Abstract: Methods and related computational techniques are presented for analyzing images from various scan modalities, such as computerized tomography (“CT”). The methods convert image values to relative differences, to highlight side-to-side asymmetry. The conversion may be performed by comparing a small region of the scan to the corresponding region in the contralateral hemisphere, quantifying the degree of relative difference using statistical techniques, and representing this quantity of relative difference in a two dimensional or three dimensional relative difference map. In exemplary embodiments the method involves assigning an axis or plane of symmetry to a medical image, computing, using the image data, at least one relative difference map based on a comparison of two substantially symmetrical areas around the axis of symmetry, and generating a representation of any relative difference between the two symmetrical areas.

Abstract: A method and related software are provided for analyzing images such as computerized tomography images obtained from a standard perfusion CT software package. This method converts image values to relative differences, which represents meaningful side-to-side asymmetry. This conversion may be performed by comparing a small region of the scan to the corresponding region in the contralateral hemisphere, quantifying the degree of relative difference using statistical techniques, and representing this quantity of relative difference in a two dimensional or three diemnsional relative difference map.