enhanced images. After tissue ablation, a disturbance of the normal vascular pattern and identification of areas with lack of blood flow was possible, following Sonazoid injection. Furthermore, the location and size of these areas were verified in all dogs by gross histology examination. Sonazoid enhances the visibility of the prostate vascular architecture and improves, thereby the delineation of areas with normal and decreased blood flow.