The Study of Two Dimensional Polar Representation of Cardiac SPECT Image

—A new method to display left ventricular wall motion—

Abstract

A new method was developed to display left ventricular wall motion using two dimensional polar representation of cardiac SPECT image. After intravenous administration of 740 MBq (20 mCi) ^99mTe (in vivo labeling of red blood cell), ECG-gated SPECT image of cardiac pool was recorded (32 directions, 180 degrees) . The short axis images of left ventricle were constructed at end-diastole (ED) and end-systole (ES) . Then the functional images of (ED-ES) /ED were calculated at each compatible slices and displayed in color according the degree of wall motion. In 8 cases with cardiac diseases this method was applied and clinically useful functional images could be obtained. The area of akinesia or hypokinesia are successfully demonstrated clearly separated from the area of normokinesia. We conclude that this method is useful to show left ventricular wall motion and to evaluate the segment and grade of abnormal wall motion of left ventricle.