Defining the Modalities of Intravenous Contrast Application During the Diagnostics of Hepatic Metastases with Computerized Tomography

Abstract

Introduction:The liver is the biggest human abdominal parenchymal organ; it weights approximately 1500 grams and is located in the right hypochondrium, under the diaphragm. Liver is able to perform multiple functions also by means of the rich dual vascularization: hepatic arterial system and the portal vein system, between which exists a short circuit (shunt) and free mixture inside the sinusoid, whilst the two flows drain in the same vein system. The discovery of CT and its application in practice fundamentally changes the importance of diagnostic methods for hepatobiliary lesions. Patients and methods: During a 4-year period, 984 patients suspected with liver or biliary tract disease were explored with CT. 117 of these patients were analyzed with liver metastases. Examinations of the liver was performed in dorsal decubitus and in absolute apnea with spiral movement of the table and in denominations of 1and 5 mm. Siemens MSCT 64 and 6 tier apparatuses enable short scanning time with almost immediate reconstruction, which offers all the necessary elements required for carrying out certain protocols. Results: The average density of metastatic lesions is about 20 HU smaller than normal liver parenchyma. Metastasis with necrosis are more hypodense (30-50 HU smaller than normal liver parenchyma), whilst necrotic metastases with smaller dimensions are almost isodense with normal parenchyma. However, metastases with diameter between 4 to 6 cm are completely isodense and will remain so even after the application of I.V. contrast. The average more frequent size according to most authors, as well as according to our material (148 patients or 90%) was 2-3 cm in transversal diameter.