Magnetic Resonance Imaging of the Hepatobiliary System Using Hepatocyte-Specific Contrast Media

Cover pictures Left: MRI overview of the upper abdomen in the coronal plane. Right: Contrast-enhanced MRI of the biliary system using Gd-EOB-DTPA. Published articles have been reprinted with the permission of the copyright holder. To Linda and Gustav " Never worry about theory as long as the machinery does what it's supposed to do. " Robert A. Heinlein Abstract vii ABSTRACT There are two Gadolinium-based liver-specific contrast media for Magnetic Resonance Imaging on the market, Gd-BOPTA (MultiHance aim of this study in two parts was to evaluate the dynamics of biliary, parenchymal and vascular enhancement using these contrast media in healthy subjects. Ten healthy volunteers were examined in a 1.5 T magnetic resonance system using three-dimensional Volumetric Interpolated Breath-Hold (VIBE) sequences for dynamic imaging with both contrast media – at two different occasions – until five hours after injection. The doses given were 0.025 mmol/kg for Gd-EOB-DTPA and 0.1 mmol/kg for Gd-BOPTA. The enhancement over time of the common biliary duct in contrast to the liver parenchyma was analyzed in the first study. This was followed by a study of the image contrasts of the hepatic artery, portal vein and middle hepatic vein versus the liver parenchyma. While Gd-EOB-DTPA gave an earlier and more prolonged enhancement of the biliary duct, Gd-BOPTA achieved higher image contrast for all vessels studied, during the arterial and portal venous phases. There was no significant difference in the maximal enhancement obtained in the liver parenchyma. At the obtained time-points and at the dosage used, the high contrast between the common biliary duct and liver parenchyma had an earlier onset and longer duration for Gd-EOB-DTPA, while Gd-BOPTA achieved higher maximal enhancement of the hepatic artery, portal vein and middle hepatic vein than Gd-EOB-DTPA. Diseases of the liver and biliary system may affect the vasculature, parenchyma, biliary excretion or a combination of these. The clinical context regarding the relative importance of vascular, hepatic parenchymal and biliary processes should determine the choice of contrast media for each patient and examination. This thesis is based on the following two papers, which are referred to by their Roman numerals (I and II). Abbreviations ix ABBREVIATIONS ANOVA Analysis of Variance ATP Adenosine Triphosphate B0 The static magnetic field B1 The varying radiofrequency magnetic field produced by the RF-coil CCC Cholangiocarcinoma CHD Common Hepatic Duct FDA United States Food and Drug Administration FOV Field Of View GRE Gradient (Recalled) Echo HBV Hepatitis …