A5000017093- Advanced MRI Techniques and Applications
- Neural dynamics and brain function
- Photoreceptor and optogenetics research
- Atomic and Subatomic Physics Research
- Functional Brain Connectivity Studies
- Medical Imaging Techniques and Applications
- Olfactory and Sensory Function Studies
- Advanced Chemical Sensor Technologies
- Neuroscience and Neuropharmacology Research
- Advanced Neuroimaging Techniques and Applications
- Sparse and Compressive Sensing Techniques
- Cardiac Imaging and Diagnostics
- Advanced Memory and Neural Computing
- Neurobiology and Insect Physiology Research
- Neuroscience and Neural Engineering
- Neuroendocrine regulation and behavior
- Memory and Neural Mechanisms
- Advanced NMR Techniques and Applications
- Electrical and Bioimpedance Tomography
- Multisensory perception and integration
- Zebrafish Biomedical Research Applications
- Advanced X-ray Imaging Techniques
- Stress Responses and Cortisol
- Electromagnetic Fields and Biological Effects
- Biochemical Analysis and Sensing Techniques
Chinese University of Hong Kong
2017-2024
University of Hong Kong
2015-2024
City University of Hong Kong
2020
Abstract Magnetic resonance imaging is a key diagnostic tool in modern healthcare, yet it can be cost-prohibitive given the high installation, maintenance and operation costs of machinery. There are approximately seven scanners per million inhabitants over 90% concentrated high-income countries. We describe an ultra-low-field brain MRI scanner that operates using standard AC power outlet low cost to build. Using permanent 0.055 Tesla Samarium-cobalt magnet deep learning for cancellation...
Despite a half-century of advancements, global magnetic resonance imaging (MRI) accessibility remains limited and uneven, hindering its full potential in health care. Initially, MRI development focused on low fields around 0.05 Tesla, but progress halted after the introduction 1.5 Tesla whole-body superconducting scanner 1983. Using permanent magnet deep learning for electromagnetic interference elimination, we developed that operates using standard wall power outlet without radiofrequency...
Significance The hippocampus with its dense reciprocal axonal projections to and from cortex is widely believed mediate numerous cognitive functions. However, it unknown whether how specific hippocampal–cortical activity contributes the brain-wide functional connectivity. Here, we use optogenetics fMRI examine excitatory neural initiated in dorsal dentate gyrus of propagates modulates resting-state (rsfMRI) We discover robust propagation at low frequency (1 Hz), which enhances...
Major depressive disorder (MDD) is a devastating mental that affects up to 17% of the population worldwide. Although brain-wide network-level abnormalities in MDD patients via resting-state functional magnetic resonance imaging (rsfMRI) exist, mechanisms underlying these network changes are unknown, despite their immense potential for depression diagnosis and management. Here, we show astrocytic calcium-deficient mice, inositol 1,4,5-trisphosphate-type-2 receptor knockout mice ( Itpr2 −/−...
Purpose Recent development of ultra‐low‐field (ULF) MRI presents opportunities for low‐power, shielding‐free, and portable clinical applications at a fraction the cost. However, its performance remains limited by poor image quality. Here, computational approach is formulated to advance ULF MR brain imaging through deep learning large‐scale publicly available 3T data. Methods A dual‐acquisition 3D superresolution model developed 0.055 T. It consists cross‐scale feature extraction, attentional...
In recent years, there has been an intensive development of portable ultralow-field magnetic resonance imaging (MRI) for low-cost, shielding-free, and point-of-care applications. However, its quality is poor scan time long. We propose a fast acquisition deep learning reconstruction framework to accelerate brain MRI at 0.055 tesla. The consists single average three-dimensional (3D) encoding with 2D partial Fourier sampling, reducing the T1- T2-weighted protocols 2.5 3.2 minutes, respectively....
One challenge in contemporary neuroscience is to achieve an integrated understanding of the large-scale brain-wide interactions, particularly spatiotemporal patterns neural activity that give rise functions and behavior. At present, little known about properties long-range neuronal networks. We examined elicited by stimulating ventral posteromedial (VPM) thalamo-cortical excitatory neurons through combined optogenetic stimulation functional MRI (fMRI). detected robust optogenetically evoked...
Significance The vestibular system provides a critical role to coordinate balance and movement, yet it remains an underappreciated sense. Functional MRI (fMRI) reveals much information about brain-wide sensory cognitive processes. However, fMRI mapping of regions that actively process technically challenging, as can permit only limited movement during scanning. Here, we deploy optogenetic stimulation excitatory neurons visualize numerous central pathways interrogate their functional roles in...
Abstract At present, MRI scans are typically performed inside fully enclosed radiofrequency (RF) shielding rooms, posing stringent installation requirements and causing patient discomfort. We aim to eliminate electromagnetic interference (EMI) for with no or incomplete RF shielding. In this study, a method of active sensing deep learning EMI prediction is presented model, predict, remove signal components from acquired signals. Specifically, during each scan, separate EMI‐sensing coils...
As a key oscillatory activity in the brain, thalamic spindle activities are long believed to support memory consolidation. However, their propagation characteristics and causal actions at systems level remain unclear. Using functional MRI (fMRI) electrophysiology recordings male rats, we found that optogenetically-evoked somatosensory spindle-like targeted numerous sensorimotor (cortex, thalamus, brainstem basal ganglia) non-sensorimotor limbic regions amygdala, hippocampus) stimulation...
Purpose To jointly reconstruct highly undersampled multicontrast two‐dimensional (2D) datasets through a low‐rank Hankel tensor completion framework. Methods A (MC‐HTC) framework is proposed to exploit the shareable information in with respect their correlated image structure, common spatial support, and shared coil sensitivity for joint reconstruction. This achieved by first organizing k‐space into single block‐wise tensor. Subsequent approximation via higher‐order singular value...
To provide a complex-valued deep learning approach for partial Fourier (PF) reconstruction of complex MR images.Conventional PF methods, such as projection onto convex sets (POCS), uses low-resolution image phase information from the central symmetrically sampled k-space reconstruction. However, this smooth constraint undermines estimation accuracy in presence rapid local variations, causing artifacts and limiting extent Using both magnitude characteristics big datasets, we propose with an...
Sensory cortices contain extensive descending (corticofugal) pathways, yet their impact on brainstem processing - particularly across sensory systems remains poorly understood. In the auditory system, inferior colliculus (IC) in midbrain receives cross-modal inputs from visual cortex (VC). However, influences VC are unclear. To investigate whether and how cortical affect IC responses, present study combines blood-oxygenation-level-dependent (BOLD) functional MRI (fMRI) with cell-type...
Purpose To provide joint calibrationless parallel imaging reconstruction of highly accelerated multislice 2D MR k‐space data. Methods Adjacent image slices in data have similar coil sensitivity maps, spatial support, and content. Such similarities can be utilized to improve quality by reconstructing multiple jointly with low‐rank tensor completion. Specifically, the multichannel from are constructed into a block‐wise Hankel iteratively updated promoting low‐rankness through higher‐order SVD....
Purpose To develop a joint denoising method that effectively exploits natural information redundancy in MR DWIs via low‐rank patch matrix approximation. Methods A is introduced to jointly reduce noise DWI dataset by exploiting nonlocal self‐similarity as well local anatomical/structural similarity within multiple 2D acquired with the same anatomical geometry but different diffusion directions. Specifically, for each small 3D reference sliding DWI, similar patches are searched matching image...
Low-rank technique has emerged as a powerful calibrationless alternative for parallel magnetic resonance (MR) imaging. Calibrationless low-rank reconstruction, such modeling of local k-space neighborhoods (LORAKS), implicitly exploits both coil sensitivity modulations and the finite spatial support constraint MR images through an iterative matrix recovery process. Although powerful, this slow iteration process is computationally demanding reconstruction requires empirical rank optimization,...
Despite its prominence in learning and memory, hippocampal influence early auditory processing centers remains unknown. Here, we examined how activity modulates sound-evoked responses the midbrain thalamus using optogenetics functional MRI (fMRI) rodents. Ventral hippocampus (vHP) excitatory neuron stimulation at 5 Hz evoked robust that propagates to primary cortex. We then tested vHP paired with either natural vocalizations or artificial/noise acoustic stimuli. enhanced (with a negative...
Purpose To provide simultaneous multislice (SMS) EPI reconstruction with k‐space implementation and robust Nyquist ghost correction. Methods 2D phase error correction SENSE (PEC‐SENSE) was recently developed for in SMS which virtual coil autocalibration estimation (VC‐SAKE) used to remove slice‐dependent ghosts intershot variations multi‐shot reference scan. However, masking sensitivity maps exclude background region PEC‐SENSE manually selecting slice‐wise target ranks VC‐SAKE are cumbersome...
Abstract Purpose To demonstrate magnetization transfer (MT) effects with low specific absorption rate (SAR) on ultra‐low‐field (ULF) MRI. Methods MT imaging was implemented by using sinc‐modulated RF pulse train (SPT) modules to provide bilateral off‐resonance irradiation. They were incorporated into 3D gradient echo (GRE) and fast spin (FSE) protocols a shielding‐free 0.055T head scanner. first verified phantoms. Brain conducted in both healthy subjects patients. Results clearly observed...
We propose a multi‐slice acquisition with orthogonally alternating phase encoding (PE) direction and subsequent joint calibrationless reconstruction for accelerated multiple individual 2D slices or Cartesian MRI. Specifically, multi‐channel data are first acquired random uniform PE undersampling while between adjacent slices. They then jointly reconstructed through recently developed low‐rank Hankel tensor completion (MS‐HTC) approach. The proposed strategy was evaluated human brain MR data....
Brain possesses a complex spatiotemporal architecture for efficient information processing and computing. However, it remains unknown how neural signal propagates to its intended targets brain-wide. Using optogenetics functional MRI, we arbitrarily initiated various discrete activity pulse trains with different temporal patterns revealed their distinct long-range propagation within the well-defined, topographically organized somatosensory thalamo-cortical circuit. We further observed that...
Alzheimer's disease (AD) is a degenerative brain and the most common cause of dementia. Early stage β-amyloid oligomers (AβOs) late Aβ plaques are pathological hallmarks AD brains. AβOs known to be more neurotoxic contribute neuronal damage. Most current approaches focused on detecting plaques, which occurs at AD, limited by poor sensitivity and/or contrast agent toxicity. In previous studies, we developed new curcumin-conjugated magnetic nanoparticle (Cur-MNPs) target pathologies. this...
The brain integrates information from different sensory modalities to form a representation of the environment and facilitate behavioral responses. auditory midbrain or inferior colliculus (IC) is pivotal station in system, integrating ascending descending various sources cortical systems. present study investigated modulation responses IC by visual stimuli frequencies intensities rats using functional MRI (fMRI). Low-frequency (1 Hz) high-intensity stimulus suppressed However,...