Samuraki Miharu, Matsunari Ichiro, Chen Wei-Ping, Yajima Kazuyoshi, Yanase Daisuke, Fujikawa Akihiko, Takeda Nozomi, Nishimura Shintaro, Matsuda Hiroshi, Yamada Masahito
Department of Neurology and Neurobiology of Aging, Kanazawa University Graduate School of Medical Science, Kanazawa, Japan.
Eur J Nucl Med Mol Imaging. 2007 Oct;34(10):1658-69. doi: 10.1007/s00259-007-0454-x. Epub 2007 May 23.
Although( 18)F-fluorodeoxyglucose (FDG) PET is an established imaging technique to assess brain glucose utilisation, accurate measurement of tracer concentration is confounded by the presence of partial volume effect (PVE) due to the limited spatial resolution of PET, which is particularly true in atrophic brains such as those encountered in patients with Alzheimer's disease (AD). Our aim was to investigate the effects of PVE correction on FDG PET in conjunction with voxel-based morphometry (VBM) in patients with mild AD.
Thirty-nine AD patients and 73 controls underwent FDG PET and MRI. The PVE-corrected grey matter PET images were obtained using an MRI-based three-compartment method. Additionally, the results of PET were compared with grey matter loss detected by VBM.
Before PVE correction, reduced FDG uptake was observed in posterior cingulate gyri (PCG) and parieto-temporal lobes (PTL) in AD patients, which persisted after PVE correction. Notably, PVE correction revealed relatively preserved FDG uptake in hippocampal areas, despite the grey matter loss in medial temporal lobe (MTL) revealed by VBM.
FDG uptake in PCG and PTL is reduced in AD regardless of whether or not PVE correction is applied, supporting the notion that the reduced FDG uptake in these areas is not the result of atrophy. Furthermore, FDG uptake by grey matter tissue in the MTL, including hippocampal areas, is relatively preserved, suggesting that compensatory mechanisms may play a role in patients with mild AD.
虽然（18）F - 氟脱氧葡萄糖（FDG）PET是一种用于评估脑葡萄糖利用情况的成熟成像技术，但由于PET空间分辨率有限，部分容积效应（PVE）的存在会干扰示踪剂浓度的准确测量，在萎缩性脑（如阿尔茨海默病（AD）患者的脑）中尤其如此。我们的目的是研究PVE校正对轻度AD患者FDG PET联合基于体素的形态学测量（VBM）的影响。
39例AD患者和73例对照者接受了FDG PET和MRI检查。使用基于MRI的三室法获得经PVE校正的灰质PET图像。此外，将PET结果与VBM检测到的灰质损失进行比较。
在PVE校正前，AD患者的后扣带回（PCG）和顶颞叶（PTL）FDG摄取减少，PVE校正后仍持续存在。值得注意的是，尽管VBM显示内侧颞叶（MTL）存在灰质损失，但PVE校正显示海马区的FDG摄取相对保留。
无论是否应用PVE校正，AD患者PCG和PTL的FDG摄取均减少，支持这些区域FDG摄取减少并非萎缩所致的观点。此外，MTL包括海马区的灰质组织的FDG摄取相对保留，提示代偿机制可能在轻度AD患者中起作用。
