1Aloka Co., Ltd., 2Department of Surgery, Saitama Medical School
Frame rate, Scanning direction, Incident angle, Maximum flow area
To investigate the feasibility of quantitative analysis of Two-Dimensional Doppler, we need to know the physical characteristics of that. For the purpose of quantification of flow display we analysed the influence of frame rate, scanning direction and incident angle by means of computer based simulation. In the simulation flow was set to have sinusoidal flow pattern and as pulsatile. Flow profile in vertical direction to the flow direction was simulated as parabolic shape. The result of the simulation was, 1) As the influence of incident angle, detected flow area was always smaller than the true flow area. 2) The distortion of the display of detected flow to the true flow was larger in the lower frame rate and scanning against the flow direction than the scanning following the flow. 3) In spite of the distortion, if we ignore the influence of incident angle the maximum flow area which was obtained at the different phase in cardiac cycle was the same in each scanning condition. Through the simulation we reached the conclusion that if we can make an adequate angle correction the true maximum flow area can be obtained regardless of the scanning condition.