PURPOSE: The purpose of this study was to evaluate change in the proton MR spectroscopic (1H-MRS) features of the liver according to changes in the severity of the chronic hepatitis spectrum (normal-chronic hepatitis-liver cirrhosis), and to determine the possibility of replacing liver biopsy by1 H-MRS. MATERIALS AND METHODS: Sixty profiles of 1H-MRS features from 15 normal volunteers, 30 cases of chronic hepatitis, and 15 of liver cirrhosis were evaluated. All cases of chronic hepatitis and liver cirrhosis were confirmed by biopsy, and histopathologic disease severity was categorized according to Ludwig 's classification. Using the STEAM(STimulated Echo-Aquisition Mode) sequence, 1H-MRS was performed. The ratios of peak areas of [glutamate+glutamine]/lipid, phosphomonoesters/lipid, [glycogen+glucose]/lipid, and [3.9-4 . 1ppm unknown peak]/lipid and their mean and standard deviation were calculated in normal, chronic hepatitis stages I and II, and early and late liver cirrhosis groups and the results were compared between these groups. One-way variable analysis was applied to the statistics. RESULTS: Mean and standard deviation of phosphomonoesters/lipid in the normal, chronic hepatitis grades I and II, and early and late liver cirrhosis groups were 0.0146 +/-0.0090, 0.0222 +/-0.0170, 0.0341 +/-0.0276, 0 . 0 6 9 8 +/-0.0360, and 0.0881 +/-0.0276, respectively, and [glycogen+ glucose]/lipid were 0.0403 +/-0.0267, 0.0922 +/-0.0377, 0.1230 +/-0.0364, 0.1853 +/-0.0667, and 0.2325 +/-0.1071, respectively. These results implied that the ra-tio of the above metabolites to lipid content increased according to increasing disease severity (p<0.05). For [g-lutamate+glutamine]/lipid however, the ratios for each group were 0.0204 +/-0.0067, 0.0117 +/-0.0078, 0.0409 +/-0.0167, 0.0212 +/-0.0103, and 0.0693 +/-0.0371, respectively, and there was no correlation with disease severity. In the chonic hepatitis grades I and II, and early and late liver cirrhosis groups, the ratios for [3.9 -4.1 ppm un-known peak]/l ipid were 0.0302 +/-0.0087, 0.0513 +/-0.0167, 0.1112 +/-0.0351, and 0.1504 +/-0 . 0 3 5 5 ,and these also increased according to increasing disease severity (p<0.05). On MR spectra of normal livers, an unknown peak at 3.9 -4.1ppm was not detected. CONCLUSION: Changes in MR spectroscopic features in cases of chronic hepatitic and liver cirrhosis correlated with changes in disease severity, and the sensitivity of the unknown peak at 3.9 -4.1ppm changed according to disease severity. It is therefore possible to differentiate between normal liver, chronic hepatitis and liver cirrhosis by analysis of the 1H-MRS features of the liver. These results indicate that in cases of chronic hepatitis and liver cirrhosis, biopsy of the liver can be replaced by 1H-MRS.