Szpinda Michał, Paruszewska-Achtel Monika, Woźniak Alina, Badura Mateusz, Mila-Kierzenkowska Celestyna, Wiśniewski Marcin
Department of Normal Anatomy, The Ludwik Rydygier Collegium Medicum in Bydgoszcz, The Nicolaus Copernicus University in Toruń, Łukasiewicza 1 Street, 85-821, Bydgoszcz, Poland,
Surg Radiol Anat. 2015 Jul;37(5):439-48. doi: 10.1007/s00276-015-1437-4. Epub 2015 Feb 3.
The fetal liver is indubitably the earliest and the most severely affected organ by abnormal fetal growth. The size of the fetal liver assessed by three-dimensional ultrasonography is indispensable in determining the status of fetal growth, nutrition and maturity, and in the early recognition and monitoring fetal micro- and macrosomias. The aim of the present study was to measure the human fetal liver length, transverse and sagittal diameters to establish their age-specific reference intervals, the 3rd, 10th, 50th, 90th, and 97th smoothed centile curves, and the relative growth of the liver calculated for the 50th centile.
Using anatomical, digital (NIS-Elements AR 3.0, Nikon) and statistical methods (one-way ANOVA test for paired data and post hoc RIR Tukey test, Shapiro-Wilk test, Fisher's test, Student's t test, the Altman-Chitty method), length, transverse and sagittal diameters of the liver for the 3rd, 10th, 50th, 90th, and 97th centiles were assessed in 69 human fetuses of both sexes (32 males and 37 females) aged 18-30 weeks, derived from spontaneous abortions or stillbirths.
No male-female differences (P > 0.05) concerning the three parameters studied were found. During the study period, the fetal liver increased tri-dimensionally: in length from 19.51 ± 1.02 to 39.65 ± 7.05 mm, in transverse diameter from 29.44 ± 3.73 to 53.13 ± 5.31 mm, and in sagittal diameter from 22.97 ± 3.79 to 43.22 ± 5.49 mm. The natural logarithmic models were found to fit the data with gestational age (P < 0.001) in the following five cutoff points: 3rd, 10th, 50th, 90th and 97th centiles. The values of liver parameters in relation to gestational age in weeks were calculated by the following logarithmic regressions: y = -82.778 + 35.752 × ln(age) ± Z × (-2.778 + 0.308 × age) for liver length, y = -123.06 + 52.668 × ln(age) ± Z × (3.156 + 0.049 × age) for liver transverse diameter, and y = -108.94 + 46.052 × ln(age) ± Z × (-0.541 + 0.188 × age) for liver sagittal diameter. For the 50th centile, at the range of 18-30 weeks, the growth rates per week were gradually decreasing from 1.93 to 1.21 mm for length, from 2.85 to 1.79 mm for transverse diameter, and from 2.49 to 1.56 mm for sagittal diameter of the liver (P < 0.05). During the study period both the length-to-transverse diameter ratio and the sagittal-to-transverse diameter ratio of the liver changed little, attaining the values of 0.71 ± 0.11 and 0.87 ± 0.12, respectively.
The fetal liver does not reveal sex differences in its length, transverse and sagittal diameters. The fetal liver length, transverse and sagittal diameters grow logarithmically. The regression equations for the estimation of the mean and standard deviation of liver length, transverse and sagittal diameters allow for calculating any desired centiles according to gestational age. The three-dimensional evolution of the fetal liver follows proportionately. The age-specific reference intervals for evolving liver length, transverse and sagittal diameters constitute the normative values of potential relevance in monitoring normal fetal development and screening for disturbances in fetal growth.
胎儿肝脏无疑是受胎儿生长异常影响最早且最严重的器官。通过三维超声测量胎儿肝脏大小对于确定胎儿生长、营养和成熟状况，以及早期识别和监测胎儿小样儿和巨大儿至关重要。本研究的目的是测量人类胎儿肝脏的长度、横径和矢状径，以建立其年龄特异性参考区间、第3、10、50、90和97平滑百分位数曲线，以及计算第50百分位数的肝脏相对生长情况。
采用解剖学、数字（NIS-Elements AR 3.0，尼康）和统计学方法（配对数据的单因素方差分析及事后RIR Tukey检验、Shapiro-Wilk检验、Fisher检验、Student's t检验、Altman-Chitty方法），对69例年龄在18 - 30周的男女胎儿（32例男性和37例女性）的肝脏长度、横径和矢状径进行评估，这些胎儿来自自然流产或死产。
在所研究的三个参数方面未发现男女差异（P > 0.05）。在研究期间，胎儿肝脏三维增长：长度从19.51 ± 1.02毫米增加到39.65 ± 7.05毫米，横径从29.44 ± 3.73毫米增加到53.13 ± 5.31毫米，矢状径从22.97 ± 3.79毫米增加到43.22 ± 5.49毫米。发现自然对数模型在以下五个百分位数切点与胎龄拟合数据（P < 0.001）：第3、10、50、90和97百分位数。通过以下对数回归计算与孕周相关的肝脏参数值：肝脏长度，y = -82.778 + 35.752 × ln(年龄) ± Z × (-2.778 + 0.308 × 年龄)；肝脏横径，y = -123.06 + 52.668 × ln(年龄) ± Z × (3.156 + 0.049 × 年龄)；肝脏矢状径，y = -108.94 + 46.052 × ln(年龄) ± Z × (-0.541 + 0.188 × 年龄)。对于第50百分位数，在18 - 30周范围内，肝脏长度每周增长率从1.93毫米逐渐降至1.21毫米，横径从2.85毫米降至1.79毫米，矢状径从2.49毫米降至1.56毫米（P < 0.05）。在研究期间，肝脏的长宽比和矢状径与横径比变化不大，分别达到0.71 ± 0.11和0.87 ± 0.12。
胎儿肝脏的长度、横径和矢状径不存在性别差异。胎儿肝脏的长度、横径和矢状径呈对数增长。用于估计肝脏长度、横径和矢状径均值及标准差的回归方程可根据孕周计算任何所需的百分位数。胎儿肝脏的三维演变成比例。不断变化的肝脏长度、横径和矢状径的年龄特异性参考区间构成了监测正常胎儿发育和筛查胎儿生长障碍潜在相关的规范值。
