Witzani Linde, Brugger Peter Christian, Hörmann Marcus, Kasprian Gregor, Csapone-Balassy Csilla, Prayer Daniela
Department of Radiology, Medical University of Vienna, Währinger Gürtel 18-20, A-1090 Vienna, Austria.
Eur J Radiol. 2006 Feb;57(2):294-302. doi: 10.1016/j.ejrad.2005.11.027. Epub 2006 Jan 6.
To evaluate age-dependent changes in fetal kidney measurements with MRI.
Fetal MRI examinations were used to study the kidney length (218 fetuses), signal intensities of renal tissue, renal pelvis, and liver tissue on T2-weighted images (223 fetuses), and the whole-kidney apparent diffusion coefficient (107 fetuses). A 1.5 T superconducting unit with a phased array coil was used in patients from 16 to 39 weeks' gestation. The imaging protocol included T2-weighted single-shot fast spin-echo, T2-weighted balanced angiography and diffusion-weighted sequences. Slice thickness ranged from 3 to 5mm.
Fetal kidney length as a function of gestational age was expressed by the linear regression: kidney length (mm)=0.190 x gestational age (d) -8.034 (R(2) = 0.883, p < 0.001). Paired t-test analysis showed a highly statistically significant difference between the ratio of renal tissue signal intensity to renal pelvis signal intensity and the ratio of liver signal intensity to renal pelvis signal intensity on T2-weighted images (t = -50.963, d.f. = 162, p < 0.001), with renal tissue hyperintense to liver tissue. The apparent diffusion coefficient in relation to gestational age was described by the equation: ADC (microm(2)/s) = 0.0302 x square (gestational age (d)) -14.202 x gestational age (d) +2,728.6 (R(2) = 0.225, p < 0.001).
The length, signal intensity on T2-weighted images, and apparent diffusion coefficient of the fetal kidney change significantly with gestational age. The presented data may help in the prenatal diagnosis of renal anomalies.
通过磁共振成像（MRI）评估胎儿肾脏测量值随年龄的变化。
采用胎儿MRI检查来研究肾脏长度（218例胎儿）、T2加权图像上肾组织、肾盂及肝组织的信号强度（223例胎儿）以及全肾表观扩散系数（107例胎儿）。对妊娠16至39周的患者使用配备相控阵线圈的1.5T超导单元。成像方案包括T2加权单次激发快速自旋回波、T2加权平衡血管造影和扩散加权序列。层厚范围为3至5毫米。
胎儿肾脏长度与胎龄的函数关系通过线性回归表示为：肾脏长度（毫米）=0.190×胎龄（天）-8.034（R² = 0.883，p < 0.001）。配对t检验分析显示，T2加权图像上肾组织信号强度与肾盂信号强度之比和肝信号强度与肾盂信号强度之比之间存在高度统计学显著差异（t = -50.963，自由度 = 162，p < 0.001），肾组织信号强度高于肝组织。表观扩散系数与胎龄的关系由以下方程描述：ADC（μm²/秒）=0.0302×胎龄（天）² -14.202×胎龄（天）+2728.6（R² = 0.225，p < 0.001）。
胎儿肾脏的长度、T2加权图像上的信号强度以及表观扩散系数随胎龄显著变化。所呈现的数据可能有助于胎儿肾脏异常的产前诊断。
