Haskin P H, Goodman L R
AJR Am J Roentgenol. 1982 Nov;139(5):879-82. doi: 10.2214/ajr.139.5.879.
The tracheal bifurcation angle was measured in 100 normal adult patients. A wide range of normal values was found. There was no relation of the bifurcation angle to age or gender. There was only a weak correlation between bifurcation angle and height or width or the thorax. Thus, absolute measurements of the tracheal bifurcation angles are of little diagnostic value. In addition, when the angle was measured on two successive films, large changes (greater than 20%) were noted about 20% of patients.
对100例正常成年患者测量了气管分叉角度。发现正常数值范围较宽。分叉角度与年龄或性别无关。分叉角度与身高、胸廓宽度或胸廓之间仅有微弱的相关性。因此，气管分叉角度的绝对测量值诊断价值不大。此外，在连续两张X线片上测量角度时，约20%的患者出现了较大变化（大于20%）。
