DIFFUSION-WEIGHTED AND MAGNETIZATION TRANSFER-WEIGHTED MRI IN CHILDHOOD MOYA-MOYA

MRI in two children with moya-moya demonstrated low signal on T2-weigh ted images in the acute and subacute phases of ischaemia. Gradient-ech o sequences, more sensitive to magnetic susceptibility, demonstrated t hese abnormalities better. Signal loss, due to temporary accumulation of iron, decreases progressively and disappears in the chronic stage o f the disease. Diffusion-weighted MRI allows early detection of ischae mic lesions and can be used to monitor progressive spreading of the le sions. Magnetisation transfer maps provide sharp contrast, useful for demonstrating cortical atrophy.