[High signal intensity of globus pallidus on T1-weighted MRI in liver cirrhosis patients: clinical and pathological study].

In some patients with liver cirrhosis, the globus pallidus shows high signal intensity on T1-weighted MRI. The relationship was examined between high signal intensity on T1-weighted images and pathological conditions such as liver function, portal venous pressure and metal concentrations in brain. The signal of the globus pallidus on T1-weighted imaging became highly enhanced in accordance with prolongation of prothrombin time, deterioration of ICG R15, or decrease in choline esterase and the Fisher ratio. Furthermore, the high signal intensity was also seen in patients with high portal pressure and large varices. In histopathological study, remarkable atrophy and loss of nerve cells were observed in globus pallidus with high signal intensity on T1-weighted imaging, changes that were similar to those in with patients with manganese poisoning. The manganese concentration in autopsied globus pallidus with high signal intensity on T1-weighted imaging showed a 9.5-fold increase compared with that with normal intensity. In conclusion, the deposition of manganese in the globus pallidus, which is accompanied with the nerve cell deciduation, brings about the high signal intensity of the globus pallidus on T1-weighted MRI in patients with liver cirrhosis.