4D-CT imaging with synchronized intravenous contrast injection to improve delineation of liver tumors for treatment planning.

We have developed a tumor-specific protocol for the 4D-CT imaging of liver tumors using synchronized intravenous (IV) contrast injection to improve the accuracy of tumor delineation for treatment planning. Most liver metastases and cholangiocarcinomas can be imaged in the portal venous phase, while hepatocellular carcinomas are most visible in the delayed phase. Combined 4D-CT imaging with synchronized IV contrast allows for both enhancement of tumor contrast and coverage over the entire breathing cycle.