A5062724086- Advanced MRI Techniques and Applications
- Advanced Neuroimaging Techniques and Applications
- Functional Brain Connectivity Studies
- Neural dynamics and brain function
- MRI in cancer diagnosis
- Medical Imaging Techniques and Applications
- Memory and Neural Mechanisms
- Neuroscience and Neuropharmacology Research
- Cardiac Imaging and Diagnostics
- Electron Spin Resonance Studies
- Visual perception and processing mechanisms
- NMR spectroscopy and applications
- Advanced NMR Techniques and Applications
- Transcranial Magnetic Stimulation Studies
- Medical Image Segmentation Techniques
- Bone and Joint Diseases
- Neurogenesis and neuroplasticity mechanisms
- Neuroscience and Music Perception
- Ultrasound Imaging and Elastography
- Atomic and Subatomic Physics Research
- Radiomics and Machine Learning in Medical Imaging
- Fetal and Pediatric Neurological Disorders
- Multiple Sclerosis Research Studies
- EEG and Brain-Computer Interfaces
- Neurobiology of Language and Bilingualism
University College London
2016-2025
Wellcome Centre for Human Neuroimaging
2015-2024
National Hospital for Neurology and Neurosurgery
2015-2024
California University of Pennsylvania
2020
Middlesex University
2010-2011
Hammersmith Hospital
2007
Imperial College London
2005
Significance Adolescence is a period of human brain growth and high incidence mental health disorders. Here, we show consistently in two MRI cohorts that changes adolescence were concentrated on the more densely connected hubs connectome (i.e., association cortical regions mediated efficient connectivity throughout structural network). Hubs less myelinated at 14 y but had faster rates myelination shrinkage 14- to 24-y period. This topologically focused process consolidation was associated...
A pressing need exists to disentangle age-related changes from pathologic neurodegeneration. This study aims characterize the spatial pattern and differences of biologically relevant measures in vivo over course normal aging. Quantitative multiparameter maps that provide neuroimaging biomarkers for myelination iron levels, parameters sensitive aging, were acquired 138 healthy volunteers (age range: 19–75 years). Whole-brain voxel-wise analysis revealed a global degeneration. Significant...
Neuroscience and clinical researchers are increasingly interested in quantitative magnetic resonance imaging (qMRI) due to its sensitivity micro-structural properties of brain tissue such as axon, myelin, iron water concentration. We introduce the hMRI-toolbox, an open-source, easy-to-use tool available on GitHub, for qMRI data handling processing, presented together with a tutorial example dataset. This toolbox allows estimation high-quality multi-parameter maps (longitudinal effective...
Misophonia is an affective sound-processing disorder characterized by the experience of strong negative emotions (anger and anxiety) in response to everyday sounds, such as those generated other people eating, drinking, chewing, breathing [1-8]. The commonplace nature these sounds (often referred "trigger sounds") makes misophonia a devastating for sufferers their families, yet nothing known about underlying mechanism. Using functional structural MRI coupled with physiological measurements,...
Significance Locus coeruleus (LC) integrity in cognitively normal older adults is a potentially important preclinical marker dementia. Our study establishes link between variability LC and cognitive decline related to noradrenergic modulation old age. We find that adults, reduced explains lower memory performance. This effect was more pronounced for negative events, accompanied by increased pupil diameter size response events. The provides strong motivation future research investigating the...
Obesity-related structural brain alterations point to a consistent reduction in gray matter with increasing body mass index (BMI) but changes white have proven be more complex and less conclusive. Hence, recently diffusion tensor imaging (DTI) has been employed investigate microstructural structure. Altogether, these studies mostly shown loss of integrity obesity-related factors several regions. However, the variety factors, including inflammation dyslipidemia, resulted competing influences...
The way we perceive the world is strongly influenced by our expectations. In line with this, much recent research has revealed that prior expectations modulate sensory processing. However, neural circuitry through which brain integrates external inputs internal expectation signals remains unknown. order to understand computational architecture of cortex, need investigate these flow cortical layers. This crucial because different layers have distinct intra- and interregional connectivity...
Rapid imaging techniques are increasingly used in functional MRI studies because they allow a greater number of samples to be acquired per unit time, thereby increasing statistical power. However, temporal correlations limit the increase sensitivity and must accurately accounted for control false-positive rate. A common approach accounting is whiten data prior estimating fMRI model parameters. Models white noise plus first-order autoregressive process have proven sufficient conventional...
Quantitative imaging aims to provide in vivo neuroimaging biomarkers with high research and diagnostic value that are sensitive underlying tissue microstructure. In order use these data examine intra-cortical differences or define boundaries between different myelo-architectural areas, resolution required. The quality of such measurements is degraded the presence motion hindering insight into brain Correction schemes therefore vital for resolution, whole coverage approaches have long...
The g-ratio, quantifying the ratio between inner and outer diameters of a fiber, is an important microstructural characteristic fiber pathways functionally related to conduction velocity. We introduce novel method for estimating MR g-ratio non-invasively across whole brain using high-fidelity magnetization transfer (MT) imaging single-shell diffusion MRI. These methods enabled us map in vivo brain's prominent group 37 healthy volunteers estimate inter-subject variability. Effective...
The longitudinal relaxation rate (R1 ) measured in vivo depends on the local microstructural properties of tissue, such as macromolecular, iron, and water content. Here, we use whole brain multiparametric data a general linear relaxometry model to describe dependence R1 these components. We explore a) validity having single fixed set coefficients for b) stability large cohort.Maps magnetization transfer (MT) effective transverse (R2 *) were used surrogates macromolecular iron content,...
Abstract Traumatic spinal cord injury (SCI) has been shown to trigger structural atrophic changes within the and brain. However, relationship between magnitude of neuropathic pain (NP) remains incompletely understood. Voxel-wise analysis anatomical magnetic resonance imaging data provided information on cross-sectional cervical area volumetric brain in 30 individuals with chronic traumatic SCI 31 healthy controls. Participants were clinically assessed including neurological examination...
Measuring the structural composition of cortex is critical to understanding typical development, yet few investigations in humans have charted markers vivo that are sensitive tissue microstructural attributes. Here, we used a well-validated quantitative MR protocol measure four parameters (R1, MT, R2*, PD*) differ their sensitivity facets environment MT: myelin, macromolecular content; R2*: paramagnetic ions, i.e., iron; PD*: free water content). Mapping these across cortical regions young...
Research ethics committee approval was obtained for this study, and written informed consent from all participants. The purpose to prospectively evaluate the feasibility of breath-hold multiecho in- out-of-phase magnetic resonance (MR) imaging simultaneous lipid quantification T2* measurement. A spoiled gradient-echo sequence with seven echo times alternately in phase out used at 3.0 T. Imaging performed a phantom, five healthy volunteers (all men; mean age, 37 years), obese individuals...
Objective In patients with subacute spinal cord injury (SCI), the motor system undergoes progressive structural changes rostral to lesion, which are associated outcome. The extent sensory is affected and how this relates outcome uncertain. Methods Changes in were prospectively followed by applying a comprehensive magnetic resonance imaging (MRI) protocol 14 traumatic SCI at baseline, 2 months, 6 12 months after injury, combined full neurological examination pain assessment. Eighteen controls...
The ability to introspectively evaluate our experiences form accurate metacognitive beliefs, or insight, is an essential component of decision-making. Previous research suggests individuals vary substantially in their level and that this variation related brain volume function, particularly the anterior prefrontal cortex (aPFC). However, neurobiological mechanisms underlying these effects are unclear, as qualitative, macroscopic measures such can be a variety microstructural features. Here...
In combination with magnetoencephalographic (MEG) data, accurate knowledge of the brain's structure and location provide a principled way reconstructing neural activity high temporal resolution. However, measuring is compromised by head movement during scanning, fiducial-based co-registration magnetic resonance imaging (MRI) data. The uncertainty from these two factors introduces errors into forward model limit spatial resolution
We evaluated the performance of an optical camera based prospective motion correction (PMC) system in improving quality 3D echo-planar imaging functional MRI data. An and external marker were used to dynamically track head movement subjects during fMRI scanning. PMC was performed by using information update sequence's RF excitation gradient waveforms such that field-of-view realigned match subject's movement. Task-free experiments on five healthy volunteers followed a 2 × 3 factorial design...
Relaxation rates provide important information about tissue microstructure. Multi-parameter mapping (MPM) estimates multiple relaxation parameters from multi-echo FLASH acquisitions with different basic contrasts, i.e., proton density (PD), T1 or magnetization transfer (MT) weighting. Motion can particularly affect maps of the apparent transverse rate R2*, which are derived signal PD-weighted images acquired at echo times. To address motion artifacts, we introduce ESTATICS, robustly R2* even...
Quantitative Susceptibility Mapping (QSM), best known as a surrogate for tissue iron content, is becoming highly relevant MRI contrast monitoring cellular and vascular status in aging, addiction, traumatic brain injury and, general, wide range of neurological disorders. In this study we present new Bayesian QSM algorithm, named Multi-Scale Dipole Inversion (MSDI), which builds on the nonlinear Morphology-Enabled (nMEDI) framework, incorporating three additional features: (i) improved...
Speech articulation requires precise control of and coordination between the effectors vocal tract (e.g., lips, tongue, soft palate, larynx). However, it is unclear how cortex represents movements contact these during speech, or cortical responses relate to inter-regional anatomical borders. Here, we used phase-encoded fMRI map somatomotor representations speech articulations. Phonetically trained participants produced phones, progressing from front (bilabial) back (glottal) place...
Abstract Motion during the acquisition of magnetic resonance imaging (MRI) data degrades image quality, hindering our capacity to characterise disease in patient populations. Quality control procedures allow exclusion most affected images from analysis. However, criterion for is difficult determine objectively and can lead a suboptimal compromise between quality sample size. We provide an alternative, data‐driven solution that assigns weights each image, computed index using restricted...