[On-line angle correction of color flow mapping images using a personal computer].

To quantitatively assess flow area or kinetic energy in color flow mapping (CFM), angle correction, which has been totally ignored using current systems, is now considered indispensable. To reconstruct flow images using angle-corrected velocity mapping, we incorporated a personal computer (NEC PC-LT) in the cine-memory of a CFM system (Aloka SSD-870). To demonstrate the effect of angle correction on CFM, the maximum left ventricular diastolic flow images were obtained in seven normal adults using the apical long-axis views where the angle of incidence was less than 10 degrees, and the parasternal long-axis view, where the angle of incidence was between 40 and 60 degrees. A 3.5 MHz probe with a 4 KHz pulse repetition frequency at a frame rate of 10/sec was used. Flow area and kinetic energy of the original and angle correction images in the aliased parts and the total flow areas were calculated and expressed as percent values of the control (color correction image of total flow area in the apical view). The total flow area of the original image in the apical view was 96.4% and 87.2% in the parasternal view, or 98.6% by effective angle correction, and the kinetic energy of the original image in the apical view was 94.0% and 58.8% in the parasternal view, or 93.3% by angle correction. In conclusion, although flow area and kinetic energy of the original image in the parasternal view were significantly less than those of the original and the angle correction images in the apical view (p less than 0.05), they could effectively be evaluated by angle correction. Thus, this system can contribute to quantitative assessment of CFM.