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Journal of Clinical Medicine Jun 2021Schizophrenia is a severe and disabling mental illness whose etiology still remains unclear. The available literature indicates that there exist white matter (WM)... (Review)
Review
Schizophrenia is a severe and disabling mental illness whose etiology still remains unclear. The available literature indicates that there exist white matter (WM) abnormalities in people with schizophrenia spectrum disorders. Recent developments in modern neuroimaging methods have enabled the identification of the structure, morphology, and function of the underlying WM fibers in vivo. The purpose of this paper is to review the existing evidence about WM abnormalities in individuals at ultra-high risk of psychosis (UHR) with the use of diffusion tensor imaging (DTI) available from the National Center for Biotechnology Information PubMed (Medline) and Health Source: Nursing/Academic Edition databases. Of 358 relevant articles identified, 25 papers published in the years 2008-2020 were ultimately included in the review. Most of them supported the presence of subtle aberrations in WM in UHR individuals, especially in the superior longitudinal fasciculus (SLF), the inferior longitudinal fasciculus (ILF), and the inferior fronto-occipital fasciculus (IFOF). These alterations may therefore be considered a promising neurobiological marker for the risk of psychosis. However, due to methodological discrepancies and the relative scarcity of evidence, further investigation is called for, especially into connectome analysis in UHR patients.
PubMed: 34204171
DOI: 10.3390/jcm10112515 -
Neurotoxicology May 2023Carbon monoxide poisoning (COP) can lead to various cerebral white matter (WM) lesions across different disease phases and clinical manifestations, and fractional... (Meta-Analysis)
Meta-Analysis
Carbon monoxide poisoning (COP) can lead to various cerebral white matter (WM) lesions across different disease phases and clinical manifestations, and fractional anisotropy (FA) of diffusion tensor imaging has been widely applied to investigate WM injury in these patients. Here we conducted a systematic review and meta-analysis to investigate the utility of FA in evaluating the regional vulnerability of WM injury caused by COP and explore differences between different disease phases and patient subtypes. We systematically searched PubMed, Medline, Scopus and reference lists of appropriate publications to identify relevant studies. Eight studies with 217 patients with COP and 207 healthy controls (HCs) were included. Eight regions of interest were available to investigate regional vulnerability. The results showed the most significant decrease in FA in orbitofrontal subcortical regions. Comparisons of different disease phases revealed lower FA in the centrum semiovale and corpus callosum in the acute phase, while in the chronic phase, only FA in the centrum semiovale remained significantly decreased. Analysis of different patient subtypes showed that the FA values in the splenium of the corpus callosum were significantly decreased in the patients with delayed neurologic sequelae (DNS) but not in the mixed population (with and without DNS). In conclusion, this meta-analysis highlights the frontal-subcortical regional vulnerability in COP. FA changes in the corpus callosum across different disease phases reflect alterations in underlying microstructures. Extended corpus callosum injury involving the splenium could be an imaging biomarker of the occurrence of DNS.
Topics: Humans; White Matter; Diffusion Tensor Imaging; Anisotropy; Carbon Monoxide Poisoning; Clinical Relevance
PubMed: 37060949
DOI: 10.1016/j.neuro.2023.04.005 -
The International Journal of Eating... Nov 2019Anorexia nervosa (AN) is characterized by white matter abnormalities in neuroimaging studies. Fractional anisotropy (FA) is a diffusion tensor imaging (DTI) index that... (Meta-Analysis)
Meta-Analysis
Anorexia nervosa and diffusion weighted imaging: An open methodological question raised by a systematic review and a fractional anisotropy anatomical likelihood estimation meta-analysis.
BACKGROUND
Anorexia nervosa (AN) is characterized by white matter abnormalities in neuroimaging studies. Fractional anisotropy (FA) is a diffusion tensor imaging (DTI) index that is considered an instrument for the evaluation of white matter alterations. However, the literature has recently pointed out the role of the partial volume effect (PVE) as a confounding factor for the identification of juxtaposed tissues. Our goal was to review the DTI literature in AN and evaluate possible confounding factors linked to the reported results.
METHOD
A systematic review of the literature was conducted to identify Diffusion Tensor Imaging studies of individuals with AN and, subsequently, an anatomical likelihood estimation (ALE) meta-analysis was performed on studies published before March 18, 2019.
RESULTS
Twenty-four studies (AN = 517, controls = 542) were included in the qualitative systematic review of the literature. Ten published studies underwent the ALE-analysis (AN = 210, controls = 229), plus data from an unpublished cohort (AN = 38, controls = 38). Two clusters of decreased FA were identified, namely in the left corona radiata, and in the left thalamus. Only one article took the PVE correction analysis into account.
CONCLUSIONS
The alterations identified must be considered within the limits of a possible methodological bias regarding PVE and free water and re-analysis of the data may be recommended. The preliminary data showed that the alteration of white matter pathways between the limbic structures and brain cortex may be linked to the processing of somatosensory information that could play a key role in the psychopathology of the disorder.
Topics: Anisotropy; Anorexia Nervosa; Diffusion Magnetic Resonance Imaging; Diffusion Tensor Imaging; Humans
PubMed: 31518016
DOI: 10.1002/eat.23160 -
The Indian Journal of Radiology &... Oct 2023High-grade gliomas (HGGs) are the most prevalent primary malignancy of the central nervous system. The tumor results in vasogenic and infiltrative edema . Exact... (Review)
Review
High-grade gliomas (HGGs) are the most prevalent primary malignancy of the central nervous system. The tumor results in vasogenic and infiltrative edema . Exact anatomical differentiation of these edemas is so important for surgical planning. Multimodal imaging could be used to differentiate the edema type. The aim of this study was to investigate the role of multimodal imaging in the differentiation of vasogenic edema from infiltrative edema in patients with HGG (grade III and grade IV). A search on PubMed, EMBASE, Scopus, and ISI Web of Science Core Collection up to June 2022 using terms related to (a) multimodal imaging AND (b) HGG AND (c) edema. (PROSPERO registration number: CRD42022336131) Two reviewers screened the articles and independently extracted the data. We included original articles assessing the role of multimodal imaging in differentiating vasogenic from infiltrative edema in patients with HGG. Six high-quality articles remained for the narrative synthesis. Dynamic susceptibility contrast imaging showed that relative cerebral blood volume and relative cerebral blood flow were higher in the infiltrative edema component than in the vasogenic edema component. Diffusion tensor imaging revealed a dispute on fractional anisotropy. The apparent diffusion coefficient was comparable between the two edematous components. Magnetic resonance spectroscopy exhibited an increment in choline/creatinine ratio and choline/N-acetyl aspartate ratio in the infiltrative edema component. Strict study selection, low sample size of relevant published studies, and heterogeneity in endpoint variables were the major drawbacks. Multimodal imaging, including dynamic susceptibility contrast and magnetic resonance spectroscopy, might help differentiate between vasogenic and infiltrative edema.
PubMed: 37811185
DOI: 10.1055/s-0043-1772466 -
Psychiatry Research. Neuroimaging Jun 2024A substantial portion of schizophrenia spectrum disorder (SSD) patients exhibit resistance to antipsychotic treatments, emphasizing the need for reliable treatment... (Review)
Review
A substantial portion of schizophrenia spectrum disorder (SSD) patients exhibit resistance to antipsychotic treatments, emphasizing the need for reliable treatment response biomarkers. Previous magnetic resonance imaging (MRI) studies have identified various imaging predictors in SSD. This study focuses on evaluating the effectiveness of diffusion MRI sequences, diffusion tensor imaging (DTI) and diffusion-weighted imaging (DWI), in predicting antipsychotic response in SSD patients. A systematic search for relevant articles was conducted in PubMed, Embase, Scopus, and Web of Science on February 11, 2024. Twelve studies involving a total of 742 patients were systematically reviewed. The baseline DTI/DWI biomarkers revealed significant associations with antipsychotic treatment response. Notably a consistent negative link was found between response and baseline fractional anisotropy (FA) in fronto-temporo-limbic white matter tracts, specifically the superior longitudinal fasciculus, providing moderate-level evidence. In addition, weak-level evidence was found for the negative association between the treatment response and baseline FA in the corpus callosum, internal, and external capsule tracts. Collectively, this review demonstrated that obtaining pre-treatment brain diffusion MRI scans, particularly from white matter tracts of fronto-temporo-limbic network, can assist in delineating the treatment response trajectory in patients with SSD. However, additional larger randomized controlled trials are required to further substantiate these findings.
PubMed: 38870842
DOI: 10.1016/j.pscychresns.2024.111841 -
Cancer Radiotherapie : Journal de La... Feb 2021Nasopharyngeal carcinoma (NPC) radiotherapy (RT) irradiates parts of the brain which may cause cerebral tissue changes. This study aimed to systematically review the...
PURPOSE
Nasopharyngeal carcinoma (NPC) radiotherapy (RT) irradiates parts of the brain which may cause cerebral tissue changes. This study aimed to systematically review the brain microstructure changes using MRI-based measures, diffusion tensor imaging (DTI), diffusion kurtosis imaging (DKI) and voxel-based morphometry (VBM) and the impact of dose and latency following RT.
METHODS
PubMed and Scopus databases were searched based on PRISMA guideline to determine studies focusing on changes following NPC RT.
RESULTS
Eleven studies fulfilled the inclusion criteria. Microstructural changes occur most consistently in the temporal region. The changes were correlated with latency in seven studies; fractional anisotropy (FA) and gray matter (GM) volume remained low even after a longer period following RT and areas beyond irradiation site with reduced FA and GM measures. For dosage, only one study showed correlation, thus requiring further investigations.
CONCLUSION
DTI, DKI and VBM may be used as a surveillance tool in detecting brain microstructural changes of NPC patients which correlates to latency and brain areas following RT.
Topics: Brain; Diffusion Tensor Imaging; Humans; Magnetic Resonance Imaging; Nasopharyngeal Carcinoma; Nasopharyngeal Neoplasms; Temporal Lobe
PubMed: 33414057
DOI: 10.1016/j.canrad.2020.07.008 -
Journal of Neurotrauma Oct 2019Competitive sport participation, in contact and collision sports, exposes athletes to repetitive head impacts. Although these impacts do not always result in overt...
Competitive sport participation, in contact and collision sports, exposes athletes to repetitive head impacts. Although these impacts do not always result in overt symptomology or a diagnosed "concussion," evidence indicates that cumulative repetitive impacts affect brain pathophysiology. The purpose of this study was to perform a systematic review of prospective, longitudinal trials evaluating repetitive head impact exposure on white matter (WM) microstructure in collision and contact sport athletes to inform clinical care and treatment strategies. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed to determine studies that met predetermined inclusion and exclusion criteria. Initially, 2498 abstracts were identified, and 20 studies were critically evaluated herein. The majority of studies demonstrated significant longitudinal changes in anisotropy and/or diffusivity metrics that were associated with the quantity and/or the magnitude of head impact exposure, highlighting the utility of diffusion tensor imaging (DTI) for measuring changes in WM microstructure. Our review also comments on study methodology and describes how age, sex, sport, and time between sport cessation and DTI measures contribute to divergent findings within the literature. Suggestions for future research are also provided to overcome previous study limitations and maximize our understanding of the role of repetitive head impact exposure on WM integrity and long-term neurological sequela.
Topics: Athletes; Athletic Injuries; Brain Concussion; Diffusion Tensor Imaging; Female; Humans; Male; Prospective Studies
PubMed: 31062655
DOI: 10.1089/neu.2019.6398 -
European Spine Journal : Official... Jan 2024Cervical Spondylotic Myelopathy (CSM) is a degenerative condition that leads to loss of cervical spinal cord (CSC) integrity. Various spinal cord Magnetic Resonance... (Review)
Review
PURPOSE
Cervical Spondylotic Myelopathy (CSM) is a degenerative condition that leads to loss of cervical spinal cord (CSC) integrity. Various spinal cord Magnetic Resonance Imaging (MRI) methods can identify and characterize the extent of this damage. This systematic review aimed to evaluate the diagnostic, biomarker, and predictive utilities of different spinal cord MRI methods in clinical research studies of CSM. The aim was to provide a comprehensive understanding of the progress in this direction for future studies and effective diagnosis and management of CSM.
METHODS
A comprehensive literature search was conducted on PubMed and EMBASE from 2010 to 2022 according to PRISMA guidelines. Studies with non-human subjects, less than 3T magnetic field strength, non-clinical design, or not quantitatively focusing on the structural integrity of CSC were excluded. The extracted data from each study included demographics, disease severity, MRI machine characteristics, quantitative metrics, and key findings in terms of diagnostic, biomarker, and predictive utilities of each MRI method. The risk of bias was performed using the guide from AHRQ. The quality of evidence was assessed separately for each type of utility for different MRI methods using GRADE.
RESULTS
Forty-seven studies met the inclusion criteria, utilizing diffusion-weighted imaging (DTI) (n = 39), magnetization transfer (MT) (n = 6), MR spectroscopy (n = 3), and myelin water imaging (n = 1), as well as a combination of MRI methods (n = 12). The metric fractional anisotropy (FA) showed the highest potential in all facets of utilities, followed by mean diffusivity. Other promising metrics included MT ratio and intracellular volume fraction, especially in multimodal studies. However, the level of evidence for these promising metrics was low due to a small number of studies. Some studies, mainly DTI, also reported the usefulness of spinal cord MRI in mild CSM.
CONCLUSIONS
Spinal cord MRI methods can potentially facilitate the diagnosis and management of CSM by quantitatively interrogating the structural integrity of CSC. DTI is the most promising MRI method, and other techniques have also shown promise, especially in multimodal configurations. However, this field is in its early stages, and more studies are needed to establish the usefulness of spinal cord MRI in CSM.
Topics: Humans; Diffusion Tensor Imaging; Spinal Cord Diseases; Spinal Cord; Magnetic Resonance Imaging; Cervical Vertebrae; Biomarkers; Spondylosis
PubMed: 37926719
DOI: 10.1007/s00586-023-07990-0 -
European Journal of Sport Science Jan 2023Hypertrophic cardiomyopathy (HCM) is a common cause of sudden cardiac death in athletes. Cardiac Magnetic Resonance (CMR) imaging is considered an excellent tool to...
Hypertrophic cardiomyopathy (HCM) is a common cause of sudden cardiac death in athletes. Cardiac Magnetic Resonance (CMR) imaging is considered an excellent tool to differentiate between HCM and athlete's heart. The aim of this systematic review was to highlight the novel CMR-derived parameters with significant discriminative capacity between the two conditions. A systematic search in the MEDLINE, EMBASE and Cochrane Reviews databases was performed. Eligible studies were considered the ones comparing novel CMR-derived parameters on athletes and HCM patients. Therefore, studies that only examined Cine-derived volumetric parameters were excluded. Particular attention was given to binary classification results from multi-variate regression models and ROC curve analyses. Bias assessment was performed with the Quality Assessment on Diagnostic Accuracy Studies. Five (5) studies were included in the systematic review, with a total of 284 athletes and 373 HCM patients. Several novel indices displayed discriminatory potential, such as native T1 mapping and T2 values, LV global longitudinal strain, late gadolinium enhancement and whole-LV fractal dimension. Diffusion tensor imaging enabled quantification of the secondary eigenvalue angle and fractional anisotropy in one study, which also proved capable of reliably detecting HCM in a mixed athlete/patient sample. Several novel CMR-derived parameters, most of which are currently under development, show promising results in discerning between athlete's heart and HCM. Prospective studies examining the discriminatory capacity of all promising modalities side-by-side will yield definitive answers on their relative importance; diagnostic models can incorporate the best performing variables for optimal results.
Topics: Humans; Cardiomegaly, Exercise-Induced; Contrast Media; Diffusion Tensor Imaging; Prospective Studies; Gadolinium; Cardiomyopathy, Hypertrophic; Magnetic Resonance Imaging
PubMed: 34720041
DOI: 10.1080/17461391.2021.2001576 -
Journal of Magnetic Resonance Imaging :... Jan 2024Lumbosacral radicular pain diagnosis remains challenging. Diffusion tensor imaging (DTI) and diffusion weighted imaging (DWI) have potential to quantitatively evaluate...
BACKGROUND
Lumbosacral radicular pain diagnosis remains challenging. Diffusion tensor imaging (DTI) and diffusion weighted imaging (DWI) have potential to quantitatively evaluate symptomatic nerve root, which may facilitate diagnosis.
PURPOSE
To determine the ability of DTI and DWI metrics, namely fractional anisotropy (FA) and apparent diffusion coefficient (ADC), to discriminate between healthy and symptomatic lumbosacral nerve roots, to evaluate the association between FA and ADC values and patient symptoms, and to determine FA and ADC reliability.
STUDY TYPE
Systematic review.
SUBJECTS
Eight hundred twelve patients with radicular pain with or without radiculopathy caused by musculoskeletal-related compression or inflammation of a single, unilateral lumbosacral nerve root and 244 healthy controls from 29 studies.
FIELD STRENGTH/SEQUENCE
Diffusion weighted echo planar imaging sequence at 1.5 T or 3 T.
ASSESSMENT
An extensive systematic review of the literature was conducted in Embase, Scopus, and Medline databases. FA and ADC values in symptomatic and contralateral lumbosacral nerve roots were extracted and summarized, together with intra- and inter-rater agreements. Where available, associations between DWI or DTI parameters and patient symptoms or symptom duration were extracted.
STATISTICAL TESTS
The main results of the included studies are summarized. No additional statistical analyses were performed.
RESULTS
The DTI studies systematically found significant differences in FA values between the symptomatic and contralateral lumbosacral nerve root of patients suffering from radicular pain with or without radiculopathy. In contrast, identification of the symptomatic nerve root with ADC values was inconsistent for both DTI and DWI studies. FA values were moderately to strongly correlated with several symptoms (eg, disability, nerve dysfunction, and symptom duration). The inter- and intra-rater reliability of DTI parameters were moderate to excellent. The methodological quality of included studies was very heterogeneous.
DATA CONCLUSION
This systematic review showed that DTI was a reliable and discriminative imaging technique for the assessment of symptomatic lumbosacral nerve root, which more consistently identified the symptomatic nerve root than DWI. Further studies of high quality are needed to confirm these results.
EVIDENCE LEVEL
N/A TECHNICAL EFFICACY: Stage 2.
PubMed: 38190195
DOI: 10.1002/jmri.29213