Ching Christopher R K, Hua Xue, Hibar Derrek P, Ward Chadwick P, Gunter Jeffrey L, Bernstein Matt A, Jack Clifford R, Weiner Michael W, Thompson Paul M
Department of Neurology, Neuroscience Graduate Program, UCLA School of Medicine, Los Angeles, CA, USA; Department of Neurology, Imaging Genetics Center, Institute for Neuroimaging & Informatics, University of Southern California, Los Angeles, CA, USA.
Department of Neurology, Imaging Genetics Center, Institute for Neuroimaging & Informatics, University of Southern California, Los Angeles, CA, USA.
Neurobiol Aging. 2015 Jan;36 Suppl 1(0 1):S167-77. doi: 10.1016/j.neurobiolaging.2014.05.039. Epub 2014 Oct 7.
The Alzheimer's Disease Neuroimaging Initiative recently implemented accelerated T1-weighted structural imaging to reduce scan times. Faster scans may reduce study costs and patient attrition by accommodating people who cannot tolerate long scan sessions. However, little is known about how scan acceleration affects the power to detect longitudinal brain change. Using tensor-based morphometry, no significant difference was detected in numerical summaries of atrophy rates from accelerated and nonaccelerated scans in subgroups of patients with Alzheimer's disease, early or late mild cognitive impairment, or healthy controls over a 6- and 12-month scan interval. Whole-brain voxelwise mapping analyses revealed some apparent regional differences in 6-month atrophy rates when comparing all subjects irrespective of diagnosis (n = 345). No such whole-brain difference was detected for the 12-month scan interval (n = 156). Effect sizes for structural brain changes were not detectably different in accelerated versus nonaccelerated data. Scan acceleration may influence brain measures but has minimal effects on tensor-based morphometry-derived atrophy measures, at least over the 6- and 12-month intervals examined here.
阿尔茨海默病神经影像倡议组织最近采用了加速T1加权结构成像技术来缩短扫描时间。更快的扫描速度或许能通过接纳无法耐受长时间扫描的人群来降低研究成本和患者流失率。然而，关于扫描加速如何影响检测纵向脑变化的效能，人们知之甚少。使用基于张量的形态测量法，在阿尔茨海默病患者、早期或晚期轻度认知障碍患者或健康对照者的亚组中，对6个月和12个月扫描间隔内加速扫描和未加速扫描的萎缩率数值汇总进行比较时，未检测到显著差异。全脑体素映射分析显示，在比较所有受试者（无论诊断情况如何，n = 345）时，6个月萎缩率存在一些明显的区域差异。在12个月扫描间隔（n = 156）时未检测到此类全脑差异。加速扫描数据与未加速扫描数据相比，脑结构变化的效应量没有明显差异。扫描加速可能会影响脑测量指标，但至少在此处研究的6个月和12个月间隔内，对基于张量的形态测量法得出的萎缩测量指标影响极小。
