SUMMARY

Purpose: Applying the brain PET/CT imaging technic in order to define imaging characteristics of cerebral glucose metabolism using 18F-FDG in studying dementia caused by Alzheimer’s Disease in the National Hospital of Geriatrics.
Methods: From 2014 to 2015, 26 demential patients with
clinically definite diagnosis of Alzheimer’s disease were selected from the National Geriatric Hospital and undergone brain 18F-FDG PET/CT scans at the Center of Nuclear Medicine and Oncology - Bach Mai Hospital.
Results: Mean age of Alzheimer’s disease patients is 66.3 ±
8.2 years old and mainly aging over 60 years old (76.7%). Female patients are dominant (female/male ratio is 1.9). 80.8% patients having low scholary - under - graduating and 65% patients living in urban areas. Main risk factors of Alzheimer’s disease patients present in different frequencies as diabetes (23.1%), hypertriglyceride (50%), hypercholesteremia (57,7%), arterosclerosis (29.2%) and
cardiopathy (33.3%). Most of Alzheimer’s disease patients examined at moderate to severe stage (84.6%) and MMSE mean at 13,50±6,24. Brain 18F-FDG PET/CT imaging on 26 Alzheimer’s disease patients shows a glucose hypometabolism in medial temporo-hippocampal
area in 96.2% of cases on left side, meanwhile 92.3% of cases having a hypometabolism in right medial temporo-hippocampal area as well as in bilateral posterior cingulate gyrus. Hypometabolism in temporo - parietal area rates 76.9% on right side and 86.5% on left side. Cerebral metabolism in occipital lobes principally reserved and
partially affected only in 15.4% of cases on right side and 11.5% on left side. Hypometabolism extending to bilateral frontal lobe in a half of cases. Brain glucose metabolism partially reserved at primary moto - sensory cortices, occipital, frontal and cerebellar lobes, as well as in anterior cingulate gyrus. High reservation of glucose metabolism
at basal ganglias in Alzheimer disease (96.2%). Visualisation of glucose hypometabolic Alzheimer like patterns in 92.3% of cases in which 84.6% on both sides and only 2 cases presenting unilaterally on left side (dominant hemisphere). Alzheimer’s disease grading by 18F-FDG PET/CT is correspondent to clinical staging which is not realy high but statistically significant.
Conclusion: Glucose metabolism characteristic imaging in 18F-FDG PET/ CT brain scans is specifically and anatomically regional with high rate in medial
temporo - hippocampal, posterior temporal, temporo parietal and posterior cingulate areas. Frontal lobes and a part of occipital lobes affected in late stage. Principally,
metabolism reserved moderately in cerebellum, occipital lobes, as well as in the
primary moto-sensory cortices, especially well reserved at basal ganglias. 18F-FDG PET/CT imaging characteristics in this study are well correspondent to glucose metabolic patterns in Alzheimer’s disease. With high diagnostic value and important role confirmed in medial literature in discriminative diagnosis of Alzheimer’s disease from other demential forms, as well as in pre-clinical diagnostic ability, brain 18F-FDG PET/CT scan can be considered as a safe and valuable imaging technic in Alzheimer’s Disease studying and clinical practice in particular as well as in dementia in general.