[Clinical usefulness of RI angiography using amplitude image and phase image by Fourier analysis for the detection of anteroseptal myocardial infarction (author's transl)].

: In 19 patients with anteroseptal myocardial infarction, the wall motion of interventricular septum was analyzed by RI angiography using the amplitude image and the phase image. Both images were obtained from ECG gated blood pool data by Fourier analysis. Namely, from the first harmonic in the Fourier series, the heart motion was detected as the amplitude and phase of time-activity curve in each pixel. The distribution of the amplitudes and phases were displayed in color scale, and then both the amplitude and phase images were acquired. Those images allowed us visualization of the ischemic area, even if the scar was parallel to the detector. Moreover, we were able to assess the wall motion of the entire interventricular septum and to distinguish hypokinetic region and dyskinetic region from the hypokinetic region with shift of phase estimated by conventional method. Abnormal region detected by those images closely corresponded with the region of decreased radioisotope concentration in thallium-201 myocardial scintigram.