MR imaging of CNS involvement in children affected by chronic liver disease.
BACKGROUND AND PURPOSE: MR imaging sheds new light on CNS involvement in the course of acquired chronic liver disease; however, the exact pathogenetic mechanisms of hepatic encephalopathy and associated MR abnormalities remain unclear. Our purpose was to relate MR signal intensity abnormalities of the CNS to clinical, biochemical, and pathologic features of childhood-onset chronic liver disease. METHODS: Twenty-one patients (12 male and nine female patients) were included in the study; two had Crigler-Najjar disease type 2, 17 had chronic liver disease of different causes, and two had idiopathic copper toxicosis. Twelve patients had histologically proved liver cirrhosis, with a median disease duration of 175 months at the time of MR study. None had clinical symptoms 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 revealed by T1-weighted MR sequences; two of the 11 had idiopathic copper toxicosis. The affected sites were the hypothalamus and globus pallidus, presenting symmetrical and bilateral high signal intensities, or the pituitary gland, which appeared homogeneously hyperintense, or both findings. Eight of the 12 patients with cirrhosis had abnormal MR signals of the brain. In these, the median cirrhosis duration was shorter (169 months) than in the remaining four patients with normal MR signals (177 months). A significant correlation 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 the globus pallidus, hypothalamus, and pituitary gland in patients with childhood-onset liver disease in the absence of clinical symptoms of encephalopathy. Signal intensity abnormalities are likely caused by an as yet unidentified metabolic process partially correlated with the severity of liver disease.