RELATIONSHIP OF P-31 MR SPECTROSCOPY TO THE HISTOPATHOLOGICAL GRADINGOF CHRONIC HEPATITIS AND RESPONSE TO THERAPY

Purpose. In vivo phosphorus-31 MR spectroscopy (P-31 MRS) was performe d in the human liver in order to investigate the relation between: the ratios of phosphorus metabolites in the liver; the histopathological grading of chronic hepatitis; and the response to therapy. Material an d Methods. Hepatic P-31 MRS using the DRESS method (depth-resolved sur face-coil spectroscopy) was carried out in 45 patients with chronic vi ral hepatitis or autoimmune hepatitis, and in 16 control subjects. We measured the ratios of the peak areas of phosphomonoesters (PME), inor ganic phosphate (Pi), or phosphodiesters (PDE) to the peak area of bet a-adenosine triphosphate (ATP). Results. The PDE/ATP ratio of patients with chronic hepatitis or liver cirrhosis was lower than that of cont rol subjects (liver cirrhosis=0.74; chronic active hepatitis=1.13-1.21 ; normal=1.43); only a small difference was found in the PME/ATP and P i/ATP ratios. There was no correlation between the spectra and histopa thological grading or response to therapy, but the response to therapy was poor when a reduced PDE/ATP ratio was present. Conclusion. The PD E/ATP ratio measured by P-31 MRS makes it possible to identify the tra nsition of chronic active hepatitis into liver cirrhosis with a poor r esponse to therapy.