In vivo and in vitro hepatic 31P magnetic resonance spectroscopy and electron microscopy of the cirrhotic liver

In vivo P-31 magnetic resonance spectroscopy(MRS) provides direct biochemical information on hepatic metabolic processes. To assess in vivo changes in hepatic P-31 MRS in liver transplant candidates, we studied 31 patients with cirrhosis of varying aetiology; 14 with compensated cirrhosis (Pugh's score less than or equal to 7) and 17 with decompensated cirrhosis (Pugh's score greater than or equal to 8). Underlying cellular abnormalities were characterised using in vitro P-31 MRS and electron microscopy. In vitro spectra were obtained from liver extracts, freeze-clamped at recipient hepatectomy, from all subjects. Electron microscopy of liver tissue was also performed in 17 cases. Relative to nucleotide triphosphates, elevations in phosphomonoesters and reductions in phosphodiesters were observed in vivo with worsening liver function. In vitro spectra showed elevated phosphoethanolamine and phosphocholine, and reduced glycerophosphorylethanolamine and glycerophosphorylcholine, mirroring the in vivo changes, but no distinction was noted between compensated and decompensated cirrhosis. With electron microscopy, functional decompensation was associated with reduced endoplasmic reticulum in parenchymal liver disease, but elevated levels in biliary cirrhosis. We conclude that in vivo spectral abnormalities in cirrhosis are consistent with alterations in phospholipid metabolism and quantity of endoplasmic reticulum. However, in individual patients the biopsy results do not always mirror in vivo findings.