The disclosure relates to an image processing method for estimating a brain shift in a patient, the method involving: the processing of a three-dimensional image of the brain of a patient, acquired before a surgical operation, in order to obtain a reference cerebral arterial tree structure of the patient the processing of three-dimensional images of the brain of the patient, acquired during the operation, in order to at least partially reconstitute a current cerebral arterial tree structure of the patient the determination from the combination of the reference and current cerebral arterial tree structures, of a field of shift of the vascular tree representing the shift of the current vascular tree in relation to the reference vascular tree the application of the determined field of shift of the vascular tree to a biomechanical model of the brain of the patient in order to estimate the brain shift of the patient and the generation, from the estimated brain shift, of at least one image of the brain of the patient, in which the brain shift is compensated.
