CEUS in the study of bladder, method, administration and evaluation, a technical note

Abstract

Contrast-enhanced ultrasound (CEUS) is the application of ultrasound contrast agents (UCAs) to traditional medical sonography. The development of UCAs allowed to overcome some of the limitations of conventional B-mode and Doppler ultrasound techniques and enabled the display of the parenchymal microvasculature. Purpose of this paper is to delineate the elements of a solid and science-based technique in the execution of urinary bladder CEUS. We describe the technical execution of urinary bladder CEUS and the use of perfusion softwares to perform contrast enhancement quantitative analysis with generation of time-intensity curves from regions of interest. During CEUS, normal bladder wall shows a wash-in time of 13s, a time to peak (TTP) >40s, a signal intensity (SI) <45% and a wash-out time >80s; Low-grade urothelial cell carcinoma (UCC) shows a wash-in time of 13s, a time to peak TTP >28s, a SI <45% and a wash-out time of 40s; High-grade UCC shows a wash-in time of 13s, a TTP >28s, a SI >50% and a wash-out time of 58s. CEUS is a useful tool for an accurate characterization of bladder UCC although it has some drawbacks. To avoid misunderstandings, a widely accepted classification and a standardized terminology about the most significant parameters of this application should be adopted in the immediate future.