RT Journal Article
SR Electronic
T1 Lewy body dementia and Posterior cortical variant of Alzheimer’s disease: Distinguishing imaging patterns based on 18F-FDG PET/CT and 99mTc-TRODAT SPECT scan
JF Journal of Nuclear Medicine
JO J Nucl Med
FD Society of Nuclear Medicine
SP 1491
OP 1491
VO 60
IS supplement 1
A1 Vanshika Gupta
A1 Ritu Verma
A1 Rajeev Ranjan
A1 Ethel Belho
A1 Harsh Mahajan
YR 2019
UL http://jnm.snmjournals.org/content/60/supplement_1/1491.abstract
AB 1491Objectives: To establish differences in imaging patterns of Posterior cortical atrophy (PCA), and Dementia with Lewy bodies (DLB) on 18F-FDG PET/CT using 99mTc-TRODAT scan as the scintigraphic gold standard. Methods: 64 patients of clinically suspected posterior dementia were retrospectively analysed. All patients underwent 18F-FDG PET/CT scan of the brain and dopamine transporter imaging with 99mTc-TRODAT-1 SPECT scan on two consecutive days. The studies were analysed both visually and semi-quantitatively. The patients were divided into possible PCA with TRODAT scan normal (n=32) and possible DLB with TRODAT scan abnormal (n=32). The FDG PET/CT uptake patterns were recorded and areas of hypometabolism that were two standard deviations from the mean were considered as abnormal. Results: All patients had abnormal pattern of FDG uptake on PET. PCA group demonstrated significantly reduced metabolism in the parieto-temporo-occipital association cortices and cingulate cortices. DLB patients showed significantly reduced uptake in the visual cortex (medial occipital cortex) with variable involvement of parieto-temporal association cortices. There was significant difference in the regional z score values between PCA and DLB patients in these regions. No significant difference was found between z score of occipital association cortex, which showed hypometabolism in both groups. Conclusions: 18F-FDG PET /CT may serve as a non-invasive diagnostic modality in differentiating the two posterior cortical dementias, despite significant clinical and imaging overlap, with or without additional TRODAT SPECT scan.