UNASSIGNED: Multiple sclerosis (MS) is recognized as the most prevalent autoimmune abnormality of the CNS. T1WI, T2WI, and FLAIR are limited in the quantification of tissue damage and detection of tissue alterations in white and grey matter in MS. This study aimed to the evaluation of changes in DTI indices in these patients at the thalamus and basal ganglia.
UNASSIGNED: 30 relapsing-remitting MS (RRMS) cases and 30 normal individuals were included. Conventional MRI (T2, FLAIR) was acquired to confirm NAGM in MS patients. A T1 MPRAGE protocol was used to normalize DTI images. FSL, SPM, and Explore DTI software were employed to reach Mean Diffusivities (MD), Axial Diffusivities (AD), Fractional anisotropy (FA), and Radial Diffusivity (RD) at the thalamus and the basal ganglia.
UNASSIGNED: The FA and RD of the thalamus were decreased in healthy controls compared to MS cases (0.319 vs. 0.296 and 0.0009 vs. 0.0006, respectively) (P < 0.05). The AD value in the thalamus and the FA value in the caudate nucleus were significantly lower in MS cases than in controls (0.0009 vs. 0.0011 and 0.16 vs. 0.18, respectively) (P < 0.05). MD values in the thalamus or basal ganglia were not significantly different between groups.
UNASSIGNED: DTI measures including FA, RD, and AD have a good diagnostic performance in detecting microstructural changes in the normal-appearing thalamus in cases with RRMS while they had no significant relationship with clinical signs in terms of EDSS.
UNASSIGNED: Not applicable.

UNASSIGNED: Diagnostic information about cell density variations and microscopic tissue anisotropy can be gained from tensor-valued diffusion magnetic resonance imaging (MRI). These properties of tissue microstructure have the potential to become novel imaging biomarkers for radiotherapy response. However, tensor-valued diffusion encoding is more demanding than conventional encoding, and its compatibility with MR scanners that are dedicated to radiotherapy has not been established. Thus, our aim was to investigate the feasibility of tensor-valued diffusion MRI with radiotherapy dedicated MR equipment.
UNASSIGNED: A tensor-valued diffusion protocol was implemented, and five healthy volunteers were scanned with different resolutions using conventional head coil and radiotherapy coil setup with fixation masks. Signal-to-noise-ratio (SNR) was evaluated to assess the risk of signal bias due to rectified noise floor. We also evaluated the repeatability and reproducibility of the microstructure parameters. One patient with brain metastasis was scanned to investigate the image quality and the transferability of the setup to diseased tissue.
UNASSIGNED: A resolution of 3 × 3 × 3 mm3 provided images with SNR > 3 for 93 % of the voxels using radiotherapy coil setup. The parameter maps and repeatability characteristics were comparable to those observed with a conventional head coil. The patient evaluation demonstrated successful parameter analysis also in tumor tissue, with SNR > 3 for 93 % of the voxels.
UNASSIGNED: We demonstrate that tensor-valued diffusion MRI is compatible with radiotherapy fixation masks and coil setup for investigations of microstructure parameters. The reported reproducibility may be used to plan future investigations of imaging biomarkers in brain cancer radiotherapy.

UNASSIGNED: The absolute number of new stroke patients is annually increasing and there still remains only a few Food and Drug Administration (FDA) approved treatments with significant limitations available to patients. Tanshinone IIA (Tan IIA) is a promising potential therapeutic for ischemic stroke that has shown success in pre-clinical rodent studies but lead to inconsistent efficacy results in human patients. The physical properties of Tan-IIA, including short half-life and low solubility, suggests that Poly (lactic-co-glycolic acid) (PLGA) nanoparticle-assisted delivery may lead to improve bioavailability and therapeutic efficacy. The objective of this study was to develop Tan IIA-loaded nanoparticles (Tan IIA-NPs) and to evaluate their therapeutic effects on cerebral pathological changes and consequent motor function deficits in a pig ischemic stroke model.
UNASSIGNED: Tan IIA-NP treated neural stem cells showed a reduction in SOD activity in in vitro assays demonstrating antioxidative effects. Ischemic stroke pigs treated with Tan IIA-NPs showed reduced hemispheric swelling when compared to vehicle only treated pigs (7.85 ± 1.41 vs. 16.83 ± 0.62%), consequent midline shift (MLS) (1.72 ± 0.07 vs. 2.91 ± 0.36 mm), and ischemic lesion volumes (9.54 ± 5.06 vs. 12.01 ± 0.17 cm3) when compared to vehicle-only treated pigs. Treatment also lead to lower reductions in diffusivity (-37.30 ± 3.67 vs. -46.33 ± 0.73%) and white matter integrity (-19.66 ± 5.58 vs. -30.11 ± 1.19%) as well as reduced hemorrhage (0.85 ± 0.15 vs 2.91 ± 0.84 cm3) 24 h post-ischemic stroke. In addition, Tan IIA-NPs led to a reduced percentage of circulating band neutrophils at 12 (7.75 ± 1.93 vs. 14.00 ± 1.73%) and 24 (4.25 ± 0.48 vs 5.75 ± 0.85%) hours post-stroke suggesting a mitigated inflammatory response. Moreover, spatiotemporal gait deficits including cadence, cycle time, step time, swing percent of cycle, stride length, and changes in relative mean pressure were less severe post-stroke in Tan IIA-NP treated pigs relative to control pigs.
UNASSIGNED: The findings of this proof of concept study strongly suggest that administration of Tan IIA-NPs in the acute phase post-stroke mitigates neural injury likely through limiting free radical formation, thus leading to less severe gait deficits in a translational pig ischemic stroke model. With stroke as one of the leading causes of functional disability in the United States, and gait deficits being a major component, these promising results suggest that acute Tan IIA-NP administration may improve functional outcomes and the quality of life of many future stroke patients.

UNASSIGNED: To investigate the relationship between bimanual performance deficits measured using kinematics and callosum (CC) white matter changes that occur in people with chronic stroke.
UNASSIGNED: Cross-sectional, observational study of participants with chronic stroke and age-matched controls.
UNASSIGNED: Recruitment and assessments occurred at a stroke recovery research center. Behavioral assessments were performed in a controlled laboratory setting. Magnetic resonance imaging scans were performed at the Center for Biomedical Imaging.
UNASSIGNED: Individuals were enrolled and completed the study (N=39; 21 participants with chronic stroke; 18 age-matched controls with at least 2 stroke risk factors).
UNASSIGNED: Diffusion imaging metrics were obtained for each individual\'s CC and corticospinal tract (CST), including mean kurtosis (MK) and fractional anisotropy (FA). A battery of motor assessments, including bimanual kinematics, were collected from individuals while performing bimanual reaching.
UNASSIGNED: Participants with stroke had lower FA and MK in the CST of the lesioned hemisphere when compared with the non-lesioned hemisphere. The FA and MK values in the CST were correlated with measures of unimanual hand performance. In addition, participants with stroke had significantly lower FA and MK in the CC than matched controls. CC diffusion metrics positively correlated with hand asymmetry and trunk displacement during bimanual performance, even when correcting for age and lesion volume.
UNASSIGNED: These data confirm previous studies that linked CST integrity to unimanual performance and provide new data demonstrating a link between CC integrity and both bimanual motor deficits and compensatory movements.

BACKGROUND: Increasing evidence supported the possible neuro-invasion potential of SARS-CoV-2. However, no studies were conducted to explore the existence of the micro-structural changes in the central nervous system after infection. We aimed to identify the existence of potential brain micro-structural changes related to SARS-CoV-2.
METHODS: In this prospective study, diffusion tensor imaging (DTI) and 3D high-resolution T1WI sequences were acquired in 60 recovered COVID-19 patients (56.67% male; age: 44.10 ± 16.00) and 39 age- and sex-matched non-COVID-19 controls (56.41% male; age: 45.88 ± 13.90). Registered fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) were quantified for DTI, and an index score system was introduced. Regional volumes derived from Voxel-based Morphometry (VBM) and DTI metrics were compared using analysis of covariance (ANCOVA). Two sample t-test and Spearman correlation were conducted to assess the relationships among imaging indices, index scores and clinical information.
RESULTS: In this follow-up stage, neurological symptoms were presented in 55% COVID-19 patients. COVID-19 patients had statistically significantly higher bilateral gray matter volumes (GMV) in olfactory cortices, hippocampi, insulas, left Rolandic operculum, left Heschl\'s gyrus and right cingulate gyrus and a general decline of MD, AD, RD accompanied with an increase of FA in white matter, especially AD in the right CR, EC and SFF, and MD in SFF compared with non-COVID-19 volunteers (corrected p value <0.05). Global GMV, GMVs in left Rolandic operculum, right cingulate, bilateral hippocampi, left Heschl\'s gyrus, and Global MD of WM were found to correlate with memory loss (p value <0.05). GMVs in the right cingulate gyrus and left hippocampus were related to smell loss (p value <0.05). MD-GM score, global GMV, and GMV in right cingulate gyrus were correlated with LDH level (p value <0.05).
CONCLUSIONS: Study findings revealed possible disruption to micro-structural and functional brain integrity in the recovery stages of COVID-19, suggesting the long-term consequences of SARS-CoV-2.
BACKGROUND: Shanghai Natural Science Foundation, Youth Program of National Natural Science Foundation of China, Shanghai Sailing Program, Shanghai Science and Technology Development, Shanghai Municipal Science and Technology Major Project and ZJ Lab.

UNASSIGNED: Diffusion tensor imaging (DTI) is widely used; however, most of the prior studies have resulted in presurgical decreased fractional anisotropy (FA) values in patients with cervical spondylotic myelopathy (CSM). We used ZOOM DTI and could acquire highly accurate FA values during perioperative periods, which indicated different insights than preceding studies. The objective of this study was to assess the perioperative FA change in patients with CSM and determine the prognostic factor.
UNASSIGNED: Twenty-eight patients with CSM and healthy control subjects were enrolled in this study. Twenty patients (71%) had intracordal high intensity before surgery. All patients underwent decompressive surgery. ZOOM DTI and the Japanese Orthopaedic Association (JOA) assessment were performed before and after surgery. The region of interest was manually contoured to omit the surrounding cerebrospinal fluid. The axial plane of the most stenotic cervical level was assessed.
UNASSIGNED: FA values before surgery and at 1 week after surgery, and FA values at 1 week after surgery and at 6 months after surgery differed significantly as determined. The FA values of patients with intracordal high intensity significantly decreased after surgery and significantly increased from 1 week to 6 months, whereas those of patients without intracordal high intensity did not significantly change. JOA scores at 6 months after surgery (13.1) improved significantly compared with JOA scores before surgery (10.8). Only FA values at 1 week after surgery had a significant positive relationship with JOA scores presurgery and at 6 months after surgery.
UNASSIGNED: The presurgical FA value in patients with CSM did not differ from that of normal control subjects, but significantly decreased after surgery, and significantly increased 6 months after surgery. We concluded that the postsurgical FA value approximates the proper state of the damaged cord and the presurgical FA value includes a masked effect as an aligned fiber effect because of compression by degenerative construction. Only the FA value at 1 week had a significant positive relationship with the JOA score presugery and at 6 months, which established that the postsurgical FA value may be a more accurate prognostic factor than the presurgical FA value.

UNASSIGNED: To study the diagnostic accuracy of Diffusion tensor imaging technique in detection of cervical spondylotic myelopathy changes.
UNASSIGNED: Study population included 50 patients with symptoms of cervical myelopathy. The patients were evaluated based on symptoms using the European myelopathy scoring system and were divided into: Grade 1, including patients with mild symptoms; Grade 2, referring to patients with moderate symptoms and Grade 3, which included patients revealing severe symptoms. All the patients were investigated with a 1.5 T MRI unit acquiring DWI and DTI sequences. FA and ADC values from each spinal segment were analyzed in terms of Frequency, Percentage, Mean, Standard Deviation and Confidence Intervals. The comparison of values was done by ANOVA and post hoc analysis by bonferroni test. Comparison of accuracy of FA, ADC and T2WI in recognizing myelopathic changes was done by t-test. Receiver Operating Characteristics (ROC) analysis was performed to obtain a cut off value of FA and ADC for each spinal level to identify myelopathic change in the spinal cord.
UNASSIGNED: The study revealed a significant difference in the mean FA and ADC value of stenotic and Non-stenotic segments. T2WI was highly significant (p = 0.000) in recognizing myelopathy changes in patients falling under Grade 2(moderate) and Grade 3(severe) according to European Myelopathy scoring system. Regarding patients under Grade 1 (mild) FA and ADC values showed significant difference compared to T2WI. The collective sensitivity in the identification of myelopathic changes was highest with FA (79%) as compared to ADC (71%) and T2WI (50%). ROC analysis was done to determine the cut off values of FA and ADC at each cervical spine segments. The proposed cut off, for FA and ADC at the level of C1-C2 is 0.68 and 0.92, C2-C3 is 0.65 and 1.03, C3-C4 is 0.63 and 1.01, C4-C5 0.61 and 0.98, At C5-C6 0.57 and 1.04, At C6-C7 0.56 and 0.96 respectively.
UNASSIGNED: FA and ADC values enhance the efficacy and accuracy of MRI in the diagnosis of cervical spondylotic myelopathy. Hence diffusion tensor imaging can be used as a non-invasive modality to recognize spondylotic myelopathy changes even in the early stages, which can be helpful in deciding on appropriate timing of decompression surgery before the irreversible chronic changes set in.

To determine the relationship between brain tissue metabolites measured by in vivo magnetic resonance spectroscopy (1H-MRS), and glial activation assessed with [11C]-PBR28 uptake in people with amyotrophic lateral sclerosis (ALS).
Forty ALS participants were evaluated clinically using the revised ALS functional rating scale (ALSFRS-R) and upper motor neuron burden (UMNB). All participants underwent simultaneous brain [11C]-PBR28 PET and MR imaging including diffusion tensor imaging to acquire fractional anisotropy (FA). [11C]-PBR28 uptake was measured as standardized uptake values normalized by whole brain mean (SUVR). 1H-MRS metabolite ratios (myo-inositol/creatine, mI/Cr; N-acetylaspartate/creatine, NAA/Cr) were measured within the precentral gyri and brain stem (regions known to be involved in ALS pathophysiology), and precuneus (which served as a control region). Whole brain voxel-wise correlation analyses were employed to identify brain regions exhibiting an association between metabolites within the VOIs and [11C]-PBR28 uptake.
In the precentral gyri, [11C]-PBR28 uptake correlated positively with mI/Cr and negatively with NAA/Cr. The same correlations were not statistically significant in the brain stem, or in the control precuneus region. Whole brain voxel-wise correlation analyses between the estimated brain metabolites within the VOIs and SUVR were highly correlated in the precentral gyri. Decreased FA values in the precentral gyri were correlated with reduced NAA/Cr and elevated mI/Cr. Higher UMNB was correlated with increased [11C]-PBR28 uptake and mI/Cr, and decreased NAA/Cr. ALSFRS-R total score correlated positively with NAA/Cr and negatively with mI/Cr.
Integrated PET-MR and 1H-MRS imaging demonstrates associations between markers for neuronal integrity and neuroinflammation and may provide valuable insights into disease mechanisms in ALS.

Locus of control (LOC) is an important personality trait. LOC over cognitive competency reflects an individual\'s perceived control of desired cognitive outcomes, which is critical for maintaining successful cognitive aging. It is important to understand the neural substrates of LOC over cognitive competency in older adults, especially for individuals at high risk of dementia. Here, we characterized a cohesive functional and structural connectivity profile underlying LOC among 55 older adults with amnestic mild cognitive impairment (aMCI), combining resting-state functional magnetic resonance imaging and diffusion tensor imaging. The results showed that both functional and structural connectivity between the medial prefrontal cortex and amygdala were significantly correlated with external LOC. The functional connectivity mediated the correlation between structural connectivity and external LOC. In addition, aging-associated neurodegeneration moderated the relationship between structural connectivity and external LOC, showing that the structural connectivity was positively correlated with external LOC in low, but not high neurodegeneration. Our results suggest a critical role of the functional amygdala-frontal network, which may serve as a bridge between its white matter tract and LOC over cognitive competency in groups at high risk for dementia.

Classification models based on magnetic resonance imaging (MRI) may aid early diagnosis of frontotemporal dementia (FTD) but have only been applied in established FTD cases. Detection of FTD patients in earlier disease stages, such as presymptomatic mutation carriers, may further advance early diagnosis and treatment. In this study, we aim to distinguish presymptomatic FTD mutation carriers from controls on an individual level using multimodal MRI-based classification.
Anatomical MRI, diffusion tensor imaging (DTI) and resting-state functional MRI data were collected in 55 presymptomatic FTD mutation carriers (8 microtubule-associated protein Tau, 35 progranulin, and 12 chromosome 9 open reading frame 72) and 48 familial controls. We calculated grey and white matter density features from anatomical MRI scans, diffusivity features from DTI, and functional connectivity features from resting-state functional MRI. These features were applied in a recently introduced multimodal behavioural variant FTD (bvFTD) classification model, and were subsequently used to train and test unimodal and multimodal carrier-control models. Classification performance was quantified using area under the receiver operator characteristic curves (AUC).
The bvFTD model was not able to separate presymptomatic carriers from controls beyond chance level (AUC = 0.570, p = 0.11). In contrast, one unimodal and several multimodal carrier-control models performed significantly better than chance level. The unimodal model included the radial diffusivity feature and had an AUC of 0.646 (p = 0.021). The best multimodal model combined radial diffusivity and white matter density features (AUC = 0.680, p = 0.005).
FTD mutation carriers can be separated from controls with a modest AUC even before symptom-onset, using a newly created carrier-control classification model, while this was not possible using a recent bvFTD classification model. A multimodal MRI-based classification score may therefore be a useful biomarker to aid earlier FTD diagnosis. The exclusive selection of white matter features in the best performing model suggests that the earliest FTD-related pathological processes occur in white matter.