scholarly journals Multimorbidity Is Associated with Preclinical Alzheimer’s Disease Neuroimaging Biomarkers

2018 ◽  
Vol 45 (5-6) ◽  
pp. 272-281 ◽  
Author(s):  
Aline Mendes ◽  
Sophie Tezenas du Montcel ◽  
Marcel Levy ◽  
Anne Bertrand ◽  
Marie-Odile Habert ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Positron Emission Tomography ◽  
Fdg Pet ◽  
Emission Tomography ◽  
Amyloid Pet ◽  
Preclinical Alzheimer’S Disease ◽  
Positron Emission ◽  
Obstructive Sleep ◽  
Neuroimaging Biomarkers

Background: Identifying comorbidities that influence preclinical Alzheimer’s disease (AD) can give some insight into the AD early stages trajectories to allow new treatment venues and to guide public health systems to prevent subsequent dementia. Objective: To examine the association of multimorbidity with AD neuroimaging markers in cognitively normal older adults. Methods: This study had a cross-sectional design. Data regarding 14 comorbidities were obtained for all 318 adults aged 70–85 years, recruited from the community to an ongoing prospective monocentric cohort. They underwent standardized neuropsychological and neuroimaging assessment with automated methods that measured hippocampal volumes, white matter hyperintensity volumes, fluorodeoxyglucose positron emission tomography (FDG-PET) standardized uptake values (SUV) in AD signature regions, and amyloid positron emission tomography (amyloid-PET) SUV ratios. Linear regression was used to assess the association of multimorbidity with AD neuroimaging biomarkers. Results: Multimorbidity is signif icantly associated with lower hippocampal volumes (–0.03 ± 0.01; p = 0.012; R2 = 0.017) and lower FDG-PET SUV (–0.027 ± 0.009; p = 0.005; R2 = 0.022), with no association with amyloid deposition (0.001 ± 0.007; p = 0.884; R2 = 0.0001). Taken individually, obesity and excessive alcohol use are associated with lower FDG-PET values, whereas obstructive sleep apnea and mood disorders are related to lower amyloid-PET SUV ratios. Conclusion: Multimorbidity is associated with preclinical AD imaging markers of neurodegeneration, but not with amyloid.

scholarly journals Longitudinal Observation of Early-Onset Alzheimer’s Disease Dementia with Positive CSF Biomarkers/Negative Amyloid-β Positron-Emission Tomography

2021 ◽  
Vol 39 (3) ◽  
pp. 214-218
Author(s):  
Min Hye Kim ◽  
Joonho Lee ◽  
Hong Nam Kim ◽  
In Ja Shin ◽  
Keun Lee ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Positron Emission Tomography ◽  
Early Onset ◽  
Brain Magnetic Resonance Imaging ◽  
Amyloid Β ◽  
Emission Tomography ◽  
Csf Biomarkers ◽  
Amyloid Pet ◽  
Positron Emission

We report a 61-year-old woman with clinical course for Alzheimer’s disease (AD) dementia and discordant amyloid-β positron-emission tomography (PET) and cerebrospinal fluid biomarkers. Brain magnetic resonance imaging revealed remarkable atrophy in the hippocampus. However, repeated delayed <sup>18</sup>F-flutemetamol brain amyloid PET images with 1 year-interval revealed no amyloid deposition, whereas her CSF revealed low Aβ42, high total tau and p-tau181. This discordant amyloid-β PET and CSF biomarkers in this early-onset AD dementia might be associated with her low resilience or mixed pathology.

scholarly journals Zero Echo Time MRAC on FDG-PET/MR Maintains Diagnostic Accuracy for Alzheimer’s Disease; A Simulation Study Combining ADNI-Data

2020 ◽  
Vol 14 ◽  
Author(s):  
Takahiro Ando ◽  
Bradley Kemp ◽  
Geoffrey Warnock ◽  
Tetsuro Sekine ◽  
Sandeep Kaushik ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Positron Emission Tomography ◽  
Diagnostic Accuracy ◽  
Attenuation Correction ◽  
Simulation Study ◽  
Fdg Pet ◽  
Emission Tomography ◽  
Positron Emission ◽  
Echo Time

AimAttenuation correction using zero-echo time (ZTE) – magnetic resonance imaging (MRI) (ZTE-MRAC) has become one of the standard methods for brain-positron emission tomography (PET) on commercial PET/MR scanners. Although the accuracy of the net tracer-uptake quantification based on ZTE-MRAC has been validated, that of the diagnosis for dementia has not yet been clarified, especially in terms of automated statistical analysis. The aim of this study was to clarify the impact of ZTE-MRAC on the diagnosis of Alzheimer’s disease (AD) by performing simulation study.MethodsWe recruited 27 subjects, who underwent both PET/computed tomography (CT) and PET/MR (GE SIGNA) examinations. Additionally, we extracted 107 subjects from the Alzheimer Disease Neuroimaging Initiative (ADNI) dataset. From the PET raw data acquired on PET/MR, three FDG-PET series were generated, using two vendor-provided MRAC methods (ZTE and Atlas) and CT-based AC. Following spatial normalization to Montreal Neurological Institute (MNI) space, we calculated each patient’s specific error maps, which correspond to the difference between the PET image corrected using the CTAC method and the PET images corrected using the MRAC methods. To simulate PET maps as if ADNI data had been corrected using MRAC methods, we multiplied each of these 27 error maps with each of the 107 ADNI cases in MNI space. To evaluate the probability of AD in each resulting image, we calculated a cumulative t-value using a fully automated method which had been validated not only in the original ADNI dataset but several multi-center studies. In the method, PET score = 1 is the 95% prediction limit of AD. PET score and diagnostic accuracy for the discrimination of AD were evaluated in simulated images using the original ADNI dataset as reference.ResultsPositron emission tomography score was slightly underestimated both in ZTE and Atlas group compared with reference CTAC (−0.0796 ± 0.0938 vs. −0.0784 ± 0.1724). The absolute error of PET score was lower in ZTE than Atlas group (0.098 ± 0.075 vs. 0.145 ± 0.122, p &lt; 0.001). A higher correlation to the original PET score was observed in ZTE vs. Atlas group (R2: 0.982 vs. 0.961). The accuracy for the discrimination of AD patients from normal control was maintained in ZTE and Atlas compared to CTAC (ZTE vs. Atlas. vs. original; 82.5% vs. 82.1% vs. 83.2% (CI 81.8–84.5%), respectively).ConclusionFor FDG-PET images on PET/MR, attenuation correction using ZTE-MRI had superior accuracy to an atlas-based method in classification for dementia. ZTE maintains the diagnostic accuracy for AD.

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