Hasselbalch H, Nielsen M B, Jeppesen D, Pedersen J F, Karkov J
Department of Radiology, Hvidovre Hospital, University of Copenhagen, Denmark.
Eur Radiol. 1996;6(5):700-3. doi: 10.1007/BF00187675.
A new method of measuring the size of the thymus in infants less than 1 year of age is presented. The width of the thymus was measured in a transverse image while the area of the largest lobe was assessed in a longitudinal image. The thymic index was then defined as the product of these two values. Intra- and interobserver variation analysis were performed in 23 infants. Each infant was scanned alternately by both of two radiologists, and later the same day the measurements were repeated. The mean differences between the first and second measurements (intraobserver variation) were -0.25 (2 SD 7.56) and -1.13 (2 SD 10.80), respectively, for the two observers. The mean difference between the first measurements of the two observers (interobserver variation) was 1.47 (2 SD 9.39). In a postmortem study of 12 infants the thymic index measured by sonography showed an acceptable correlation to the actual volume (c = 0.80) and weight (c = 0.87) of the thymus. In conclusion, our sonographic estimate of the volume of the thymus, the thymic index, in infants under 8 months of age seems to be easy, reliable and reproducible.
本文介绍了一种测量1岁以下婴儿胸腺大小的新方法。在横向图像中测量胸腺宽度，在纵向图像中评估最大叶的面积。然后将胸腺指数定义为这两个值的乘积。对23名婴儿进行了观察者内和观察者间变异分析。两名放射科医生分别交替对每名婴儿进行扫描，同一天晚些时候重复测量。两名观察者第一次和第二次测量之间的平均差异（观察者内变异）分别为-0.25（2标准差7.56）和-1.13（2标准差10.80）。两名观察者第一次测量之间的平均差异（观察者间变异）为1.47（2标准差9.39）。在对12名婴儿进行的尸检研究中，超声测量的胸腺指数与胸腺的实际体积（c = 0.80）和重量（c = 0.87）显示出可接受的相关性。总之，我们对8个月以下婴儿胸腺体积的超声估计，即胸腺指数，似乎简单、可靠且可重复。
