Monique Boukobza1,2. 1. Department of Neuroradiology and Therapeutic Angiography, Assistance publique -Hôpitaux de Paris, Lariboisière-St-Louis-Fernand-Widal University Hospitals, -2, rue Ambroise Paré, 75010, Paris, France. m.boukobza@orange.fr. 2. Department of Radiology, Assistance Publique -Hôpitaux de Paris, Bichat University Hospital, 46 rue Henri Huchard, 75018, Paris, France. m.boukobza@orange.fr.