Status of Transrectal Ultrasound Imaging of the Prostate

Purpose: To describe the current and new developments in transrectal ultrasound (US) imaging of the prostate. Patients and Methods: Grayscale imaging of the prostate is the standard method for diagnostic evaluation and biopsy guidance. Color Doppler (CD) imaging, including CD and power Doppler US, allows for detection of macrovascularity and may therefore be helpful for assessment of prostatic blood flow. The use of US microbubbles for CD imaging and new contrast-specific techniques enable assessment of prostate microvascularity associated with prostate cancer (PCa). Recently, real-time elastography has been introduced to improve detection of cancer based upon changes in tissue stiffness. Results: Contrast-enhanced CD imaging has shown to enable PCa detection by performing targeted biopsies into suspicious areas. Comparisons between systematic and contrast-enhanced targeted biopsies have shown that the targeted approach detects more cancers and cancers with higher Gleason scores with a reduced number of biopsy cores. New microbubble-specific US techniques can improve sensitivity and specificity of US imaging for PCa detection. Real-time elastography has been demonstrated to be useful for the detection of PCa, and may further improve PCa staging. Conclusions: The new US techniques seem to have the potential to improve PCa detection, and also PCa grading and staging. As these diagnostic methods improve, the ultimate hope is to eliminate biopsy in patients without cancer.