Mô Tả đặc điểm Hình ảnh Cộng Hưởng Từ Và Hình ảnh18F-FDG PET ...

Description of MR and brain 18F-FDG PET/CT imaging characteristics in Alzheimer’s Disease patients in National Hospital of Geriatrics

SUMMARY

Purpose: Study realised is aimed to describe MRI features as well as brain 18F-FDG PET/CT characteristics of Alzheimer’s Disease patients in the National Hospital of Geriatrics.

Methods: From 2014 to 2015, it is the first time in Vietnam, brain 18F-FDG PET/CT scan applied in studying Alzheimer disease with 32 cases including 16 Aalzheimer patients in pathologic group and 16 non-demential elderly individuals (“Normals” or NLs) in control group, brain 18F-FDG PET/CT scans performed at the Center of Nuclear Medicine and Oncology - Bach Mai Hospital. Brain MRI investigation was also realized for all Alzheimer patients. 18F-FDG PET/CT data in Alzheimer group was confronted to Nls group.

Results: Mean age in AD patients is 65.1± 8.2 years old. Most of AD patients examined at moderate to severe stage (90%). Brain MRI shows 93% AD patients with brain atrophy (mild to severe level), 75% with pathological medial temporal lobe atrophy (abnormal MTA scale) and 81.3% having parietal cortical atrophy. Evan index is higher than normal in 65% of cases. No abnormal regional cortical glucose hypometabolism on brain 18F-FDG PET/ CT imaging seen in all persons in Nls group. On the other hand, in Alzheimer group, 93,8% of cases having a hypometabolism occurred in temporo-parietal association region and 81.3% of cases on right side, meanwhile all Alzheimer patients suffering from a glucose hypometabolism affecting bilateral posterior cingulate gyrus as well as left hippocampus. Occipital glucose metabolism in Alzheimer group is principally well reserved and hypometabolism extending to frontal regions in about a half of all cases.

Conclusion: Most of Alzheimer patients having cerebral degenerative abnormalities on brain MRI presented by multi-grade cerebral parenchymal atrophy. Characteristic atrophic regions in Alzheimer patients include medial temporal and parietal lobes. Glucose hypometabolisme imaging in 18F-FDG PET/CT scans in Alzheimer group is quite specific with anatomically regional hypometabolism patterns seen in temporo-parietal association regions as well as in posterior cingulate gyri, with dominance on left side. Brain MRI and brain 18F-FDG PET/CT scan are wellknown as imaging technics with a high sensibility, high medical safety which are objective valued imaging technics and applied more and more in clinical and recherch Alzheimer disease in particular as well as in dementia in general, helping and taking part in to improve definitive and discriminative diagnostic ability of Alzheimer disease and other dementia.

Key words: Alzheimer’s Disease (AD), MRI, Brain 18F-FDG PET/CT, dementia.