250 results match your criteria: "CIBM Center for Biomedical Imaging[Affiliation]"

Cardiovascular magnetic resonance imaging (MRI) in patients with cardiac implants, such as pacemakers and defibrillators, has gained importance in recent years with the development of modern cardiac implantable electronic devices. The increasing clinical need to perform MRI examinations in patients with cardiac implants has driven the development of new advanced MRI sequences to mitigate image artifacts associated with cardiac implants. More specifically, advances in imaging techniques, such as wideband late gadolinium enhancement imaging, wideband T1 mapping, and wideband perfusion, have been designed to improve image quality and examinations in patients with cardiac implants, enabling a comprehensive and more reliable diagnosis, which was previously unattainable in these patients.

View Article and Find Full Text PDF

The thalamus has a key role in mediating cortical-subcortical interactions but is often neglected in neuroimaging studies, which mostly focus on changes in cortical structure and activity. One of the main reasons for the thalamus being overlooked is that the delineation of individual thalamic nuclei via neuroimaging remains controversial. Indeed, neuroimaging atlases vary substantially regarding which thalamic nuclei are included and how their delineations were established.

View Article and Find Full Text PDF
Article Synopsis
  • The study aimed to evaluate the effectiveness of two blind source separation techniques (SOBI and ICA) against principal component analysis (PCA) for identifying cardiac triggers in 5D whole-heart MRI.
  • Data was collected from three different groups: healthy volunteers, congenital heart disease patients, and patients with suspected coronary artery disease, each undergoing MRI scans with different protocols.
  • Results showed SOBI provides more accurate and sharper cardiac triggers compared to PCA and ICA, demonstrating its reliability across varying patient conditions and noise levels.
View Article and Find Full Text PDF
Article Synopsis
  • Phosphorus Magnetic Resonance Spectroscopy (P MRS) is a noninvasive technique used to assess energy metabolism, but high magnetic fields often create sensitivity and spatial issues; the novel fast double-angle method (fDAM) is proposed to address these challenges.
  • The fDAM method utilizes advanced 3D acquisitions and frequency-selective pulses to efficiently map phosphocreatine signals at 7T, showing promising results in both phantom studies and human brain/muscle applications.
  • The study findings demonstrate that fDAM provides a strong correlation with traditional methods while significantly reducing mapping time and improving coverage, suggesting its potential for quick P MRSI applications in future research.
View Article and Find Full Text PDF

Resting-state functional connectivity abnormalities in subjective cognitive decline: A 7T MRI study.

Neurobiol Aging

December 2024

Laboratory of Neuroimaging of Aging (LANVIE), University of Geneva, Geneva, Switzerland; Geneva Memory Center, Department of Rehabilitation and Geriatrics, Geneva University Hospitals, Geneva, Switzerland.

Resting-state functional connectivity (FC) MRI is sensitive to brain changes in Alzheimer's disease in preclinical stages, however studies in persons with subjective cognitive decline (SCD) have reported conflicting findings, and no study is available at 7T MRI. In this study, we investigated FC alterations in sixty-six participants recruited at the Geneva Memory Center (24 controls, 14 SCD, 28 cognitively impaired [CI]). Participants were classified as SCD if they reported cognitive complaints without objective cognitive deficits, and underwent 7T fMRI to assess FC in canonical brain networks and their association with cognitive/clinical features.

View Article and Find Full Text PDF

Functional connectivity patterns in the human brain, like the friction ridges of a fingerprint, can uniquely identify individuals. Does this "brain fingerprint" remain distinct even during Alzheimer's disease (AD)? Using fMRI data from healthy and pathologically ageing subjects, we find that individual functional connectivity profiles remain unique and highly heterogeneous during mild cognitive impairment and AD. However, the patterns that make individuals identifiable change with disease progression, revealing a reconfiguration of the brain fingerprint.

View Article and Find Full Text PDF

Tonic and burst-like locus coeruleus stimulation distinctly shift network activity across the cortical hierarchy.

Nat Neurosci

November 2024

Neural Control of Movement Lab, Department of Health Sciences and Technology, ETH Zürich, Zürich, Switzerland.

Article Synopsis
  • Noradrenaline (NA) release from the locus coeruleus (LC) affects brain activity and behavior by utilizing different firing patterns, specifically tonic and burst-like activity.
  • Research using advanced techniques in mice shows that moderate tonic activation of the LC influences areas linked to associative processing, while burst-like stimulation shifts focus towards sensory processing.
  • The study also identifies that these different firing patterns alter local brain activity and structure, demonstrating the LC-NA system's complex role in regulating brain circuits.
View Article and Find Full Text PDF

Diffusion Magnetic Resonance Imaging (dMRI) is a noninvasive method for depicting brain microstructure . Fiber orientation distributions (FODs) are mathematical representations extensively used to map white matter fiber configurations. Recently, FOD estimation with deep neural networks has seen growing success, in particular, those of neonates estimated with fewer diffusion measurements.

View Article and Find Full Text PDF

Aging is associated with structural brain changes, cognitive decline, and neurodegenerative diseases. Brain age, an imaging biomarker sensitive to deviations from healthy aging, offers insights into structural aging variations and is a potential prognostic biomarker in neurodegenerative conditions. This study introduces BrainAgeNeXt, a novel convolutional neural network inspired by the MedNeXt framework, designed to predict brain age from T1-weighted magnetic resonance imaging (MRI) scans.

View Article and Find Full Text PDF

Alzheimer's Disease (AD) is characterized by an accumulation of pathologic amyloid-beta (Aβ) and Tau proteins, neuroinflammation, metabolic changes and neuronal death. Reactive astrocytes participate in these pathophysiological processes by releasing pro-inflammatory molecules and recruiting the immune system, which further reinforces inflammation and contributes to neuronal death. Besides these neurotoxic effects, astrocytes can protect neurons by providing them with high amounts of lactate as energy fuel.

View Article and Find Full Text PDF

FetMRQC: A robust quality control system for multi-centric fetal brain MRI.

Med Image Anal

October 2024

CIBM - Center for Biomedical Imaging, Switzerland; Department of Diagnostic and Interventional Radiology, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland.

Fetal brain MRI is becoming an increasingly relevant complement to neurosonography for perinatal diagnosis, allowing fundamental insights into fetal brain development throughout gestation. However, uncontrolled fetal motion and heterogeneity in acquisition protocols lead to data of variable quality, potentially biasing the outcome of subsequent studies. We present FetMRQC, an open-source machine-learning framework for automated image quality assessment and quality control that is robust to domain shifts induced by the heterogeneity of clinical data.

View Article and Find Full Text PDF

Proton magnetic resonance spectroscopic imaging (H-MRSI) is a powerful tool that enables the multidimensional non-invasive mapping of the neurochemical profile at high resolution over the entire brain. The constant demand for higher spatial resolution in H-MRSI has led to increased interest in post-processing-based denoising methods aimed at reducing noise variance. The aim of the present study was to implement two noise-reduction techniques, Marchenko-Pastur principal component analysis (MP-PCA) based denoising and low-rank total generalized variation (LR-TGV) reconstruction, and to test their potential with and impact on preclinical 14.

View Article and Find Full Text PDF

Correction to: EANM perspectives for CZT SPECT in brain applications.

Eur J Nucl Med Mol Imaging

October 2024

Department of Nuclear Medicine and Nancyclotep Imaging Platform, CHRU Nancy, Université de Lorraine, IADI, INSERM U1254, Allée du Morvan, Nancy, 54500, France.

View Article and Find Full Text PDF

Across development, experience has a strong impact on the way we think and adapt. School experience affects academic and social-emotional outcomes, yet whether differences in pedagogical experience modulate underlying brain network development is still unknown. In this study, we compared the brain network dynamics of students with different pedagogical backgrounds.

View Article and Find Full Text PDF

Purpose: Phosphorus Magnetic Resonance Spectroscopy (P MRS) enables non-invasive assessment of energy metabolism, yet its application is hindered by sensitivity limitations. To overcome this, often high magnetic fields are used, leading to challenges such as spatial inhomogeneity and therefore the need for accurate flip angle determination in accelerated acquisitions with short repetition times . In response to these challenges, we propose a novel short and look-up table-based Double-Angle Method for fast 3D P mapping (fDAM).

View Article and Find Full Text PDF

Introduction: Morphometric similarity is a recently developed neuroimaging phenotype of inter-regional connectivity by quantifying the similarity of a region to other regions based on multiple MRI parameters. Altered average morphometric similarity has been reported in psychotic disorders at the group level, with considerable heterogeneity across individuals. We used normative modeling to address cross-sectional and longitudinal inter-individual heterogeneity of morphometric similarity in health and schizophrenia.

View Article and Find Full Text PDF

Advanced age is the most important risk factor for Alzheimer's disease (AD), and carrier-status of the Apolipoprotein E4 (APOE4) allele is the strongest known genetic risk factor. Many studies have consistently shown a link between APOE4 and synaptic dysfunction, possibly reflecting pathologically accelerated biological aging in persons at risk for AD. To test the hypothesis that distinct functional connectivity patterns characterize APOE4 carriers across the clinical spectrum of AD, we investigated 128 resting state functional Magnetic Resonance Imaging (fMRI) datasets from the Alzheimer's Disease Neuroimaging Initiative database (ADNI), representing all disease stages from cognitive normal to clinical dementia.

View Article and Find Full Text PDF

High-Resolution Magnetic Resonance Neurography at 7T: A Pilot Study of Hand Innervation.

Diagnostics (Basel)

June 2024

Image Guided Interventions Laboratory (GR-949), Faculty of Medicine, University of Geneva, 1211 Geneva, Switzerland.

The emergence of 7T clinical MRI technology has sparked our interest in its ability to discern the complex structures of the hand. Our primary objective was to assess the sensory and motor nerve structures of the hand, specifically nerves and Pacinian corpuscles, with the dual purpose of aiding diagnostic endeavors and supporting reconstructive surgical procedures. Ethical approval was obtained to carry out 7T MRI scans on a cohort of volunteers.

View Article and Find Full Text PDF
Article Synopsis
  • Amyloid-β plaques are a key indicator of Alzheimer's disease, and dual PET scans are used to assess both amyloid presence and glucose metabolism to aid in diagnosis.
  • The study involved 166 participants across various cognitive states who underwent multiple imaging techniques, including innovative deep learning models to predict FDG PET results from early-phase amyloid scans.
  • Results indicated a moderate clinical similarity score between synthetic and actual FDG PET scans, suggesting potential for reducing the number of scans while still accurately assessing neurodegeneration.
View Article and Find Full Text PDF

EANM perspectives for CZT SPECT in brain applications.

Eur J Nucl Med Mol Imaging

October 2024

Department of Nuclear Medicine and Nancyclotep Imaging Platform, CHRU Nancy, Université de Lorraine, IADI, INSERM U1254, Allée du Morvan, Nancy, 54500, France.

View Article and Find Full Text PDF

Purpose: Wideband phase-sensitive inversion recovery (PSIR) late gadolinium enhancement (LGE) enables myocardial scar imaging in implantable cardioverter defibrillators (ICD) patients, mitigating hyperintensity artifacts. To address subendocardial scar visibility challenges, a 2D breath-hold single-shot electrocardiography-triggered black-blood (BB) LGE sequence was integrated with wideband imaging, enhancing scar-blood contrast.

Methods: Wideband BB, with increased bandwidth in the inversion pulse (0.

View Article and Find Full Text PDF

Longitudinal Analysis of Brain Function-Structure Dependencies in 22q11.2 Deletion Syndrome and Psychotic Symptoms.

Biol Psychiatry Cogn Neurosci Neuroimaging

September 2024

Developmental Imaging and Psychopathology Laboratory, University of Geneva School of Medicine, Geneva, Switzerland; Department of Genetic Medicine and Development, University of Geneva School of Medicine, Geneva, Switzerland.

Background: Compared with conventional unimodal analysis, understanding how brain function and structure relate to one another opens a new biologically relevant assessment of neural mechanisms. However, how function-structure dependencies (FSDs) evolve throughout typical and abnormal neurodevelopment remains elusive. The 22q11.

View Article and Find Full Text PDF

Our brain adeptly navigates goals across time frames, distinguishing between urgent needs and those of the past or future. The hippocampus is a region known for supporting mental time travel and organizing information along its longitudinal axis, transitioning from detailed posterior representations to generalized anterior ones. This study investigates the role of the hippocampus in distinguishing goals over time: whether the hippocampus encodes time regardless of detail or abstraction, and whether the hippocampus preferentially activates its anterior region for temporally distant goals (past and future) and its posterior region for immediate goals.

View Article and Find Full Text PDF