Liver oxygenation in chronic ethanol-treated rats: Analysis by functional magnetic resonance imaging
This thesis is an investigation of functional Magnetic Resonance Imaging (MRI) to examine oxygenation changes in pair-fed and chronic ethanol-treated rat livers during hypoxic, hyperoxic, hypercapnic or carbogen inhalation challenge, or after acute ethanol administration. The change in signal intensity in Magnetic Resonance images was positively correlated (r2 = 0.92, p < 0.05) with oxygen saturation measurements in both pair-fed and chronic ethanol-treated rats. The hepatic artery and the portal vein extraction coefficients and the lactate-to-pyruvate ratios were all in agreement with functional MRI results during each challenge. The magnitudes of signal intensity change in T 2 and T2*-weighted Magnetic Resonance images were smaller in chronic ethanol-treated rats in comparison to their pair-fed controls for all the inhalation challenges, consistent with chronic ethanol-induced hepatic microvascular dysfunction. In conclusion, functional MRI was shown to be a sensitive, reliable indicator of hepatic oxygenation changes, and showed subtle, early effects of chronic ethanol consumption on the liver.