Keywords: fMRI Analysis, fMRI (resting state), Transcutaneous auricular vagus nerve stimulation; Auricular acupressure; maintenance hemodialysis; sleep disorders

Motivation: Transcutaneous auricular vagus nerve stimulation (taVNS) and auricular acupressure(AA) represent two promising auricular therapes for insomnia  in china. However, to data the investiagation of the mechanism of taVNS compared with AA among maintenance hemodialysis with insomnia (MHDSD) cohort is lacking.

Goal(s): This study investigates the neural mechanisms of taVNS for MHDSD by using fMRI technique.

Approach: Using fMRI technique, we investigated the fMRI patterns across groups after treatment using a fractional amplitude of low-frequency fluctuation (fALFF) approach. 

Results: The brain regions with interactive effects of fALFF between two groups mainly located in the right middle/suproccipital gyrus, left cuneus gyrus, and left cerebellar/lingual gyrus.

Impact: With MRI techniques, our study for the first systematically shows  that after 4 weeks of taVNS, patients with MHDSD have altered functional activity which mainly distributed in emotional and sensorimotor networks. 

Keywords: Neurotransmission, Genetics, Biomarkers, fMRI (resting state)

Motivation: The genetic mechanisms underlying the structural and functional changes in the brain of patients with obstructive sleep apnea (OSA) are largely unknown.

Goal(s): This study investigates the gene expression patterns related to brain structure and function in patients with OSA.

Approach: We explore the gene expression profiles associated with changes in brain structure and function in OSA based on transcriptome-neuroimaging spatial correlation analysis.

Results: The brain regions associated with cognition, emotion, and sleep regulation have undergone changes in the OSA group. Genes associated with altered brain structure and function are predominantly enriched in activities related to gated channels and synaptic communication.

Impact: Our study suggests that complex polygenic genetic mechanisms play a role in brain morphological and functional abnormalities in OSA, providing a new perspective on the relationship between  genes, and brain function in patients with obstructive sleep apnea.

Keywords: fMRI Acquisition, fMRI (resting state)

Motivation: Understanding the neuropathological mechanisms through which total sleep deprivation (TSD) leads to cognitive impairments is crucial for developing effective cognitive protection strategies and treatment measures.

Goal(s): Assess the effects of TSD on the brain functioning of medical staff. By investigating the impact of TSD on the brain, we aim to gain insights into the specific changes that occur and their potential implications for cognitive performance.

Approach: Thirty-six primary medical staff were enrolled, and each participant underwent resting-state functional Magnetic Resonance Imaging (rs-fMRI) to assess brain activity patterns.

Results: Our findings revealed significant enhancements in rs-fMRI features across multiple brain regions following sleep deprivation

Impact: Enhanced rs-fMRI features might be potential imaging biomarkers for distinguishing between RW and TSD states. Such distinctions can contribute to early detection and intervention, ultimately improving the management of sleep deprivation-related cognitive impairments among medical staff.

Keywords: fMRI Acquisition, fMRI, z-shim

Motivation: Slice-specific z-shimming reduces signal losses in T2*-weighted EPI of the human spinal cord at 3T.

Goal(s): To investigate its impact for acquisitions at 7T performed with thinner slices and shorter echo times that are less susceptible to signal losses.

Approach: EPI images (16 slices, 0.8×0.8×3.0 mm³) with 31 different z-shim settings compensating linear field inhomogeneities within ±0.3 mT m^-1 were acquired. For each slice, the image with the maximum signal in the spinal cord was determined and compared to the image without z-shim.

Results: Averaged across 20 healthy volunteers, slice-specific z-shimming significantly improves overall EPI signal intensity and reduces signal variations across slices.

Impact:  Z-shimming can improve the signal intensity and homogeneity of T2*-weighted EPI of the human cervical spinal cord at 7T and could thus help to improve the performance of spinal cord fMRI.

Keywords: fMRI Analysis, fMRI (resting state)

Motivation: A growing body of research focuses on the impact of night shifts and fatigue on radiologists' diagnostic accuracy. 

Goal(s): This study investigates the changes in local brain activity and their association with low-level basal cognitive functions (e.g., alertness) in radiologists following night shift–related sleep deprivation (SD).

Approach: Regional homogeneity (ReHo) variability was calculated to reflect the characteristics of brain activity.

Results: The ReHo values changed in some brain regions after seven days of rest after a night shift. 

Impact: The results of this study can be the basis for radiologists to advocate for effective countermeasures to deal with the adverse consequences of SD.

Keywords: Task/Intervention Based fMRI, fMRI

Motivation: Test-retest reliability of human activity in a single day has not yet been elucidated.

Goal(s): To determine the reliability of ASL perfusion MRI within a single day and determine the diurnal impact on the test-retest reliability of fMRI.

Approach: Participants were scanned at six time points in a day, during resting-state and Psychomotor Vigilance Test (PVT).

Results: The study revealed a higher test-retest reliability for task-based CBF compared to resting-state, with a notable diurnal decline in reliability at 20:00, and showed a decline with time intervals.

Impact: These findings underscore the importance of accounting for diurnal variations when designing functional MRI studies to ensure reliable and reproducible results, especially suggest avoiding nighttime data collection.

Keywords: fMRI Analysis, Brain

Motivation: This study aims to investigate the neuroimaging mechanisms underlying synergistic abnormalities in both hemispheres of the brain in radiologists who experienced sleep deprivation (SD) due to night shifts.

Goal(s):  To explore the interhemispheric information synergy ability of the brain in radiologists following night shift–related SD using the voxel-mirrored homotopic connectivity (VMHC).

Approach: This study involves calculating the VMHC values of the symmetrical interhemispheric voxels in the whole brain.

Results: The VMHC values were found changed in certain brain regions after seven days of rest following a night shift.

Impact:  Changes in VMHC could potentially serve as a potential imaging marker to indicate the brain regions vulnerable to night-shift related damage in radiologists, as well as key brain region that affect work performance.

Keywords: fMRI Analysis, Brain

Motivation:  This study aims to explore the spontaneous activity of the radiologists brain following night shift–related sleep deprivation (SD). 

Goal(s): To study the potential brain network activity in radiologists following night shift–related SD by the degree centrality (DC) method.

Approach: Radiologists following night shift–related sleep deprivation and seven days' rest were recruited and analyzed by the voxel‐wise DC analysis.

Results: The DC values changed throughout the brain after seven days of rest after a night shift.
The left cerebellum and right thalamus were positively correlated with reaction time, and the right supplementary motor area (SMA) was negatively correlated with reaction time

Impact: Identifying DC variability abnormalities may broaden our understanding of neural substrates underlying night shift-related SD function alterations, The premise is to promote health and improve the efficiency of night shift work. 

Keywords: fMRI Analysis, Neurofluids, Consciousness

Motivation: Vasomotor waves increase in sleep but their causal impact on brain electrical activity and hydrodynamics is not understood.

Goal(s): We wanted to find out what is driving sleep related glymphatic solute transport.

Approach: We used multimodal 3D whole brain MREG, dcEEG and waterNIRS simultaneously to find out what VLF < 0.1 Hz pulsation is driving the other(s).

Results: In sleep the normal causal electro/hydrodynamic drive of the vasomotor BOLD waves reverses locally near upper parasagital and deeper structures.

Impact: The driver of the increase brain solute transport in human sleep has been unknown. In out ultrafast multimodal MREG study, we show significant reversals in the causal drive of vasomotor waves locally.

Keywords: Functional Connectivity, fMRI (resting state), dynamic brain functional connectivity

Motivation: Excessive daytime sleepiness (EDS) is a frequent nonmotor symptoms in Parkinson's disease (PD) patients. Previous studies on EDS used static analyses that ignored the temporal evolution of resting-state functional magnetic resonance imaging signals.

Goal(s): This study aimed to identify dynamic functional network connectivity (dFNC) characteristics in PD with EDS (PD-EDS) patients.

Approach: The sliding window approach, k-means clustering and independent component analysis were applied to estimate dFNC parameters.

Results: The PD-EDS patients showed increased fractional time and mean dwell time in state IV. The strong connectivity within and between the sensorimotor and visual network was related to EDS in PD patients.

Impact: Our research provided new insights into the neural mechanisms underlying PD patients with EDS. The alterations of dynamic functional connectivity may serve as biomarkers of the pathophysiological features of PD with EDS patients.

Keywords: Task/Intervention Based fMRI, fMRI (resting state)

Motivation: tDCS clinical expansion application

Goal(s): Investigating the value of tDCS in brain networks returning to the "rebalance state" of total sleep deprivation

Approach: A repeated-measures pre-to-post design was used. 16 healthy subjects received two 24-hour SD intervals and were randomly given True/Sham tDCS after SD. fMRI data and 2-back task testing were collected after true and sham tDCS, respectively. Observing the changes in topological properties of the whole-brain network.

Results: The topological properties of the whole brain network tend to be in a "rebalanced state" after tDCS.

Impact: Based on the results of this research, tDCS may be more widely applied to intervene in brain functional network disorders.

Keywords: Functional Connectivity, Brain Connectivity

Motivation: Sleeping well at night and feeling awake in the day play key roles in human health and well-being, yet little research examines how sleep-wake patterns affect daytime sleepiness individually.

Goal(s): To investigate inter-individual differences in sleepiness and its neural basis.

Approach: Seventy-one healthy adults participated in a fMRI investigation.

Results: The findings revealed a substantial negative correlation between the RSFC of the hypothalamus with the dorsal striatum in the morning and the subsequent changes in subjective sleepiness from morning to evening.

Impact: These outcomes provide valuable insights into the differential accumulation of subjective sleepiness and underscore the predictive significance of functional connectivity between the hypothalamus and the dorsal striatum in predisposition to sleepiness.

Keywords: Functional Connectivity, Brain Connectivity

Motivation: Sleep, accounting for one-third of human life, is a universal biological function, and sleep disorders may adversely affect health and well-being. 

Goal(s): Sleep disorder affect functional structure of brain and the effect on white matter functional connectivity is unclear.

Approach: we divided white and gray matter into 48 and 82 regions and calculated Pearson's correlation coefficients between the regions to explore the functional connectivity of white and gray matter affected by sleep quality.

Results: The left secondary visual cortex and the dorsal anterior cingulate cortex were significantly correlated with the sleep quality.

Impact: Which suggests that V2 and dACC, as well as the white matter fiber tracts connected to these two brain regions, need more attention in the diagnosis and treatment of sleep disorders.

Keywords: Functional Connectivity, fMRI (resting state)

Motivation: Effective countermeasures are sought for radiologists to deal with the adverse consequences of sleep deprivation (SD). 

Goal(s): Resting-state functional magnetic resonance imaging (rs-fMRI) was used to analyze changes in local brain activity after night shifts and after seven days' rest for radiologists, and to analyze whether increased water intake affected local brain activity.

Approach: Amplitude of low-frequency fluctuation (ALFF), fraction ALFF (fALFF) were used to characterize regional neural function.

Results: Compared to seven days of rest, the ALFF and fALFF values changed in some brain regions after night shift. 

Impact: Increased water intake during night shifts may help radiologists cope with the adverse consequences of SD.

Keywords: Functional Connectivity, Aging

Motivation: Normal aging involves human brain changes. Recognizing healthy aging patterns can advance age care, help understand unhealthy aging, and guide interventions.

Goal(s): We aim to characterise age-related functional changes and explore how they can be predicted and interpreted. 

Approach: Using deep learning, we predicted age with cortical functional connectivity of the whole, anterior, and posterior hippocampus. LayerCAM generates the whole brain saliency map.

Results: Models yielded a mean prediction error of 6.9 years. Personalised saliency maps revealed highly contributing regions to age prediction, such as the precuneus. Models also capture the prediction and saliency difference between anterior and posterior hippocampal-cortical functional connectivity. 

Impact: We introduced an interpretable deep learning approach to explore age-related brain functional changes. Our work generates new knowledge that could lead to early detection and better management of aging-related disorders.

Keywords: fMRI Analysis, fMRI (resting state), fMRI (sleep)

Motivation: While the significance of light sleep in health is gradually acknowledged, yet the specific neural dynamics during this phase is unclear. Our research emphasizes EEG microstates as vital markers of light sleep's brain networks, crucial for therapeutic innovation.

Goal(s): We aimed to delineate the relationship between EEG microstates and corresponding fMRI networks during N1 and N2 sleep stages.

Approach: We combined EEG-fMRI with custom regressors and GLM analysis, alongside Group-ICA, to model BOLD responses linked to EEG microstates.

Results: Microstate D showed significantly lower activity across parameters in both sleep stages, with BOLD patterns revealing unique neural correlations for each microstate.

Impact: This study sheds light on sleep's neural intricacies via fMRI, linking EEG microstates to brain networks, with implications for sleep disorder diagnosis, treatment, and overall sleep quality improvement.