Department of Radiology, University of California, San Diego, La Jolla, CA 92093, USA.
Radiology. 2010 Sep;256(3):932-42. doi: 10.1148/radiol.10091402.
To quantify the effect sizes of regional metabolic and morphometric measures in patients with preclinical and mild Alzheimer disease (AD) to aid in the identification of noninvasive biomarkers for the early detection of AD.
The study was conducted with institutional review board approval and in compliance with HIPAA regulations. Written informed consent was obtained from each participant or participant's legal guardian. Fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET) and magnetic resonance (MR) imaging data were analyzed from 80 healthy control (HC) subjects, 68 individuals with AD, and 156 with amnestic mild cognitive impairment (MCI), 69 of whom had single-domain amnestic MCI. Regions of interest (ROIs) were derived after coregistering FDG PET and MR images by using high-throughput, subject-specific procedures. The Cohen d effect sizes were calculated for 42 predefined ROIs across the brain. Statistical comparison of the largest overall effect sizes for MR imaging and PET was performed. Metabolic effect sizes were determined with and without accounting for regional atrophy. Discriminative accuracy of ROIs showing the largest effect sizes were compared by calculating receiver operating characteristic curves.
For all disease groups, the hippocampus showed the largest morphometric effect size and the entorhinal cortex showed the largest metabolic effect size. In mild AD, the Cohen d effect size for hippocampal volume (1.92) was significantly larger (P < .05) than that for entorhinal metabolism (1.43). Regression of regional atrophy substantially reduced most metabolic effects. For all group comparisons, the areas under the receiver operating characteristic curves were significantly larger for hippocampal volume than for entorhinal metabolism.
The current results show no evidence that FDG PET is more sensitive than MR imaging to the degeneration occurring in preclinical and mild AD, suggesting that an MR imaging finding may be a more practical clinical biomarker for early detection of AD.
量化临床前和轻度阿尔茨海默病（AD）患者的区域性代谢和形态计量测量的效应大小，以帮助确定用于早期检测 AD 的非侵入性生物标志物。
本研究经机构审查委员会批准，并符合 HIPAA 法规。每位参与者或参与者的法定监护人都获得了书面知情同意。对 80 名健康对照（HC）受试者、68 名 AD 患者和 156 名遗忘型轻度认知障碍（MCI）患者的氟 18 氟脱氧葡萄糖（FDG）正电子发射断层扫描（PET）和磁共振（MR）成像数据进行了分析，其中 69 名患者为单域遗忘性 MCI。通过使用高通量、受试者特异性的程序对 FDG PET 和 MR 图像进行配准后，得出了感兴趣区域（ROI）。计算了大脑 42 个预定义 ROI 的 Cohen d 效应大小。对 MR 成像和 PET 的最大总体效应大小进行了统计学比较。在不考虑区域萎缩的情况下，确定了代谢效应大小。通过计算受试者工作特征曲线比较了显示最大效应大小的 ROI 的判别准确性。
对于所有疾病组，海马体显示出最大的形态计量学效应大小，而内嗅皮层显示出最大的代谢学效应大小。在轻度 AD 中，海马体体积的 Cohen d 效应大小（1.92）明显大于（P <.05）内嗅皮层代谢（1.43）。区域萎缩的回归大大降低了大多数代谢效应。对于所有组间比较，海马体体积的受试者工作特征曲线下面积均明显大于内嗅皮层代谢。
目前的结果表明，FDG PET 对临床前和轻度 AD 发生的变性的敏感性并不高于 MR 成像，这表明 MR 成像发现可能是 AD 早期检测更实用的临床生物标志物。
