Dynamic sequential computed tomography in abdominal tumours. Some aspects for differential diagnosis

Dynamic CT in combination with intravenous bolus injection of contrast material provides a study of the pharmacokinetics in great vessels as well as in tissues. If the enhancement in the region of interest is plotted against time, the time-enhancement diagrams obtained reflect the contrast material passage mathematically. In abdominal tumours a great variety of patterns in time-enhancement diagrams is available. Some characteristic patterns could be related to the theoretical aspects of contrast medium distribution in vessels and tissues, i.e. the rapid arterial enhancement corresponding to aortic perfusion, a portal enhancement in liver and portal vein and a rather slow "extravascular" enhancement due to diffusion into the extravascular space. The very short period just behind the capillary passage of contrast material seems to be the most interesting one concerning identification of benign and malignant tumours. In 48 abdominal tumours time-enhancement diagrams were taken and correlated to the histological findings; preliminary findings are discussed concerning to a possible differential diagnosis between benign and malignant tissue.