Data from a tomographic scan (14) that provides three-dimensional information about a patient's brain comprises the steps of: filtering and re-sampling (21) the data to produce a three- dimensional image; performing registration (23) to align the three-dimensional image with a reference image (16), using 3-D rigid and/or non-rigid transformations; identifying (25) image features in the aligned image, to identify which voxels or regions of adjacent voxels correspond to image features that represent structures within the brain that are expected to be evident; classifying (26) each voxel within an identified image feature by a voxel score that corresponds to the difference between the attenuation of that voxel and the expected attenuation at that region of the brain; and deducing a cumulative score that combines the voxel scores from all the voxels of at least a region of the brain. This method can provide a medical professional with a rapid indication of the status of the brain tissue, which can be used to guide the selection of treatment to best improve the prospects for a patient, particularly a patient who has had an ischaemic stroke.
TOMOGRAPHIC DATA ANALYSIS