功能连接磁共振成像揭示了发育中大脑的皮质功能连接。
Functional connectivity MR imaging reveals cortical functional connectivity in the developing brain.
作者信息
Lin W, Zhu Q, Gao W, Chen Y, Toh C-H, Styner M, Gerig G, Smith J K, Biswal B, Gilmore J H
机构信息
Department of Radiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
出版信息
AJNR Am J Neuroradiol. 2008 Nov;29(10):1883-9. doi: 10.3174/ajnr.A1256. Epub 2008 Sep 10.
BACKGROUND AND PURPOSE
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.
MATERIALS AND METHODS
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.
RESULTS
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.
CONCLUSIONS
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.
背景与目的
与传统功能磁共振成像不同，传统功能磁共振成像需要外部感觉/认知范式来特异性激活大脑的不同区域，静息功能连接磁共振成像在无认知需求（静息状态）下采集图像，并检测时间上高度相关的脑区。因此，静息功能磁共振成像非常适合用于研究儿科受试者的脑功能发育。本研究旨在确定2周龄至2岁健康儿科受试者静息功能连接（rfc）的时间和空间模式。
材料与方法
对85名儿童进行了rfc研究：38名新生儿（2 - 4周龄）、26名1岁儿童和21名2岁儿童。所有受试者在睡眠状态下成像；未使用镇静剂。选择了六个感兴趣区域，包括每个半球的初级运动、感觉和视觉皮层。使用每个感兴趣区域的平均信号强度在整个大脑中逐像素进行相关分析，识别具有高时间相关性的区域。
结果
在所有受试者的感觉运动和视觉区域均观察到功能连接。表现出rfc的脑体积百分比和rfc的强度从2周龄至2岁持续增加。感觉运动和视觉区域rfc脑体积百分比的生长轨迹似乎有所不同，而z分数相似。2周龄受试者（P = .008）和1岁受试者（P = .017）感觉运动区域rfc的脑体积百分比显著大于视觉区域，但2岁受试者则不然。
结论
这些发现表明，2周龄至1岁时感觉运动区域的rfc先于视觉区域，但在2岁时两者相当。相比之下，所有年龄组感觉运动和视觉区域之间可比的z分数值表明脑体积百分比与皮层rfc强度之间存在分离。
Zotero 插件