LEFT-VENTRICULAR MOTION ANALYSIS OF 4-D SPECT IMAGING USING NORMAL DIRECTION CONSTRAINT

For medical imaging, non-rigid motion analysis of the heart deformabil ity is a nontrivial problem. This paper introduces a new method to ana lyze the gated SPECT (Single Photon Emission Computed Tomography) imag es for 3-D motion information of left ventricular. Our motion estimati on method is based on a new concept called ''normal direction constrai nt'' in that the normal of a surface patch of some deforming objects a t certain time instant is constant. This paper consists of the followi ng processes: contour extraction, slices interpolation, normal vector field generation, expanding process, motion estimation for producing a 2-D motion vector field, and deprojection for a 3-D motion vector fie ld. In the experiments, we will demonstrate the accuracy of our method in analyzing the 3-D motion field of deforming object.