627 results match your criteria: "Gordon center for medical imaging[Affiliation]"

Associations of 24-Hour Rest-Activity Rhythm Fragmentation, Cognitive Decline, and Postmortem Locus Coeruleus Hypopigmentation in Alzheimer's Disease.

Ann Neurol

April 2024

Faculty of Health, Medicine and Life Sciences, School for Mental Health and Neuroscience, Alzheimer Centre Limburg, Maastricht University, Maastricht, The Netherlands.

Objective: While studies suggested that locus coeruleus (LC) neurodegeneration contributes to sleep-wake dysregulation in Alzheimer's disease (AD), the association between LC integrity and circadian rest-activity patterns remains unknown. Here, we investigated the relationships between 24-hour rest-activity rhythms, cognitive trajectories, and autopsy-derived LC integrity in older adults with and without cortical AD neuropathology.

Methods: This retrospective study leveraged multi-modal data from participants of the longitudinal clinical-pathological Rush Memory and Aging Project.

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Acute Stress Increases Striatal Connectivity With Cortical Regions Enriched for μ and κ Opioid Receptors.

Biol Psychiatry

November 2024

Center for Depression, Anxiety and Stress Research, Department of Psychiatry, McLean Hospital, Harvard Medical School, Boston, Massachusetts. Electronic address:

Background: Understanding the neurobiological effects of stress is critical for addressing the etiology of major depressive disorder (MDD). Using a dimensional approach involving individuals with differing degree of MDD risk, we investigated 1) the effects of acute stress on cortico-cortical and subcortical-cortical functional connectivity (FC) and 2) how such effects are related to gene expression and receptor maps.

Methods: Across 115 participants (37 control, 39 remitted MDD, 39 current MDD), we evaluated the effects of stress on FC during the Montreal Imaging Stress Task.

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Driving Hebbian plasticity over ventral premotor-motor projections transiently enhances motor resonance.

Brain Stimul

April 2024

Centro Studi e Ricerche in Neuroscienze Cognitive, Dipartimento di Psicologia "Renzo Canestrari", Campus di Cesena, Alma Mater Studiorum Università di Bologna, 47521, Cesena, Italy; Centro de Investigación en Neuropsicología y Neurociencias Cognitivas (CINPSI Neurocog), Universidad Católica Del Maule, 346000, Talca, Chile. Electronic address:

Background: Making sense of others' actions relies on the activation of an action observation network (AON), which maps visual information about observed actions onto the observer's motor system. This motor resonance process manifests in the primary motor cortex (M1) as increased corticospinal excitability finely tuned to the muscles engaged in the observed action. Motor resonance in M1 is facilitated by projections from higher-order AON regions.

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Harnessing Placebo Effects for the Treatment of Functional Cognitive Disorder: A Feasibility Pilot Study.

J Neuropsychiatry Clin Neurosci

July 2024

Neuropsychiatry Program, Department of Psychiatry, and Division of Neurology, Department of Medicine, Sunnybrook Health Sciences Center, University of Toronto, Toronto (Burke); Hurvitz Brain Sciences Program, Sunnybrook Research Institute, Toronto (Burke); Berenson-Allen Center for Noninvasive Brain Stimulation, Department of Neurology (Burke, Cappon, Santarnecchi) and Program in Placebo Studies (Burke), Beth Israel Deaconess Medical Center, Harvard Medical School, Boston; Hinda and Arthur Marcus Institute for Aging Research and Deanna and Sidney Center for Memory Health, Hebrew SeniorLife, Boston (Cappon, Pascual-Leone); Department of Neurology, Harvard Medical School, Boston (Cappon, Pascual-Leone, Santarnecchi); Departments of Neurology and Psychiatry (Perez) and Precision Neuroscience and Neuromodulation Program, Gordon Center for Medical Imaging (Santarnecchi), Massachusetts General Hospital and Harvard Medical School, Boston; Guttmann Brain Health Institute, Barcelona, Spain (Pascual-Leone).

Objective: Limited research has directly investigated whether and how placebo effects can be harnessed for the treatment of functional neurological disorder (FND), despite a long-standing and controversial history of interest in this area.

Methods: A small exploratory study was conducted with adults with a cognitive subtype of FND recruited from a single cognitive neurology center in the United States. Participants were given the expectation of receiving cranial stimulation that could benefit their memory symptoms; however, the intervention was sham transcranial magnetic stimulation (placebo).

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Gold nanoshells have been actively applied in industries beyond the research stage because of their unique optical properties. Although numerous methods have been reported for gold nanoshell synthesis, the labor-intensive and time-consuming production process is an issue that must be overcome to meet industrial demands. To resolve this, we report a high-throughput synthesis method for nanogap-rich gold nanoshells based on a core silica support (denoted as SiO@Au NS), affording a 50-fold increase in scale by combining it with a dual-channel infusion pump system.

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Near-infrared (NIR) phototheranostics provide promising noninvasive imaging and treatment for head and neck squamous cell carcinoma (HNSCC), capitalizing on its adjacency to skin or mucosal surfaces. Activated by laser irradiation, targeted NIR fluorophores can selectively eradicate cancer cells, harnessing the power of synergistic photodynamic therapy and photothermal therapy. However, there is a paucity of NIR bioprobes showing tumor-specific targeting and effective phototheranosis without hurting surrounding healthy tissues.

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Animal models suggest that experiencing high-stress levels induces changes in amygdalar circuitry and gene expression. In humans, combat exposure has been shown to alter amygdalar responsivity and connectivity, but abnormalities have been indicated to normalize at least partially upon the termination of stress exposure. In contrast, other evidence suggests that combat exposure continues to exert influence on exposed individuals well beyond deployment and homecoming, as indicated by longitudinal psychosocial evidence from veterans, and observation of greater health decline in veterans late in life.

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Transcranial random noise stimulation to augment hand function in individuals with moderate-to-severe stroke: A pilot randomized clinical trial.

Restor Neurol Neurosci

February 2024

Director of NeuRRo Lab, Department of Physical Medicine and Rehabilitation, Michigan Medicine, Ann Arbor, MI, USA.

Background: Interventions to recover upper extremity (UE) function after moderate-to-severe stroke are limited. Transcranial random noise stimulation (tRNS) is an emerging non-invasive technique to improve neuronal plasticity and may potentially augment functional outcomes when combined with existing interventions, such as functional electrical stimulation (FES).

Objective: The objective of this study was to investigate the feasibility and preliminary efficacy of combined tRNS and FES-facilitated task practice to improve UE impairment and function after moderate-to-severe stroke.

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Aberrant White Matter Development in Cerebral Visual Impairment: A Proposed Mechanism for Visual Dysfunction Following Early Brain Injury.

J Integr Neurosci

January 2024

Laboratory for Visual Neuroplasticity, Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA 02114, USA.

Background: Cerebral visual impairment (CVI) is a common sequala of early brain injury, damage, or malformation and is one of the leading individual causes of visual dysfunction in pediatric populations worldwide. Although patients with CVI are heterogeneous both in terms of underlying etiology and visual behavioural manifestations, there may be underlying similarities in terms of which white matter pathways are potentially altered. This exploratory study used diffusion tractography to examine potential differences in volume, quantitative anisotropy (QA), as well as mean, axial, and radial diffusivities (mean diffusivity (MD), axial diffusivity (AD) and radial diffusivity (RD), respectively) focusing on the dorsal and ventral visual stream pathways in a cohort of young adults with CVI compared to typically sighted and developing controls.

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Article Synopsis
  • The paper presents an innovative unsupervised deep learning method for correcting motion artifacts in turbo-spin echo MRI, which typically requires extensive and resource-heavy training data.
  • The method utilizes a framework that combines image parameterization, spatial transformation, and motion simulation to effectively remove motion artifacts from MR images.
  • Results from simulations and real datasets indicate that the proposed approach significantly enhances image quality, outperforming baseline methods in both quantitative and qualitative assessments of motion artifact correction.
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We and others have shown that [F]-Flortaucipir, the most validated tau PET tracer thus far, binds with strong affinity to tau aggregates in Alzheimer's (AD) but has relatively low affinity for tau aggregates in non-AD tauopathies and exhibits off-target binding to neuromelanin- and melanin-containing cells, and to hemorrhages. Several second-generation tau tracers have been subsequently developed. [F]-MK-6240 and [F]-PI-2620 are the two that have garnered most attention.

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Background: Segmentectomy is a type of limited resection surgery indicated for patients with very early-stage lung cancer or compromised function because it can improve quality of life with minimal removal of normal tissue. For segmentectomy, an accurate detection of the tumor with simultaneous identification of the lung intersegment plane is critical. However, it is not easy to identify both during surgery.

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Learn from orientation prior for radiograph super-resolution: Orientation operator transformer.

Comput Methods Programs Biomed

March 2024

Department of Communications Engneering, Graduate School of Engineering, Tohoku University, Sendai, 9808579, Japan.

Background And Objective: High-resolution radiographic images play a pivotal role in the early diagnosis and treatment of skeletal muscle-related diseases. It is promising to enhance image quality by introducing single-image super-resolution (SISR) model into the radiology image field. However, the conventional image pipeline, which can learn a mixed mapping between SR and denoising from the color space and inter-pixel patterns, poses a particular challenge for radiographic images with limited pattern features.

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Purpose: [F]MK-6240, a second-generation tau PET tracer, is increasingly used for the detection and the quantification of in vivo cerebral tauopathy in Alzheimer's disease (AD). Given that neurological symptoms are better explained by the topography rather than by the nature of brain lesions, our study aimed to evaluate whether cognitive impairment would be more closely associated with the spatial extent than with the intensity of tau-PET signal, as measured by the standard uptake value ratio (SUVr).

Methods: [F]MK6240 tau-PET data from 82 participants in the AD spectrum were quantified in three different brain regions (Braak ≤ 2, Braak ≤ 4, and Braak ≤ 6) using SUVr and the extent of tauopathy (EOT, percentage of voxels with SUVr ≥ 1.

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Previously, refractory high-entropy alloys (HEAs) with high crystallinity were synthesized using a configurable target without heat treatment. This study builds upon prior investigations to develop nonrefractory elemental HEAs with low crystallinity using a novel target system. Different targets with various elemental compositions, i.

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Small molecule fluorophores often face challenges such as short blood half-life, limited physicochemical and optical stability, and poor pharmacokinetics. To overcome these limitations, we conjugated the zwitterionic near-infrared fluorophore ZW800-PEG to human serum albumin (HSA), creating HSA-ZW800-PEG. This conjugation notably improves chemical, physical, and optical stability under physiological conditions, addressing issues commonly encountered with small molecules in biological applications.

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Throat tumour margin control remains difficult due to the tight, enclosed space of the oral and throat regions and the tissue deformation resulting from placement of retractors and scopes during surgery. Intraoperative imaging can help with better localization but is hindered by non-image-compatible surgical instruments, cost, and unavailability. We propose a novel method of using instrument tracking and FEM-multibody modelling to simulate soft tissue deformation in the intraoperative setting, without requiring intraoperative imaging, to improve surgical guidance accuracy.

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Association of Sleep Duration and Change Over Time With Imaging Biomarkers of Cerebrovascular, Amyloid, Tau, and Neurodegenerative Pathology.

Neurology

January 2024

From the Douglas Mental Health University Institute (A.-A.B.), McGill University, Montreal, Quebec, Canada; The Framingham Heart Study (A.-A.B., D.J.K., J.J.H., D.H., M.P.P., A.S.B., S.S.); Boston University School of Public Health (D.J.K., J.J.H.), MA; Boston University School of Medicine (J.J.H., S.S.), MA; Glenn Biggs Institute for Alzheimer's & Neurodegenerative Diseases (J.J.H., S.S.), UT Health San Antonio, TX; UC Davis Center for Neuroscience (C.S.D.), CA; Sunnybrook Research Institute (E.S.), University of Toronto, Ontario, Canada; Harvard Aging Brain Institute (K.A.J.), Harvard Medical School, Boston, MA; Gordon Center for Medical Imaging (G.E.F., E.T.), Radiology Department, Massachusetts General Hospital, Harvard Medical School, Boston; Turner Institute for Brain and Mental Health (S.R.Y., M.G.C., M.P.P.), Monash University, Clayton, Australia; and Harvard T.H. Chan School of Public Health (M.P.P.), Harvard University, Boston, MA.

Article Synopsis
  • The study aimed to analyze the relationship between self-reported sleep duration and neuroimaging markers related to Alzheimer's disease, focusing on amyloid, tau, neurodegeneration, and vascular factors.
  • It utilized data from participants in the Framingham Heart Study who underwent various imaging tests, assessing their sleep duration categorized into short, average, and long at two different times: at the testing point and approximately 13 years prior.
  • The results indicated no significant direct link between sleep duration and neuroimaging measures; however, long-term changes to longer sleep duration were associated with increased brain damage markers, while consistently long sleepers showed lower levels of brain damage compared to those with average sleep duration.
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Article Synopsis
  • - The study investigates tau pathology in chronic traumatic encephalopathy (CTE) using tau PET imaging from 218 participants, including former professional and college football players, and a control group of individuals without head impact exposure.
  • - Elevated tau levels were found in former football players compared to controls, especially in older players over 60 with cumulative head impact exposure, but PET imaging didn't effectively distinguish between individuals with and without traumatic encephalopathy syndrome.
  • - The authors emphasize the need for further research to better understand the link between tau pathology and chronic traumatic brain injuries, as current findings only partially clarify these relationships.
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Spatiotemporal Correlation between Amyloid and Tau Accumulations Underlies Cognitive Changes in Aging.

J Neurosci

February 2024

Department of Radiology, Gordon Center for Medical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston 02114, Massachusetts

It is poorly known how Aβ and tau accumulations associate at the spatiotemporal level in the in vivo human brain to impact cognitive changes in older adults prior to AD symptoms onset. In this study, we used a graph theory-based spatiotemporal analysis to characterize the cortical patterns of Aβ and tau deposits and their relationship with cognitive changes in the Harvard Aging Brain Study (HABS) cohort. We found that the temporal accumulations of interlinked Aβ and tau pathology display distinctive spatiotemporal correlations associated with early cognitive decline.

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Finite element models (FEM) of the tongue have facilitated speech studies through analysis of internal muscle forces indirectly derived from imaging data. In this work, we build a uniform hexahedral FEM of a tongue atlas constructed from magnetic resonance imaging data of a healthy population. The FEM is driven by inverse internal tongue tissue kinematics of speakers temporally aligned and deformed into the same atlas space, while performing the speech task "a souk" allowing muscle activation predictions.

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Article Synopsis
  • Double-balloon endoscopy (DBE) is commonly used for diagnosing small-bowel Crohn's disease (CD), but misdiagnosis can happen due to inexperienced endoscopists and subjective assessments.
  • A study collected over 28,000 DBE images and trained a deep learning model, EfficientNet-b5, to accurately detect and grade CD lesions, including ulcers and stenosis.
  • The AI model demonstrated high accuracy rates, outperforming human endoscopists, suggesting it can enhance detection and management of small-bowel CD in clinical settings.
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Source-free domain adaptive segmentation with class-balanced complementary self-training.

Artif Intell Med

December 2023

Harvard Medical School, Harvard University, Boston, MA, USA; Gordon Center for Medical Imaging, Massachusetts General Hospital, Boston, MA, USA. Electronic address:

Unsupervised domain adaptation (UDA) plays a crucial role in transferring knowledge gained from a labeled source domain to effectively apply it in an unlabeled and diverse target domain. While UDA commonly involves training on data from both domains, accessing labeled data from the source domain is frequently constrained, citing concerns related to patient data privacy or intellectual property. The source-free UDA (SFUDA) can be promising to sidestep this difficulty.

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Mechanical response luminescence (MRL) describes the photophysical properties triggered by mechanical stimulation. Usually, MRL can be regulated by intermolecular interactions, molecular conformation or molecular packing, to achieve the desirable optical properties. Herein, at the molecular level, this review covers the factors that influence mechanically responsive fluorescent materials, involving the single- or multifactorial modulation of aliphatic chains, donor-receptor switch, substituent adjustment, and position isomerism.

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Investigating the relationship between internal tissue point motion of the tongue and oropharyngeal muscle deformation measured from tagged MRI and intelligible speech can aid in advancing speech motor control theories and developing novel treatment methods for speech related-disorders. However, elucidating the relationship between these two sources of information is challenging, due in part to the disparity in data structure between spatiotemporal motion fields (i.e.

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