Diffusion-weighted MR imaging in the brain in children:: Findings in the normal brain and in the brain with white matter diseases
Diffusion-weighted MR imaging in the brain in children:: Findings in the normal brain and in the brain with white matter diseases
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DOI：
10.1148/radiol.2222010492
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发表时间：
2002-02-01
期刊：
影响因子：
19.7
通讯作者：
Mödder, U
中科院分区：
文献类型：
--
作者：
Engelbrecht, V;Scherer, A;Mödder, U
目的：建立健康儿童脑白质扩散受限的年龄相关变化的定量标准，并将数据与白质疾病患儿的结果进行比较。
材料与方法：对44名无脑部异常的儿童（年龄范围为7天至7.5岁）和13名确诊为脑白质营养不良的儿童进行扩散加权磁共振成像。在白质内的11个感兴趣区域测量表观扩散系数（ADC）和表观各向异性（AA）。通过回归分析年龄相关变化。
结果：在正常脑髓鞘形成过程中，不同解剖区域的ADC在出生时较高（范围为1.04×10⁻⁹ m²/秒±0.05[标准差]至1.64×10⁻⁹ m²/秒±0.09），在脑成熟后较低（范围为0.75×10⁻⁹ m²/秒±0.02至0.92×10⁻⁹ m²/秒±0.02）。AA在出生时较低（范围为0.05±0.01至0.52±0.04），在脑成熟后较高（范围为0.25±0.02至0.85±0.03）。所有解剖区域的年龄关系都可以用单指数函数表示。各向异性在磁共振成像上髓鞘形成相关变化之前出现。4名佩利措伊斯 - 梅尔茨巴赫病患儿的ADC和AA与健康新生儿的结果相同，且无年龄依赖性。在过氧化物酶体疾病、克拉伯病和线粒体病中，T1和T2加权磁共振图像上的脱髓鞘导致扩散加权磁共振成像出现预期结果，即ADC高而AA低，而在卡纳万病和异染性脑白质营养不良中，结果相反，脱髓鞘的白质内ADC较低。
结论：在早期脑髓鞘形成过程中，正常白质的扩散受限增加。各向异性在磁共振成像可见的髓鞘形成变化之前出现。与T1和T2加权磁共振成像相比，白质疾病的扩散加权磁共振成像揭示了更多信息。
PURPOSE: To establish quantitative standards for age-related changes in diffusion restriction of cerebral white matter in healthy children and to compare data with results in children with white matter diseases.MATERIALS AND METHODS: Diffusion-weighted magnetic resonance (MR) imaging was performed in 44 children (age range, 7 days to 7.5 years) without brain abnormalities and in 13 children with proved leukodystrophy. Apparent diffusion coefficient (ADC) and apparent anisotropy (AA) were measured in 11 regions of interest within white matter. Age-related changes were analyzed with regression analysis.RESULTS: During normal brain myelination, ADCs in different anatomic regions were high at birth (range, 1.04 X 10(-9) m(2)/sec +/- 0.05 [SD] to 1.64 X 10(-9) m(2)/sec +/- 0.09) and low after brain maturation (range, 0.75 X 10(-9) m(2)/sec +/- 0.02 to 0.92 X 10(-9) m(2)/sec +/- 0.02). AA was low at birth (range, 0.05 +/- 0.01 to 0.52 +/- 0.04) and high after brain maturation (range, 0.25 +/- 0.02 to 0.85 +/- 0.03). Age relationship could be expressed with monoexponential functions for all anatomic regions. Anisotropy preceded the myelination-related changes at MR imaging. ADC and AA in four children with Pelizaeus-Merzbacher disease were identical with results in healthy newborn children and showed no age dependency. In peroxisomal disorders, Krabbe disease, and mitochondriopathy, demyelination on T1- and T2-weighted MR images led to expected findings at diffusion-weighted MR imaging, with high ADC and low AA, whereas in Canavan disease and metachromatic leukodystrophy, the opposite findings were revealed, with low ADC within the demyelinated white matter.CONCLUSION: During early brain myelination, diffusion restriction in normal white matter increases. Anisotropy precedes myelination changes that are visible at MR imaging. Compared with T1- and T2-weighted MR imaging, diffusion-weighted MR imaging in white matter diseases reveals additional information.