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Journal of Neuroimaging : Official... Sep 2016Abnormalities in apparent diffusion coefficient (ADC), fractional anisotropy (FA), and mean diffusivity (MD) values can be used to assess microstructural damage to white... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND & PURPOSE
Abnormalities in apparent diffusion coefficient (ADC), fractional anisotropy (FA), and mean diffusivity (MD) values can be used to assess microstructural damage to white matter tracts and could represent a quantitative marker of chronic ischemia and thereby potentially serve as a stroke risk factor or a measure of existing subclinical ischemic disease burden. We performed a systematic review and 3 separate meta-analyses to evaluate the association between unilateral carotid steno-occlusion and ipsilateral ADC, FA, or MD abnormality.
MATERIALS & METHODS
A comprehensive literature search evaluating the association of carotid disease and quantitative white matter diffusion imaging was performed. The included studies examined patients for ADC, FA, and MD values ipsilateral and contralateral to the site of carotid artery disease. Three meta-analyses using standardized mean differences with assessment of study heterogeneity were performed.
RESULTS
Of the 2,920 manuscripts screened, 6 met eligibility for meta-analysis. Of the included manuscripts, 2 studied ADC values, 6 studied FA values, and 2 studied MD values. Our 3 meta-analyses showed standardized mean difference for ADC, FA, and MD values between cerebral hemispheres ipsilateral and contralateral to carotid artery disease site as 1.13 (95% CI: .79-1.47, P < .001), -.42 (95% CI: -.62 to -.21, P < .001), and .23 (95% CI: -.32 to -.77, P = .41), respectively. Measures of heterogeneity showed mild heterogeneity in the 3 meta-analyses.
CONCLUSION
Carotid artery disease is associated with significant ADC and FA value changes, suggesting that carotid disease is associated with quantifiable white matter microstructural damage.
Topics: Anisotropy; Brain Ischemia; Carotid Stenosis; Chronic Disease; Diffusion Magnetic Resonance Imaging; Humans; Risk Factors; Stroke; White Matter
PubMed: 27079165
DOI: 10.1111/jon.12347 -
Autoimmunity Reviews Jan 2018Diffusion tensor imaging (DTI) maps the brain's microstructure by measuring fractional anisotropy (FA) and mean diffusivity (MD). This systematic review describes brain... (Review)
Review
Diffusion tensor imaging (DTI) maps the brain's microstructure by measuring fractional anisotropy (FA) and mean diffusivity (MD). This systematic review describes brain diffusion tensor Magnetic resonance imaging (MRI) studies in systemic lupus erythematosus (SLE).The literature was reviewed following the PRISMA guidelines and using the terms "lupus", "systemic lupus erythematosus", "SLE", "diffusion tensor imaging", "DTI", "white matter" (WM), "microstructural damage", "tractography", and "fractional anisotropy"; the search included articles published in English from January 2007 to April 2017. The subjects included in the study were selected according to the ACR criteria and included 195 SLE patients with neuropsychiatric manifestation (NPSLE), 299 without neuropsychiatric manifestation (non-NPSLE), and 423 healthy controls (HC). Most studies identified significantly reduced FA and increased MD values in several WM regions of both NPSLE and non-NPSLE patients compared to HC. Subclinical microstructural changes were observed in either regional areas or the entire brain in both the non-NPSLE and NPSLE groups.
Topics: Adult; Brain; Diffusion Tensor Imaging; Female; Humans; Lupus Erythematosus, Systemic; Magnetic Resonance Imaging; Male
PubMed: 29108821
DOI: 10.1016/j.autrev.2017.11.008 -
Frontiers in Neurology 2020Diffusion tensor imaging (DTI) allows measuring fractional anisotropy and similar microstructural indices of the brain white matter. Lower than normal fractional... (Review)
Review
Diffusion tensor imaging (DTI) allows measuring fractional anisotropy and similar microstructural indices of the brain white matter. Lower than normal fractional anisotropy as well as higher than normal diffusivity is associated with loss of microstructural integrity and neurodegeneration. Previous DTI studies in Parkinson's disease (PD) have demonstrated abnormal fractional anisotropy in multiple white matter regions, particularly in the dopaminergic nuclei and dopaminergic pathways. However, DTI is not considered a diagnostic marker for the earliest Parkinson's disease since anisotropic alterations present a temporally divergent pattern during the earliest Parkinson's course. This article reviews a majority of clinically employed DTI studies in PD, and it aims to prove the utilities of DTI as a marker of diagnosing PD, correlating clinical symptomatology, tracking disease progression, and treatment effects. To address the challenge of DTI being a diagnostic marker for early PD, this article also provides a comparison of the results from a longitudinal, early stage, multicenter clinical cohort of Parkinson's research with previous publications. This review provides evidences of DTI as a promising marker for monitoring PD progression and classifying atypical PD types, and it also interprets the possible pathophysiologic processes under the complex pattern of fractional anisotropic changes in the first few years of PD. Recent technical advantages, limitations, and further research strategies of clinical DTI in PD are additionally discussed.
PubMed: 33101169
DOI: 10.3389/fneur.2020.531993 -
Memory (Hove, England) Jan 2023Inaccurate memory reports can have serious consequences within forensic and clinical settings, where emotion and misinformation are two common sources of memory... (Review)
Review
Inaccurate memory reports can have serious consequences within forensic and clinical settings, where emotion and misinformation are two common sources of memory distortion. Many studies have investigated how these factors are related; does emotion protect memory or leave it more vulnerable to the distorting effects of misinformation? The findings remain diffused. Thus, the present review aimed to clarify the relationship between emotion and susceptibility to misinformation. 39 eligible studies were reviewed. Results varied according to the type and dimension of emotion measured. Level of arousal may be unrelated to susceptibility to misinformation when retrieval occurs without delay; studies including delayed retrieval were limited. Stimuli valence may be associated with increased susceptibility to peripheral misinformation but unrelated to other misinformation. The following results were reported by limited studies: short-term distress and moderate levels of stress may decrease susceptibility, while anger and greater cortisol response to stress may increase susceptibility to misinformation. Source memory may also be unaffected by emotion. The results have important potential implications for forensic and clinical practice, for example by highlighting the value of enquiring witnesses' source memory. Methodological recommendations for future studies are made.
Topics: Humans; Emotions; Communication; Memory Disorders; Arousal; Health Status; Mental Recall
PubMed: 36093958
DOI: 10.1080/09658211.2022.2120623 -
Clinical Otolaryngology : Official... Jun 2017Diagnosis and management of recurrent or residual cholesteatoma can be problematic. Diffusion-weighted imaging magnetic resonance imaging (MRI) sequences have been used... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Diagnosis and management of recurrent or residual cholesteatoma can be problematic. Diffusion-weighted imaging magnetic resonance imaging (MRI) sequences have been used for follow-up of such lesions. More recent non-echoplanar imaging (non-EPI) sequences are thought to be superior to older echoplanar imaging (EPI) sequences.
OBJECTIVE OF REVIEW
Evaluate whether diffusion-weighted magnetic resonance imaging is useful in the diagnosis of recurrent or residual cholesteatoma.
TYPE OF REVIEW
Systematic review and meta-analysis.
SEARCH STRATEGY
MEDLINE, EMBASE, CINAHL, Web of Science and the Cochrane Database were searched, with no limits on date or language.
STUDY SELECTION
Adults or children who had previously undergone tympanomastoid surgery by any method with confirmation of recurrence/residual disease by second-look/revision surgery.
EVALUATION METHODS
Two reviewers independently reviewed studies. Data extracted on 11 domains and rechecked.
DATA SYNTHESIS
Statistical analysis with SPSS.
RESULTS
A total of 575 studies were identified of which 27 met the inclusion criteria. These covered 727 patient episodes. For EPI studies: sensitivity (sd) 71.82 (24.5), specificity (sd) 89.36 (13.4), PPV (sd) 93.36 (8.1) and NPV (sd) 73.36 (15.8). For non-EPI studies: sensitivity 89.79 (12.1), specificity (sd) 94.57 (5.8), PPV (sd) 96.50 (4.2) and NPV 80.46 (20.2). Improved sensitivity of non-EPI sequences reached significance (P = 0.02).
CONCLUSIONS
Diffusion-weighted MRI is both sensitive and specific for the detection of recurrent or residual cholesteatoma following ear surgery. Non-EPI techniques are superior to EPI techniques.
Topics: Cholesteatoma, Middle Ear; Diffusion Magnetic Resonance Imaging; Humans; Otologic Surgical Procedures; Recurrence
PubMed: 27701821
DOI: 10.1111/coa.12762 -
Abdominal Radiology (New York) Feb 2017A meta-analysis was performed to assess the diagnostic performance of diffusion-weighted imaging (DWI) in liver fibrosis (LF) staging. (Meta-Analysis)
Meta-Analysis Review
PURPOSE
A meta-analysis was performed to assess the diagnostic performance of diffusion-weighted imaging (DWI) in liver fibrosis (LF) staging.
METHODS
We conducted a comprehensive literature search to identify relevant articles. Diagnostic data were extracted for each METAVIR fibrosis stage (F0-F4). A bivariate binomial model was used to combine sensitivities and specificities. Summary receiver operating characteristics (SROC) curves were performed and areas under SROC curve (AUC) were calculated to indicate diagnostic accuracies. Subgroup analyses were performed between different study characteristics.
RESULTS
Twelve studies met the inclusion criteria for LF ≥F1, 16 for ≥F2, 18 for ≥F3, and 12 for F4. AUCs of DWI were 0.8554, 0.8770, 0.8836, and 0.8596 for ≥F1, ≥F2, ≥F3, and F4, respectively. Subgroup analyses showed that for LF ≥F2 and ≥F3, maximal b values (b ) ≥ 800 s/mm performed significantly better than b < 800 s/mm. The diagnostic accuracies of 3.0 T and intravoxel incoherent motion (IVIM)-DWI were significantly higher than those of 1.5 T and conventional DWI for diagnosing liver cirrhosis (F4).
CONCLUSIONS
DWI is a reliable noninvasive technique with good diagnostic accuracy for LF staging. Using b ≥ 800 s/mm, high-field strength (3.0 T) and IVIM-DWI can optimize the diagnostic performance of DWI.
Topics: Diffusion Magnetic Resonance Imaging; Humans; Liver Cirrhosis
PubMed: 27678393
DOI: 10.1007/s00261-016-0913-6 -
European Journal of Radiology Jun 2023The evaluation of response to chemotherapy and targeted therapies in colorectal liver metastases has traditionally been based on size changes, as per the RECIST... (Meta-Analysis)
Meta-Analysis Review
The evaluation of response to chemotherapy and targeted therapies in colorectal liver metastases has traditionally been based on size changes, as per the RECIST criteria. However, therapy may alter tissue composition and not only tumor size, therefore, functional imaging techniques such as diffusion-weighted magnetic resonance imaging (DWI) may offer a more comprehensive assessment of treatment response. The aim of this systematic review and meta-analysis was to evaluate the use of DWI in the prediction and assessment of response to treatment in colorectal liver metastases and to determine if there is a baseline apparent diffusion coefficient (ADC) cut-off value that can predict a favorable response. A literature search was conducted using the MEDLINE/PubMed database, and risk of bias was evaluated using the QUADAS-2 tool. The mean differences between responders and non-responders were pooled. A total of 16 studies met the inclusion criteria, and various diffusion-derived techniques and coefficients were found to have potential for predicting and assessing treatment response. However, discrepancies were noted between studies. The most consistent predictor of response was a lower baseline ADC value calculated using traditional mono-exponential methods. Non-mono-exponential techniques for calculating DWI-derived parameters were also reported. A meta-analysis of a subset of studies failed to establish a cut-off value of ADC due to heterogeneity, but revealed a pooled mean difference of -0.12 × 10 mm/s between responders and non-responders. The results of this systematic review suggest that diffusion-derived techniques and coefficients may contribute to the evaluation and prediction of treatment response in colorectal liver metastases. Further controlled prospective studies are needed to confirm these findings and to guide clinical and radiological decision-making in the management of patients with CRC liver metastases.
Topics: Humans; Colorectal Neoplasms; Diffusion Magnetic Resonance Imaging; Liver Neoplasms; Embolization, Therapeutic; Prospective Studies; Treatment Outcome
PubMed: 37075628
DOI: 10.1016/j.ejrad.2023.110810 -
Developmental Medicine and Child... Feb 2014Preterm birth is associated with an increased risk of adverse neurodevelopmental outcomes. Diffusion magnetic resonance imaging (dMRI) combined with tractography can be... (Review)
Review
AIM
Preterm birth is associated with an increased risk of adverse neurodevelopmental outcomes. Diffusion magnetic resonance imaging (dMRI) combined with tractography can be used to assess non-invasively white matter microstructure and brain development in preterm infants. Our aim was to conduct a systematic review of the current evidence obtained from tractography studies of preterm infants in whom MRI was performed up to term-equivalent age.
METHOD
Databases were searched for dMRI tractography studies of preterm infants.
RESULTS
Twenty-two studies were assessed. The most frequently assessed tracts included the corticospinal tract, the corpus callosum, and the optic radiations. The superior longitudinal fasciculus, and the anterior and superior thalamic radiations were investigated less frequently. A clear relationship exists between diffusion metrics and postmenstrual age at the time of scanning, although the evidence of an effect of gestational age at birth and white matter injury is conflicting. Sex and laterality may play an important role in the relationship between diffusion metrics, early clinical assessment, and outcomes.
INTERPRETATION
Studies involving infants of all gestational ages are required to elucidate the relationship between gestational age and diffusion metrics, and to establish the utility of tractography as a predictive tool. There is a need for more robust acquisition and analysis methods to improve the accuracy of assessing development of white matter pathways.
Topics: Brain; Brain Damage, Chronic; Developmental Disabilities; Diffusion Magnetic Resonance Imaging; Dominance, Cerebral; Gestational Age; Humans; Image Enhancement; Image Interpretation, Computer-Assisted; Infant, Newborn; Infant, Premature, Diseases; Neurologic Examination; Prognosis; Risk Factors; Sex Factors
PubMed: 24102176
DOI: 10.1111/dmcn.12250 -
Reproductive Toxicology (Elmsford, N.Y.) Jan 2012It is clear that cocaine and cocaine metabolites are present in the placenta and may harm the fetus. The results of the experimental manipulation of cocaine exposure are... (Review)
Review
It is clear that cocaine and cocaine metabolites are present in the placenta and may harm the fetus. The results of the experimental manipulation of cocaine exposure are not reported in the literature in a consistent manner. We conducted a systematic review of selected articles that demonstrated the analytical detection of cocaine and its metabolites in the placenta and that were published from January 1, 1956-June 30, 2011 using Medline, Toxline and Scopus databases. The collected data confirm that the placenta does not act as a barrier to fetal exposure, that cocaine quickly crosses the placenta and that one of the essential roles of the placenta is to metabolize cocaine during pregnancy. Our systematic review summarized the results showing that cocaine, benzoylecgonine and norcocaine are stored in the myometrium and the placental membrane and maintain continuous drug delivery to the amniotic fluid (and to the fetus) probably via diffusion.
Topics: Amniotic Fluid; Animals; Biological Assay; Biotransformation; Central Nervous System Stimulants; Cocaine; Cocaine-Related Disorders; Diffusion; Female; Fetal Blood; Humans; Maternal-Fetal Exchange; Myometrium; Placenta; Placental Circulation; Pregnancy; Pregnancy Complications
PubMed: 22094170
DOI: 10.1016/j.reprotox.2011.10.012 -
Applied Bionics and Biomechanics 2022Magnetic resonance imaging (MRI) has a high sensitivity for differentiating between malignant and non-malignant breast lesions but is sometimes limited due to its low... (Review)
Review
PURPOSE
Magnetic resonance imaging (MRI) has a high sensitivity for differentiating between malignant and non-malignant breast lesions but is sometimes limited due to its low specificity. Here, we performed a meta-analysis to evaluate the diagnostic performance of mean kurtosis (MK) and mean diffusivity (MD) values in magnetic resonance diffusion kurtosis imaging (DKI) for benign and malignant breast lesions.
METHODS
Original articles on relevant topics, published from 2010 to 2019, in PubMed, EMBASE, and WanFang databases were systematically reviewed. According to the purpose of the study and the characteristics of DKI reported, the diagnostic performances of MK and MD were evaluated, and meta-regression was conducted to explore the source of heterogeneity.
RESULTS
Fourteen studies involving 1,099 (451 benign and 648 malignant) lesions were analyzed. The pooled sensitivity, pooled specificity, positive likelihood ratio, and negative likelihood ratio for MD were 0.84 (95% confidence interval (CI), 0.81-0.87), 0.83 (95% CI, 0.79-0.86), 4.44 (95% CI, 3.54-5.57), and 0.18 (95% CI, 0.13-0.26), while those for MK were 0.89 (95% CI, 0.86-0.91), 0.86 (95% CI, 0.82-0.89), 5.72 (95% CI, 4.26-7.69), and 0.13 (95% CI, 0.09-0.19), respectively. The overall area under the curve (AUC) was 0.91 for MD and 0.95 for MK.
CONCLUSIONS
Analysis of the data from 14 studies showed that MK had a higher pooled sensitivity, pooled specificity, and diagnostic performance for differentiating between breast lesions, compared with MD.
PubMed: 35721236
DOI: 10.1155/2022/2042736