From the Department of Diagnostic and Interventional Neuroradiology (I.R., C.P., C.Z.), Department of Diagnostic and Interventional Radiology (I.R.), Department of Nuclear Medicine (K.P.B., E.W., S.F.), TUM Neuroimaging Center (TUM-NIC) (C.P., S.F.), and Departments of Psychiatry and Psychotherapy (P.A.), Klinikum Rechts der Isar, Technische Universität München, Ismaninger Str 22, 81675 Munich, Germany.
Radiology. 2018 Jul;288(1):198-206. doi: 10.1148/radiol.2018170575. Epub 2018 May 15.
Purpose To compare PET/MR hypoperfusion and hypometabolism in patients with Alzheimer disease (AD) and mild cognitive impairment (MCI) compared with healthy control (HC) participants. Materials and Methods Maps of cerebral blood flow (CBF; pulsed arterial spin-labeling [ASL] MRI), glucose metabolism (fluorine 18 [F] fluorodeoxyglucose [FDG] PET), and gray matter (GM) volume (structural T1-weighted MRI) were calculated from integrated PET/MR data in 45 patients with AD (mean age, 69 years ± 9 [standard deviation]; age range, 51-89 years), 20 patients with MCI (mean age, 64 years ± 10; age range, 45-82 years), and 11 HC participants (mean age, 65 years ± 8; age range, 54-80 years) between 2011 and 2014. After preprocessing, voxel-wise analyses of variance, volume of interest, and independent component analyses were performed for comparisons of CBF and glucose metabolism. Results Analyses revealed high overlap between components, regional and quantitative hypoperfusion, and hypometabolism in patients with AD compared with HC participants in precuneus, parietal, temporal, and occipital cortex. In patients with MCI compared with HC participants, FDG PET exclusively demonstrated quantitative hypometabolism and a component in the precuneus. Volume-of-interest analysis in global GM in patients with AD compared with HC participants showed lower CBF (42 mL/100 g per minute ± 8 vs 49 mL/100 g per minute ± 7, respectively; P = .035) and lower FDG uptake (0.8 ± 0.1 vs 1 ± 0.1, respectively; P < .001). Conclusion In patients with AD, pulsed ASL MRI revealed regional and quantitative abnormalities and components similar to F-FDG PET with a reduced extent. In patients with MCI, F-FDG PET exclusively demonstrated quantitative hypometabolism and a component in the precuneus, indicating higher sensitivity to detect preclinical AD compared with the currently used pulsed ASL MRI sequence.
目的 比较正电子发射断层扫描/磁共振（PET/MR）灌注和代谢低下在阿尔茨海默病（AD）和轻度认知障碍（MCI）患者与健康对照（HC）参与者中的表现。
材料与方法 从 2011 年至 2014 年期间纳入的 45 例 AD 患者（平均年龄 69 岁±9[标准差]；年龄范围，51-89 岁）、20 例 MCI 患者（平均年龄 64 岁±10；年龄范围，45-82 岁）和 11 例 HC 参与者（平均年龄 65 岁±8；年龄范围，54-80 岁）的整合 PET/MR 数据中计算了脑血流（CBF；脉冲动脉自旋标记[ASL]MRI）、葡萄糖代谢（氟 18[F]氟脱氧葡萄糖[FDG]PET）和灰质（GM）体积（结构 T1 加权 MRI）图。预处理后，对 CBF 和葡萄糖代谢进行了方差分析、感兴趣区和独立成分分析。
结果 分析显示，与 HC 参与者相比，AD 患者的脑区包括楔前叶、顶叶、颞叶和枕叶存在高重叠的成分、区域性和定量低灌注及低代谢。与 HC 参与者相比，MCI 患者仅在楔前叶存在 FDG PET 定量低代谢和一个成分。与 HC 参与者相比，AD 患者的全脑 GM 体积分析显示 CBF 较低（分别为 42 mL/100 g/分钟±8 和 49 mL/100 g/分钟±7；P =.035）和 FDG 摄取较低（分别为 0.8±0.1 和 1±0.1；P<.001）。
结论 在 AD 患者中，脉冲 ASL MRI 显示了区域性和定量异常以及与 F-FDG PET 相似的成分，且范围较小。在 MCI 患者中，FDG PET 仅在楔前叶显示出定量低代谢和一个成分，表明与目前使用的脉冲 ASL MRI 序列相比，对检测临床前 AD 具有更高的敏感性。
