Diffusion Tensor Imaging Indices Research Articles

Wallerian Degeneration Assessed by Multi-Modal Magnetic Resonance Imaging of Cervical Spinal Cord Is Associated With Neurological Impairment After Spinal Cord Injury.

While Wallerian degeneration (WD) is a crucial pathological process induced with spinal cord injury (SCI), its underlying mechanisms is still understudied. In this study, we aim to assess structural alterations and clinical significance of WD in the cervical cord following SCI using multi-modal magnetic resonance imaging (MRI), which combines T2*-weighted imaging and diffusion tensor imaging (DTI). T2*-weighted images allow segmentation of anatomical structures and the detection of WD on macrostructural level. DTI, on the other hand, can identify the reduction in neuroaxonal integrity by measuring the diffusion of water molecules on the microstructural level. In this prospective study, 35 SCI patients (19 paraplegic and 16 tetraplegic patients) and 12 healthy controls were recruited between July 2020 and May 2022. The hyperintensity voxels in the dorsal column was manually labeled as WD on T2*-weighted images. The mean cross-sectional area (CSA) and mean DTI indexes of WD at the C2 level were calculated and compared between groups. Correlation analysis was used to determine the associations of the magnitude of WD with lesion characteristics and clinical outcomes. Compared with controls, SCI patients showed evident hyperintensity (35/35) and decreased neuroaxonal integrity (p < 0.05) within the dorsal column at the C2 level. A higher neurological level of injury was associated with a larger mean CSA and reduction in neuroaxonal integrity within WD (p < 0.05). Smaller total and dorsal tissue bridges were related to greater mean CSA and lower fractional anisotropy values in WD (p < 0.05), respectively. Moreover, SCI participants with significantly larger CSAs and significantly lower microstructural integrity had worse sensory outcomes (p < 0.05). This comprehensive evaluation of WD can help us better understand the mechanisms of WD, monitor progression, and assess the effectiveness of therapeutic interventions after SCI.

Leverage of applying diffusion tensor imaging (DTI) indices in assessment of cervical spondylotic myelopathy

BackgroundCervical spondylotic myelopathy (CSM) is the most prevalent form of dysfunction in the cervical cord. For best results, CSM must be identified and treated quickly, before spinal cord injury develops. We aimed at determining the diagnostic value of quantitative and qualitative diffusion tensor imaging (DTI) indices in the assessment of CSM. Thirty patients were included in this prospective study with clinically suspected CSM of both sexes. This study aimed at determining the diagnostic value of quantitative and qualitative DTI indices in early assessment of CSM and subsequently early and proper management decision rendering better clinical outcome.ResultsThis prospective study included 30 patients: with clinically suspected CSM with a mean age of 51.88 ± 10.28 years. Patients with CSM were graded to 3 grades, mild (No. = 17), moderate (No. = 13) and severe (No. = 0) according to the modified Japanese orthopedic association (mJOA) grading system. Correlation test was performed between mJOA grades of severity with fractional anisotropy (FA), apparent diffusion coefficient (ADC) and T2 cord signal. We found a negative correlation between ADC and FA with Spearman’s rho value of − 0.612 and “P value 0.000” (P value < 0.05), a positive correlation between FA with mJOA clinical score with Spearman’s rho value of − 0.504 & “P value 0.036” (P value < 0.05) and a negative correlation between ADC and mJOA clinical score with Spearman’s rho value of 0.385 and P value 0.005 (P value < 0.05), and no significant correlation was found between mJOA clinical score and T2 hyperintense signal with Spearman’s rho value of − 0.304 and “P value 0.102” (P value < 0.05). Qualitative maps grading by 3D tractography images were done, and 18 patients in the study (60%) showed homogenous intact fiber tracts (grade I), 9 patients (30%) showed reduction or alteration of anisotropy or mixed colors intensity (grade II), and 3 patients (10%) showed fiber tract disruption or displaced cord (grade III). Three DTI parameters (other than FA and ADC) were measured, and two of them show significant difference between their measures in the stenotic and non-stenotic portions of the spinal cord—RA (P value = 0.00) and RD (P value = 0.00).ConclusionsWe concluded that DTI is a crucial tool for early diagnosis and grading of CSM (cervical spondylosis myelopathy)—quantitatively and qualitatively—hence, it should be routinely integrated with conventional cervical spine MRI in case of clinically or radiologically suspected cervical cord compression, as the FA parameter together with the clinical assessment formulates the management plan decision for the CSM whether surgical or non-surgical and depicts the need for early surgical decision rendering better clinical outcome compared to that based on T2 hyperintense cord signal.

Abnormal microstructure of corpus callosum in children with primary nocturnal enuresis: a DTI study.

Primary nocturnal enuresis (PNE) is a common childhood disorder with abnormal sleep or arousal. The corpus callosum (CC) continues to develop into adulthood and plays an important role in sleep arousal. This study aimed to evaluate the microstructure of the CC in children with PNE. Diffusion tensor imaging (DTI) indices were extracted throughout the CC and its seven subregions were compared between the children with PNE and healthy children (HC). The correlation between abnormal DTI indices of the CC and cognitive condition was also tested. Compared to HC, decreased fiber number (NF) (F = 8.492, PFDR = 0.032) and fractional anisotropy (FA) value (F = 8.442, PFDR = 0.040) were found in the posterior midbody of the CC, increased RD was found in the posterior midbody (F = 6.888, PFDR = 0.040) and isthmus (F = 7.967, PFDR = 0.040) in children with PNE. The reduction of FA value was more obvious in boys than girls with PNE. In children with PNE, there was a significant positive correlation between the NF of the posterior midbody and full IQ (r = 0.322, P = 0.025) and between the FA value and the general knowledge memory (r = 0.293, P = 0.043). This study provides imaging evidence for abnormalities in the microstructure of the CC in children with PNE, especially in male PNE, which might affect the children's cognitive performance.

Association of Vascular Risk Factors and CSF and Imaging Biomarkers With White Matter Hyperintensities in Former American Football Players.

Recent data link exposure to repetitive head impacts (RHIs) from American football with increased white matter hyperintensity (WMH) burden. WMH might have unique characteristics in the context of RHI beyond vascular risk and normal aging processes. We evaluated biological correlates of WMH in former American football players, including markers of amyloid, tau, inflammation, axonal injury, neurodegeneration, and vascular health. Participants underwent clinical interviews, MRI, and lumbar puncture as part of the Diagnostics, Imaging, and Genetics Network for the Objective Study and Evaluation of Chronic Traumatic Encephalopathy Research Project. Structural equation modeling tested direct and indirect effects between log-transformed total fluid-attenuated inversion recovery (FLAIR) lesion volumes (TLV) and the revised Framingham stroke risk profile (rFSRP), MRI-derived global metrics of cortical thickness and fractional anisotropy (FA), and CSF levels of amyloid β1-42, p-tau181, soluble triggering receptor expressed on myeloid cells 2 (sTREM2), and neurofilament light. Covariates included age, race, education, body mass index, APOE ε4 carrier status, and evaluation site. Models were performed separately for former football players and a control group of asymptomatic men unexposed to RHI. In 180 former football players (mean age = 57.2, 36% Black), higher log(TLV) had direct associations with the following: higher rFSRP score (B = 0.26, 95% CI 0.07-0.40), higher p-tau181 (B = 0.17, 95% CI 0.01-0.43), lower FA (B = -0.28, 95% CI -0.42 to -0.13), and reduced cortical thickness (B = -0.25, 95% CI -0.45 to -0.08). In 60 asymptomatic unexposed men (mean age = 59.3, 40% Black), there were no direct effects on log(TLV) (rFSRP: B = -0.03, 95% CI -0.48 to 0.57; p-tau181: B = -0.30, 95% CI -1.14 to 0.37; FA: B = -0.07, 95% CI -0.48 to 0.42; or cortical thickness: B = -0.28, 95% CI -0.64 to 0.10). The former football players showed stronger associations between log(TLV) and rFSRP (1,069% difference in estimates), p-tau181 (158%), and FA (287%) than the unexposed men. Risk factors and biological correlates of WMH differed between former American football players and asymptomatic unexposed men. In addition to vascular health, p-tau181 and diffusion tensor imaging indices of white matter integrity showed stronger associations with WMH in the former football players. FLAIR WMH may have specific risk factors and pathologic underpinnings in RHI-exposed individuals.

Correlation Between Pre-Operative Diffusion Tensor Imaging Indices and Post-Operative Outcome in Degenerative Cervical Myelopathy: A Systematic Review and Meta-Analysis.

Systematic review. The correlation between pre-operative diffusion tensor imaging (DTI) metrics and post-operative clinical outcomes in patients with degenerative cervical myelopathy (DCM) has been widely investigated with different studies reporting varied findings. We conducted a systematic review to determine the association between DTI metric and clinical outcomes after surgery. We identified relevant articles that investigated the relationship between pre-operative DTI indices and post-operative outcome in DCM patients by searching PubMed/MEDLINE, Web of Science, Scopus, and EMBASE from inception until October 2023. In addition, quantitative synthesis and meta-analyses were performed. FA was significantly correlated with postoperative JOA or mJOA across all age and follow up subgroups, changes observed in JOA or mJOA from preoperative to postoperative stages (Δ JOA or Δ mJOA) in subgroups aged 65 and above and in those with a follow-up period of 6 months or more, as well as recovery rate in all studies pooled together and also in the under-65 age bracket. Additionally, a significant correlation was demonstrated between recovery rate and ADC across all age groups. No other significant correlations were discovered between DTI parameters (MD, AD, and ADC) and post-operative outcomes. DTI is a quantitative noninvasive evaluation tool that correlates with severity of DCM. However, the current evidence is still elusive regarding whether DTI metric is a validated tool for predicting the degree of post-operative recovery, which could potentially be useful in patient selection for surgery.

Diffusion tensor imaging and voxel-based morphometry in differentiating multiple sclerosis and its mimics

BackgroundThe discrimination between multiple sclerosis (MS) and other white matter lesions in adults is still problematic as multiple diseases have similar clinical and radiological findings, especially at the disease onset. This case–control study aimed to evaluate the efficacy of diffusion tensor imaging (DTI) and brain morphometry in the differentiation between adult MS and its magnetic resonance imaging (MRI) mimics.MethodsFifty-eight patients (49 women and 9 men; mean age 35.74 ± 11.86 years, range 18–50 years) with clinically suspected MS and age- and sex-matched fifteen healthy subjects were included. All study subjects underwent MRI using 3D FLAIR, 3D T1 MPRAGE, axial T2WI fast spin echo, and DTI sequences. The included patients were classified into MS and mimics groups according to MC Donald’s criteria 2017. Image post-processing using the region of interest (ROI) analysis for DTI parameters and automated voxel brain morphometry and segmentation was done for all study groups. Statistical comparison between the two patient groups and between them and the control group was performed regarding DTI indices (fractional anisotropy [FA], mean diffusivity [MD], and relative anisotropy [RA]) and brain morphometry parameters (including white matter volume (WMV), grey matter volume (GMV), cerebrospinal fluid volume (CSFV), T2 lesion load and deep grey matter volume).ResultsA statistically significant difference was observed between the MD, FA, and RA values of the patients and control groups. The MD values were significantly higher in the MS than in its mimics with a cut-off value of > 1.058 × 10−3 mm2/s (p < 0.001). Compared to the mimics group, the MS patients showed significantly lower WMV (33.31 ± 4.40 versus 35.71 ± 4.58; p = 0.047) and higher CSFV (16.38 ± 5.93 versus 13.06 ± 3.09; p = 0.012) with no significant difference regarding the GMV.ConclusionsMD analysis of DTI, WMV, and CSFV are useful quantitative measurements in confirming the diagnosis of MS and differentiating it from its imaging mimics.

Relationship between disproportionately enlarged subarachnoid-space hydrocephalus and white matter tract integrity in normal pressure hydrocephalus

Normal pressure hydrocephalus (NPH) patients had altered white matter tract integrities on diffusion tensor imaging (DTI). Previous studies suggested disproportionately enlarged subarachnoid space hydrocephalus (DESH) as a prognostic sign of NPH. We examined DTI indices in NPH subgroups by DESH severity and clinical symptoms. This retrospective case–control study included 33 NPH patients and 33 age-, sex-, and education-matched controls. The NPH grading scales (0–12) were used to rate neurological symptoms. Patients with NPH were categorized into two subgroups, high-DESH and low-DESH groups, by the average value of the DESH scale. DTI indices, including fractional anisotropy, were compared across 14 regions of interest (ROIs). The high-DESH group had increased axial diffusivity in the lateral side of corona radiata (1.43 ± 0.25 vs. 1.72 ± 0.25, p = 0.04), and showed decreased fractional anisotropy and increased mean, and radial diffusivity in the anterior and lateral sides of corona radiata and the periventricular white matter surrounding the anterior horn of lateral ventricle. In patients with a high NPH grading scale, fractional anisotropy in the white matter surrounding the anterior horn of the lateral ventricle was significantly reduced (0.36 ± 0.08 vs. 0.26 ± 0.06, p = 0.03). These data show that DESH may be a biomarker for DTI-detected microstructural alterations and clinical symptom severity.

Disturbed white matter integrity on diffusion tensor imaging in young children with epilepsy

To evaluate whether abnormalities in white matter (WM) integrity are present in young children with epilepsy. Twelve children (3-6 years old) with epilepsy and six matched healthy controls were recruited for brain diffusion tensor imaging (DTI). Track-based spatial statistics (TBSS) was used to analyse and compare DTI indices of mean diffusivity (MD), fractional anisotropy (FA), axial and radial diffusivity (AD/RD) between patients and controls, and correlations between clinical variables and DTI parameters were analysed. Compared with controls, patients showed increased FA in the left superior corona radiata and increased AD in the bilateral superior corona radiata. In children with generalised epilepsy, FA was increased in the left external capsule, while AD was decreased in the body of the corpus callosum, the left external capsule and the left superior longitudinal fasciculus. In those with focal epilepsy, FA was increased in the genu and body of the corpus callosum, and RD was decreased in the genu of the corpus callosum and left external capsule. Compared with partial epilepsy, generalised epilepsy was associated with increased FA in the right anterior corona radiata and decreased RD in the right anterior corona radiata and the genu and body of the corpus callosum. No significant correlations were observed between clinical variables and DTI parameters. The results of this study indicate that the microstructure of the white matter is disturbed by epileptic discharges and a compensatory response occurs during early brain development.

[Changes in Plasma Amyloid-β Level and Their Relationship With White Matter Microstructure in Patients With Mild Cognitive Impairment].

Objective To investigate the changes in plasma amyloid-β (Aβ) level and their relationship with white matter microstructure in the patients with amnesic mild cognitive impairment(aMCI) and vascular mild cognitive impairment (vMCI).Methods A total of 36 aMCI patients,20 vMCI patients,and 34 sex and age matched healthy controls (HC) in the outpatient and inpatient departments of the First Affiliated Hospital of Anhui Medical University were enrolled in this study.Neuropsychological scales,including the Mini-Mental State Examination,the Montreal Cognitive Assessment,and the Activity of Daily Living Scale,were employed to assess the participants.Plasma samples of all the participants were collected for the measurement of Aβ42 and Aβ40 levels.All the participants underwent magnetic resonance scanning to obtain diffusion tensor imaging (DTI) data.The DTI indexes of 48 white matter regions of each individual were measured (based on the ICBM-DTI-81 white-matter labels atlas developed by Johns Hopkins University),including fractional anisotropy (FA) and mean diffusivity (MD).The cognitive function,plasma Aβ42,Aβ40,and Aβ42/40 levels,and DTI index were compared among the three groups.The correlations between the plasma Aβ42/40 levels and DTI index of aMCI and vMCI patients were analyzed.Results The Mini-Mental State Examination and the Montreal Cognitive Assessment scores of aMCI and vMCI groups were lower than those of the HC group (all P<0.001).There was no significant difference in the Activity of Daily Living Scale score among the three groups (P=0.654).The plasma Aβ42 level showed no significant difference among the three groups (P=0.227).The plasma Aβ40 level in the vMCI group was higher than that in the HC group (P=0.014),while it showed no significant difference between aMCI and HC groups (P=1.000).The plasma Aβ42/40 levels in aMCI and vMCI groups showed no significant differences from that in the HC group (P=1.000,P=0.105),while the plasma Aβ42/40 level was lower in the vMCI group than in the aMCI group (P=0.016).The FA value of the left anterior limb of internal capsule in the vMCI group was lower than those in HC and aMCI groups (all P=0.001).The MD values of the left superior corona radiata,left external capsule,left cingulum (cingulate gyrus),and left superior fronto-occipital fasciculus in the vMCI group were higher than those in HC (P=0.024,P=0.001,P=0.003,P<0.001) and aMCI (P=0.015,P=0.004,P=0.019,P=0.001) groups,while the MD values of the right posterior limb of internal capsule (P=0.005,P=0.001) and left cingulum (hippocampus) (P=0.017,P=0.031) in the aMCI and vMCI groups were higher than those in the HC group.In the aMCI group,plasma Aβ42/40 level was positively correlated with FA of left posterior limb of internal capsule (r=0.403,P=0.015) and negatively correlated with MD of the right fonix (r=-0.395,P=0.017).In the vMCI group,plasma Aβ42/40 level was positively correlated with FA of the right superior cerebellar peduncle and the right anterior limb of internal capsule (r=0.575,P=0.008;r=0.639,P=0.002),while it was negatively correlated with MD of the right superior cerebellar peduncle and the right anterior limb of internal capsule (r=-0.558,P=0.011;r=-0.626,P=0.003).Conclusions Plasma Aβ levels vary differently in the patients with aMCI and vMCI.The white matter regions of impaired microstructural integrity differ in the patients with different dementia types in the early stage.The plasma Aβ levels in the patients with aMCI and vMCI are associated with the structural integrity of white matter,and there is regional specificity between them.

Anesthetic modulation of water diffusion: Insights from a diffusion tensor imaging study.

Diffusion tensor imaging (DTI) in animal models are essential for translational neuroscience studies. A critical step in animal studies is the use of anesthetics. Understanding the influence of specific anesthesia regimes on DTI-derived parameters, such as fractional anisotropy (FA) and mean diffusivity (MD), is imperative when comparing results between animal studies using different anesthetics. Here, the quantification of FA and MD under different anesthetic regimes, alpha-chloralose and isoflurane, is discussed. We also used a range of b-values to determine whether the anesthetic effect was b-value dependent. The first group of rats (n=6) was anesthetized with alpha-chloralose (80mg/kg), whereas the second group of rats (n=7) was anesthetized with isoflurane (1.5%). DTI was performed with b-values of 500, 1500, and 1500s/mm2, and the MD and FA were assessed individually. Anesthesia-specific differences in MD were apparent, as manifested by the higher estimated MD under isoflurane anesthesia than that under alpha-chloralose anesthesia (P<0.001). MD values increased with decreasing b-value in all regions studied, and the degree of increase when rats were anesthetized with isoflurane was more pronounced than that associated with alpha-chloralose (P<0.05). FA quantitation was also influenced by anesthesia regimens to varying extents, depending on the brain regions and b-values. In conclusion, both scanning parameters and the anesthesia regimens significantly impacted the quantification of DTI indices.

Evaluation of white matter integrity by diffusion tensor imaging in the deficiencies of vitamin B12 and folate in older patients.

The aim of this study is to investigate whether white matter (WM) integrity is impaired in vitamin B12 and folate deficiency with Diffusion Tensor Imaging (DTI) in older patients. All the patients aged ≥65 years admitted to the geriatric clinic and performed DTI-MRI were included in the study. DTI parameters (fractional anisotropy, mean diffusivity, axial diffusivity, radial diffusivity) were calculated by ROI-based method in white matter tracts. Deficiency threshold for vitamin B12 were defined as <200 pg ml-1 and <400 pg ml-1 separately; and for folate as <3 ng ml-1 and <6 ng ml-1, separately. DTI was performed to older patients having serum vitamin B12 level (n = 106, mean age = 80.7±7.7, 66% female) and folate level (n = 101, mean age = 80.7±7.5, 67.3% female). Significantly lower FA and higher MD and RD levels were observed in multiple WM areas including superior and middle cerebellar peduncles, cingulum and genu of corpus callosum in patients with vitamin B12 <400 pg ml-1 (p < 0.05). DTI indices also showed significant changes in the genu of corpus callosum, and right and left superior longitudinal fasciculus in patients with folate <6 ng ml-1 (p < 0.05). Deficiencies of vitamin B12 and folate may be associated with impaired white matter integrity in elderly even at high laboratory levels, and DTI is a useful method to detect it. Early detection of impaired WM integrity caused by micronutrient deficiencies poses a great significance in terms of prevention and intervention, and DTI is an effective non-invasive method to be used for this purpose.

Abnormal white matter along fibers by automated fiber quantification in patients undergoing hemodialysis.

Abnormal white matter has been reported in patients with end-stage renal disease (ESRD). However, few studies have investigated the relationship between specific damage segments and cognition in ESRD. This study aimed to delineate white matter alterations in ESRD and its relationship with cognition. A total of 36 patients undergoing hemodialysis and 25 healthy controls underwent diffusion tensor imaging (DTI) and a series of neuropsychiatric tests. Automated fiber quantification was used to extract distinct DTI indices, and the relationship between the specific segment of the white matter and clinical properties was investigated. Furthermore, a support vector machine was applied to differentiate patients with ESRD from healthy controls. Fractional anisotropy values decreased in multiple fiber bundles, including bilateral thalamic radiata, cingulum cingulate, inferior fronto-occipital fasciculus (IFOF), uncinate, Callosum_Forceps_Major/Callosum_Forceps_Minor (CFMaj/CFMin), and left uncinate from the tract level in patients with ESRD. Specific damaged segments were detected in 8 fiber bundles, including bilateral thalamic radiation, cingulum cingulate, IFOF, CFMin, and left corticospinal tract. Few alterations in these fiber bundles were correlated with cognition impairment and hemoglobin levels. The tract profiles of the left thalamic radiata and left cingulum cingulate could be used to differentiate hemodialysis patients from healthy controls, with an accuracy of 76.9% and 67.6%, respectively. This study revealed white matter damage in hemodialysis patients. This damage occurred in specific segments of the tract, especially in the left thalamic radiata and left cingulum cingulate, which might become a new biomarker for patients with ESRD and cognition impairment.

P.115 MRI based methodology for assessment of white matter neuroplasticity: preclinical validation using human motor training data

Background: Disruption of white matter (WM) tracts is common in traumatic injury to the brain and spinal cord. However, imaging techniques for prognostication and monitoring of recovery are lacking. Myelin Water Imaging (MWI) is a validated MRI based method of quantifying myelin volume and represents a potential tool for application in a clinical environment. Methods: 12 healthy, right-handed participants completed a two-week visuomotor maze training program with MRI scans at baseline and endpoint. The task was designed to be difficult for the non-dominant hand and easy for the dominant, allowing for an inbuilt control. Diffusion Tensor Imaging (DTI) along with MWI data were collected at both timepoints using a 3T MRI. Results: Performance metrics confirmed task performance increased only in the non-dominant hand, and a corresponding endpoint&gt;baseline comparison showed significant increases in the MWF (p&lt;0.05) and DTI indices (p&lt;0.05) in the right corticospinal tract (CST), and no significant change in the left CST. Conclusions: This preclinical validation shows MWI is capable of quantitatively tracking WM changes over the course of weeks in humans. MWI’s clinical utility lies in its ability to assess WM changes over short time periods, as monitoring changes in tissue integrity will assist in guiding treatment decisions after critical injury.

Detection of mild cognitive impairment in Parkinson’s disease using gradient boosting decision tree models based on multilevel DTI indices

BackgroundCognitive dysfunction is the most common non-motor symptom in Parkinson’s disease (PD), and timely detection of a slight cognitive decline is crucial for early treatment and prevention of dementia. This study aimed to build a machine learning model based on intra- and/or intervoxel metrics extracted from diffusion tensor imaging (DTI) to automatically classify PD patients without dementia into mild cognitive impairment (PD-MCI) and normal cognition (PD-NC) groups.MethodsWe enrolled PD patients without dementia (52 PD-NC and 68 PD-MCI subtypes) who were assigned to the training and test datasets in an 8:2 ratio. Four intravoxel metrics, including fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD), and two novel intervoxel metrics, local diffusion homogeneity (LDH) using Spearman’s rank correlation coefficient (LDHs) and Kendall’s coefficient concordance (LDHk), were extracted from the DTI data. Decision tree, random forest, and eXtreme gradient boosting (XGBoost) models based on individual and combined indices were built for classification, and model performance was assessed and compared via the area under the receiver operating characteristic curve (AUC). Finally, feature importance was evaluated using SHapley Additive exPlanation (SHAP) values.ResultsThe XGBoost model based on a combination of the intra- and intervoxel indices achieved the best classification performance, with an accuracy of 91.67%, sensitivity of 92.86%, and AUC of 0.94 in the test dataset. SHAP analysis showed that the LDH of the brainstem and MD of the right cingulum (hippocampus) were important features.ConclusionsMore comprehensive information on white matter changes can be obtained by combining intra- and intervoxel DTI indices, improving classification accuracy. Furthermore, machine learning methods based on DTI indices can be used as alternatives for the automatic identification of PD-MCI at the individual level.

The Prediction of Neurological Prognosis for Cervical Spondylotic Myelopathy Using Diffusion Tensor Imaging.

Although cervical spondylotic myelopathy (CSM) can be easily diagnosed using magnetic resonance imaging (MRI), prediction of surgical effect using preoperative radiological examinations remains difficult. In previous studies, it was reported that diffusion tensor imaging (DTI) may be used for the prediction of surgical effect; however, these studies did not consider the influences of spinal cord compression even though the values of DTI indexes can be distorted by compressive lesions in patients with CSM. Therefore, it is uncertain whether preoperative DTI indexes can actually predict the surgical effect. The aim of this study was to investigate DTI metrics that are hardly affected by spinal cord compression and can accurately predict neurological status after decompressive surgery. Twenty-one patients with CSM who underwent surgery and 10 healthy volunteers were enrolled in this study. The subjects underwent cervical MRI, and values of DTI indexes including axial diffusivity (AD), radial diffusivity (RD), apparent diffusion coefficient (ADC), and fractional anisotropy (FA) were recorded at each intervertebral level. Further, the Japanese Orthopaedic Association (JOA) score of each patient with CSM was recorded before and after surgery for neurological status evaluation. Preoperative and postoperative values of DTI indexes were compared, and correlations between preoperative DTI parameters and postoperative neurological recovery were assessed. After surgery, the lesion-adjacent (LA) ratios of RD and ADC increased (p = 0.04 and p = 0.062, respectively), while the LA ratio of FA decreased (p = 0.075). In contrast, the LA ratio of AD hardly changed. A negative correlation was observed between preoperative LA ratio of AD and JOA recovery rate 6 months after surgery (r = -0.379, p = 0.091). Based on preoperative LA ratio of AD, the patients were divided into a low AD group and a high AD group, and JOA recovery rate 6 months after surgery was found to be higher in the low AD group than in the high AD group (p = 0.024). In patients with CSM, preoperative LA ratio of AD is seldom affected by spinal cord compression, and it negatively correlates with JOA recovery rate 6 months after surgery.

Diffusion tensor imaging discriminates focal cortical dysplasia from normal brain parenchyma and differentiates between focal cortical dysplasia types

ObjectivesAlthough diffusion tensor imaging (DTI) may facilitate the identification of cytoarchitectural changes associated with focal cortical dysplasia (FCD), the predominant aetiology of paediatric structural epilepsy, its potential has thus far remained unexplored in this population. Here, we investigated whether DTI indices can differentiate FCD from contralateral brain parenchyma (CBP) and whether clinical features affect these indices.MethodsIn this single-centre, retrospective study, we considered children and adolescents with FCD-associated epilepsy who underwent brain magnetic resonance (MRI), including DTI. Fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity, and radial diffusivity, were calculated in both FCD and CBP. The DTI indices best discriminating between FCD and CBP were subsequently used to assess the link between DTI and selected clinical and lesion-related parameters.ResultsWe enrolled 32 patients (20 male; median age at MRI 4 years), including 15 with histologically confirmed FCD. FA values were lower (p = 0.03), whereas MD values were higher in FCD than in CBP (p = 0.04). The difference in FA values between FCD and CBP was more pronounced for a positive vs. negative history of status epilepticus (p = 0.004). Among histologically confirmed cases, the difference in FA values between FCD and CBP was more pronounced for type IIb versus type I FCD (p = 0.03).ConclusionsFA and MD discriminate between FCD and CBP, while FA differentiates between FCD types. Status epilepticus increases differences in FA, potentially reflecting changes induced in the brain. Our findings support the potential of DTI to serve as a non-invasive biomarker to characterise FCD in the paediatric population.

Characteristics of white matter structural connectivity in healthy adults with childhood maltreatment

ABSTRACT Background: Childhood maltreatment (CM) is a common psychological stressor associated with multiple mental disorders. While CM is associated with vulnerability to depression and anxiety, little is known about the specific mechanism underlying this relationship. Objective: This study aimed to investigate the white matter (WM) of healthy adults with CM and their relationships with depression and anxiety to provide biological evidence for the development of mental disorders in subjects with childhood trauma. Methods: The CM group included 40 healthy adults with CM. The non-CM group included 40 healthy adults without CM. Diffusion tensor imaging (DTI) data were collected, and tract-based spatial statistics (TBSS) were applied to the whole brain to assess WM differences between the two groups; post-hoc fibre tractography was used to characterise the developmental differences; and mediation analysis was used to assess the relationships among the Child Trauma Questionnaire (CTQ) results, DTI indices, and depression and anxiety scores. Results: Relative to the non-CM group, the CM group revealed significantly lower fractional anisotropy (FA) in the right posterior corona radiata (PCR-R), right anterior corona radiata (ACR-R), left super corona radiata (SCR-L), anterior thalamic radiation (ATR), and right posterior limb of the internal capsule (PLIC-R). Additionally, shorter fibre bundles passed through the PCR-R, ACR-R, and ATR in the CM group compared with the non-CM group. Besides, the length of the ACR-R mediated the relationship between CM and trait anxiety. Conclusions: The alteration of white matter microstructure associated with childhood trauma in healthy adults may reflect biomarkers of childhood trauma. Besides, an alteration of WM microstructure in healthy adults with CM mediates the association between CM and trait anxiety, which may represent the vulnerability to developing mental disorders after childhood trauma experiences.

Diffusion tensor imaging and quantitative T2 mapping to monitor muscle recovery following hamstring injury.

MRI examinations are accurate for diagnosing sports-related acute hamstring injuries. However, sensitive imaging methods for assessing recovery of these injuries are lacking. Diffusion tensor imaging (DTI) and quantitative T2 (qT2) mapping have both shown promise for assessing recovery of muscle micro trauma and exercise effects. The purpose of this study was to explore the potential of DTI and qT2 mapping for monitoring the muscle recovery processes after acute hamstring injury. In this prospective study, athletes with an acute hamstring injury underwent a 3-T MRI examination of the injured and contralateral hamstrings including DTI and qT2 measurements at three time points: (1) within 1 week after sustaining the injury, (2) 2 weeks after time point 1, and (3) return to play (RTP). A linear mixed model was used for time-effect analysis and paired t-tests for the detection of differences between injured and uninjured muscles. Forty-one athletes (age 27.8 ± 7 years; two females and 39 males) were included. Mean RTP time was 50 (range 12-169) days. A significant time effect was found for mean diffusivity, radial diffusivity, and the second and third eigenvalues (p ≤ 0.001) in the injured muscles. Fractional anisotropy (p = 0.40), first eigenvalue (p = 0.02), and qT2 (p = 0.61) showed no significant time effect. All DTI indices, except for fractional anisotropy, were significantly elevated compared with control muscles right after the injury (p < 0.001). Values normalized during the recovery period, with no significant differences between control and injured muscles at RTP (p values ranged from 0.08 to 0.51). Mean qT2 relaxation times in injured muscles were not significantly elevated compared with control muscles at any time point (p > 0.04). In conclusion, DTI can be used to monitor recovery after an acute hamstring injury. Future work should explore the potential of DTI indices to predict RTP and recovery times in athletes after an acute strain injury.

The comparison of diffusion tensor imaging in human hearts between 1.5 T and 3.0 T

BackgroundThe aim was to compare the diffusion tensor imaging (DTI) indices derived from human hearts between 1.5 T and 3.0 T scanners. Additionally, the reproducibility of DTI indices was assessed between 1.5 T and 3.0 T scanners.MethodsA total of 18 ex-vivo hearts were derived from patients who underwent heart transplantation. The DTI schemes were performed at 1.5 T and 3.0 T, respectively. Then, the same slices from each ex-vivo heart were selected for image analysis. The student’s t-test or Wilcoxon-rank test was used to compare the statistical differences. The agreement of DTI indices was mainly reported as the interclass correlation coefficient (ICC).ResultsNo significant differences (all P > 0.05) were found in the DTI indices between 1.5 T and 3.0 T scanners. Interestingly, the ICC of all DTI indices was relatively lower with a low b-value. The reproducibility of the helix angle (HA) was relatively lower when compared to the other DTI indices.ConclusionThe DTI indices of ex-vivo human hearts between 1.5 T and 3.0 T scanners had no significant differences. The consistency of DTI indices needed caution using a low b-value with different field strengths, and the relatively low reproducibility of HA should be considered.

Changes in diffusion tensor imaging indices in basal ganglia and thalamus of patients with Relapsing-Remitting Multiple Sclerosis and relation with clinical conditions: A case-control study

BackgroundMultiple 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. Methods30 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. ResultsThe 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. ConclusionsDTI 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. Availability of data and materialNot applicable