A study on the diagnosis of Alzheimer's disease by cerebral region analysis in PET

Objective: Visual analysis and semiquantitative analysis of cerebral cortex/cerebellum radioactivity ratio are used to diagnose Alzheimer's disease by a new method of dividing the cerebral cortex. Methods: The study includes four groups: Fifteen normal subjects, 15 mild AD patients, 15 moderate AD patients and 15 severe AD patients. All participants received static PET scanning. In the transverse images, we divide the bilateral frontal?parietal and temporal lobes into 16 regions, that is superior frontal lobe, middle frontal lobe, inferior frontal lobe, superior temporal lobe, middle temporal lobe, inferior temporal lobe, superior parietal lobe and inferior parietal lobe. We first use visual analysis to recognize the metabolic abnormalities. Radioactivity ratio as a semiquantitative index were also used in 16 region of cerebral lobes to analyze the characteristics of AD. Results: Fifteen age-matched healthy volunteers show that the radioactivity of all regions are bilaterally symmetric. All 45 AD patients show abnormal radioactivity. The metabolic abnormality grows severer as degree of dementia increased. In mild AD, radioactivity ratio of inferior parietal lobe and middle temporal lobe show statistic significance. In moderate AD, radioactivity ratios of inferior parietal lobe, superior temporal lobe, middle temporal lobe and left superior frontal lobe show statistic significance. In severe AD, all parts show statistic significance. Conclusion: Using cerebral region analysis to diagnose AD is more precise than traditional cerebral lobe analysis especially in early diagnosis.