MR differential diagnosis of acute deep grey matter pathology in paediatric patients.

A high metabolic demand, rich vascularization and high concentrations of ionic elements leading to the generation of oxygen free radicals, give to the deep grey matter (DGM) nuclei specific susceptibility to both acute and chronic insults, especially in paediatric patients. Reaching a diagnosis in the early stages of acute diseases in many patients is crucial for instigating prompt specific therapy leading to a favourable outcome. On the basis of a review of a 10-year in-house database and a review of the literature on CNS pathology involving the DGM nuclei in paediatric patients, we summarize the MR findings and clinical clues that may help the radiologist in the difficult differential diagnosis process. The terms "acute" and "chronic" refer to the clinical onset of the disease. MR imaging allows the detection of an injury, determination of its precise anatomical location and characterization of the signal changes. This, combined with a knowledge of specific MRI patterns, may be a roadmap to a definite diagnosis. Clinical history, physical and laboratory findings, timing of the MR examination and advanced MR imaging techniques (diffusion-weighted imaging and (1)H-MR spectroscopy), are crucial in some patients.