RESUMO
<p><b>OBJECTIVE</b>To investigate the value of conventional magnetic resonance imaging (MRI) and diffusion weighed imaging (DWI) in the differentiation of hypoxic-ischemic encephalopathy (HIE) and acute bilirubin encephalopathy in neonates.</p><p><b>METHODS</b>The MRI findings along with DWI characteristics in 15 neonates with HIE involving basal ganglia and in 18 neonates with acute bilirubin encephalopathy between November 2006 and June 2008 were retrospectively reviewed.</p><p><b>RESULTS</b>On T1WI, only 5 patients presented hyperintensity in the globus pallidus in the HIE group, but 16 in the acute bilirubin encephalopathy group (p<0.01). Nine patients in the HIE group showed hyperintensity in the putamen, but the hyperintensity in the putamen was not found in the acute bilirubin encephalopathy group. The frequency of hyperintensity in the subthalamus in the acute bilirubin encephalopathy group (55.6%) was significantly higher than that in the HIE group (13.3%) (p<0.05). Eight patients in the HIE group showed abnormal signals in the other regions on T1WI, but only two patients in the acute bilirubin encephalopathy group (p<0.05). On DWI, 7 out of 11 patients with HIE presented hyperintensity in the basal ganglia, while all 10 patients of the acute bilirubin encephalopathy group presented normal in the basal ganglia.</p><p><b>CONCLUSIONS</b>Conventional MRI along with DWI is useful in differentiating HIE from acute bilirubin encephalopathy in neonates.</p>