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15
result(s) for
"Ma, Laiyang"
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Altered brain functional network dynamics in classic trigeminal neuralgia: a resting-state functional magnetic resonance imaging study
2021
BackgroundAccumulating studies have indicated a wide range of brain alterations with respect to the structure and function of classic trigeminal neuralgia (CTN). Given the dynamic nature of pain experience, the exploration of temporal fluctuations in interregional activity covariance may enhance the understanding of pain processes in the brain. The present study aimed to characterize the temporal features of functional connectivity (FC) states as well as topological alteration in CTN.MethodsResting-state functional magnetic resonance imaging and three-dimensional T1-weighted images were obtained from 41 CTN patients and 43 matched healthy controls (HCs). After group independent component analysis, sliding window based dynamic functional network connectivity (dFNC) analysis was applied to investigate specific FC states and related temporal properties. Then, the dynamics of the whole brain topological organization were estimated by calculating the coefficient of variation of graph-theoretical properties. Further correlation analyses were performed between all these measurements and clinical data.ResultsTwo distinct states were identified. Of these, the state 2, characterized by complicated coupling between default mode network (DMN) and cognitive control network (CC) and tight connections within DMN, was expressed more in CTN patients and presented as increased fractional windows and dwell time. Moreover, patients switched less frequently between states than HCs. Regarding the dynamic topological analysis, disruptions in global graph-theoretical properties (including network efficiency and small-worldness) were observed in patients, coupled with decreased variability in nodal efficiency of anterior cingulate cortex (ACC) in the salience network (SN) and the thalamus and caudate nucleus in the subcortical network (SC). The variation of topological properties showed negative correlation with disease duration and attack frequency.ConclusionsThe present study indicated disrupted flexibility of brain topological organization under persistent noxious stimulation and further highlighted the important role of “dynamic pain connectome” regions (including DMN/CC/SN) in the pathophysiology of CTN from the temporal fluctuation aspect. Additionally, the findings provided supplementary evidence for current knowledge about the aberrant cortical-subcortical interaction in pain development.
Journal Article
Application of multi-echo Dixon and MRS in quantifying hepatic fat content and staging liver fibrosis
2023
This study associated the liver proton density fat fraction (PDFF), measured by multi-echo Dixon (ME-Dixon) and breath-hold single-voxel high-speed T2-corrected multi-echo
1
H magnetic resonance spectroscopy (HISTO) at 1.5 T, with serum biomarkers and liver fibrosis stages. This prospective study enrolled 75 patients suspected of liver fibrosis and scheduled for liver biopsy and 23 healthy participants with normal liver function. The participant underwent ME-Dixon and HISTO scanning. The agreement of PDFF measured by ME-Dixon (PDFF-D) and HISTO (PDFF-H) were compared. Correlations between PDFF and serum fat biomarkers (total cholesterol, triglyceride, and high- and low-density lipoproteins) and the liver fibrosis stages were assessed. PDFF were compared among the liver fibrosis stages (F0–F4) based on clinical liver biopsies. The Bland–Altman plot showed agreement between PDFF-D and PDFF-H(LoA, − 4.44 to 6.75), which have high consistency (ICC 0.752,
P
< 0.001). The correlations with the blood serum markers were mild to moderate (PDFF-H: r = 0.261–0.410,
P
< 0.01; PDFF-D: r = 0.265–0.367,
P
< 0.01). PDFF-D, PDFF-H, and steatosis were distributed similarly among the liver fibrosis stages. PDFF-H showed a slight negative correlation with the liver fibrosis stages (r = − 0.220,
P
= 0.04). Both ME-Dixon and HISTO sequences measured liver fat content noninvasively. Liver fat content was not directly associated with liver fibrosis stages.
Journal Article
Imaging and Hemodynamic Characteristics of Vulnerable Carotid Plaques and Artificial Intelligence Applications in Plaque Classification and Segmentation
2023
Stroke is a massive public health problem. The rupture of vulnerable carotid atherosclerotic plaques is the most common cause of acute ischemic stroke (AIS) across the world. Currently, vessel wall high-resolution magnetic resonance imaging (VW-HRMRI) is the most appropriate and cost-effective imaging technique to characterize carotid plaque vulnerability and plays an important role in promoting early diagnosis and guiding aggressive clinical therapy to reduce the risk of plaque rupture and AIS. In recent years, great progress has been made in imaging research on vulnerable carotid plaques. This review summarizes developments in the imaging and hemodynamic characteristics of vulnerable carotid plaques on the basis of VW-HRMRI and four-dimensional (4D) flow MRI, and it discusses the relationship between these characteristics and ischemic stroke. In addition, the applications of artificial intelligence in plaque classification and segmentation are reviewed.
Journal Article
Tractography in Type 2 Diabetes Mellitus With Subjective Memory Complaints: A Diffusion Tensor Imaging Study
2022
The brain white matter (WM) structural injury caused by type 2 diabetes mellitus (T2DM) has been linked to cognitive impairment. However, the focus was mainly on the mild cognitive impairment (MCI) stage in most previous studies, with little attention made to subjective memory complaints (SMC). The main purpose of current study was to investigate the characteristics of white matter injury in T2DM patients and its correlation with SMC symptoms. In a group of 66 participants (33 HCs and 33 T2DM-S), pointwise differences along WM tracts were identified using the automatic fiber quantitative (AFQ) approach. Then, we investigated the utility of DTI properties along major WM tracts as features to distinguish patients with T2DM-S from HCs via the support vector machine (SVM). Based on AFQ analysis, 10 primary fiber tracts that represent the subtle alterations of WM in T2DM-S were identified. Lower fractional anisotropy (FA) in the right SLF tract (r = -0.538, p = 0.0013), higher radial diffusivity (RD) in the thalamic radiation tract (r = 0.433, p = 0.012) and higher mean diffusivity (MD) in the right inferior fronto-occipital fasciculus (IFOF) tract (r = 0.385, p = 0.0029), were significantly associated with long period of disease. Decreased axial diffusivity (AD) in left arcuate was associated with HbA1c (r = -0.368, p = 0.049). In addition, we found a significant negative correlation between delayed recall and abnormal MD in the left corticospinal tract (r = -0.546, p = 0.001). The FA of the right SLF tracts and bilateral arcuate can be used to differentiate the T2DM-S and the HC at a high accuracy up to 88.45% and 87.8%, respectively. In conclusion, WM microstructure injury in T2DM may be associated with SMC, and these abnormalities identified by DTI can be used as an effective biomarker.
Journal Article
Altered Cerebro-Cerebellar Effective Connectivity in New-Onset Juvenile Myoclonic Epilepsy
2022
(1) Objective: Resting-state fMRI studies have indicated that juvenile myoclonic epilepsy (JME) could cause widespread functional connectivity disruptions between the cerebrum and cerebellum. However, the directed influences or effective connectivities (ECs) between these brain regions are poorly understood. In the current study, we aimed to evaluate the ECs between the cerebrum and cerebellum in patients with new-onset JME. (2) Methods: Thirty-four new-onset JME patients and thirty-four age-, sex-, and education-matched healthy controls (HCs) were included in this study. We compared the degree centrality (DC) between the two groups to identify intergroup differences in whole-brain functional connectivity. Then, we used a Granger causality analysis (GCA) to explore JME-caused changes in EC between cerebrum regions and cerebellum regions. Furthermore, we applied a correlation analysis to identify associations between aberrant EC and disease severity in patients with JME. (3) Results: Compared to HCs, patients with JME showed significantly increased DC in the left cerebellum posterior lobe (CePL.L), the right inferior temporal gyrus (ITG.R) and the right superior frontal gyrus (SFG.R), and decreased DC in the left inferior frontal gyrus (IFG.L) and the left superior temporal gyrus (STG.L). The patients also showed unidirectionally increased ECs from cerebellum regions to the cerebrum regions, including from the CePL.L to the right precuneus (PreCU.R), from the left cerebellum anterior lobe (CeAL.L) to the ITG.R, from the right cerebellum posterior lobe (CePL.R) to the IFG.L, and from the left inferior semi-lunar lobule of the cerebellum (CeISL.L) to the SFG.R. Additionally, the EC from the CeISL.L to the SFG.R was negatively correlated with the disease severity. (4) Conclusions: JME patients showed unidirectional EC disruptions from the cerebellum to the cerebrum, and the negative correlation between EC and disease severity provides a new perspective for understanding the cerebro-cerebellar neural circuit mechanisms in JME.
Journal Article
Noninvasive Classification of Glioma Subtypes Using Multiparametric MRI to Improve Deep Learning
2022
Background: Deep learning (DL) methods can noninvasively predict glioma subtypes; however, there is no set paradigm for the selection of network structures and input data, including the image combination method, image processing strategy, type of numeric data, and others. Purpose: To compare different combinations of DL frameworks (ResNet, ConvNext, and vision transformer (VIT)), image preprocessing strategies, magnetic resonance imaging (MRI) sequences, and numerical data for increasing the accuracy of DL models for differentiating glioma subtypes prior to surgery. Methods: Our dataset consisted of 211 patients with newly diagnosed gliomas who underwent preoperative MRI with standard and diffusion-weighted imaging methods. Different data combinations were used as input for the three different DL classifiers. Results: The accuracy of the image preprocessing strategies, including skull stripping, segment addition, and individual treatment of slices, was 5%, 10%, and 12.5% higher, respectively, than that of the other strategies. The accuracy increased by 7.5% and 10% following the addition of ADC and numeric data, respectively. ResNet34 exhibited the best performance, which was 5% and 17.5% higher than that of ConvNext tiny and VIT-base, respectively. Data Conclusions: The findings demonstrated that the addition of quantitatively numeric data, ADC images, and effective image preprocessing strategies improved model accuracy for datasets of similar size. The performance of ResNet was superior for small or medium datasets.
Journal Article
Aberrant dynamic structure–function relationship of rich‐club organization in treatment‐naïve newly diagnosed juvenile myoclonic epilepsy
2022
Neuroimaging studies have shown that juvenile myoclonic epilepsy (JME) is characterized by impaired brain networks. However, few studies have investigated the potential disruptions in rich‐club organization—a core feature of the brain networks. Moreover, it is unclear how structure–function relationships dynamically change over time in JME. Here, we quantify the anatomical rich‐club organization and dynamic structural and functional connectivity (SC–FC) coupling in 47 treatment‐naïve newly diagnosed patients with JME and 40 matched healthy controls. Dynamic functional network efficiency and its association with SC–FC coupling were also calculated to examine the supporting of structure–function relationship to brain information transfer. The results showed that the anatomical rich‐club organization was disrupted in the patient group, along with decreased connectivity strength among rich‐club hub nodes. Furthermore, reduced SC–FC coupling in rich‐club organization of the patients was found in two functionally independent dynamic states, that is the functional segregation state (State 1) and the strong somatomotor‐cognitive control interaction state (State 5); and the latter was significantly associated with disease severity. In addition, the relationships between SC–FC coupling of hub nodes connections and functional network efficiency in State 1 were found to be absent in patients. The aberrant dynamic SC–FC coupling of rich‐club organization suggests a selective influence of densely interconnected network core in patients with JME at the early phase of the disease, offering new insights and potential biomarkers into the underlying neurodevelopmental basis of behavioral and cognitive impairments observed in JME. We quantified the anatomical rich club organization and dynamic structural and functional connectivity coupling in treatment‐naïve newly diagnosed patients with JME. Our results showed that the anatomical rich club organization was disrupted in the patient, along with reduced structural and functional connectivity coupling in two functionally independent dynamic states.
Journal Article
Neurite orientation dispersion and density imaging reveals abnormal white matter and glymphatic function in active young boxers
by
Liu, Guangyao
,
Zhang, Jing
,
Huang, Wenjing
in
Adolescent
,
Athletes
,
Athletic Injuries - diagnostic imaging
2024
The neurological effects and underlying pathophysiological mechanisms of sports‐related concussion (SRC) in active young boxers remain poorly understood. This study aims to investigate the impairment of white matter microstructure and assess changes in glymphatic function following SRC by utilizing neurite orientation dispersion and density imaging (NODDI) on young boxers who have sustained SRC. A total of 60 young participants were recruited, including 30 boxers diagnosed with SRC and 30 healthy individuals engaging in regular exercise. The assessment of whole‐brain white matter damage was conducted using diffusion metrics, while the evaluation of glymphatic function was performed through diffusion tensor imaging (DTI) analysis along the perivascular space (DTI‐ALPS) index. A two‐sample t‐test was utilized to examine group differences in DTI and NODDI metrics. Spearman correlation and generalized linear mixed models were employed to investigate the relationship between clinical assessments of SRC and NODDI measurements. Significant alterations were observed in DTI and NODDI metrics among young boxers with SRC. Additionally, the DTI‐ALPS index in the SRC group exhibited a significantly higher value than that of the control group (left side: 1.58 vs. 1.48, PFDR = 0.009; right side: 1.61 vs. 1.51, PFDR = 0.02). Moreover, it was observed that the DTI‐ALPS index correlated with poorer cognitive test results among boxers in this study population. Repetitive SRC in active young boxers is associated with diffuse white matter injury and glymphatic dysfunction, highlighting the detrimental impact on brain health. These findings highlight the importance of long‐term monitoring of the neurological health of boxers. Highlights Boxing is a contact sport involving direct physical impact, leading to the occurrence of repeated concussions and sub‐concussions among boxers throughout their careers; however, the routine detection of brain tissue lesions through CT and MRI remains a challenging task. Advanced magnetic resonance diffusion imaging diffusion MRI is performed on young active boxers to assess the extent of white matter damage and glymphatic function. The brains of active young boxers have extensive white matter microstructure damage and glymphatic dysfunction, which is associated with poorer cognitive performance.
Journal Article
γ-Aminobutyric acid and glutamate dysregulation in the dorsolateral prefrontal cortex of adolescents with first-episode major depressive disorder and the modulatory effects of repetitive transcranial magnetic stimulation
2026
Abstract
Background
Major depressive disorder (MDD) is associated with dysregulation of γ-aminobutyric acid (GABA) and glutamate(Glu) neurotransmission in the prefrontal cortex. Proton magnetic resonance spectroscopy (1H-MRS) enables non-invasive in vivo quantification of GABA and Glx(glutamate + glutamine) levels. This study investigated neurochemical characteristics of the bilateral dorsolateral prefrontal cortex (DLPFC) in first-episode adolescent MDD (FEA-MDD) and repetitive transcranial magnetic stimulation (rTMS)’s impact on these changes.
Methods
42 drug-naïve FEA-MDD patients underwent bilateral DLPFC MRS scans before and after rTMS, with 42 healthy controls (HCs) as baseline. All participants were right-handed. The Mescher–Garwood point-resolved spectroscopy (MEGA-PRESS) protocol detected GABA+ (GABA plus macromolecules and high carnosine) and Glx levels, processed via Gannet software.
Results
FEA-MDD patients exhibited significantly lower GABA+ and higher Glx levels in the left DLPFC than HCs; in the right DLPFC, no significant difference in GABA+ levels was observed, though Glx levels were elevated. After rTMS treatment, GABA+ levels in the left DLPFC increased significantly, whereas Glx levels showed a non-significant decreasing trend. Additionally, HCs had no hemispheric differences, while in FEA-MDD, the left DLPFC showed lower GABA+ and Glx levels compared to the right. We also found that in the left DLPFC, baseline GABA+ levels were negatively correlated with Hamilton Depression Scale (HAMD) scores; Glx levels showed positive correlations with scores on the Ruminative Response Scale (RRS), Self-Rating Depression Scale (SDS), and Self-Esteem Scale (SES).
Conclusions
FEA-MDD involves prefrontal GABA+/Glx dysregulation, and rTMS may aid in restoring neurotransmitter balance within the DLPFC. This study adds to the expanding body of evidence supporting the application of targeted neurochemical modulation in the treatment of FEA-MDD, while also providing insights into potential intervention mechanisms.
Journal Article
Cross-ancestry genome-wide association meta-analyses of hippocampal and subfield volumes
2023
The hippocampus is critical for memory and cognition and neuropsychiatric disorders, and its subfields differ in architecture and function. Genome-wide association studies on hippocampal and subfield volumes are mainly conducted in European populations; however, other ancestral populations are under-represented. Here we conduct cross-ancestry genome-wide association meta-analyses in 65,791 individuals for hippocampal volume and 38,977 for subfield volumes, including 7,009 individuals of East Asian ancestry. We identify 339 variant–trait associations at
P
< 1.13 × 10
−9
for 44 hippocampal traits, including 23 new associations. Common genetic variants have similar effects on hippocampal traits across ancestries, although ancestry-specific associations exist. Cross-ancestry analysis improves the fine-mapping precision and the prediction performance of polygenic scores in under-represented populations. These genetic variants are enriched for Wnt signaling and neuron differentiation and affect cognition, emotion and neuropsychiatric disorders. These findings may provide insight into the genetic architectures of hippocampal and subfield volumes.
Genome-wide association meta-analyses in populations of East Asian and European ancestries identify variant–trait associations for 44 hippocampal traits and provide insight into the genetic architectures of hippocampal and subfield volumes.
Journal Article