Contrast-Enhanced Ultrasound (CEUS) and elastographic imaging

Ultrasound imaging has found applications in several areas of interventional urology prior to treatment (diagnosis), after treatment (follow-up), and also during treatment (monitoring/guidance). Contrast-enhanced ultrasound (CEUS) imaging and elastographic imaging are the two widely used imaging techniques. CEUS modalities, such as harmonic and multi-pulse imaging, are increasingly applied in interventional urology, because the contrast agents give a clear enhancement of blood vessels in the tissue. Among others, CEUS is used to study the microvasculature of the prostate and kidney for cancer detection to more accurately identify malignant lesions. Elastography is a technique that has been coined in 1991 for the quantification of elastic properties of biological tissue. Various elastographic techniques have been developed, such as Acoustic radiation force imaging (ARFI) and shear wave elastography. These techniques have found various applications in interventional urology such as monitoring the degree of fibrosis in renal allografts after transplantation and the identification of renal masses and prostatic lesions.
These enhanced ultrasound modalities represent novel techniques in the evaluation of the prostate and kidney in urology. There are multiple putative benefits of enhanced ultrasound modalities, including improved targeting for prostate biopsy; improved characterization of suspicious renal masses, especially when contrast-enhanced axial imaging (CT or MRI) are contraindicated; and lower cost than CT or MRI. Further investigations and refinements are necessary to define the role of these techniques in current urologic practice.