The DWI 'reversal sign' of white matter hypoxic ischaemic injury in older children: An unusual MRI pattern for age
We present two children beyond the neonatal and infant age who suffered global hypoxic events and showed an MRI appearance of reversal of the diffusion-weighted (DWI) and apparent diffusion coefficient (ADC) signal involving exclusively the white matter. This is an unusual distribution for this age group and may represent delayed postanoxic leukoencephalopathy. The appearance of this type of insult has been described as occurring in younger children more frequently than in adults. Awareness of this condition, the fact that it may occur earlier, and the peculiar and possibly deceptive DWI/ADC signal reversal pattern exclusively involving the white matter is critical for making a correct diagnosis and giving a prognosis. © 2009 Springer-Verlag.