Flow, firmness, or FNA? Is enhanced EUS fantastic or just fancy?

摘要

It is well-known that a noncontrast CT of the pancreas is almost useless at detecting, or ruling out, a pancreatic mass. Adding a perfusion dimension to the imaging with intravenous contrast changes that situation dramatically for CT. So it seems logical to make use of a lesion's perfusion abnormalities on contrast-enhanced EUS (CE-EUS). CE-EUS involves using microbubble contrast agents to either enhance the Doppler signal (with or without bubble destruction for first-generation agents) or to detect higher-order harmonics produced when nonlinear echoes result from asymmetrical deformation of higher-generation bubbles or to exploit the differing summation properties of linear and nonlinear wave reflections of repeated pulses in an effort to digitally separate perfused and nonperfused tissue. The physics involved is complex, yet truly amazing, and one cannot help but be in awe of the technology.