Manfred Brauer1, Melissa Yau1, Leslie M. Foley2
1Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada; 2Pittsburgh NMR Ctr. for Biomedical Research, Carnegie Mellon University, Pittsburgh, PA, USA
Long-term alcohol consumption causes hypoxic liver damage. Functional MRI can measure tissue oxygenation changes in situ. Here we report gradient echo fMRI studies of liver oxygenation changes in chronic ethanol-treated rats showing that alcohol causes a greatly decreased and slower response to hyperoxia, hypoxia and carbogen challenge vs. controls. Liver signal intensities doubled with carbogen inhalation in controls, with no significant increase in alcoholic rats. TE-dependence studies confirm that both SE and GE fMRI studies are consistent with BOLD contrast. Low-volume hemoximetry showed that chronic ethanol decreases blood oxygen levels in the portal vein, hepatic artery and hepatic vein under all challenge conditions. Morphometric histology showed that alcoholic liver vasculature was compressed and less responsive to systemic challenge, confirming the fMRI results. This shows that fMRI can noninvasive monitor organ oxygenation status.