1. To evaluate the difficult balance between emergency, safety of diagnostic procedures and patient information. 2. To learn how to inform the patients' relatives in case of unconscious or irresponsible patient. 3. To learn the criteria for cerebral death and the necessity of appropriate communication with the clinician before information is provided to the family. In this presentation the new classification of posterior fossa malformations will be presented. This classification is based on embryology, making it easier to understand and remember. Embryology and radiological features will play together to teach the audience how to differentiate and diagnose this malformations. Knowing the features of these malformations is important, making it possible to look for them in MR scans, done on the paediatric population, suffering from developmental delay, and will lighten the way to the correct diagnosis. Developmental and genetic classification of mid-hindbrain malformations: 1. Malformations secondary to early anteroposterior and dorsoventral patterning defects, or to misspecification of mid-hindbrain germinal zone. 2. Malformations associated with later generalised developmental disorders that significantly affect the brainstem and cerebellum. 3. Localised brain malformations that significantly affect the brainstem and cerebellum. 4. Combined hypoplasia and atrophy in putative prenatal onset degenerative disorders.