Quantitative evaluation of callosal abnormalities in relapsing-remitting multiple sclerosis using diffusion tensor imaging: A systemic review and meta-analysis

The main aim of our study was to compare diffusion tensor imaging (DTI) parameters in patients with myotonic dystrophy types 1 and 2 (DM1 and DM2). To ascertain whether DTI could be used to assess the integrity of white matter tracts in the brain and identify any abnormalities or disruptions in connectivity between different brain regions in patients with DM. By providing a more detailed understanding of the structural changes in the brain associated with DM, could DTI potentially be used to develop more effective treatments for the cognitive and neurological symptoms of the disorder? We retrospectively compared MRI scans of 19 patients with DM1 to those of 23 healthy, matched controls, and of 16 patients with DM2 to those of 20 healthy, matched controls, and finally compared the DM1 and DM2 samples. Fraction anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD), and axial diffusivity (AD) values were assessed using Tract Based Spatial Statistics (TBSS). In patients with DM1, a statistically significant decrease in the values of the FA parameter was revealed in 45/48 white matter tracts compared to patients with DM2. There was no statistically significant decrease in the values of the FA parameter in patients with DM2 compared to DM1. The values of MD and RD were significantly higher in 47 tracts in DM1 patients compared to DM2 patients. AD values were significantly higher in all 48 tracts in DM1 patients compared to DM2 patients. There were no tracts with increased MD, AD, or RD values in DM2 patients compared to DM1. Our results indicate diffuse disintegration of white matter pathways in DM patients, especially in the DM1 group. The damage to all types of fibres (association, commissural, and projection) may explain the diversity of clinical symptoms, which were more severe in the DM1 group of patients than in the DM2 group. DTI in patients with DM may help us to understand the neural mechanisms underlying brain involvement during the disease. In future, it may help to identify biomarkers for disease progression and treatment response.

Recent studies have shown that diffusion tensor imaging (DTI) parameters are used to follow the patients with breast cancer and correlate well as a prognostic parameter of breast cancer. However, as far as we know, there is no data to compare the DTI features of breast cancer brain metastases according to molecular subtypes in the literature. Our aim is to evaluate whether there are any differences in DTI parameters of brain metastases in patients with breast cancer according to molecular subtypes. Twenty-seven patients with breast cancer and 82 metastatic brain lesions were included. We classified subjects into three subgroups according to their hormone expression; Group 0, triple- negative (n; 6, 19 lesions), group 1, HER2-positive (n;16, 54 lesions) and group 2, hormone-- positive group (n; 5, 9 lesions). The apparent diffusion coefficient (ADC), fractional anisotropy (FA), axial diffusivity (AD), and radial diffusivity (RD) values in DTI were measured and compared between three groups. ADC, AD and RD values of group 2 were significantly lower compared to group 0. No significant differences were found in FA, ADC, AD and RD values between the group 0 and 1 and the group 1 and 2. Metastasis of aggressive triple-negative breast cancer showed higher ADC values compared to the less aggressive hormone-positive group. Higher ADC values in brain metastases of breast cancer may indicate a poor prognosis, so DTI findings could play a role in planning appropriate treatment.

Diffusion tensor imaging of rectal carcinoma: Clinical evaluation and its correlation with histopathological findings

To determine the role of diffusion tensor imaging (DTI) metrics as biomarkers for the therapeutic effects of mesenchymal stem cells (MSCs) in acute peripheral nerve injury. Forty-four adult rats received subepineurial microinjection of MSCs (n = 22) or phosphate buffered saline (PBS, n = 22) 1 week after the sciatic nerve trunk crush injury. Sequential fat-suppressed T2-weighted imaging, T2 measurement, DTI and sciatic nerve functional assessment were performed at a 3.0 Tesla MR unit over an 8-week follow-up, with histological assessments performed at regular intervals. The sciatic nerve function index, T2 value, and DTI metrics, including fractional anisotropy (FA), axial diffusivity, radial diffusivity (RD), and mean diffusivity values of the distal stumps of crushed nerves were measured and compared between the two groups. Nerves treated with MSCs showed better functional recovery and exhibited more pronounced nerve regeneration compared with nerves treated with PBS. T2 values in nerves treated with MSCs or PBS showed a similar change pattern (P = 0.174), while FA and RD values in nerves treated with MSCs showed more rapid return (one week earlier) to baseline level than nerves treated with PBS (P = 0.045; 0.035). Nerves treated with MSCs had higher FA and lower RD values than nerves treated with PBS during the period from 2 to 3 weeks after surgery (P ≤ 0.0001, 0.004; P = 0.004, 0.006). FA and RD values derived from DTI might be used as sensitive biomarkers for detecting the therapeutic effect of stem cells in acute peripheral nerve crush injuries. 2 J. Magn. Reson. Imaging 2017;45:855-862.

Objective: To study the alteration of the optic radiations in patients with primary open-angle glaucoma (POAG) by diffusion tensor imaging (DTI) and tractography, and to reveal the correlation between the DTI derived parameters and the severity of the disease. Methods: A total of 24 patients with POAG and 20 age- and gender-matched healthy controls were enrolled in this study from January 2011 to June 2013.All subjects underwent ophthalmoscopy, standard automatic perimetry, intraocular pressure measurement and MRI scanning.All the eyes of POAG patients were evaluated by Hodapp-Anderson-Parrish (HAP) system.Then the stages of bilateral eyes were added together to evaluate the disease severity.Tractography was used to measure the fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD) and axial diffusivity (AD) of the optic radiations of these subjects.The results of the two groups were compared.Partial correlation was then used to reveal the correlation between these derived DTI parameters and the severity of POAG. Results: Compared with health controls, POAG patients showed significant decreased FA (t=-3.299, P=0.002) and AD (t=-2.485, P=0.013), increased RD (t=2.365, P=0.018) in optic radiation .The alteration of MD was not significant (t=0.719, P=0.454). Mean FA values of the optic radiations were negatively correlated with POAG stages (r=-0.643, P= 0.001), while mean RD values (r=0.570, P= 0.004) and mean MD values (r= 0.448, P= 0.028) were positively correlated with POAG stages.No correlation between AD values and severity of POAG was found. Conclusion: In the optic radiations of POAG patients, the FA values and AD values decrease, while RD values increase, indicating the fiber integrity changes.The alterations of FA, RD and MD are correlated with disease severity.

BackgroundNon-small cell lung cancer (NSCLC) is a leading cause of morbidity and mortality. Carboplatin and cisplatin based regimens are used in the treatment of NSCLC. The aim of the study was to find out whether there is a difference in white matter (WM) changes between two platinum-based chemotherapy agents using diffusion tensor imaging (DTI).Patients and methods25 patients who received chemotherapy for NSCLC and 27 age-matched healthy controls were enrolled in the study. Fractional anisotropy (FA), axial diffusivity (AD), mean diffusivity (MD) and radial diffusivity (RD) values of the study population were measured from 11 regions of interest in pre-chemotherapy and post-chemotherapy MRI data.ResultsCisplatin group showed a significant decrease in the FA of the inferior longitudinal fasciculus (P = 0.028). Carboplatin group showed a significant FA decrease and RD increase in the forceps minor (P = 0.022 and P = 0.011, respectively), and a significant reduction in AD and increase in MD in frontal white matter (WM) (P = 0.008 and P = 0.029, respectively). In comparison of post chemotherapy DTI values of the two groups, carboplatin group showed lower FA, and higher MD and RD values than cisplatin group in parieto-occipital WM (P = 0.034, P = 0.034, P = 0.029, respectively).ConclusionsThe findings of the study suggest that subtle effects of chemotherapy detectable with DTI may emerge after the treatment. In addition, carboplatin regimen may have more impact on WM than cisplatin regimen.

Purpose: Focal cortical dysplasia (FCD) is a common developmental malformation disease of the cerebral cortex. Although mounting evidence has suggested that FCD lesions have variable locations and topographies throughout the cortex, few studies have explored consistencies in structural connectivity among different lesion types. In this study, we analyzed microscopic structural changes via lesion analysis and explored structural changes in nonlesion regions across the brain. Methods: Diffusion tensor imaging (DTI) and magnetization transfer imaging were used to compare FCD lesions and contralateral normal appearing gray/white matter (cNAG/WM). Voxel-based morphometry was calculated for 28 children with FCD and 34 sex- and age-matched healthy participants. DTI indices of the FCD and healthy control groups were analyzed via the tract-based spatial statistic method to evaluate the microstructure abnormalities of WM fiber tracts in individuals with FCD. Results: In terms of FCD lesions, compared with those of the cNAG, the fractional anisotropy (FA) values were decreased, and the mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) values were increased; the magnetization transfer ratios were also decreased. In terms of whole-brain changes due to FCD, compared with the healthy control group, the FCD group showed a decrease in the volume of the right hippocampus and left anterior cingulate cortex. FCD patients had lower FA values, higher MD values, lower AD values, and mainly increased RD values in relation to WM microstructure. Conclusions: Microstructural abnormalities outside lesion regions may be related to injury to the epileptic network, and the identification of such abnormalities may complement diagnoses of FCD in pediatric patients.

To confirm the hypothesis that brain white matter damage is involved in the pathogenesis and disease progression of Langerhans cell histiocytosis (LCH)-associated neurodegenerative disease (ND), we aimed to analyze pediatric patients with LCH using diffusion tensor imaging (DTI). We enrolled 33 patients with LCH and obtained 33 DTI datasets. Using DTI-based tractography, fractional anisotropy (FA), apparent diffusion coefficient (ADC), axial diffusivity (AD), and radial diffusivity (RD) were measured in the cerebral and cerebellar white matter tracts. The participants were divided into three groups-non-ND, ND without clinical symptoms (r-ND), and ND with clinical symptoms (c-ND)-according to their clinical status during the examination with DTI. We compared the DTI parameters in white matter tracts were compared among the three groups. In the order of non-ND, r-ND, and c-ND groups, the FA in superior cerebellar peduncle (SCP) and middle cerebellar peduncle (MCP) significantly decreased, the ADC, AD, and RD of MCP, and the RD of SCP were significantly elevated (FA-SCP; p < 0.001, FA-MCP; p = 0.026, ADC-MCP; p < 0.001, AD-MCP; p = 0.002, RD-MCP; p = 0.003, and RD-SCP; p = 0.018). Furthermore, in the simple linear regression analysis, the FA, ADC, AD, and RD values in the MCP and the FA value in the SCP were significantly influenced by the presence of neurological symptoms and ND findings on MRI (all p < 0.001). In LCH-ND, we identified microstructural damage in the SCP and MCP. DTI parameters in these tracts may help monitor LCH-ND; therefore, future studies are required to validate these results in a large cohort.

Damage to cerebellar peduncles is common in patients with relapsing-remitting multiple sclerosis (RRMS). This can lead to a diverse range of motor and cognitive disabilities. Here, we aimed to evaluate the quantitative alterations of cerebellar peduncles using diffusion tensor imaging (DTI).After a comprehensive search in Web of Science, PubMed, Embase, and Scopus and a rigorous screening, eligible studies underwent data extraction and risk of bias assessment. Standardized Mean Difference (SMD) with a 95% CI was used as effect size. We compared DTI metrics in the cerebellar peduncle regions (SCP, MCP, ICP) between RRMS patients and healthy controls (HC). Sensitivity analysis employed the leave-one-out method. Contour-enhanced funnel plots and Pustejovsky test were used to evaluate the publication bias. Additionally, subgroup analysis was performed using available variables.In eleven included studies encompassing 623 RRMS patients and 416 HC, RRMS patients exhibited significantly decreased fractional anisotropy (FA) values in the SCP (SMD - 0.26) and MCP (SMD - 1.03), increased mean diffusivity (MD) values in the SCP (SMD 1.46), MCP (SMD 0.48) and ICP (SMD 0.70), elevated radial diffusivity (RD) values in the MCP (SMD 0.85) and ICP (SMD 1.20) compared to HC. The subgroup analysis revealed that individuals with elevated EDSS scores exhibited reduced FA and increased MD in the SCP region. No considerable publication bias was detected. No outliers were detected in the sensitivity analysis.DTI proves promising for identifying microstructural abnormalities in cerebellar peduncles of RRMS patients, with decreased FA and increased RD, and MD values observed.

BackgroundNew daily persistent headache (NDPH) is a rare primary headache disorder characterized by daily and persistent sudden onset headaches. The pathogenesis of NDPH remains unclear, and there are few white matter imaging studies related to NDPH. The purpose of this study was to investigate the micro-structural abnormalities of white matter in NDPH and provided insights into the pathogenesis of this disease based on tract-based spatial statistics (TBSS).MethodsTwenty-one patients with NDPH and 25 healthy controls (HCs) were included in this study. T1 structural and diffusion magnetic resonance imaging (MRI) were acquired from all participants. Differences in the fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) between patients with NDPH and HCs were investigated using TBSS analysis.ResultsSignificantly decreased FA, increased MD and RD were found in patients with NDPH compared to HCs. White matter regions overlaid with decreased FA, increased MD and RD were found in 16 white matter tracts from the Johns Hopkins University ICBM-DTI-81 White-Matter Atlas and Johns Hopkins University White-Matter Tractography Atlas. Specifically, these white matter regions included the right anterior thalamic radiation (ATR), body of the corpus callosum (BCC), bilateral cingulum, left hippocampal cingulum (CGH), left corticospinal tract (CST), forceps major, fornix, left inferior fronto-occipital fasciculus (IFOF), bilateral inferior longitudinal fasciculus (ILF), left posterior limb of the internal capsule (PLIC), right retrolenticular part of the internal capsule (RPIC), splenium of the corpus callosum (SCC), right superior longitudinal fasciculus (SLF) and left uncinate fasciculus (UF). After Bonferroni correction, there were no correlations between the FA, MD, AD and RD values and the clinical characteristics of patients with NDPH (p > 0.05/96).ConclusionThe results of our research indicated that patients with NDPH might have widespread abnormalities in the white matter of the brain.

Comparative Evaluation of Brain Tuberculosis and Metastases Using Combined Analysis of Arterial Spin Labeling Perfusion and Diffusion Tensor Imaging

ObjectiveThis study examined the association of lifetime experiences, measured by a cognitive reserve (CR) composite score composed of years of education, literacy, and vocabulary measures, to level and rate of change in white matter microstructure, as assessed by diffusion tensor imaging (DTI) measures. We also examined whether the relationship between the proxy CR composite score and white matter microstructure was modified by participant age, APOE-ε4 genetic status, and level of vascular risk.MethodsA sample of 192 non-demented (n = 166 cognitively normal, n = 26 mild cognitive impairment) older adults [mean age = 70.17 (SD = 8.5) years] from the BIOCARD study underwent longitudinal DTI (mean follow-up = 2.5 years, max = 4.7 years). White matter microstructure was quantified by fractional anisotropy (FA) and radial diffusivity (RD) values in global white matter tracts and medial temporal lobe (MTL) white matter tracts.ResultsUsing longitudinal linear mixed effect models, we found that FA decreased over time and RD increased over time in both the global and MTL DTI composites, but the rate of change in these DTI measures was not related to level of CR. However, there were significant interactions between the CR composite score and age for global RD in the full sample, and for global FA, global RD, and MTL RD among those with normal cognition. These interactions indicated that among participants with a lower baseline age, higher CR composite scores were associated with higher FA and lower RD values, while among participants with higher age at baseline, higher CR composite scores were associated with lower FA and higher RD values. Furthermore, these relationships were not modified by APOE-ε4 genotype or level of vascular risk.ConclusionThe association between level of CR and DTI measures differs by age, suggesting a possible neuroprotective effect of CR among late middle-aged adults that shifts to a compensatory effect among older adults.

The aim is to investigate whether there is a microstructural change in the white matter pathways in patients with spontaneous intracranial hypotension (SIH). Additionally, the relationship between conventional magnetic resonance imaging (MRI) findings and diffusion tensor imaging (DTI) parameters is determined. Thirty patients diagnosed with SIH and 31 control patients (between January 2019 and February 2024) were included in the case-control study. MRI findings constituting the Bern score were evaluated in contrast-enhanced brain MRI. Ten different white matter pathways were evaluated with the following DTI parameters: fractional anisotropy (FA), apparent diffusion coefficient (ADC), axial diffusion (AD), and radial diffusion (RD). We also examined the association between MRI findings and DTI parameters. In the cingulum, a decreased FA value (Z = -3.18, p = 0.002) was observed in patients with SIH, indicating disruption of white matter integrity and weakened synaptic transmission in this region. In the corona radiata, significant reductions were observed in both FA (Z = -5.67, p < 0.001) and AD (Z = -3.59, p < 0.001), alongside an increase in RD (Z = -4.99, p < 0.001). The concomitant increase in RD further supports the idea of potential damage to the myelin sheath, which, together with other findings, may reflect disruptions in white matter architecture that underlie the cognitive and motor deficits frequently seen in patients with SIH. In the splenium of the corpus callosum, a significant reduction in AD (Z = -3.00, p = 0.007) was also noted. In the anterior limb of the internal capsule (ALIC), both FA (Z = -4.57, p < 0.001) and AD (Z = -2.73, p = 0.012) values decreased, while RD increased (Z = -2.93, p = 0.007). These alterations suggest the involvement of motor and sensory pathways. In the posterior limb of the internal capsule (PLIC), significant reductions were found in both FA (Z = -5.59, p < 0.001) and AD (Z = -3.82, p < 0.001), along with an increase in RD (Z = -5.49, p < 0.001). In the corticospinal tract, patients with SIH exhibited a decrease in FA (Z = -4.15, p < 0.001), an increase in ADC (Z = -2.87, p = 0.008), and an increase in RD (Z = -3.73, p < 0.001). These findings represent significant microstructural changes reflecting a reduction in the integrity of motor pathways in white matter. In the middle cerebellar peduncle (MCP), patients with SIH showed increased ADC (Z = -4.78, p < 0.001) and RD (Z = -3.23, p = 0.002). Similarly, in optic radiation, there was decreased FA (Z = -4.55, p < 0.001) and AD (Z = -2.59, p = 0.018), with increased RD (Z = -2.95, p = 0.007). In the correlation analysis, positive correlations were found between suprasellar distance and AD values in both the ALIC (rs = 0.451, p = 0.012) and MCP (rs = 0.416, p = 0.022). These findings suggest that structural changes and anatomical shifts, especially in the suprasellar region, may be associated with microstructural changes in the adjacent white matter pathways. We revealed microstructural changes in white matter in SIH. The alterations in DTI parameters may suggest that the white matter microarchitecture is changed as a result of mechanical compression of the axons in the white matter pathways due to brain prolapse and venous congestion.

BackgroundDespite dietary intervention, individuals with early treated phenylketonuria (ETPKU) could present neurocognitive deficits and white matter (WM) abnormalities. The aim of the present study was to evaluate the microstructural integrity of WM pathways across the whole brain in a cohort of paediatric ETPKU patients compared with healthy controls (HCs), by collecting DTI-MRI (diffusion tensor magnetic resonance imaging) data and diffusion values (mean diffusivity (MD), radial diffusivity (RD) and fractional anisotropy (FA)).MethodsDTI-MRI data and diffusion values (MD, RD, FA) from WM tracts across the whole brain were analized using Tract Based Spatial Statistics (TBSS), in 15 paediatrics TPKU patients (median age: 12 years) and compared with 11 HCs. Areas showing abnormal values in the patient group were correlated (Pearson) with age, lifetime Phe values, last year median and mean Phe, concurrent Phe values in plasma, urine neurotransmitters status biomarkers, and with a processing speed task.ResultsETPKU showed bilaterally decreased MD values compared with HCs in the body and splenium of the corpus callosum, superior longitudinal fasciculus, corona radiata and in the posterior limb of the internal capsule. RD values followed a similar pattern, although decreased RD values in PKU patients were also found in the anterior limb of the internal capsule and in the cerebral peduncle. Decreased MD and RD values within the aforementioned regions had significant negative correlations with age, last year median and mean Phe and concurrent Phe values. No correlations were found with monoamines in urine or processing speed task.ConclusionsETPKU patients showed MD and RD values significantly decreased across the whole brain when compared with HCs, and this damage was associated with high Phe values and the age of patients. Despite this microstructural damage, no affectation in processing speed was observed in patients with good metabolic control. DTI-MRI sequences could be used as a technique to quantify WM damage that is difficult to be detect in T1 or T2-weighted images, but also to quantify damage of WM through the follow up of patients with poor metabolic control in prospective studies.

We evaluated white matter microstructure integrity in perinatally HIV-infected (PHIV)youths receiving cART compared to age- and gender-matched healthy youths through DTI metrics using voxel-based morphometry (VBM). We investigated 14 perinatally HIV-infected patients (age 17.9 ± 2.5years) on cART and 17 healthy youths (HC) (age 18.0 ± 3.0years) using a 3T MRI scanner. Four DTI-derived metrics were fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD). Statistical analysis was done with voxel-based analysis of covariance (ANCOVA), with age and gender as covariates. Region-of-interest secondary analyses in statistically significant regions were also performed. Regional increases in FA in the PHIV youths were found in left middle frontal gyrus, right precuneus, right lingual gyrus, and left supramarginal gyrus. Increased MD was found in the right precentral gyrus while decreased MD was found in the white matter of the right superior parietal lobule and right inferior temporal gyrus/fusiform gyrus. Regions of increased/decreased RD overlapped with regions of increased/decreased MD. Both increased and decreased AD were found in three to four regions respectively. The regional FA, MD, RD, and AD values were consistent with the voxel-based analysis findings. The findings are mostly consistent with previous literature, but increased FA has not been previously reported for perinatally HIV-infected youths. Potentially early and prolonged therapy in our population may have contributed to this new finding. Both toxicity of antiretroviral therapy and indolent infection must be considered as causative factors in the DTI metric changes that we have observed.