Gayane Aghakhanyan (Italy)

University of Pisa Nuclear Medicine Unit

Author Of 1 Presentation

Free Communication

LOCUS COERULEUS MAGNETIC RESONANCE IMAGING CORRELATES WITH [18F]FLUORO DEOXYGLUCOSE UPTAKE IN ALZHEIMER’S DISEASE PATIENTS

Session Type
Free Communication
Date
07.10.2021, Thursday
Session Time
11:30 - 13:00
Room
Free Communication A
Lecture Time
12:10 - 12:20
Presenter
  • Alessandro Galgani (Italy)

Abstract

Background and Aims:

Locus Coeruleus (LC) is the main noradrenergic nucleus in the brain; it is involved in several physiological functions and modulates cell survival in its target regions. Post-mortem studies show that LC significantly degenerates in Alzheimer’s disease (AD). We assessed the association between LC-MRI and [18F]Fluorodeoxyglucose (FDG) PET uptake in amnestic Mild Cognitive Impairment (aMCI) and AD dementia (ADD) patients.

Methods:

30 aMCI,14 ADD, and 16 healthy controls (HC) underwent LC-MRI measurement through 2DFast-Spin-Echo T1-weighted sequence; a template-based approach was then used to extrapolate LC contrast-ratio (LCCR) and LC volume (LCvol). MCI and ADD underwent also FDG-PET scan acquired in three-dimensional list mode. Voxel-wise regression analysis was applied to investigate the association between metabolic activity in brain regions-of-interest (ROI) and the LC MRI-signal.

Results:

LCvol and LCCR were significantly reduced in HC when compared to patients. We observed that in aMCI and AD patients, left LCvol was positively associated with FDG uptake in the left superior and middle frontal gyrus, while left LCCR correlated with frontal regions with explicit left hemispheric dominance. Right LCvol was associated with the left frontal-parietal-occipital regions, and right LCCR with the right middle frontal and left superior frontal and parietal regions.

Conclusions:

LC parameters assessed by MRI correlate with FDG uptake measured by Brain PET in MCI and ADD patients. In particular, the reduction of LCvol and LCCR corresponded to cortical hypometabolism, in line with current literature on LC involvement in AD and its role in both cortical degeneration and brain metabolism.

This work is supported by the Italian Ministry of Health -Ministero della Salute, Ricerca Finalizzata #PE- 2013-02359574 (P.I.: FSG).

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