New developments in ultrasonography for the detection of prostate cancer

The introduction of contrast agents has changed the diagnostic role of ultrasonography dramatically. Advanced ultrasound techniques, although currently largely unexplored, especially for prostate applications, were introduced to improve, for example, differential diagnosis. Also, new technologies became available using the interaction of the angioemboli with the transmitted ultrasound waves, and sensitive methods to detect microbubbles were developed. As the traveling of microbubbles through the vascular system is a dynamic process, new information becomes available: when the concentration of the contrast agent can be determined as a function of time, a measure for the actual blood flow can be obtained that provides quantitative information. Initially developed to enhance the ultrasound examinations in cardiac applications, contrast agents can currently be found in radiologic applications as well. The first reports of enhanced Doppler examinations of prostatic blood flow have been published, and the results indicate that contrast agents are a promising addition to the conventional ultrasound examination. In this paper, we present a short overview of the status of transrectal ultrasound imaging in prostate cancer, background information on contrast agents and imaging modalities, and early results of enhanced Doppler studies of the prostate to identify cancer. The early results suggest the feasibility of using angioemboli to enhance ultrasound imaging of prostate diseases, and although many issues remain to be solved, angioemboli in combination with a dedicated imaging modality have the potential to improve the diagnostic application of ultrasound in evaluating the prostate for disease.