A quantitative assessment of liver metabolites during jaundice using three dimensional phosphorus chemical shift imaging☆

Phosphorus metabolites in the jaundiced rat liver were studied by three-dimensional phosphorus chemical shift imaging (CSI). Animals were studied at 1, 2, and 3 weeks post-ligation of the common bile duct. Quantitation of metabolites was performed using an external standard. Metabolite T1 values were assessed in CSI experiments on normal untreated animals. High-performance liquid chromatography (HPLC) was used to measure adenine nucleotides in a separate group of jaundiced rats. 3D-CSI did not detect significant changes in NTP in jaundiced animals relative to baseline controls. At two and three weeks post bile duct ligation, pH was significantly elevated. HPLC data comparing ATP levels to baseline controls also detected no change except for elevated ATP detected on Day 21. 31P NMR chemical shift imaging may be used to assess liver metabolites under conditions of stress such as jaundice. However, absolute quantitation requires careful attention to many factors including point spread function, correct T1 values, and adequate signal-to-noise ratio.