Improving reliability of Bull's Eye method [SPECT]

Bull's Eye, or polar map, is a semi-automatic method for the quantification and evaluation of coronary artery disease from SPECT tomograms obtained by marking the myocardium with /sup 201/Tl or MIBI /sup 99/Tc. The polar map is computed from cross-sectional slices of the left ventricle (LV). For each slice, the center and a radius of search that contains the LV are determined and the LV is divided into radial sectors. The maximum count value of each sector is computed generating a profile. Profiles are plotted as concentric circle onto the map. The resulting map is a compression of 3D information (LV perfusion) onto a single 2D image. The major problem with this technique is that it is strongly dependent on the operator. The method requires a great deal of operator interaction. The authors present a new method that reduces operator dependence by automatically determining the parameters required for generating the Bull's Eye.<
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