Magnetic resonance imaging for the diagnosis of acute leukoencephalopathy in children treated with tacrolimus.

The leukoencephalopathy induced by tacrolimus is increasingly recognised as an important cause of neurological complications after transplantation. Magnetic resonance imaging (MRI) is of major help in the differential diagnosis of infection or vascular injury. We describe two children with coma and seizures after transplantation, in whom the results of MRI with FLAIR (fluid-attenuated inversion-recovery) and DWI (diffusion-weighted images) were the main positive elements for the diagnosis of drug-induced toxicity. The results of DWI favoured the role of oedema and/or demyelination in the pathophysiology of this disorder. Unlike other reported patients, in whom all symptoms resolved, lesions persisted, albeit improved, on the control MRI, and both children demonstrated learning disabilities after several years of follow-up.