An algorithm for coronary calcification diagnosis based on helical CT images

We describe a computer assisted diagnosis algorithm of coronary calcifications based on helical X-ray CT images which are used at the mass screening process for lung cancer diagnosis. Our diagnostic algorithm consists of three processes: 1) we choose the CT slices including the heart region by recognition of the heart shape and the diaphragm, and we extract the heart region on each slice by the shape of the lung area and the body of vertebra; 2) the candidate regions of the coronary calcifications are detected by the difference calculus and thresholding process; and 3) to increase the effectiveness of the diagnostic processing, we cancel the artifacts included in the candidate regions by the diagnostic rules defined by us. We show here the result of our algorithm which is applied to helical CT images of 461 patients analyzed for lung cancer screening.