Yakushev Igor, Landvogt Christian, Buchholz Hans-Georg, Fellgiebel Andreas, Hammers Alexander, Scheurich Armin, Schmidtmann Irene, Gerhard Alexander, Schreckenberger Mathias, Bartenstein Peter
Department of Nuclear Medicine, University of Mainz, Mainz, Germany.
Psychiatry Res. 2008 Nov 30;164(2):143-53. doi: 10.1016/j.pscychresns.2007.11.004. Epub 2008 Oct 19.
At present, there is still no consensus on the choice of the reference area in positron emission tomography (PET) studies of Alzheimer's disease (AD). In this study, PET scans with fluorodeoxyglucose-F18 were carried out in the following groups of subjects: 47 patients with probable AD, 8 patients with mild cognitive impairment, and 15 age-similar healthy subjects. Scans normalized to the cerebral global mean (CGM), cerebellum (CBL), and the primary sensorimotor cortex (SMC). We evaluated the effect of the different count normalization procedures on the accuracy of (18)F-FDG PET to detect AD-specific metabolic abnormalities (voxel-based group comparison) and to differentiate between patients and healthy subjects (ROI-based discriminant analysis) with regard to the degree of clinical deterioration. Metabolic reductions in groups of very mildly, mildly and moderate-to-severely affected patients appeared, respectively, 2.2, 2.6, and 2.7 times greater in spatial extent when tracer uptake was normalized to SMC rather than to CGM. The overall accuracy of discrimination was 94%, 91%, and 80% after normalization to SMC, CBL, and CGM, respectively. In general, normalization to SMC was somewhat superior to cerebellar normalization, allowing the detection of more pronounced metabolic deficits and the more accurate discrimination of patients from non-patients. Normalization to CGM should be used with great caution not only in advanced stages of dementia, but also in very mild AD cases.
目前，在阿尔茨海默病（AD）的正电子发射断层扫描（PET）研究中，关于参考区域的选择仍未达成共识。在本研究中，对以下几组受试者进行了氟代脱氧葡萄糖-F18的PET扫描：47例可能患有AD的患者、8例轻度认知障碍患者和15名年龄相仿的健康受试者。扫描结果分别归一化至大脑全局均值（CGM）、小脑（CBL）和初级感觉运动皮层（SMC）。我们评估了不同计数归一化程序对（18）F-FDG PET检测AD特异性代谢异常（基于体素的组间比较）以及区分患者和健康受试者（基于感兴趣区域的判别分析）在临床恶化程度方面准确性的影响。当示踪剂摄取归一化至SMC而非CGM时，极轻度、轻度和中度至重度受影响患者组的代谢降低在空间范围上分别增大2.2倍、2.6倍和2.7倍。归一化至SMC、CBL和CGM后，总体判别准确率分别为94%、91%和80%。一般来说，归一化至SMC略优于小脑归一化，能够检测到更明显的代谢缺陷，并更准确地区分患者与非患者。不仅在痴呆晚期，而且在非常轻度的AD病例中，归一化至CGM都应极其谨慎地使用。
