The application of magnetic resonance spectroscopy to the study of hepatic encephalopathy

In vivo cerebral MRS techniques provide a non-invasive means of studying high energy phosphates levels and metabolites such as glutamine, glutamate and myoinositol in patients with CHE. Although there are differences in the 31P MRS findings between published studies, these are largely methodological, owing to variations in data acquisition with results on differing areas of the brain in small, but widely different patient populations. In order to obviate these discrepancies, future studies should concentrate on localised information from specific areas of the brain in clinically well-characterised groups of patients. There is greater concordance with proton MRS studies, all of which show an increased glutamine/glutamate resonance with increasing severity of CHE. MRS may be used to gain insight into the pathogenesis of the condition. Furthermore, since both 31P and proton MRS abnormalities correlate with neuropsychiatric status, the technique may afford the possibility of an objective and dynamic means of patient monitoring. MRS may also be of use in assessing the effectiveness of various treatment regimens.