In brain tumor surgery we are confronted mainly with two types of difficulties: (i) the identification of the tumor and its limitations in relation to the healthy brain; (ii) the identification of functional cerebral regions, ie implicated in neurological function (motor skills, sensitivity, language, vision, cognition, etc.). The reference method currently used to improve the quality of resection of brain tumors while minimizing neurological risk for patients is so called "wakeful" surgery with direct electrical stimulation (DES) of the brain. The investigators routinely use ultrasound to localize the tumor within the brain, but to date there is no pre- or intra-operative imaging tool to reliably identify tumors and functional brain regions. There is therefore a need for innovative imaging in this field.