Imaging diagnosis of acute necrotizing encephalopathy of childhood

Objective To analyze the imaging features of acute necrotizing encephalopathy of childhood (ANEC), and try to investigate its potential clinical value. Methods The clinical and imaging findings of 22 children from Wuhan Children′s Hospital diagnosed with ANEC were retrospective analyzed, from January 2013 to October 2018. All children were presented with hyperpyrexia and rapidly developed into rapid neurological deterioration after prodromic infection. In the initial imaging examination, all patients underwent head MRI, and 6 cases underwent additional head CT. During MRI follow-up, 4 cases were lost, 6 cases were followed up only once ( 14 days).The presence of hemorrhage and encephalomalacia in thalamus, brainstem, white matter and basal ganglia was carefully investigated throughout the follow-up. Results For the imaging manifestations of ANEC, bilateral thalamus were involved in all children. Other symmetrical lesions included white matter (14 cases), basal ganglia (15 cases), brainstem (16 cases), cerebellum (9 cases), corpus callosum (2 cases) and hippocampus (1 case). There were 3 children with asymmetric lesions, which were found in white matter (2 cases) and cerebellum (1 case).In the acute phase, the most typical head MRI showed "tricolor pattern"(high signal intensity in the center with surrounding low-signal, and hyperintense signals in the periphery of thalamus) or "bicolor pattern"(low signal in the central thalamus with surrounding hyperintense signals) of the thalamus on the apparent diffusion coefficient (ADC) imaging. Hemorrhage and encephalomalacia on MRI may suggest poor clinical outcome. Conclusions ANEC is a rapid progressive encephalopathy with typical imaging features. Hemorrhage and encephalomalacia on MRI may be associated with poor prognosis. Key words: Brain diseases; Child; Magnetic resonance imaging; Thalamus