PURPOSE: The purpose of this study was to determine the proton MR spectroscopic features of liver cirrhosis and the different proton MR spectroscopic features between liver cirrhosis and the normal human liver by comparing the two different conditions. MATERIALS AND METHODS: The investigation involved 30 cases of in-vivo proton MR spectra obtained from 15 patients with liver cirrhosis demonstrated on the basis of radiologic and clinical findings, and from 15 normal volunteers without a past or current history of liver disease. MR spectroscopy involved the use of a 1.5T GE Signa Horizon system (GE Medical Systems, Milwaukee, U.S.A.) with body coil. STEAM (STimulated Echo-Aquisition Mode) with 3000/30 msec of TR/TE was used for signal acquisition; patients were in the prone position and respiration was not interrupted. Cases were assigned to either the cirrhosis or normal group, and using the proton MR spectra of cases of in each group, peak changes occurring in lipids (at 1.3ppm), glutamate and glutamine (at 2.4 -2 .5ppm), phosphomonoesters (at 3.0 -3 .1ppm), and glycogen and glucose (at 3.4 -3 .9ppm) were evaluated. Mean and standard deviation of the ratio of glutamate + glutamine/lipids, phospho-monoesters/lipids, glycogen + glucose/lipids were calculated from the area of their peaks. The ratio of various metabolites to lipid content was compared between the normal and cirrhosis group. RESULTS: The main characteristic change in proton MR spectra in cases of liver cirrhosis compared with normal liver was decreased relative intensity of lipid peak. Mean and standard deviation of ratio of glutamate + g-lutamine/ lipids, phosphomonoesters/lipids, glycogen + glucose/lipids calculated from the area of their peaks of normal and cirrhotic liver were 0.0204 +/-0.0067 and 0.0693 +/-0.0371 (p<0.05), 0.0146 +/-0.0090 and 0.0881 +/-0.0276 (p<0.05), 0.0403 +/-0.0267 and 0.2325 +/-0.1071 (p<0.05), respectively. The other character-istic feature of proton MR spectra of liver cirrhosis was the peak detected at 3.9 - 4.1 ppm with unknown nature. Mean and standard deviation of area ratio of the unknown peak to lipid peak in proton MR spectra of liver cirrhosis was 0.1504 +/-0 . 0 3 5 5 . CONCLUSION: Proton MR spectra of liver cirrhosis revealed decreased intensity of lipid with statistical signifi-cance compared with that of normal liver, and peak at 3.9 -4.1 ppm with unknown nature. In conclusion, liver cirrhosis can be diagnosed non-invasively by the analysis of observed proton MR spectroscopic features.