2,436 results match your criteria suvr


Dementia with Lewy bodies: association of Alzheimer pathology with functional connectivity networks.

Brain 2021 Jun 11. Epub 2021 Jun 11.

Department of Radiology, Mayo Clinic, Rochester, Minnesota.

Dementia with Lewy bodies (DLB) is neuropathologically defined by the presence of α-synuclein aggregates, but many DLB cases show concurrent Alzheimer's disease (AD) pathology in the form of β-amyloid plaques and tau neurofibrillary tangles. The first objective of this study was to investigate the effect of AD co-pathology on functional network changes within the default mode network (DMN) in DLB. Secondly, we studied how the distribution of tau pathology measured with PET relates to functional connectivity in DLB. Read More

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Early-phase F-FP-CIT and F-flutemetamol PET were significantly correlated.

Sci Rep 2021 Jun 10;11(1):12297. Epub 2021 Jun 10.

Department of Nuclear Medicine and Molecular Imaging, School of Medicine, Ajou University, 206, World cup-ro, Yeongtong-gu, Suwon-si, 16499, Gyeonggi-do, Korea.

Little is known about whether early-phase PET images of F-FP-CIT match those of amyloid PET. Here, we compared early-phase F-FP-CIT and F-flutemetamol PET images in patients who underwent both within a 1-month interval. The SUVR on early-phase F-FP-CIT PET (median, 0. Read More

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Sex differences in off-target binding using tau positron emission tomography.

Neuroimage Clin 2021 May 29;31:102708. Epub 2021 May 29.

Clinical Memory Research Unit, Department of Clinical Sciences, Malmö, Lund University, Sweden; Memory Clinic, Skåne University Hospital, Malmö, Sweden.

Purpose: Off-target binding in the skull and meninges is observed in some subjects undergoing tau positron emission tomography (PET) and could potentially differ between men and women. In this study we elucidate sex differences in tau off-target binding using three different tau PET tracers.

Methods: 541 cognitively unimpaired amyloid-β negative participants underwent tau PET using [F]flortaucipir (n = 165), [F]RO948 (n = 189) and [F]MK6240 (n = 187). Read More

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Associations Between Amyloid and Tau Pathology, and Connectome Alterations, in Alzheimer's Disease and Mild Cognitive Impairment.

J Alzheimers Dis 2021 May 22. Epub 2021 May 22.

Neurodegeneration Imaging Group, Institute of Psychiatry, Psychology and Neuroscience (IoPPN), King's College London, UK.

Background: The roles of amyloid-β and tau in the degenerative process of Alzheimer's disease (AD) remain uncertain. [18F]AV-45 and [18F]AV-1451 PET quantify amyloid-β and tau pathology, respectively, while diffusion tractography enables detection of their microstructural consequences.

Objective: Examine the impact of amyloid-β and tau pathology on the structural connectome and cognition, in mild cognitive impairment (MCI) and AD. Read More

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Dual-Phase β-Amyloid PET Captures Neuronal Injury and Amyloidosis in Corticobasal Syndrome.

Front Aging Neurosci 2021 13;13:661284. Epub 2021 May 13.

Department of Nuclear Medicine, University Hospital of Munich, LMU Munich, Munich, Germany.

In recent years several F-labeled amyloid PET (Aβ-PET) tracers have been developed and have obtained clinical approval. There is evidence that Aβ-PET perfusion can provide surrogate information about neuronal injury in neurodegenerative diseases when compared to conventional blood flow and glucose metabolism assessment. However, this paradigm has not yet been tested in neurodegenerative disorders with cortical and subcortical affection. Read More

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Multimodal neuroimaging of sex differences in cognitively impaired patients on the Alzheimer's continuum: greater tau-PET retention in females.

Neurobiol Aging 2021 Apr 22;105:86-98. Epub 2021 Apr 22.

Memory and Aging Center, Department of Neurology, Weill Institute for Neurosciences, University of California San Francisco, San Francisco, CA, USA; Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA; Helen Wills Neuroscience Institute, University of California Berkeley, Berkeley, CA, USA; Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, USA.

We assessed sex differences in amyloid- and tau-PET retention in 119 amyloid positive patients with mild cognitive impairment or Alzheimer's disease (AD) dementia. Patients underwent 3T-MRI, C-PIB amyloid-PET and F-Flortaucipir tau-PET. Linear ordinary least squares regression models tested sex differences in Flortaucipir-PET SUVR in a summary temporal region of interest as well as global PIB-PET. Read More

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Effect of different examination conditions on image quality and quantitative value of amyloid positron emission tomography using F-flutemetamol.

Ann Nucl Med 2021 May 27. Epub 2021 May 27.

Advance Radiation Research, Education, and Management Center, Tokushima University, 3-18-15 Kuramoto-cho, Tokushima, 770-8503, Japan.

Objective: The recommended start time for F-flutemetamol amyloid positron emission tomography (PET) examination is 60-120 min after F-flutemetamol injection, while an acquisition time of 10-30 min is generally recommended. We aimed to elucidate the effects of different examination conditions on image quality, diagnostic ability, and quantitative value of amyloid PET using F-flutemetamol.

Methods: We acquired data on a Discovery PET/computed tomography 710 scanner using Hoffman brain and pillar phantoms with 20 MBq of F for 30 min. Read More

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A dual-time-window protocol to reduce acquisition time of dynamic tau PET imaging using [F]MK-6240.

EJNMMI Res 2021 May 27;11(1):49. Epub 2021 May 27.

Nuclear Medicine and Molecular Imaging, Department of Imaging and Pathology, KU Leuven, Herestraat 49 - Bus 7003, 3000, Leuven, Belgium.

Background: [F]MK-6240 is a PET tracer with sub-nanomolar affinity for neurofibrillary tangles. Therefore, tau quantification is possible with [F]MK-6240 PET/CT scans, and it can be used for assessment of Alzheimer's disease. However, long acquisition scans are required to provide fully quantitative estimates of pharmacokinetic parameters. Read More

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Binding characteristics of [F]PI-2620 distinguish the clinically predicted tau isoform in different tauopathies by PET.

J Cereb Blood Flow Metab 2021 May 27:271678X211018904. Epub 2021 May 27.

Center for Neuropathology and Prion Research, University Hospital of Munich, LMU Munich, Munich, Germany.

The novel tau-PET tracer [F]PI-2620 detects the 3/4-repeat-(R)-tauopathy Alzheimer's disease (AD) and the 4R-tauopathies corticobasal syndrome (CBS) and progressive supranuclear palsy (PSP). We determined whether [F]PI-2620 binding characteristics deriving from non-invasive reference tissue modelling differentiate 3/4R- and 4R-tauopathies. Ten patients with a 3/4R tauopathy (AD continuum) and 29 patients with a 4R tauopathy (CBS, PSP) were evaluated. Read More

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A multicenter comparison of [F]flortaucipir, [F]RO948, and [F]MK6240 tau PET tracers to detect a common target ROI for differential diagnosis.

Eur J Nucl Med Mol Imaging 2021 Jul 27;48(7):2295-2305. Epub 2021 May 27.

Clinical Memory Research Unit, Department of Clinical Sciences, Lund University, Malmö, Sweden.

Purpose: This study aims to determine whether comparable target regions of interest (ROIs) and cut-offs can be used across [F]flortaucipir, [F]RO948, and [F]MK6240 tau positron emission tomography (PET) tracers for differential diagnosis of Alzheimer's disease (AD) dementia vs either cognitively unimpaired (CU) individuals or non-AD neurodegenerative diseases.

Methods: A total of 1755 participants underwent tau PET using either [F]flortaucipir (n = 975), [F]RO948 (n = 493), or [F]MK6240 (n = 287). SUVR values were calculated across four theory-driven ROIs and several tracer-specific data-driven (hierarchical clustering) regions of interest (ROIs). Read More

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In Vivo Amyloid, Neurodegeneration, and Verbal Learning in Late Middle-Aged Hispanics.

J Alzheimers Dis 2021 May 18. Epub 2021 May 18.

Department of Medicine, College of Physicians and Surgeons, Columbia University Irving Medical Center, New York, NY, USA.

Background: The National Institute on Aging (NIA)/Alzheimer's Association (AA) 2018 framework conceptualizes Alzheimer's disease (AD) biologically. Evidence of brain amyloid by biomarkers defines AD pathologic change and the Alzheimer's continuum. The presence of tau or neurodegeneration in the absence of amyloid defines non-AD pathologic change. Read More

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Feasibility of short imaging protocols for [F]PI-2620 tau-PET in progressive supranuclear palsy.

Eur J Nucl Med Mol Imaging 2021 May 22. Epub 2021 May 22.

Department of Psychiatry, University Hospital Cologne, Cologne, Germany.

Purpose: Dynamic 60-min positron emission tomography (PET) imaging with the novel tau radiotracer [F]PI-2620 facilitated accurate discrimination between patients with progressive supranuclear palsy (PSP) and healthy controls (HCs). This study investigated if truncated acquisition and static time windows can be used for [F]PI-2620 tau-PET imaging of PSP.

Methods: Thirty-seven patients with PSP Richardson syndrome (PSP-RS) were evaluated together with ten HCs. Read More

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Relationship between F-18 florbetapir uptake in occipital lobe and neurocognitive performance in Alzheimer's disease.

Jpn J Radiol 2021 May 21. Epub 2021 May 21.

Institute of Advanced Clinical Medicine, Kindai University Hospital, 377-2 Ohnohigashi, Osaka-Sayama, Osaka, 589-8511, Japan.

Purpose: To determine the association between occipital amyloid-PET uptake and neurocognitive performance in Alzheimer's disease (AD).

Materials And Methods: Fifty-eight participants with normal aged, mild cognitive impairment (MCI) due to AD and AD subjects who underwent F-18 florbetapir brain PET/CT scans were divided into four groups (A, normal; B, MCI; C, mild AD; and D, moderate/severe AD). Semiquantitative analyses of SUVR images were performed. Read More

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Ibudilast (MN-166) in amyotrophic lateral sclerosis- an open label, safety and pharmacodynamic trial.

Neuroimage Clin 2021 Apr 15;30:102672. Epub 2021 Apr 15.

Sean M Healey & AMG Center for ALS, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.

Ibudilast (MN-166) is an inhibitor of macrophage migration inhibitory factor (MIF) and phosphodiesterases 3,4,10 and 11 (Gibson et al., 2006; Cho et al., 2010). Read More

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Effects of APOE ε2 on the Fractional Amplitude of Low-Frequency Fluctuation in Mild Cognitive Impairment: A Study Based on the Resting-State Functional MRI.

Front Aging Neurosci 2021 29;13:591347. Epub 2021 Apr 29.

Department of Radiology, The 2nd Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China.

Background: Apolipoprotein E (APOE) ε2 is a protective genetic factor for Alzheimer's disease (AD). However, the potential interaction effects between the APOE ε2 allele and disease status on the intrinsic brain activity remain elusive.

Methods: We identified 73 healthy control (HC) with APOE ε3/ε3, 61 mild cognitive impairment (MCI) subjects with APOE ε3/ε3, 24 HC with APOE ε2/ε3, and 10 MCI subjects with APOE ε2/ε3 from the ADNI database. Read More

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Combination of automated brain volumetry on MRI and quantitative tau deposition on THK-5351 PET to support diagnosis of Alzheimer's disease.

Sci Rep 2021 May 14;11(1):10343. Epub 2021 May 14.

Department of Nuclear Medicine, Asan Medical Center, University of Ulsan College of Medicine, 88 Olympic-ro 43-gil, Songpa-Gu, Seoul, 05505, South Korea.

Imaging biomarkers support the diagnosis of Alzheimer's disease (AD). We aimed to determine whether combining automated brain volumetry on MRI and quantitative measurement of tau deposition on [18F] THK-5351 PET can aid discrimination of AD spectrum. From a prospective database in an IRB-approved multicenter study (NCT02656498), 113 subjects (32 healthy control, 55 mild cognitive impairment, and 26 Alzheimer disease) with baseline structural MRI and [18F] THK-5351 PET were included. Read More

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Validation of amyloid PET positivity thresholds in centiloids: a multisite PET study approach.

Alzheimers Res Ther 2021 05 10;13(1):99. Epub 2021 May 10.

Helen Wills Neuroscience Institute, University of California Berkeley, Berkeley, CA, USA.

Background: Inconsistent positivity thresholds, image analysis pipelines, and quantitative outcomes are key challenges of multisite studies using more than one β-amyloid (Aβ) radiotracer in positron emission tomography (PET). Variability related to these factors contributes to disagreement and lack of replicability in research and clinical trials. To address these problems and promote Aβ PET harmonization, we used [F]florbetaben (FBB) and [F]florbetapir (FBP) data from the Alzheimer's Disease Neuroimaging Initiative (ADNI) to derive (1) standardized Centiloid (CL) transformations and (2) internally consistent positivity thresholds based on separate young control samples. Read More

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A 4-Year Follow-Up of Subjects with Visually Equivocal Amyloid Positron Emission Tomography Findings from the Alzheimer's Disease Neuroimaging Initiative Cohort.

Nucl Med Mol Imaging 2021 Apr 4;55(2):71-78. Epub 2021 Mar 4.

Department of Nuclear Medicine, Asan Medical Center, Seoul, Korea.

Background: To date, the clinical significance of visually equivocal amyloid positron emission tomography (PET) has not been well established.

Objective: We studied the clinical significance of equivocal amyloid PET images from the Alzheimer's Disease Neuroimaging Initiative (ADNI).

Methods: Subjects with F-18 florbetapir PET scans at baseline who were followed up for 4 years were selected. Read More

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Relationship between a novel learning slope metric and Alzheimer's disease biomarkers.

Neuropsychol Dev Cogn B Aging Neuropsychol Cogn 2021 May 5:1-21. Epub 2021 May 5.

Center for Alzheimer's Care, Imaging, and Research, Department of Neurology, University of Utah, Salt Lake City, UT, USA.

The Learning Ratio (LR) is a novel learning score examining the proportion of information learned over successive learning trials relative to information available to be learned. Validation is warranted to understand LR's sensitivity to Alzheimer's disease (AD) pathology. One-hundred twenty-three participants across the AD continuum underwent memory assessment, quantitative brain imaging, and genetic analysis. Read More

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Investigating the relationship between BMI across adulthood and late life brain pathologies.

Alzheimers Res Ther 2021 04 30;13(1):91. Epub 2021 Apr 30.

Dementia Research Centre, UCL Queen Square Institute of Neurology, University College London, Box 16, Queen Square, London, WC1N 3BG, UK.

Background: In view of reported associations between high adiposity, particularly in midlife and late-life dementia risk, we aimed to determine associations between body mass index (BMI), and BMI changes across adulthood and brain structure and pathology at age 69-71 years.

Methods: Four hundred sixty-five dementia-free participants from Insight 46, a sub-study of the British 1946 birth cohort, who had cross-sectional T1/FLAIR volumetric MRI, and florbetapir amyloid-PET imaging at age 69-71 years, were included in analyses. We quantified white matter hyperintensity volume (WMHV) using T1 and FLAIR 3D-MRI; β-amyloid (Aβ) positivity/negativity using a SUVR approach; and whole brain (WBV) and hippocampal volumes (HV) using 3D T1-MRI. Read More

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A blood-based diagnostic test incorporating plasma Aβ42/40 ratio, ApoE proteotype, and age accurately identifies brain amyloid status: findings from a multi cohort validity analysis.

Mol Neurodegener 2021 05 1;16(1):30. Epub 2021 May 1.

C2N Diagnostics, 20 S Sarah Street, St. Louis, MO, 63108, USA.

Background: The development of blood-based biomarker tests that are accurate and robust for Alzheimer's disease (AD) pathology have the potential to aid clinical diagnosis and facilitate enrollment in AD drug trials. We developed a high-resolution mass spectrometry (MS)-based test that quantifies plasma Aβ42 and Aβ40 concentrations and identifies the ApoE proteotype. We evaluated robustness, clinical performance, and commercial viability of this MS biomarker assay for distinguishing brain amyloid status. Read More

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Development of molecular tools for diagnosis of Alzheimer's disease that are based on detection of amyloidogenic proteins.

Prion 2021 Dec;15(1):56-69

Laboratory of Amyloid Biology, St. Petersburg State University, St. Petersburg, Russia.

Alzheimer's disease (AD) is the most common form of dementia that usually occurs among older people. AD results from neuronal degeneration that leads to the cognitive impairment and death. AD is incurable, typically develops over the course of many years and is accompanied by a loss of functional autonomy, making a patient completely dependent on family members and/or healthcare workers. Read More

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December 2021

Mitochondrial complex I abnormalities is associated with tau and clinical symptoms in mild Alzheimer's disease.

Mol Neurodegener 2021 04 26;16(1):28. Epub 2021 Apr 26.

Translational Neuroimaging Laboratory, McGill University Research Centre for Studies in Aging, Douglas Research Institute, Le Centre intégré universitaire de santé et de services sociaux (CIUSSS) de l'Ouest-de-l'Île-de-Montréal; Department of Neurology and Neurosurgery, Psychiatry and Pharmacology and Therapeutics, McGill University, 6875 Boulevard LaSalle, Montreal, H4H 1R3, Canada.

Background: Mitochondrial electron transport chain abnormalities have been reported in postmortem pathological specimens of Alzheimer's disease (AD). However, it remains unclear how amyloid and tau are associated with mitochondrial dysfunction in vivo. The purpose of this study is to assess the local relationships between mitochondrial dysfunction and AD pathophysiology in mild AD using the novel mitochondrial complex I PET imaging agent [F]BCPP-EF. Read More

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Reduced Synaptic Density in Patients with Lewy Body Dementia: An [ C]UCB-J PET Imaging Study.

Mov Disord 2021 Apr 25. Epub 2021 Apr 25.

Department of Nuclear Medicine and PET, Aarhus University Hospital, Aarhus, Denmark.

Background: Patients with Parkinson's disease (PD) often develop dementia, but the underlying substrate is incompletely understood. Generalized synaptic degeneration may contribute to dysfunction and cognitive decline in Lewy body dementias, but in vivo evidence is lacking.

Objective: The objective of this study was to assess the density of synapses in non-demented PD (nPD) subjects (N = 21), patients with PD-dementia or Dementia with Lewy bodies (DLB) (N = 13), and age-matched healthy controls (N = 15). Read More

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Sex differences in in vivo tau neuropathology in a multiethnic sample of late middle-aged adults.

Neurobiol Aging 2021 Jul 23;103:109-116. Epub 2021 Mar 23.

Department of Medicine, College of Physicians and Surgeons, Columbia University Irving Medical Center, New York, NY, USA; Department of Epidemiology, Joseph P. Mailman School of Public Health, Columbia University Irving Medical Center, New York, NY, USA.

It is unclear whether women have higher brain tau pathology. The objective of this study was to examine whether women have higher tau burden than men, and whether tau differences are independent of amyloid β (Aβ) burden. We conducted a cross-sectional analysis of a multiethnic sample of 252 nondemented late middle-aged (mean age: 64. Read More

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Strategies to reduce sample sizes in Alzheimer's disease primary and secondary prevention trials using longitudinal amyloid PET imaging.

Alzheimers Res Ther 2021 04 19;13(1):82. Epub 2021 Apr 19.

Barcelonaβeta Brain Research Center, Pasqual Maragall Foundation, Barcelona, Spain.

Background: Detecting subtle-to-moderate biomarker changes such as those in amyloid PET imaging becomes increasingly relevant in the context of primary and secondary prevention of Alzheimer's disease (AD). This work aimed to determine if and when distribution volume ratio (DVR; derived from dynamic imaging) and regional quantitative values could improve statistical power in AD prevention trials.

Methods: Baseline and annualized % change in [C]PIB SUVR and DVR were computed for a global (cortical) and regional (early) composite from scans of 237 cognitively unimpaired subjects from the OASIS-3 database ( www. Read More

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A randomized, double-blind, phase 2b proof-of-concept clinical trial in early Alzheimer's disease with lecanemab, an anti-Aβ protofibril antibody.

Alzheimers Res Ther 2021 04 17;13(1):80. Epub 2021 Apr 17.

Chambers-Grundy Center for Transformative Neuroscience, Department of Brain Health, School of Integrated Health Sciences, University of Nevada Las Vegas, Las Vegas, NV, USA.

Background: Lecanemab (BAN2401), an IgG1 monoclonal antibody, preferentially targets soluble aggregated amyloid beta (Aβ), with activity across oligomers, protofibrils, and insoluble fibrils. BAN2401-G000-201, a randomized double-blind clinical trial, utilized a Bayesian design with response-adaptive randomization to assess 3 doses across 2 regimens of lecanemab versus placebo in early Alzheimer's disease, mild cognitive impairment due to Alzheimer's disease (AD) and mild AD dementia.

Methods: BAN2401-G000-201 aimed to establish the effective dose 90% (ED90), defined as the simplest dose that achieves ≥90% of the maximum treatment effect. Read More

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Direct comparison of the tau PET tracers [F]flortaucipir and [F]MK-6240 in human subjects.

J Nucl Med 2021 Apr 16. Epub 2021 Apr 16.

University of Pittsburgh, United States.

Tau PET tracers exhibit varying levels of specific signal and distinct off-target binding patterns that are more diverse than amyloid PET tracers. This study compares two frequently used tau PET tracers, [F]flortaucipir (FTP) and [F]MK-6240, in the same subjects. [F]flortaucipir and [F]MK-6240 scans were collected within two months in 15 elderly subjects varying in terms of clinical diagnosis and cognition. Read More

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Integrated F-T807 Tau PET, Structural MRI, and Plasma Tau in Tauopathy Neurodegenerative Disorders.

Front Aging Neurosci 2021 29;13:646440. Epub 2021 Mar 29.

Department of Neurology, National Taiwan University Hospital, Taipei, Taiwan.

Tau-specific positron emission topography (PET) imaging enables assessment of Alzheimer's disease (AD). We aimed to investigate its performance in combination with plasma tau levels in patients with non-AD tauopathy. A total of 47 participants were enrolled, including 10 healthy controls, 16 with tauopathy parkinsonism syndromes (9 with corticobasal syndrome [CBS], 7 with progressive supranuclear palsy [PSP]), 9 with frontotemporal dementia (FTD), 4 with AD, and 8 with Parkinson's disease (PD). Read More

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Analysis of amyloid and tau deposition in Alzheimer's disease using C-Pittsburgh compound B and F-THK 5351 positron emission tomography imaging.

World J Nucl Med 2021 Jan-Mar;20(1):61-72. Epub 2020 Oct 8.

National Cyclotron and PET Centre, Chulabhorn Hospital, Chulabhorn Royal Academy, Bangkok, Thailand.

This study aims to determine the deposition of C-Pittsburgh compound B (C-PiB) and F-THK 5351 using a normal database of the optimal cut-off-points for standardized uptake value ratios (SUVRs) in Alzheimer's disease (AD) patients. Sixteen AD patients and 24 cognitively normal individuals were enrolled in this study. The optimal cutoff points for the SUVR from the normal database were used for quantitative analysis. Read More

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October 2020