Hepatic imaging with multidetector CT

Combining the advantages of a multirow detector array with a fast gantry rotation time, multidetector computed tomographic (CT) scanners can acquire sections at a faster rate than was previously possible. As a result, multidetector CT permits scanning during multiple specific phases of intravenous contrast enhancement and the acquisition of very thin sections over a large area, allowing the creation of multiplanar reconstructions with high z-axis resolution. The authors present an imaging strategy for the diagnosis and staging of hepatic pathologic conditions that emphasizes the role of multidetector CT. Users must master several scanning parameters to obtain the best image quality. For hepatic CT, it is practical to use relatively narrow collimation, increasing the pitch as needed to cover the entire liver. The choice of reconstruction interval is dependent on the problem for which the study is being performed. Water is recommended as an oral contrast agent for nonaxial reconstructions, since high-attenuation oral contrast agents might degrade them. Appropriate scanning delays for hepatic CT are dependent on the contrast-agent injection strategy used. A triple-pass technique, highlighting the arterial, parenchymal, and portal venous phases of enhancement, is recommended.