SKULL, MRI. Photo essay at the regional hospital complex of Lille, France, hospital Roger Salengro, department of neurosurgery, Gamma knife. Treatment of an acoustic neuroma by stereotaxic radiosurgery Gamma knife. The neurosurgeon is processing the data acquired by Scanner and MRI. Two systems of imagery that can be combined to increase the accuracy and a better definition of lesion borders. A schwannoma of the auditory nerve, also called acoustic neuroma is a benign tumor of Schwann cells form