A data processing method for determining a path of a neural fibre in a patient, comprising the steps of:a) acquiring an atlas dataset representing an atlas of a fibrous structure comprising the neural fibreb) acquiring a nerve indicating dataset comprising information suitable for identifying the neural fibre in the patientc) calculating a matched atlas dataset by registering the atlas dataset with the nerve indicating datasetd) obtaining a generic path of the neural fibre from the matched atlas datasete) defining a constraining volume in the patient around the generic path, the constraining volume having at least two end surfaces on which the generic path ends andf) determining the path of the neural fibre between end surfaces using a probabilistic approach, wherein the determined path lies completely within the constraining volume.
