Computed Tomography of Hypoxic-ischaemic Brain Injury in Infants, Children, and Adults: Three Illustrative Cases and Literature Review

AYH Wan, JSF Shum, SSW Lo, JCK Lee, ANL Sy, CY Chu, SYJ Ka, SCS Cheng

Hong Kong J Radiol 2011;14:44-8

Global hypoxic-ischaemic injuries to the brain are devastating and result in high mortality and morbidity in both children and adults. We report three cases from different causes of hypoxic-ischaemic injury to the brain in these age-groups. Computed tomography plays an important role in the diagnosis and acute management of this condition. Diffuse hypodense changes with effacement of the cerebrospinal spaces, decreased cortical gray matter attenuation with loss of normal gray-white differentiation, the 'reversal sign' and 'white cerebellum sign' can all be discerned by computed tomography.

However, such changes can be subtle and may mimic other conditions such as subarachnoid haemorrhage and dural sinus thrombosis. Magnetic resonance imaging, including conventional T1- and T2-weighted images, diffusion-weighted imaging and proton spectroscopy are accurate and useful modalities for further evaluating hypoxic-ischaemic brain injury in cases with no overt computed tomography abnormalities. To facilitate prompt patient management, recognition of differing imaging features in infants / young children versus older children / adults is crucial for radiologists and clinicians.

中文摘要

替缺氧缺血性腦損傷的嬰兒、小童及成人作電腦斷層掃描：三個病例報告及文獻回顧

尹宇瀚、岑承輝、盧成瑋、李仲啟、施雅倫、朱志揚、賈亦尊、鄭志成

缺氧缺血性腦損傷無論對小童或成人的破壞性都很大，導致高罹病率及死亡率。本文報告三宗因不同成因而導致缺氧缺血性腦損傷的病例。電腦斷層造影對於分析及緊急處理這類腦損傷扮演著很重要的角色。瀰漫性低密度改變伴有腦脊髓液空間消失會令皮層灰質密度衰減，繼而使灰質／白質失去正常的密度差異。電腦斷層造影可以顯示「反轉徵」及「白色小腦徵」。可是這些變化可以極細微，可能被誤以為是蛛網膜下腔出血和腦靜脈竇栓塞。磁力共振影像（包括常規的T1加權及T2加權）、彌散加權成像及氫質子磁振頻譜都能準確地評估一些缺氧缺血性腦損傷而又無明顯異常CT的病人。要盡快處理病者，臨床醫生和放射科醫生必須要認識嬰兒／小童以及年青人／成人不同的放射學徵狀。