^18F-FDG PET和^11C-PIB PET显像对后部皮质萎缩的早期诊断价值

Diagnostic value of ^(18)F-FDG PET and ^(11)C-PIB PET on early stage posterior cortical atrophy

研究背景后部皮质萎缩作为一种以皮质视觉障碍为首发症状的进展性神经变性病,具有临床少见、发病较早、临床表现特殊、早期MRI表现不典型等特点,明确诊断困难。本研究对MRI表现不明显的后部皮质萎缩患者行18F-脱氧葡萄糖(18F-FDG)PET和11C-匹兹堡复合物B(11C-PIB)PET显像,探讨PET显像在后部皮质萎缩早期诊断中的价值。方法选择5例MRI无明显顶枕叶皮质萎缩的后部皮质萎缩患者,分别采用简易智能状态检查量表、蒙特利尔认知评价量表、日常生活活动能力量表和画钟测验评价认知功能,18F-FDG PET和11C-PIB PET显像观察大脑后部皮质葡萄糖代谢和灌注情况。结果神经心理学测验提示5例患者书写能力、计算力、视空间能力、执行功能均明显受损并色觉测试异常。MRI检查后皮质萎缩评分左侧0~2分、平均1分,右侧0~1分、平均0.80分;内侧颞叶萎缩评分左侧1~3分、平均1.80分,右侧1~4分、平均2分;脑室扩大评分左侧1~2分、平均1.80分,右侧1~2分、平均1.60分。18F-FDG PET显示,双侧颞顶枕联合区皮质、楔前叶和扣带回葡萄糖代谢显著降低,额叶和皮质下结构少量降低;11C-PIB PET可见双侧额颞顶枕联合区皮质放射性11C-PIB滞留、小脑皮质廓清。结论对于MRI显示顶枕叶皮质萎缩不明显的后部皮质萎缩患者,18F-FDG PET联合11C-PIB PET显像具有一定早期诊断价值。

Background Posterior cortical atrophy（PCA） is a kind of progressiveneurodegenerative disease with cortical visual impairment as the first symptom. Because of rare clinicalincidence, early onset age, special clinical symptoms and unobvious MRI abnormality, the definitive diagnosisof PCA is difficult. This study used ^18F- fluoro- 2- deoxy- D- glucose（^18F- FDG） PET and11C- Pittsburghcompound B（^11C-PIB） PET for PCA patients with unobvious MRI abnormality, so as to discuss the value ofPET in the early diagnosis of PCA.Methods Five patients diagnosed as PCA in our hospital betweenApril 2012 and March 2015 were enrolled in this study. Cognitive function was measured by Mini-MentalState Examination（MMSE）, Montreal Cognitive Assessment（Mo CA）, Activities of Daily Living（ADL） andClock Drawing Test（CDT）. Brain MRI,^18F-FDG PET and ^11C-PIB PET were performed to analyze glucose metabolism and perfusion of posterior cortex.Results Neuropsychological tests revealed that the ability ofwriting, calculating, visuospatial and executive function of all these patients were impaired. Color visiontests showed abnormal results. MRI showed that the posterior atrophy（PA） scores were 0-2（average 1） onthe left side and 0-1（average 0.80） on the right side. The medial temporal atrophy（MTA） scores were 1-3（average 1.80） on the left side and 1-4（average 2） on the right side. The ventricular enlargement（VE）scores were 1-2（average 1.80） on the left side and 1-2（average 1.60） on the right side.^18F-FDG PETshowed glucose metabolism decreased obviously on bilateral temporo-parieto-occipital cortex, precuneus andcingulate gyrus, and slightly on frontal lobes and subcortical structure.^11C-PIB PET showed radioactive ^11C-PIB deposition on bilateral frontal, temporal, parietal and occipital cortex, and the outline of cerebellarcortex was clear.Conclusions For PCA patients whose parietal and occipital cortical atrophy is notobvious on MRI,^18F-FDG PET combined with11C-PIB PET plays an important role in early diagnosis.