Cerebral magnetic resonance imaging in patients with chronic liver disease

Bilateral, symmetrical hyperintensity of the globus pallidus is observed in T-1-weighted cerebral magnetic resonance images in from 52 to 100% of pati ents with chronic liver disease. No significant relationship exists between the presence of these cerebral changes in image signal intensity and the p atients' neuropsychiatric status. However, their presence significantly rel ates to both the severity of the liver disease and the presence and degree of portal-systemic shunting of blood. This shortening of the T-1-relaxation time is associated with pallidal deposition of manganese most likely refle cting the presence of an adaptive process designed to improve the efficacy of ammonia detoxification by astrocytes. Future studies employing magnetic resonance imaging techniques to obtain information on cerebral function or combined with magnetic resonance spectroscopy to obtain localized biochemic al information might further our understanding of the pathogenesis of hepat ic encephalopathy in cirrhotic patients.