Molecular connectivity studies in neurotransmission: a scoping review.

Positron emission tomography (PET) and single photon emission computed tomography (SPECT) are essential molecular imaging tools for the in vivo investigation of neurotransmission. Traditionally, PET and SPECT images are analysed in a univariate manner, testing for changes in radiotracer binding in regions or voxels of interest independently of each other. Over the past decade, there has been an increasing interest in the so-calledapproach that captures relationships of molecular imaging measures in different brain regions.

Comparison of two preprocessing methods for F-Flortaucipir PET quantification in Alzheimer's disease.

Background: Tau-Positron Emission Tomography (PET) has become central in Alzheimer's disease (AD) research and clinical settings. Multiple preprocessing pipelines for tau-PET quantification have been described, with satisfactory performance but direct comparisons remain scarse. Our study evaluates the comparability of two commonly used PET preprocessing methods, respectively in native and standard spaces, in quantifying tau deposition and in their ability to discriminate AD patients.

[18F]flutemetamol uptake in the colon of a memory clinic population and its association with brain amyloidosis and the gut microbiota profile: an exploratory study.

Purpose: Some Alzheimer's disease (AD) patients report gastro-intestinal symptoms and present alterations in the gut microbiota (GM) composition. Elevated colonic amyloid immunoreactivity has been shown in patients and animal models. We evaluated the colonic uptake of the amyloid positron emission tomography (PET) imaging agent [18F]flutemetamol (FMM) in a memory clinic population and investigated its association with brain amyloidosis and GM composition.

Sex differences in the association of Alzheimer's disease biomarkers and cognition in a multicenter memory clinic study.

Background: This study investigated sex differences in the associations between Alzheimer's disease (AD) biomarkers, cognitive performance, and decline in memory clinic settings.

Methods: 249 participants (females/males:123/126), who underwent tau-PET, amyloid-PET, structural MRI, and plasma glial fibrillary acidic protein (GFAP) measurement were included from Geneva and Lausanne Memory Clinics. Mann-Whitney U tests investigated sex differences in clinical and biomarker data.

Early-phase F-Flortaucipir tau-PET as a proxy of brain metabolism in Alzheimer's disease: a comparison with F-FDG-PET and early-phase amyloid-PET.

Purpose: As dual-phase amyloid-PET can evaluate amyloid (A) and neurodegeneration (N) with a single tracer injection, dual-phase tau-PET might be able to provide both tau (T) and N. Our study aims to assess the association of early-phase tau-PET scans and F-fluorodeoxyglucose (FDG) PET and their comparability in discriminating Alzheimer's disease (AD) patients and differentiating neurodegenerative patterns.

Methods: 58 subjects evaluated at the Geneva Memory Center underwent dual-phase F-Flortaucipir-PET with early-phase acquisition (eTAU) and F-FDG-PET within 1 year.

Automatic Classification of Conclusions from Multi-Tracer Reports of PET Brain Imaging in Cognitive Impairment.

The goal of this paper is to build an automatic way to interpret conclusions from brain molecular imaging reports performed for investigation of cognitive disturbances (FDG, Amyloid and Tau PET) by comparing several traditional machine learning (ML) techniques-based text classification methods. Two purposes are defined: to identify positive or negative results in all three modalities, and to extract diagnostic impressions for Alzheimer's Disease (AD), Fronto-Temporal Dementia (FTD), Lewy Bodies Dementia (LBD) based on metabolism of perfusion patterns. A dataset was created by manual parallel annotation of 1668 conclusions of reports from the Nuclear Medicine and Molecular Imaging Division of Geneva University Hospitals.

The impact of tau deposition and hypometabolism on cognitive impairment and longitudinal cognitive decline.

Introduction: Tau and neurodegeneration strongly correlate with cognitive impairment, as compared to amyloid. However, their contribution in explaining cognition and predicting cognitive decline in memory clinics remains unclarified.

Methods: We included 94 participants with Mini-Mental State Examination (MMSE), tau positron emission tomography (PET), amyloid PET, fluorodeoxyglucose (FDG) PET, and MRI scans from Geneva Memory Center.

Sex differences in dementia with Lewy bodies: an imaging study of neurotransmission pathways.

Purpose: Dementia with Lewy bodies (DLB) is characterized by a wide clinical and biological heterogeneity, with sex differences reported in both clinical and pathologically confirmed DLB cohorts. No research evidence is available on sex differences regarding molecular neurotransmission. This study aimed to assess whether sex can influence neurotransmitter systems in patients with probable DLB (pDLB).