Functional connectivity MR imaging reveals cortical functional connectivity in the developing brain.
Functional connectivity MR imaging reveals cortical functional connectivity in the developing brain.
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DOI：
10.3174/ajnr.a1256
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发表时间：
2008-11
期刊：
影响因子：
--
通讯作者：
Gilmore JH
中科院分区：
文献类型：
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作者：
Lin W;Zhu Q;Gao W;Chen Y;Toh CH;Styner M;Gerig G;Smith JK;Biswal B;Gilmore JH
与传统的功能磁共振成像不同，传统的功能磁共振成像需要外部感觉/认知范例来具体激活大脑的不同区域，而静息功能连接磁共振成像在没有认知需求(一种休息条件)的情况下获取图像，并检测高度时间相关的大脑区域。因此，静息功能磁共振成像非常适合于儿童脑功能发育的研究。本研究旨在确定2周至2岁健康儿科受试者RFC的时间和空间模式。对85名儿童进行了RFC研究：38名新生儿(2-4周大)，26名一岁儿童和21名两岁儿童。所有受试者都是在睡觉时进行成像；没有使用镇静剂。研究人员选择了六个感兴趣的区域，包括每个半球的初级运动皮质、感觉皮质和视觉皮质。每个感兴趣区域的平均信号强度被用来在整个大脑中逐个像素地执行相关性分析，以识别具有高度时间相关性的区域。在所有受试者的感觉运动和视觉区域观察到功能连接。显示RFC的脑体积百分比和RFC强度从2周持续增加到2年。RFC脑体积百分比的增长轨迹在感觉运动区和视觉区似乎不同，而z分数相似。2周龄(P=0.008)和1岁(P=0.017)受试者RFC在感觉运动区的百分比脑体积显著大于视区(P=0.008)，而在2岁组则不明显。这些发现表明，感觉运动的RFC在2周到1岁时先于视觉区域的RFC，但在2岁时变得可比。相比之下，所有年龄段的感觉运动和视觉区域之间的可比z分值表明，大脑体积的百分比和皮质RFC的强度之间没有关联。
Unlike conventional functional MR imaging where external sensory/cognitive paradigms are needed to specifically activate different regions of the brain, resting functional connectivity MR imaging acquires images in the absence of cognitive demands (a resting condition) and detects brain regions, which are highly temporally correlated. Therefore, resting functional MR imaging is highly suited for the study of brain functional development in pediatric subjects. This study aimed to determine the temporal and spatial patterns of rfc in healthy pediatric subjects between 2 weeks and 2 years of age. Rfc studies were performed on 85 children: 38 neonates (2–4 weeks of age), 26 one-year-olds, and 21 two-year-olds. All subjects were imaged while asleep; no sedation was used. Six regions of interest were chosen, including the primary motor, sensory, and visual cortices in each hemisphere. Mean signal intensity of each region of interest was used to perform correlation analysis pixel by pixel throughout the entire brain, identifying regions with high temporal correlation. Functional connectivity was observed in all subjects in the sensorimotor and visual areas. The percent brain volume exhibiting rfc and the strength of rfc continued to increase from 2 weeks to 2 years. The growth trajectories of the percent brain volume of rfc appeared to differ between the sensorimotor and visual areas, whereas the z-score was similar. The percent brain volume of rfc in the sensorimotor area was significantly larger than that in the visual area for subjects 2 weeks of age (P = .008) and 1-year-olds (P = .017) but not for the 2-year-olds. These findings suggest that rfc in the sensorimotor precedes that in the visual area from 2 weeks to 1 year but becomes comparable at 2 years. In contrast, the comparable z-score values between the sensorimotor and visual areas for all age groups suggest a disassociation between percent brain volume and the strength of cortical rfc.