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有几种结构在超声检查中显示为椭圆或近似椭园形轮廓。椭园形体积使用下列公式计算 V=π/6(D_1 D_2 D_3)〔D_(?)=最大直径〕,其精确度取决于直径的测量和运用椭圆计算模式的适合程度。椭圆形横截面积的计算公式是 A=π/4(D_1 D_2)。这两个公式也同样适用于球形和圆形;球形和圆形可看作为两直径轴相同的椭圆形。将公式 P=π(D_1+D_2)/2延伸用于近似园形周长计算的倾向是不合适的,(例如计算胎儿头围),计算值不精确,所得结果是直径介于椭圆形最大和最小直径轴之间的圆的周长,可能(或不能)近似实际周长。“离心率”或椭圆展平度,以 k~2=1-D~2 最小
There are several structures that appear as elliptical or approximately elliptical outlines in an ultrasound examination. The elliptical volume is calculated using the following formula: V = π / 6 (D_1 D_2 D_3) [D_ (?) = Maximum diameter], the accuracy of which depends on the diameter measurement and the suitability of the elliptical calculation mode. The elliptical cross-sectional area is calculated as A = π / 4 (D_1 D_2). The two formulas apply equally to spheres and circles; spheres and circles can be seen as ellipses that have the same diameter axis. The propensity to extend the formula P = π (D_1 + D_2) / 2 for approximate circular perimeter calculations is not appropriate (eg, calculating the fetal head circumference) and the results are inaccurate. The result is that the diameter is between the largest And the smallest diameter axis of the circumference of the circle, may (or not) approximate the actual circumference. “Centrifugation rate” or ellipse flatness, with k ~ 2 = 1-D ~ 2 minimum