Keywords: fMRI Analysis, Diabetes, Cerebellum; Insulin Resistance;

Motivation: The neuropathophysiological mechanisms of cerebellar damage in type 2 diabetes mellitus patients with insulin resistance (T2DM-IR) are not yet fully understood.

Goal(s): To investigate how insulin resistance affects the cerebellar structure and function.

Approach:  We employed voxel-based morphometry analysis based on SUIT template and seed-based functional connectivity (FC) to assess the gray matter volume (GMV) and functional connectivity in cerebellar subregions of T2DM patients with insulin resistance and examine their correlation with clinical variables.

Results: We exhibited more pronounced reductions in GMV and FC of specific cerebellar subregions in T2DM-IR and negative correlation between GMV of lobules VIIb-VIII and insulin resistance.

Impact: These findings contribute to our understanding of the pathophysiological role of cerebellum damage in T2DM-IR. It provides a new research idea and method for us to elucidate brain impairment of T2DM.

Keywords: Functional Connectivity, Multiple Sclerosis, cerebellum

Motivation: The cerebellum is a prevalent lesion site in Multiple Sclerosis but due to lack of acquisition methods its function remains understudied in MS. 

Goal(s): Our goal was to compare the cerebellar motor (network) function of Multiple Sclerosis  patients to Healthy Controls using 7T fMRI. 

Approach: We employed a B1-shimmed 7T fMRI protocol and submillimetre anatomical acquisitions. This enabled us to identify cerebellar function during a motor task and  identify subject specific regions of interest to analyse cerebellar motor network connectivity. 

Results: Our methods revealed decreased connectivity as well as lower motor task activation in Multiple Sclerosis patients compared to Healthy Controls. 

Impact: Our results demonstrate the use of 7T-fMRI to study cerebellar function in patients with Multiple Sclerosis. The differences found in motor and resting state activation may contribute to the overall understanding of the role of cerebellar function in Multiple Sclerosis. 

Keywords: fMRI Analysis, Brain

Motivation: The objective of this study was to evaluate the role of cerebellum in gait freezing pathophysiology in multiple system atrophy.

Goal(s): Obtain neuroimaging evidence for clinical understanding of cerebellum role in MSA patients with FOG injury.

Approach: A SUIT method was used to obtain cerebellum subregion gray matter alterations. In addition, seed-based FC was used to evaluate abnormal cerebello-cortical circuits. Spearman’s correlation analysis was used to evaluate cerebellum structural changes, cerebello-cortical circuit abnormality, and freezing severity.

Results: MSA-FOG patients showed an abnormal cerebellum atrophy in subregion VI and VIII,Cerebellar-cortical “executive-control” and “visual-auditory” networks are associated with FOG in MSA.

Impact: This study provided neuroimaging evidence for clinical understanding of cerebellum role in MSA patients with FOG injury

Keywords: fMRI Acquisition, High-Field MRI, Neuroscience

Motivation: The role of proprioception in controlling the movement of the eyes is currently unknown. 

Goal(s): To investigate cortical and subcortical activity in response to a proprioceptive stimulation task. 

Approach: 7T fMRI was used to measure BOLD signal in the whole cortex and the brainstem while volunteers performed a previously published proprioceptive task. 

Results: BOLD response was measured in the spinal trigeminal nucleus and the central sulcus/postcentral gyrus, as well as the abducens nuclei, frontal eye fields, supplementary eye fields and the cerebellum.

Impact: A better understanding of the role of proprioception in eye movement control, can open up new avenues for research into the neural mechanisms underlying disorders of eye position and movement like childhood strabismus. 

Keywords: Functional Connectivity, fMRI

Motivation: Efforts to characterize the function of DR, MR and LC in humans using functional magnetic resonance imaging (fMRI) have been hampered by their small size and location near a large source of noise.

Goal(s): The aim of this study is to compare the functional connectivity (FC) of small nucleus in brainstem with multi- (ME) and single-echo (SE) resting state fMRI.

Approach: The whole-brain FC of LC, DR and MR were generated by using ME-fMRI and SE-fMRI.

Results: Precuneus was correlated with LC in both methods. Meanwhile, both methods shown cerebellum was correlated with DR, the cingulum was correlated with MR.

Impact: It suggests that ME-fMRI may also provide significant advantages over single echo fMRI approaches when investigating the FC of small nucleus of brainstem. ME-fMRI offers substantial advantages over single echo fMRI.

Keywords: Task/Intervention Based fMRI, Translational Studies, high-field MRI, multimodal, traumatic brain injury

Motivation: There is a lack of effective treatments and understanding of the mechanisms behind disorders of consciousness, including coma.

Goal(s): Explore the mechanisms behind thalamus-mediated subcortical reactivation to promote effective therapies for disorders of consciousness.

Approach: Study brain changes induced by optogenetic stimulation of the central thalamus (CThal) at different frequencies in unconscious rats with fMRI and electrophysiology.

Results: CThal stimulation can trigger brain state changes and electrophysiologically activate the cingulate cortex and other areas of the cortex similar to a more conscious state. BOLD signal activation in the cortex seems to be dependent on the CThal stimulation frequency.

Impact: This study provides useful insights into frequency-dependent central thalamus-mediated brain state changes and offers opportunities to investigate the potential of CThal stimulation in promoting subcortical reactivation and acute coma recovery in a rodent model.

Keywords: Functional Connectivity, fMRI (resting state), Resilience, Trauma, PTSD, Thalamus, UHF-MRI

Motivation: To discern why some individuals develop stress-related disorders post-trauma while others don't, focusing on the role of thalamus in emotional regulation and resilience.

Goal(s): Investigate thalamic functional connectivity differences in trauma-exposed individuals to identify neural mechanisms of resilience.

Approach: Acquired MRI data from 35 Syrian refugees using a 7T scanner, analyzed for trauma-related connectivity differences via seed-to-voxel thalamic analysis with the CONN toolbox, informed by RS-25 and HTQ questionnaires to distinguish between asymptomatic and symptomatic groups.

Results: Significant right thalamic connectivity differences were found, indicating potential neural resilience correlates and adaptive changes in sensory-motor processing related to PTSD symptom severity.

Impact: This study enhances our understanding of trauma's neural basis and resilience, potentially directing new therapeutic strategies targeting thalamic connectivity to prevent stress-related disorders, thereby improving trauma care and mental health outcomes. Ref. 

Keywords: Functional Connectivity, fMRI (resting state), High-Field MRI, Neuroscience, fMRI, Thalamus, Thalamic nuclei

Motivation: The thalamic nuclei play vital roles in brain function, but are challenging to image. Notably, clusters found by fMRI approaches do not fully match features from structural MRI studies.

Goal(s): To clarify the existing mismatches via high-resolution fMRI, contrast-focused structural MRI, and atlas information, at 7T.

Approach: From the same individual brains, we compared structural MRI, atlas delineations and functional clusters in the thalamus, using ICA and seed-based analysis of rs-fMRI.

Results: Clusters from fMRI tend to coincide with nuclei labels from histological atlases, but deviate in some cases, while remaining more consistent with the individual’s structural MRI features.

Impact: This study provides novel insights into the structural and functional organization of the thalamus. The ability to localize and characterize thalamic nuclei is of strong interest to basic and clinical neuroscience, and for development of effective non-invasive surgical targeting approaches.

Keywords: Functional Connectivity, fMRI (resting state)

Motivation: The Hypothalamic-Pituitary-Adrenal (HPA) axis dysfunction is crucial in stress response in schizophrenia. The hypothalamus is an essential part of the HPA axis. The hypothalamic connections with brain regions in schizophrenia.

Goal(s): This study examined hypothalamic resting-state functional connectivity (FC) in schizophrenia and how hypothalamic FCs related to symptom severity.

Approach: Resting-state functional magnetic resonance imaging data were obtained from 235 patients with schizophrenia and 222 healthy controls. We processed the imaging data with published routines and evaluated the results at a corrected threshold.

Results: Relative to healthy controls, schizophrenia showed lower hypothalamic FCs with mesocorticolimbic regions, which were connected with symptom severity.

Impact: Decreased hypothalamic functional connectivities, which are associated with symptomology, extend the understanding of functional connectivity alterations and suggest the potential pathophysiology of stress response dysfunction in schizophrenia, which needs further study.

Keywords: Task/Intervention Based fMRI, Parkinson's Disease

Motivation: Maximization of clinical benefits in the treatment of Parkinson’s disease (PD) using deep brain stimulation (DBS) requires clinical parameter optimization with a time-to-optimization per patient of ~1year.

Goal(s): To build a deep-learning-based model for the prediction of optimal DBS parameters from a single functional MRI response map obtained during DBS.

Approach: Multilayer perceptron based optimal DBS parameter prediction model was trained and tested (five-fold cross-validation) using features extracted by an autoencoder model from DBS-fMRI responses.

Results: Accuracies of 79.1%, 84.5%, 81.7%, 83.3% and 70.2% (at 10% deviation from ground truth) were achieved in the prediction of voltage, frequency, and x-y-z contact locations respectively.

Impact: This study gives an initial evaluation of a prediction model for DBS parameter optimization, which has the potential to reduce the time-to-optimization per patient from ~1 year to few hours during a single clinical visit, thereby reducing patient’s financial burden.

Keywords: Functional Connectivity, Diffusion/other diffusion imaging techniques, Multimodal, Ventral Tegmental Area, resting state

Motivation: The ventral tegmental area (VTA) is theorized to contribute to the unique pathogenesis of depressive symptoms in Parkinson’s Disease (PD) but remains understudied.

Goal(s): We aim to characterize the functional and structural connectivity changes in the VTA as they relate to depressive symptoms in PD.

Approach: Resting state functional MRI and correlational tractography approaches were used to map the functional connectivity and tract projection changes associated with increased depressive symptoms in 54 patients and 100 controls.

Results: The left VTA was found to have functional connectivity changes and tract profiles that correlate with clinical symptoms in manners unique to the PD subgroup.

Impact: This study supports the idea of the ventral tegmental area playing a role in and potentially becoming a therapeutic target for the unique pathogenesis of depressive symptoms in patients with Parkinson’s disease.

Keywords: fMRI Analysis, Neurodegeneration, Quantitative Susceptibility Mapping;Subcortical Nuclei;Registration

Motivation: Conventional rs-fMRI analysis of  basal ganglia in Parkinson's disease(PD) relies on T1WI atlases, posing challenges to localizing subcortical nuclei in fMRI.

Goal(s): This study aims to validate a novel method incorporating Quantitative Susceptibility Mapping(QSM) into fMRI analysis for precise subcortical nuclei segmentation.

Approach: fMRI registration to QSM and T1WI respectively in the study. Intraclass Correlation Coefficient and Mutual Information to assess the consistency and accuracy of the two registration approaches. Various Machine learning models utilized functional connectivity derived from two methods for PD classification.

Results: Two methods showed measurement inconsistency. The QSM-guided approach displayed superior accuracy and significantly outperformed in classification models.

Impact: Our study introduces a groundbreaking approach by incorporating QSM into the fMRI analysis of subcortical nuclei in Parkinson’s disease. Shedding light on the potential of the QSM-guided method in capturing meaningful alterations in Parkinson's disease-related neural networks.  

Keywords: Functional Connectivity, fMRI (resting state), Bright light therapy, amygdala, subthreshold depression, serotoninergic system

Motivation: The presence of subthreshold depression significantly increases the likelihood of developing major depressive disorder and is linked to a higher burden of illness and suicide risk.

Goal(s): The objective of this clinical trial was to evaluate the relationship between BLT and the functional connectivity (FC) alterations of the amygdala, as well as the serotoninergic distribution in subthreshold depression.

Approach: Subthreshold depression subjects were randomly divided into two groups: the BLT group and the placebo group.

Results: BLT group showed increased sFC of right basolateral amygdala (BLA)/superficial amygdala (SFA)-right middle temporal gyrus and dFC of right centralmedial amygdala and right inferior orbital frontal gyrus.

Impact: These findings indicated that BLT could relieve depressive symptoms and alter FC of the amygdala in subthreshold depression (StD). Combining baseline sFC and dFC of the amygdala may have the potential to assess the effectiveness of BLT in treating StD.

Keywords: Functional Connectivity, fMRI (resting state), Transcranial Magnetic Stimulation

Motivation: Personalized TMS targeting based on functional connectivity has been proposed. However, the dispersion of personalized TMS targets remains unknown.

Goal(s): Characterize brain areas functionally connected to the hippocampus in a population.

Approach: Identify hippocampus-based memory networks using the resting-state fMRI data from the Human Connectome Project.

Results: The medial prefrontal cortex (mPFC) and lateral parietal cortex (PPC) were found to be connected to the hippocampus. The centroids of group-average results were separated from the atlas coordinates by about 11 mm. Individualized targets are dispersed around the group-average coordinates (mPFC: 11.1 +/- 3.8; PPC: 3.4 +/- 2.3 mm).

Impact: The functional connectivity analysis on the Human Connectome Project resting-state fMRI data with the seed at the hippocampus revealed that the medial prefrontal cortex (mPFC) and lateral parietal cortex (PPC) connected to the hippocampus significantly dispersed across individuals.

Keywords: Task/Intervention Based fMRI, Spinal Cord, brainstem

Motivation: Motor-task fMRI is a critical modality for studying post-stroke neuronal changes in the brainstem and spinal cord, but data quality is reduced in these regions.

Goal(s): We aimed to anticipate the degree of head-motion confounds before a motor-task fMRI scan and assess how this head motion affects fMRI data quality. 

Approach: Six post-stroke individuals performed a hand-grasp task during a head motion-capture session, then during cortical-brainstem and spinal-cord fMRI scans. 

Results: Head motion in the lab was positively correlated with head and spinal-cord motion during fMRI. Head and spinal-cord motion were correlated with decreased tSNR in the cortex, brainstem, and spinal cord. 

Impact: Head motion outside of the scanner is linked with head and spinal-cord fMRI motion and tSNR. With lab-based motion capture systems, we can anticipate motion and tSNR impacts in motor-task fMRI, useful as screening in clinical populations with increased movement.  

Keywords: Functional Connectivity, fMRI, dual FOV

Motivation: Functional neuroimaging target either the brain or the spinal cord, but usually not both because simultaneous acquisitions from distant fields of view are challenging with conventional MRI.

Goal(s): To establish a novel MRI approach for artefact-free, quiet fMRI simultaneously from brain and spinal cord, avoiding the need of dynamic shimming.

Approach: Our approach is to use MB-SWIFT in a simultaneous dual-FOV configuration with a Dual Amplifier Blanking Selector Unit (DABSU) that employs two transmitters and two receiver channels. 

Results: The results established feasibility of the novel approach for task-based fMRI and connectivity analyses between lumbar spinal cord and brain in rat.
 

Impact: The method could be used for unprecedented investigations of the central nervous system, and could be extended to any two separate parts of the body.