Tangshewinsirikul Chayada, Panburana Panyu
Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand.
J Clin Ultrasound. 2017 Mar 4;45(3):150-159. doi: 10.1002/jcu.22419. Epub 2016 Nov 10.
To establish sonographic reference ranges of the normal fetal thymus size between 17 and 38 weeks of gestational age (GA).
The study was conducted between April 1 and December 31, 2013. Low-risk singleton pregnancies without obstetrical and medical complications at the GAs between 17 and 38 weeks were recruited for thymus measurement. The fetal thymus was identified on transabdominal sonography at the three-vessel view. Maximal transverse diameter, perimeter, and thymus/thoracic ratio were measured. The best-fit models in predicting thymic dimensions as a function of GA and biparietal diameter (BPD) were determined using regression analysis, and percentile charts for predicting thymic dimensions were constructed.
A total of 296 singleton pregnancies were recruited in this study. Maximal transverse diameter, perimeter, and thymus/thoracic ratio increased throughout pregnancy. The regression equation for maximal transverse diameter of the thymus as a function of GA was as follows: Predicted mean thymus diameter (mm) = -25.904 + 2.476 × GA - 0.019 × GA (r = 0.915; p < 0.001) with predicted standard deviations of thymus diameter (mm) = 1.428 + 0.044 × GA (r = 0.017; p < 0.001).
Sonographic reference ranges of the normal fetal thymic dimensions between 17 and 38 weeks of GA have been established. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 45:150-159, 2017.
建立孕17至38周正常胎儿胸腺大小的超声参考范围。
研究于2013年4月1日至12月31日进行。招募孕17至38周无产科及内科并发症的低风险单胎妊娠孕妇进行胸腺测量。经腹部超声在三血管切面识别胎儿胸腺。测量胸腺最大横径、周长及胸腺/胸廓比值。采用回归分析确定预测胸腺大小与孕周及双顶径（BPD）关系的最佳拟合模型，并构建预测胸腺大小的百分位数图表。
本研究共招募296名单胎妊娠孕妇。胸腺最大横径、周长及胸腺/胸廓比值在整个孕期均增加。胸腺最大横径与孕周关系的回归方程如下：预测胸腺平均直径（mm）=-25.904 + 2.476×孕周 - 0.019×孕周²（r = 0.915；p < 0.001），胸腺直径预测标准差（mm）= 1.428 + 0.044×孕周（r = 0.017；p < 0.001）。
已建立孕17至38周正常胎儿胸腺大小的超声参考范围。© 2016威利期刊公司。《临床超声杂志》45:150 - 159，2017年。
