MR imaging of CNS involvement in children affected by chronic liver disease

BACKGROUND AND PURPOSE: MR imaging sheds new light on CNS involvement in th e course of acquired chronic liver disease; however, the exact pathogenetic mechanisms of hepatic encephalopathy and associated MR abnormalities remai n unclear. Our purpose was to relate MR signal intensity abnormalities of t he CNS to clinical, biochemical, and pathologic features of childhood-onset chronic liver disease. METHODS: Twenty-one patients (12 male and nine female patients) were includ ed in the study; two had Crigler-Najjar disease type 2, 17 had chronic live r disease of different causes, and two had idiopathic copper toxicosis, Twe lve patients had histologically proved liver cirrhosis, with a median disea se duration of 175 months at the time of MR study, None had clinical sympto ms of hepatic encephalopathy, MR imaging was performed using spin-echo T1- and T2-weighted sequences. RESULTS: Eleven patients had abnormal MR imaging findings of the brain reve aled by T1-weighted MR sequences; two of the 11 had idiopathic copper toxic osis, The affected sites were the hypothalamus and globus pallidus, present ing symmetrical and bilateral high signal intensities, or the pituitary gla nd, which appeared homogeneously hyperintense, or both findings. Eight of t he 12 patients with cirrhosis had abnormal MR signals of the brain. In thes e, the median cirrhosis duration was shorter (169 months) than in the remai ning four patients with normal MR signals (177 months). A significant corre lation was found between abnormal MR signals of the brain and cirrhosis (P =.008) and factor V activity (P =.008). CONCLUSION: MR imaging confirms the presence of abnormal brain signals in t he globus pallidus, hypothalamus, and pituitary gland in patients with chil dhood-onset liver disease in the absence of clinical symptoms of encephalop athy, Signal intensity abnormalities are likely caused by an as yet unident ified metabolic process partially correlated with the severity of liver dis ease.