Department of Ultrasound Diagnosis, The Second Xiangya Hospital of Central South University, Changsha, China.
Department of Ultrasound, Guangxi Maternal and Children Health Hospital, Nanning, China.
Prenat Diagn. 2019 Jan;39(1):33-37. doi: 10.1002/pd.5394. Epub 2018 Dec 27.
To develop Z scores for the trachea and main bronchi in normal fetuses.
This was a prospective cross-sectional study in 823 normal singleton fetuses. The tracheal diameter immediately proximal to the bifurcation and the left and right main bronchial diameters were measured from their inner to inner edge in the coronal view. Z scores were created for the trachea and main bronchial diameters using gestational age (GA), femur length (FL), and biparietal diameter (BPD) as independent variables.
Between gestational weeks 20 and 40, the inner diameters of the trachea, left principal bronchi (LPB), and right principal bronchi (RPB) increased from 1.8 to 4.7 mm, 0.8 to 2.2 mm, and 0.9 to 2.3 mm, respectively. A simple linear regression equation was fitted to model the mean of each diameter. There was however significant heteroscedasticity of the standard deviation (SD) with increasing GA, FL, or BPD. Eventually, the following formula was used to calculate Z scores for the diameters: [measured value - equation for mean]/equation for SD.
We have developed Z scores for the fetal trachea and main bronchi by applying standard statistical methods. These Z scores may be useful to evaluate the early development of the respiratory system.
为正常胎儿的气管和主支气管制定 Z 分数。
这是一项在 823 例正常单胎胎儿中进行的前瞻性横断面研究。在冠状面测量气管分叉处近端的气管直径以及左右主支气管的直径，从内缘到内缘进行测量。使用胎龄（GA）、股骨长度（FL）和双顶间径（BPD）作为自变量，为气管和主支气管直径创建 Z 分数。
在妊娠 20 周到 40 周期间，气管、左主支气管（LPB）和右主支气管（RPB）的内径从 1.8 毫米增加到 4.7 毫米、从 0.8 毫米增加到 2.2 毫米、从 0.9 毫米增加到 2.3 毫米。拟合了一个简单的线性回归方程来模拟每个直径的平均值。然而，随着 GA、FL 或 BPD 的增加，标准差（SD）的异方差性显著。最终，采用以下公式计算直径的 Z 分数：[实测值 - 均值方程]/SD 方程。
我们应用标准统计方法为胎儿气管和主支气管制定了 Z 分数。这些 Z 分数可能有助于评估呼吸系统的早期发育。
