Fourier-phase imaging can be used to objectively analyze myocardial contrast echocardiograms

To objectively display myocardial opacification following intravenous injection of ultrasound contrast agents, we applied a first harmonic Fourier transformation to precordial harmonic Power-Doppler images in 21 patients undergoing Tl-201-SPECT, in 13 control subjects, and to epicardial second harmonic B-mode images in 10 patients undergoing CABG. Temporal and spatial distribution of myocardial intensities were analyzed. Marked temporal delays (phase shift 106±90°), and low intensities (30±20) were found in 13/14 perfusion defects. Epicardial imaging showed higher intensity increases in septal (Δ 40±22) than in posterolateral segments (Δ 20±10, p<0.005) but regional phase angles were not different (Δ 47±11°, n.s.), indicating homogenous resting perfusion. Thus, Fourier analysis can be applied to Power-Doppler- and epicardial harmonic B-mode images to display myocardial opacification in a simple objective format