Keywords: Parkinson's Disease, Neurodegeneration, Rapid eye movement sleep behavior disorder

Motivation: Rapid eye movement sleep behavior disorder (RBD) significantly impacts clinical outcomes in Parkinson's disease (PD).

Goal(s):  Our goal was to investigates the neurophysiological mechanisms related to motor and cognitive decline longitudinally in PD with RBD (PD-RBD). 

Approach: We used diffusion tensor imaging and clinical assessments on 83 PD patients over 2 years, two groups were formed: PD-RBD and PD without RBD (PD-nonRBD). 

Results: PD-RBD experienced widespread decline in white matter microstructure which are associated with motor symptoms aggravation, while PD-nonRBD patients showed limited changes.

Impact: The presence of RBD suggests more extensive white matter degeneration in PD, particularly affecting motor symptoms.

Keywords: Other Neurodegeneration, Neurodegeneration, Glaucoma

Motivation: Glaucoma is a neurodegenerative, multi-faceted disease resulting in irreversible blindness. Previous studies demonstrated both ocular and cerebral involvement, but brain findings remained mixed from small studies.

Goal(s): To elucidate structural and functional brain changes associated with glaucoma using big data.

Approach: We compared UK Biobank's extensive multi-parametric brain MRI data, ophthalmic parameters, and physiometabolic data between 1,229 glaucoma subjects and 12,290 age- and gender-matched healthy subjects.

Results: In addition to clinical ophthalmic and physiometabolic differences, smaller brain volumes and lower fractional anisotropy were found along the posterior visual pathway of glaucoma patients, with weakened functional brain activation upon Hariri faces/shapes task.

Impact: Changes in both the structure and function of the posterior visual brain pathways point to trans-synaptic degeneration in glaucoma. Additionally, glaucoma may impair both the lower-level visual processing areas and the structural and functional aspects of higher-level visual processing regions.

Keywords: Aging, Aging, ZTE pseudo-CT calcification

Motivation: Patients with Down Syndrome may undergo nearly ten times as many medical imaging procedures in their childhood alone compared to the general population, exposing this already high-risk group to elevated levels of radiation. 

Goal(s): We want to explore the potential of Zero Echo-Time (ZTE) MRI as a radiation-free alternative to CT scans for imaging cortical bone and calcifications in Down's Syndrome patients. 

Approach: We employed a published method for tissue segmentation, assigning Standard Hounsfield Units for air and soft tissue, while a continuous linear mapping technique was used for bone. 

Results: The images obtained resemble true CT images and calcifications are also visible.

Impact: ZTE to pseudo-CT image conversion offers a one-stop-shop solution for imaging patients without ionising radiation. The calcifications found and their potential clinical implications in ageing, or as markers for other conditions, warrant further investigation. 

Keywords: Gray Matter, Neurodegeneration

Motivation: Patients with chronic kidney disease (CKD) often have brain iron overload and with cognitive impairment, so it is important to control clinical iron overload.

Goal(s): To evaluate the changes of gray matter nucleus iron deposition in CKD patients, and analyze the correlation between iron deposition and cognitive function.

Approach: Recruit CKD patients undergoing hemodialysis, non-hemodialysis patients and healthy controls. The magnetic susceptibility value of gray matter nuclei was measured by quantitative susceptibility mapping (QSM) and compare QSM data and cognitive scores among three groups.

Results: Brain iron deposition is increased in CKD patients, especially in hemodialysis patients, and is related to cognitive function.

Impact: Compared with full-structure analysis, regional analysis seems to be more sensitive to related changes. In addition, CKD patients were divided into groups to explore not only the effect of CKD on brain iron deposition, but also the role of hemodialysis.

Keywords: Other Neurodegeneration, Neuro

Motivation: Investigations of amide proton signal changes in the brain of children with OSA may provide imaging markers for early diagnosis.

Goal(s): To explore the APTw signal changes in children with OSA and to evaluate the association of APTw signal in different brain regions with the cognitive impairment.

Approach: Forty-six children with mild to severe OSA and 20 HV underwent whole brain APTw imaging scan. Statistical analysis was performed for inter-group comparison and correlation analysis.

Results: The APTw signals in some brain regions in children with moderate-severe OSA were significantly lower than that of HV. The APTw signals were significantly associated with cognitive scores.

Impact: APTw imaging could be used for assessment of neurocognitive impairment in children with OSA.

Keywords: Parkinson's Disease, Segmentation

Motivation: Parkinson’s disease (PD) is a progressive neurodegenerative disorder characterized by loss of dopaminergic neurons in the substantia nigra pars compacta resulting in classical motor and nonmotor symptoms.

Goal(s): Our goal was to characterise the gray matter atrophy in 6-OHDA PD model as compared to sham control.

Approach: Structural MRI (3D T1W images) combined with behavioural techniques was used.

Results: Voxel based morphometry (VBM) revealed reductions of gray matter volume in Fimbria (Ipsi), hippocampal formation (Ipsi) and accumbens nucleus (contra) in 3rd week PD and cerebellum (Ipsi and contra both) in 7th week PD as compared to sham.

Impact: Identification of gray matter atrophy longitudinally helps in understanding the progression of structural alterations in response to dopaminergic cell loss.

Keywords: Parkinson's Disease, Quantitative Susceptibility mapping

Motivation: Quantification of iron overload in relevant brain regions is crucial for Parkinson’s disease (PD) diagnosis and monitoring.

Goal(s): To evaluate and compare manual and automated approaches for substantia nigra (SN) and nigrosome1 (N1) identification and iron content assessment using quantitative susceptibility mapping (QSM)

Approach: Histogram analysis to assess distributions of iron content in SN and N1, and compare them in patients with PD and controls

Results: Histogram analysis of automatically defined SN regions of interest in PD can be a promising tool to complement current diagnostic procedures. Nigrosome1 identification is confirmed to be more challengeing, and should be carefully checked by expert raters.

Impact: Lean and accurate quantification of iron overload in Substantia Nigra and Nigrosome1 in parkinsonian patients could represent an added value to routine clinical evaluation, enhancing accuracy of early diagnosis, possibly in pre-morbid conditions, as well as optimal treatment monitoring

Keywords: Neurotransmission, Spectroscopy, GABA, Wilson disease, Copper Metabolism

Motivation: To better understand the effect of abnormal copper metabolism on the brain GABA level in patients with neurologic Wilson disease.

Goal(s): To explore brain GABA level alterations in patients with neurologic Wilson disease compared to healthy controls.

Approach: Five neurologic WD patients and five healthy controls underwent magnetic resonance spectroscopy (MRS) on a 3.0 scanner and GABA signal was acquired from left striatum and left thalamus using MEGA-PRESS.

Results: The GABA level in the left striatum was significant reduced while in left thalamus it had no changes.

Impact: This study suggests that the abnormality of GABA energy system may exist in the pathogenesis of neurologic WD, and adjusting neurotransmission of γ-aminobutyric acid may be an important target for neuroprotection in WD.

Keywords: Alzheimer's Disease, Alzheimer's Disease

Motivation: Cerebral microbleeds (CMBs) are small hemosiderin-laden macrophage clusters resulting from blood leakage about damaged cerebral vessels, often linked to β-amyloid (Aβ) deposition.

Goal(s): To improve the visualization of CMBs that might be missed or undetectable with lower field strengths in mild cognitive impairment (MCI) and AD patients.

Approach: A new SWI technique named CLEAR-SWI was reported to eliminate the artifacts common in standard, single-echo SWI, reduce signal dropouts, and improve image homogeneity and contrast-to-noise.

Results: We found a significant correlation between the number of lobar CMBs and the Aβ PET SUVR levels in AD/MCI patients.

Impact: Improved visualization of CMBs with CLEAR SWI sequences at 7T may contribute to more accurate identification of MCI and AD patients, who typically present a lobar distribution of CMBs.

Keywords: Alzheimer's Disease, Alzheimer's Disease, ultrashort echo time magnetization transfer ratio; in vivo

Motivation: Alzheimer’s disease is a degenerative brain disorder. Conventional MRI primarily focuses on quantifying the volume of the hippocampus and gray matter (GM). 

Goal(s): This study employed ultrashort echo time magnetization transfer ratio (UTE-MTR) mapping to identify myelin changes in white matter (WM) and grey matter (GM) within brain samples from AD and regular donors. 

Approach: Six ROIs were selected for each specimen, comprising three WM regions and three GM regions. 

Results: The UTE-MTR values of both WM and GM from AD donors were lower than those of controls, indicating the capability of UTE-MTR to detect myelin loss in individuals with AD. 

Impact: Decreased UTE-MTR values of WM and GM were found in AD brains compared to control brains, indicating myelin loss in AD brain regions. This biomarker provides valuable assistance for the diagnosis of AD. 

Keywords: Parkinson's Disease, Parkinson's Disease, Brain connectivity, Diffusion MRI

Motivation: Putamen, a subcortical grey matter (SGM) structure and its associated brain connectivity networks are often implicated in the early stages of Parkinson’s Disease (PD).

Goal(s): With more detailed structural connectivity analysis using SGM parcellation, we characterise the structural connectivity of putamen subregions in healthy brains, and their alterations in early PD.

Approach: Using data from Parkinson’s Progressive Markers Initiative, structural connectivity analysis, and by incorporating SGM parcellation, we have revealed the connectivity networks specific to four putamen subregions.

Results: Heterogeneous connectivity alteration was identified in PD subjects, demonstrating weakening of intra-SGM connectivity within hemisphere and strengthening of it across hemispheres.

Impact: We identified structural connectivity networks specific to four putamen subregions in healthy brain and in early Parkinson’s Disease. Our method allows focused connectivity analysis while our findings provide new insight into the intra- and inter-hemispheric connectivity alterations with disease progression.

Keywords: Stroke, Aging

Motivation: Exploring alterations in brain microstructure and neurotransmitter content in post-stroke cognitive impairment (PSCI).

Goal(s): To investigate the influence of T2 mapping and MEGA-PRESS on brain microstructure and neurotransmitter content in PSCI individuals.

Approach: MRI scans were performed on 14 patients from the PSCI group and 11 healthy volunteers. GABA and Glx spectra were gathered, followed by T2 mapping.

Results: The study found lower GABA+/Water ratios in the prefrontal cortex of the PSCI group than the healthy group. Additionally, the PSCI group showed significantly higher T2 values in the right frontal and left occipital lobes.

Impact: This study confirmed that the combined measurement of brain GABA content and relaxation using MEGA-PRESS and T2 mapping sequence has clinical value. This provides a clinical idea for exploring the occurrence and development of cognitive disorders such as PSCI.

Keywords: Stroke, Ischemia

Motivation: Recurrent stroke is associated to hemodynamic abnormalities in ischemic stroke population, and MRI may play a major role in routine clinical setting.

Goal(s): Our goal was to assess hemodynamic variation in aortic region in stroke population (especially in subacute phase) undergoing routine treatment.

Approach: we used 4D flow imaging method which employs a non-contrast method with respiratory motion compensation method to acquire flow dynamics in stroke population to assess the aortic flow quantification.

Results: Flow abnormalities are significantly differing across subacute phase suggesting changes in hemodynamic.

Impact: Understanding cardiac flow dynamics in subacute phase of stroke population (undergoing clinical treatment) can help in understanding the functional recovery pattern to stratify recovery from recurrent stroke condition in future.

Keywords: Stroke, Stroke, synthetic sequence, white matter hyperintensity,acute ischemic stroke

Motivation: The application of MTP synthetic sequence can shorten the examination time of patients and obtain routine and quantitative MRI images, widely used in clinical.

Goal(s): This study aims to distinguish acute ischemic stroke and white matter hyperintensity (WMH) as well as normal tissue using MTP synthetic sequence.

Approach: We compared acute ischemic stroke, WMH and normal gray-white matter ADC and MTP values, investigated the clinical value of MTP in distinguishing these two kinds of diseases.

Results: The signal of acute cerebral infarction was obviously different from WMH and normal cerebral tissue.

Impact: MTP imaging offers the potential to distinct acute ischemic stroke from WMH and normal brain regions in just a few minutes.

Keywords: Stroke, Stroke, Resting-state fMRI, ischemic stroke, regional homogeneity, amplitude of low-frequency, penumbra, perfusion

Motivation: Functional changes in ischemic penumbra after cerebral infarction may indicate different degrees of hypoperfusion and different prognosis.

Goal(s): To explore the functional characteristics of infarction and its penumbra region using rs-fMRI.

Approach: The functional differences between infarct, penumbra and contralateral normal tissue were evaluated by Paired sample t test and Wilcoxon paired sign-rank test. Spearman correlation analysis was used to evaluate the correlation between the degree of hypoperfusion of the penumbra and the functional impairment.

Results: Substantial differences in functional characteristics were observed between infarction and normal tissue. The degree of ischemic penumbra was considerably correlated with its functional characteristics.

Impact: The elucidation of penumbral functional characteristics may influence its reversibility potential. Such knowledge can be pivotal in guiding clinical decision-making related to thrombolytic and neuroprotective treatments, optimizing patient outcomes.