Figure 6a. (a) Delayed color Doppler image obtained after injection of 0.16 mL/kg SHU 563A shows acoustic emission signals from within a woodchuck hepatic tumor. The tumor is surrounded by normal liver tissue eliciting acoustic emission. Additional acoustic emission signals (arrow) are present from within the tumor. While this may represent contrast-enhanced blood flow, (b) pathologic specimen confirms a small amount of normal liver tissue (arrow) within the tumor.