Measurement of Brain Perfusion by a MR Perfusion Imaging Called eASL in Children's Cerebral Arteriopathies.

The MR sequence called MR-ASL is used to measure cerebral perfusion in children. This ASL sequence is used with a unique post-labeling delay (PLD) due to the technical impossibility of setting different post-labeling delays. The use of a single post-labeling, chosen by the pediatric radiology department of the Necker hospital, optimal in children without arteriopathy, may not be suitable for the lengthened arterial transit time of the spins marked in the pathological carotid network of a child with arterial disease. Recently, ASL sequences with multiple delays (multi-PLD, called eASL) have been developed to overcome this limitation in arterial disease. To date, their use in the pre- and post-treatment evaluation of a child with acute or chronic arterial disease has not been evaluated. The study hypothesis is that this eASL sequence is more efficient than single-delay ASL in measuring cerebral perfusion. The study will be performed in a population of children with acute or chronic arterial disease.