A5003132438- Advanced MRI Techniques and Applications
- Traumatic Brain Injury and Neurovascular Disturbances
- MRI in cancer diagnosis
- Advanced Neuroimaging Techniques and Applications
- Neonatal and fetal brain pathology
- Atomic and Subatomic Physics Research
- Cerebrovascular and Carotid Artery Diseases
- Cardiovascular Health and Disease Prevention
- Functional Brain Connectivity Studies
- Acute Ischemic Stroke Management
- Cerebrospinal fluid and hydrocephalus
- Lanthanide and Transition Metal Complexes
- Long-Term Effects of COVID-19
- Optical Imaging and Spectroscopy Techniques
- Medical Imaging Techniques and Applications
- Neurological Disease Mechanisms and Treatments
- Bone and Joint Diseases
- Hemoglobinopathies and Related Disorders
- Dementia and Cognitive Impairment Research
- Fetal and Pediatric Neurological Disorders
- Infectious Encephalopathies and Encephalitis
- Intensive Care Unit Cognitive Disorders
- Anesthesia and Neurotoxicity Research
- Cerebral Venous Sinus Thrombosis
- Neural dynamics and brain function
Johns Hopkins University
2015-2025
Johns Hopkins Medicine
2018-2024
Dalian Medical University
2019
Chongqing Medical University
2019
Second Affiliated Hospital of Chongqing Medical University
2019
Tsinghua University
2012
Background Perfusion imaging of the brain has important clinical applications in detecting neurological abnormalities neonates. However, such tools have not been available to date. Although arterial‐spin‐labeling (ASL) MRI is a powerful noninvasive tool measure perfusion, its application neonates encountered obstacles related low signal‐to‐noise ratio (SNR), large‐vessel contaminations, and lack technical development studies. Purpose To systematically develop optimize ASL perfusion healthy...
Objective Blood–brain barrier (BBB) breakdown has been suggested to be an early biomarker in human cognitive impairment. However, the relationship between BBB and brain pathology, most commonly Alzheimer disease (AD) vascular disease, is still poorly understood. The present study measured function mild impairment (MCI) patients on 2 molecular scales, specifically BBB's permeability water albumin molecules. Methods Fifty‐five elderly participants were enrolled, including 33 MCI 22 controls....
Background and Purpose The vascular tortuosity (VT) of the internal carotid artery (ICA), vertebral (VA) can impact blood flow neuronal function. However, few studies involved quantitative investigation VT based on magnetic resonance imaging (MRI). main purpose our study was to evaluate age gender effects ICA VA regarding changes by applying automatic vessel segmentation, centerline tracking, phase mapping MR angiography. Methods A total 247 subjects (86 males 161 females) without...
Background Alzheimer's disease and vascular cognitive impairment (VCI), as well their concurrence, represent the most common types of dysfunction. Treatment strategies for these two conditions are quite different; however, there exists a considerable overlap in clinical manifestations, biomarkers reveal similar abnormalities between conditions. Purpose To evaluate potential cerebral oxygen extraction fraction (OEF) biomarker differential diagnosis VCI. We hypothesized that OEF will be...
Abnormal oxygen extraction fraction (OEF), a putative biomarker of cerebral metabolic stress, may indicate compromised delivery and ischemic vulnerability in patients with sickle cell disease (SCD). Elevated OEF was observed at the tissue level across brain using an asymmetric spin echo (ASE) MR method, while variable global OEFs were found from superior sagittal sinus (SSS) T2-relaxation-under-spin-tagging (TRUST) MRI method different calibration models. In this study, we aimed to compare...
Purpose To evaluate the accuracy of T 2 ‐based whole‐brain oxygen extraction fraction (OEF) estimation by comparing it with gold standard 15 O‐PET measurements. Methods Sixteen healthy adult subjects underwent MRI and OEF measurements on same day. On MRI, was quantified ‐relaxation‐under‐spin‐tagging (TRUST) based subject‐specific hematocrit. The TRUST compared to averaged produced O‐PET. Agreement between examined in terms intraclass correlation coefficient (ICC) absolute values. In a...
Abstract Introduction Oxygen extraction fraction (OEF) reflects the balance between oxygen delivery and consumption. We longitudinally measured OEF in older adults to examine relationship with markers of Alzheimer's disease (AD) vascular pathology. Methods One hundred thirty‐seven participants were studied at two time‐points an interval 2.16 years. was using T 2 ‐relaxation‐under‐spin‐tagging (TRUST) magnetic resonance imaging (MRI). The association risks, white matter hyperintensities...
Cerebrovascular reactivity (CVR) mapping using CO2-inhalation can provide important insight into vascular health. At present, blood-oxygenation-level-dependent (BOLD) MRI acquisition is the most commonly used CVR method due to its high sensitivity, spatial resolution, and relatively straightforward processing. However, large variations in across subjects different sessions of same subject are often observed, which cloud ability this promising measure detecting diseases or monitoring...
The specific cytopathology that causes abnormal fractional anisotropy (FA) and mean diffusivity (MD) from diffusion tensor imaging (DTI) after neonatal hypoxia-ischemia (HI) is not completely understood. panoply of cell types in the brain might contribute differentially to changes DTI metrics. Because glia are predominant type brain, we hypothesized FA MD would signify perturbations glial microstructure. Using a 3-Tesla clinical scanner, conducted vivo MRI nine piglets at 20-96 h excitotoxic...
Vascular pathology is the second leading cause of cognitive impairment and represents a major contributing factor in mixed dementia. However, biomarkers for vascular dementia (VCID) are under-developed. Here we aimed to investigate potential role CO2 Cerebrovascular Reactivity (CVR) measured with phase-contrast quantitative flow MRI Forty-five (69 ± 7 years) impaired (37 mild-cognitive-impairment 8 mild-dementia by syndromic diagnosis) 22 cognitively-healthy-control (HC) participants were...
Abstract INTRODUCTION Vascular contributions to cognitive impairment and dementia (VCID) represent a major factor in decline older adults. The present study examined the relationship between cerebrovascular reactivity (CVR) measured by magnetic resonance imaging (MRI) function multi‐site study, using predefined hypothesis. METHODS We conducted total of three analysis sites 263 subjects. Each site performed an identical CVR MRI procedure 5% carbon dioxide inhalation. A global measure Montreal...
Cerebrovascular disease is a leading cause of death globally. Prevention and early intervention are known to be the most effective forms its management. Non-invasive imaging methods hold great promises for stratification, but at present lack sensitivity personalized prognosis. Resting-state functional magnetic resonance (rs-fMRI), powerful tool previously used mapping neural activity, available in hospitals. Here we show that rs-fMRI can map cerebral hemodynamic function delineate...
Purpose Cerebral venous oxygenation (Y v ) is an important physiological parameter and has potential clinical application in many brain diseases. T 2 ‐relaxation‐under‐spin‐tagging (TRUST) a commonly used MRI method to measure Y . Harmonization of this technique across vendors for dissemination multicenter studies metabolism as disease biomarker. Methods TRUST pulse sequence components imaging parameters were carefully matched between two major vendors, Philips Siemens. Each subject ( N =...
Purpose Assessment of the blood–brain barrier (BBB) permeability without need for contrast agent is desirable, and ability to measure small molecules such as water may further increase sensitivity in detecting diseases. This study proposed a time‐efficient, noncontrast method BBB water, evaluated its test–retest reproducibility, compared it with agent–based method. Methods A single‐delay extraction phase‐contrast arterial spin tagging (WEPCAST) was devised which spatial profile signal along...
Purpose Caffeine is known to alter brain perfusion by acting as an adenosine antagonist, but its effect on blood–brain barrier (BBB) permeability not fully elucidated. This study aimed dynamically monitor BBB water after a single dose of caffeine tablet using non‐contrast MRI technique. Methods Ten young healthy volunteers who were regular coffee drinkers studied. The experiment began with pre‐caffeine measurement, followed four measurements at the post‐caffeine stage....
Post-acute COVID-19 syndrome (PCS) is highly prevalent. Critically ill patients requiring intensive care unit (ICU) admission are at a higher risk of developing PCS. The mechanisms underlying PCS still under investigation and may involve microvascular damage in the brain. Cerebral misery perfusion, characterized by reduced cerebral blood flow (CBF) elevated oxygen extraction fraction (OEF) affected brain areas, has been demonstrated cerebrovascular diseases such as carotid occlusion stroke....
Abstract Purpose Abnormalities in cerebral veins are a common finding many neurological diseases, yet there is scarcity of MRI techniques to assess venous hemodynamic function. The present study aims develop noncontrast technique measure novel blood flow circulatory measure, transit time (VTT), which denotes the it takes for water travel from capillary major veins. Methods proposed sequence, imaging by changes T 1 relaxation (VICTR), based on notion that as molecules transition tissue into...
Purpose Noninvasive measurement of cerebral venous oxygenation (Y v ) in neonates is important the assessment brain oxygen extraction and consumption, may be useful characterizing development neonatal diseases. This study aims to develop a rapid method for vessel‐specific Y neonates. Methods We developed pulse sequence, named accelerated T 2 ‐relaxation‐under‐phase‐contrast (aTRUPC), which consists velocity‐encoding phase‐contrast module isolate pure blood signal, flow‐insensitive...
Coronavirus disease 2019 (COVID-19) results in severe inflammation at the acute stage. Chronic neuroinflammation and abnormal immunological response have been suggested to be contributors neuro-long-COVID, but direct evidence has scarce. This study aims determine integrity of blood-brain barrier (BBB) COVID-19 intensive care unit (ICU) survivors using a novel MRI technique.
Purpose To optimize phase‐contrast (PC) MRI for the measurement of global cerebral blood flow (CBF) in mouse at 11.7T. Methods We determined proper velocity encoding (VENC) internal carotid arteries (ICAs) and vertebral (VAs). Next, we optimized spatial resolution sequence. shorten scan time without compromising data quality, further repetition developed a reduced field‐of‐view (FOV) scheme ICA VA PC MRI. Whole‐brain volume was with T 2 ‐weighted image to obtain unit‐volume CBF. Results Peak...
Background Disruption of brain oxygen delivery and consumption after hypoxic–ischemic injury contributes to neonatal mortality neurological impairment. Measuring cerebral hemodynamic parameters, including blood flow (CBF), extraction fraction (OEF), metabolic rate (CMRO 2 ), is clinically important. Purpose Phase‐contrast (PC), velocity‐selective arterial spin labeling (VSASL), T ‐relaxation‐under‐phase‐contrast (TRUPC) are magnetic resonance imaging (MRI) techniques that have shown...
Cerebral oxygen extraction fraction is an important physiological index of the brain’s consumption and supply has been suggested to be a potential biomarker for number diseases such as stroke, Alzheimer’s disease, multiple sclerosis, sickle cell metabolic disorders. However, in order sensitive personalized disease diagnosis, inter-subject variations normal subjects must minimized or accounted for, which will otherwise obscure its interpretation. Therefore, it essential investigate...
Abstract Purpose To quantify the T 1 and 2 values of CSF in subarachnoid space (SAS) at 3 interpret them context water exchange between brain tissues. Methods was measured using inversion recovery, assessed ‐preparation. SAS were compared with those frontal horns lateral ventricles, which have less brain‐CSF exchange. Phantom experiments performed to examine whether there spatial variations that unrelated Simulations conducted investigate relationship rate apparent CSF. Results The 4308.7 ±...