MR OF THE BRAIN IN CHILDREN

MR imaging has firmly established its place as the cornerstone of pedi atric neuroimaging. Recent advances in MR imaging have led to decrease d imaging time, high resolution studies, and new methods for obtaining tissue contrast. Magnetic resonance angiography (MRA) now obviates th e need for angiography in some children, although its extended role is still to be defined. Normal and-abnormal development and myelination patterns have been further defined with MR imaging. The patterns of br ain injury resulting from hypoxia and ischemia vary with the degree of the insult as well as the gestational age of the child. These pattern s of hypoxic-ischemic encephalopathy can be analyzed to determine when the insult occurred. Neuronal migration disorders and phakomatoses:da n be diagnosed with confidence at an early age, thus facilitating gene tic counseling. MR imaging can detect the most common lesions associat ed with childhood: epilepsy, such as hippocampal sclerosis, focal cort ical dysplasias, and low-grade tumors. Other areas, including pediatri c AIDS, toxicity-related ,injury,. metabolic/mitochondrial conditions, and disorders associated with iatrogenic injury, can be diagnosed wit h MR. Spectroscopy provides information that should prove useful in ev aluating and monitoring neuronal and other brain tissue disorders in c hildren.