Keywords: Traumatic Brain Injury, Brain

Motivation: The alteration of the blood-brain barrier (BBB) and cerebral perfusion in the short period of time after cardiac arrest remains unclear.

Goal(s): To determine the changes of BBB and cerebral blood flow (CBF) in patients with cardiac arrest.

Approach: Diffusion prepared pseudo-continuous arterial spin labeling was used to estimate the water exchange rate across the BBB (kw) and CBF in 21 cardiac arrest patients and 21 matched healthy controls.

Results: The kw was significantly decreased in cardiac arrest patients compared to healthy controls, whereas CBF was not significantly different. Reduced kw was associated with neurologic dysfunction in surviving patients after cardiac arrest.

Impact: This study demonstrated that the kw decreased within 14 days after cardiac arrest, suggesting that BBB dysfunction occurred in the short term after cardiac arrest, which will help clarify the pathophysiological changes in the brain after cardiac arrest.

Keywords: Traumatic Brain Injury, Neurodegeneration, TBI, White matter, DTI, NODDI

Motivation: Diffusion MRI-derived NODDI demonstrated promise as biomarkers of post-TBI long-term symptoms and clinical outcomes in single-center studies, but hasn't been validated in large-scale multi-center trials. 

Goal(s): This study aimed to detect post-TBI white matter degeneration and its significance to outcomes using analysis methods incorporating RISH-based harmonization, followed by DTI and NODDI fitting.

Approach: Harmonized DTI and NODDI are analyzed for a longitudinal comparison between 2 weeks and 6 months post-TBI, and for associations with GOSE, RPQ, and WAIS-PSI outcomes.

Results: Widespread white matter degeneration was evident in longitudinal changes of DTI and NODDI. The 2-week metrics were predictive of 3 and 6-month outcomes.

Impact: This study applies RISH-based harmonization to a multi-shell, multi-center dMRI study that involved 7 scanners of different manufacturers and models with different software versions and pulse-sequence parameters. These efforts brought new insights into post-traumatic white matter injury and patient outcomes.  

Keywords: Traumatic Brain Injury, Traumatic brain injury

Motivation: It is important to understand how neurotrauma accelerates the progression of Alzheimer's disease.

Goal(s): The project's goal is to use ultra-high isotropic resolution (60μm) diffusion-MRI for exploring changes in white matter integrity after neurotrauma.

Approach: Ex vivo diffusion-MRI was acquired using a 9.4T Bruker scanner in a transgenic mouse model of Alzheimer's disease with and without neurotrauma.

Results: We observed decreased quantitative anisotropy in mice 8 months post the brain injury. 

Impact: Our preliminary finding demonstrated that neurotrauma can induce accelerated white matter degeneration in Alzheimer's disease.

Keywords: Traumatic Brain Injury, Traumatic brain injury, neuroinflammation, ischemia

Motivation: Ischemia and neuroinflammation, two key endophenotypes post-TBI, are difficult to assess in vivo.

Goal(s): Our goal was to evaluate the feasibility of utilizing amide proton transfer-weighted (APTw) imaging as a biomarker for detecting neuroinflammation and ischemia post-TBI.

Approach: Brain APTw MRI signals of 55 rats subjected to a mild, moderate, or severe TBI were analyzed and compared to other criteria defining neuroinflammation and ischemia.

Results: The areas under curve (AUCs) of the ipsilateral cortex APTw signals at 3 days and 1 hour post-TBI were 0.725 for detecting neuroinflammation and 0.411 for detecting ischemia, respectively.

Impact: The feasibility of detecting neuroinflammation and ischemia using APTw MRI would improve the capability of MRI to objectively assess TBI and enable the accurate detection of these pathological processes at an early stage post-TBI.

Keywords: Traumatic Brain Injury, Traumatic brain injury, functional MRI, diffusion MRI, tractometry

Motivation: Understanding brain changes occurring during recovery from a sword-inflicted head injury.
 

Goal(s): To detect longitudinal changes in diffusion and functional MRI accompanying the patient’s functional recovery after the trauma.

Approach: Diffusion MRI and tractometry to assess white matter tract changes and task-based and resting-state functional MRI to monitor changes in brain function.

Results: Reduced diffusion metrics were found in the affected white matter tracts, which seemed to partially recover over time. Task-based fMRI showed significantly (p < 0.05) increased functional activity over time for the right-hand and language scans reflecting gradual clinical improvement in right hand, and language functions.

Impact: This longitudinal case study reveals significant brain recovery post-penetrating trauma, which is less common in clinical practice, and highlights the value of diffusion and functional MRI in tracking brain changes that parallel rehabilitation progress.

Keywords: Traumatic Brain Injury, Traumatic brain injury, repetitive brain injury, fixel-based analysis, post-concussion syndrome, post-traumatic stress disorder

Motivation: Identifying brain changes that are associated with repetitive insult and persistent post-concussive symptoms can be potentially useful in differentiating mild traumatic brain injury from purely psychological disorders.

Goal(s): Apply fixel-based analysis (FBA) method  to assess the relationships between clinical symptoms and tissue features using advanced dMRI techniques, and to identify WM changes that are associated with repetitive insult in service members (SMs).

Approach: Employ FBA, tractography and TSA on NODDI in SMs with mTBI.

Results: Unique anatomical locations where structural properties related to clinical symptoms. The white matter changes over the brainstem fibers are associated with the number of total lifetime TBI.

Impact: Advanced diffusion MRI techniques using higher model should be considered as a choice of option in assessing subtle white matter alterations in mild traumatic brain injury presenting due to the great heterogeneity of underlying pathological features. 

Keywords: Traumatic Brain Injury, fMRI (resting state)

Motivation: Incidence of traumatic brain injury (TBI) are rising over years.

Goal(s): Accurately and objectively evaluate the degree of brain injury and judge the prognosis of patients with mTBI.

Approach: Neuropsychological assessment results, brain volume from morphological MR data, and brain functional connectivity from fMRI data were compared between 48 acute mTBI patients and 30 healthy controls. 

Results: Acute mTBI patients exhibit reduced volume in the right frontal lobe compared to the healthy control group, which is associated with cognitive decline.

Impact: The morphological changes in the right frontal lobe observed in this study may serve as a potential biomarker for acute mTBI, offering a more objective measure for the diagnosis and treatment of brain injury in acute mTBI patients.

Keywords: Traumatic Brain Injury, Traumatic brain injury, repetitive head impacts

Motivation: Neurodegenerative changes in the cortical sulci and gyri have been associated with repetitive head impacts (RHI) but have only been observed post-mortem.

Goal(s): To detect sulcal and gyral extrema white matter microstructure changes in vivo.

Approach: Automated image-analysis algorithms were used to average the fractional anisotropy (FA) of sulcal fundi and gyral crowns in a cohort of amateur adult soccer players and age- and sex- matched non-collision amateur athletes.

Results: We found soccer players’ FA was significantly lower within the fundi and crowns of the frontal, orbitofrontal, temporal regions, as well as the cingulate and parietal regions for fundi only.

Impact: Here we report the first in vivo imaging study demonstrating white matter microstructure changes within sulci and gyri due to RHI. We anticipate our approach to be a starting point for more sophisticated use of DTI to study RHI effects.

Keywords: Traumatic Brain Injury, Traumatic brain injury

Motivation: mTBI can lead to myelin damage, culminating in substantial cognitive function impairment. Yet, conventional neuroimaging methodologies often fall short in identifying abnormalities in a significant proportion of mTBI instances.

Goal(s): To assess the potential of UTE sequence in detecting demyelination in mTBI mice subject to an open-field LIB injury. 

Approach: A new STAIR-UTE sequence was employed to study demyelination in mTBI mice subject to an open-field LIB injury at 3T.

Results: The STAIR-UTE measured MPFs in the corpus callosum region for the mTBI mice are significantly lower (8.5±0.4% vs. 8.8±0.4%; p-value = 0.0055) than those for the control mice. 

Impact: STAIR-UTE sequence enables quantitative myelin imaging at 3T MRI, facilitating the detection of demyelination within the mouse brain's white matter following open-field LIB exposure. This innovative STAIR-UTE technique holds significant promise for in vivo mTBI diagnosis and treatment monitoring.

Keywords: Traumatic Brain Injury, Traumatic brain injury, Brain Connectivity, high-contact sports, resting state functional connectivity

Motivation: Repetitive head impact in contact sports is linked to long-term cognitive sequelae, but the complexities of these changes remain unclear.

Goal(s): Determine potential relationships between resting-state functional connectivity (rsFC) and cognitive performance differential between high- and low-contact sports.

Approach: We assessed baseline rsFC and cognitive performance in PAC-12 athletes using rsfMRI and the ImPACT test.

Results: Enhanced ImPACT visual-motor-speed performance was present in low-contact sports and associated with increased connectivity between attentional networks and sensorimotor/visual/auditory regions. High-contact sports showed less connectivity between these motor and auditory regions, but more connectivity between these motor and visual regions.

Impact: This research sheds light on how repetitive head impacts in contact sports affect cognitive function and brain connectivity. 

Keywords: Traumatic Brain Injury, Traumatic brain injury, brain entropy

Motivation: Mild traumatic brain injury (mTBI) is a prevalent neurological condition involved with physical, cognitive, and emotional impairments. Brain dynamics measured with sample entropy and its association with cognitive functions in mTBI patients remains unexplored.

Goal(s): We aim to investigate brain entropy changes in mTBI as compared to non-TBI control patients and explore their potential associations with cognitive function in mTBI patients.

Approach: Brain entropy mapping was applied based on rs-fMRI images.

Results: Results show hyper-entropy within hippocampus and para-hippocampal gyrus which has significant negative association with cognitive scores related to working memory and processing speed.

Impact: This study underscores the promise of brain entropy analysis as a valuable addition to mTBI research, with implications for improved diagnostic and treatment strategies.

Keywords: Traumatic Brain Injury, Traumatic brain injury, network-based statistic, Connectome-based Predictive Modeling, post-concussion syndrome, post-traumatic stress disorder

Motivation: Mild traumatic brain injury (mTBI) presents with a wide array of clinical features due to the great heterogeneity of underlying pathological features.

Goal(s): To identify aberrant structural connectivity in mTBI service members (SMs) and to evaluate the usefulness of predictive models of brain-behavior relationships from structural connectivity data.

Approach: Employ Network-Based Statistic (NBS) and Connectome-based Predictive Modeling (CPM) to evaluate the structural connectome of SMs who had a remote mTBI, as mapped by advanced diffusion MRI.

Results: NBS identified sub-networks involving the default mode networks with decreased connectivity density; CPM revealed an association between the predicted post-concussive symptom scores and the self-report  scores.

Impact: Structure connectome-based analysis using advanced diffusion MRI techniques has the potential for the objective evaluation of white matter properties, which can become biomarkers in monitoring clinical symptoms in SMs after a remote brain injury

Keywords: Traumatic Brain Injury, Traumatic brain injury

Motivation: The effects of repeated concussions on the structural covariance network of active young boxers are unknown.

Goal(s): To reveal the effects of sport-related concussion (SRC) on the brain morphology of boxers and to construct a structural covariance network to investigate global and local property changes in SRC networks.

Approach: The cortical thickness and structural covariance network properties were calculated using 3D-T1WI of 57 SRC athletes and 72 healthy controls (HCs).

Results: Compared with the HCs group, the SRC group had a thicker cortex in the bilateral hemisphere, reduced small-world properties, and reduced local efficiency.

Impact: The topological properties of boxers' structural covariance networks were significantly abnormal, indicating that both network integration and separation functions were impaired due to repeated concussions.

Keywords: Quantitative Imaging, Quantitative Susceptibility mapping, lesion filling, individualised profiling

Motivation: Quantitative susceptibility mapping (QSM) is being increasingly used to investigate pathophysiological changes in traumatic brain injury (TBI). However, generating artefact-free quantitative susceptibility maps in brains with large focal lesions, as in the case of moderate-to-severe TBI (ms-TBI), is particularly challenging.  

Goal(s): To generate artefact-free quantitative susceptibility maps in moderate-to-severe TBI patients with large focal lesions.

Approach: We utilized a novel two-pass masking technique and reconstruction procedure in combination with a recently developed virtual brain grafting tool for brain repair.

Results: Our innovative approach allowed us to generate artefact-free personalised QSM profiles of individual ms-TBI patients with reference to a sample of healthy controls.

Impact: We outline an approach to obtain magnetic susceptibility values in the presence of large focal lesions and provide a framework to generate personalised QSM profiles that may be used by clinicians to characterise TBI pathophysiology or implement neuroscience-guided rehabilitation programs.

Keywords: Traumatic Brain Injury, Traumatic brain injury

Motivation: The neurological effects of active young boxers with sport-related concussions (SRC) are still unclear.

Goal(s): To reveal the micro- and macrostructural changes in active young boxers with SRC.

Approach: Using 3D-T1WI and neurite orientation dispersion and density imaging (NODDI) in young boxers with SRC (n=57) were compared to matched healthy control groups (HCs) (n=72).

Results: In the gray and white matter of concussed boxers, T1WI and NODDI measures showed lower white matter volume, greater CSF and CSP, and significant white matter abnormalities than in the controls.

Impact: This study demonstrated the significant effects of repeated concussions on the micro- and macrostructural in active young boxers, suggesting that we should monitor and maintain the neurological health of these athletes over the long term.