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Global Spine Journal Jun 2024Systematic review.
STUDY DESIGN
Systematic review.
OBJECTIVE
Degenerative cervical myelopathy (DCM) is a common spinal cord disorder necessitating surgery. We aim to explore how effectively diffusion tensor imaging (DTI) can distinguish DCM from healthy individuals and assess the relationship between DTI metrics and symptom severity.
METHODS
We included studies with adult DCM patients who had not undergone decompressive surgery and implemented correlation analyses between DTI parameters and severity, or compared healthy controls and DCM patients.
RESULTS
57 studies were included in our meta-analysis. At the maximal compression (MC) level, fractional anisotropy (FA) exhibited lower values in DCM patients, while apparent diffusion coefficient (ADC), mean diffusivity (MD), and radial diffusivity (RD) were notably higher in the DCM group. Moreover, our investigation into the diagnostic utility of DTI parameters disclosed high sensitivity, specificity, and area under the curve values for FA (.84, .80, .83 respectively) and ADC (.74, .84, .88 respectively). Additionally, we explored the correlation between DTI parameters and myelopathy severity, revealing a significant correlation of FA (.53, 95% CI:0.40 to .65) at MC level with JOA/mJOA scores.
CONCLUSION
Current guidelines for DCM suggest decompressive surgery for both mild and severe cases. However, they lack clear recommendations on which mild DCM patients might benefit from conservative treatment vs immediate surgery. ADC's role here could be pivotal, potentially differentiating between healthy individuals and DCM. While it may not correlate with symptom severity, it might predict surgical outcomes, making it a valuable imaging biomarker for clearer management decisions in mild DCM.
PubMed: 38877604
DOI: 10.1177/21925682241263792 -
Radiotherapy and Oncology : Journal of... Nov 2014After neoadjuvant radiochemotherapy (RCT) for locally advanced rectal cancer, 15-27% of the patients experience a pathological complete response (pCR). This observation... (Review)
Review
After neoadjuvant radiochemotherapy (RCT) for locally advanced rectal cancer, 15-27% of the patients experience a pathological complete response (pCR). This observation raises the question as to whether invasive surgery could be avoided in a selected cohort of patients who obtain a clinical complete response after preoperative RCT. In this respect, there has been growing interest in functional imaging techniques to improve clinical response assessment. This systematic review focuses on the role of diffusion-weighted imaging (DWI) and (18)F-fluorodeoxyglucose positron emission tomography/computed tomography ((18)F-FDG PET/CT) in the prediction of pCR after RCT for rectal cancer. A total of 14 publications on DWI and 25 on (18)F-FDG PET/CT were retrieved. Pooled analysis of individual patient data shows both imaging modalities have a low positive predictive value in the prediction of pCR (mean PPV of 54% and 39% for DWI- and (18)F-FDG PET/CT-based parameters respectively). Especially pre-RCT imaging is unable to predict pCR with overall accuracies of 68-72% for DWI and 44% for (18)F-FDG PET/CT. Qualitative DWI assessment 5-10weeks after the end of RCT may outperform apparent diffusion coefficient (ADC)-based DWI-parameters (overall accuracy of 87% vs. 74-78%). Although few data are available, early changes in FDG-uptake seem promising in the prediction of pCR and the role of (18)F-FDG PET/CT during RCT should be further investigated. Quantitative and qualitative (18)F-FDG PET/CT measurements are equally effective in the assessment of pCR after RCT. The major strength of DWI and (18)F-FDG PET/CT lies in the identification of non-responders who are not candidates for organ preservation. Up to now, DWI and (18)F-FDG PET/CT are not accurate enough to safely select patients for organ-sparing strategies. Future research must focus on the integration of functional imaging with clinical data and molecular biomarkers.
Topics: Chemoradiotherapy; Diffusion Magnetic Resonance Imaging; Fluorodeoxyglucose F18; Humans; Neoplasm Staging; Positron-Emission Tomography; Radiopharmaceuticals; Rectal Neoplasms; Tomography, X-Ray Computed; Treatment Outcome
PubMed: 25483833
DOI: 10.1016/j.radonc.2014.11.026 -
The British Journal of Radiology Jul 2021We undertook a systematic review and meta-analysis of the diagnostic performance of mean apparent diffusion coefficient (ADC) values derived by diffusion-weighted... (Meta-Analysis)
Meta-Analysis
OBJECTIVES
We undertook a systematic review and meta-analysis of the diagnostic performance of mean apparent diffusion coefficient (ADC) values derived by diffusion-weighted (DW)-MRI in the characterization of solid benign and malignant liver lesions, and to assess their value in discriminating these lesions in daily routine practice.
METHODS
A systematic review of PubMed, Embase, Scopus, and Web of Science was conducted to retrieve studies that used ADC values for differentiating solid benign/dysplastic nodules and malignant liver lesions. A bivariate random-effects model with pooled sensitivity and specificity values with 95% CI (confidence interval) was used. This meta-analysis was performed on the per-lesion basis. Summary receiver operating characteristic (SROC) plot and area under curve (AUC) were created.
RESULTS
A total of 14 original articles were retrieved. The combined (95% CI) sensitivity and specificity of mean ADC values for differentiating solid benign from malignant lesions were 78% (67-86%) and 74% (64-81%), respectively. The pooled (95% CI) positive and negative LRs were respectively 3 (2.3-3.8) and 0.3 (0.21-0.43). The DOR (95% CI) was 10 (7-15). The AUC (95% CI) of the SROC plot was 82% (78-85%). Reporting bias was negligible ( value of regression test = 0.36). Mean size of malignant lesions and breathing pattern of MRI were found to be sources of heterogeneity of pooled sensitivity.
CONCLUSION
ADC measurement independently may not be an optimal diagnostic imaging method for differentiating solid malignant from solid benign hepatic lesions. The meta-analysis showed that ADC measurement had moderate diagnostic accuracy for characterizing solid liver lesions. Further prospective and comparative studies with pre-specified ADC thresholds could be performed to investigate the best MRI protocol and ADC threshold for characterizing solid liver lesions.
ADVANCES IN KNOWLEDGE
ADC measurement by DW-MRI does not have a good diagnostic performance to differentiate solid malignant from solid benign lesions. Therefore, we suggest not using ADC values in clinical practice to evaluate solid liver lesions.
Topics: Diagnosis, Differential; Diffusion Magnetic Resonance Imaging; Humans; Liver Neoplasms; Sensitivity and Specificity
PubMed: 34111960
DOI: 10.1259/bjr.20210059 -
NeuroImage. Clinical 2022Attention deficit hyperactivity disorder (ADHD) is a common neurodevelopmental disorder. Advances in diffusion magnetic resonance imaging (MRI) acquisition sequences and... (Review)
Review
Attention deficit hyperactivity disorder (ADHD) is a common neurodevelopmental disorder. Advances in diffusion magnetic resonance imaging (MRI) acquisition sequences and analytic techniques have led to growing body of evidence that abnormal white matter microstructure is a core pathophysiological feature of ADHD. This systematic review provides a qualitative assessment of research investigating microstructural organisation of white matter amongst children and adolescents with ADHD. This review included 46 studies in total, encompassing multiple diffusion MRI imaging techniques and analytic approaches, including whole-brain, region of interest and connectomic analyses. Whole-brain and region of interest analyses described atypical organisation of white matter microstructure in several white matter tracts: most notably in frontostriatal tracts, corpus callosum, superior longitudinal fasciculus, cingulum bundle, thalamic radiations, internal capsule and corona radiata. Connectomic analyses, including graph theory approaches, demonstrated global underconnectivity in connections between functionally specialised networks. Although some studies reported significant correlations between atypical white matter microstructure and ADHD symptoms or other behavioural measures there was no clear pattern of results. Interestingly however, many of the findings of disrupted white matter microstructure were in neural networks associated with key neuropsychological functions that are atypical in ADHD. Limitations to the extant research are outlined in this review and future studies in this area should carefully consider factors such as sample size, sex balance, head motion and medication status.
Topics: Adolescent; Attention Deficit Disorder with Hyperactivity; Brain; Child; Diffusion Magnetic Resonance Imaging; Diffusion Tensor Imaging; Humans; White Matter
PubMed: 35149304
DOI: 10.1016/j.nicl.2022.102957 -
Frontiers in Neuroscience 2023White matter disconnection is the primary cause of cognition and affection abnormality in mild cognitive impairment (MCI). Adequate understanding of behavioral... (Review)
Review
Characterization of diffusion magnetic resonance imaging revealing relationships between white matter disconnection and behavioral disturbances in mild cognitive impairment: a systematic review.
White matter disconnection is the primary cause of cognition and affection abnormality in mild cognitive impairment (MCI). Adequate understanding of behavioral disturbances, such as cognition and affection abnormality in MCI, can help to intervene and slow down the progression of Alzheimer's disease (AD) promptly. Diffusion MRI is a non-invasive and effective technique for studying white matter microstructure. This review searched the relevant papers published from 2010 to 2022. Sixty-nine studies using diffusion MRI for white matter disconnections associated with behavioral disturbances in MCI were screened. Fibers connected to the hippocampus and temporal lobe were associated with cognition decline in MCI. Fibers connected to the thalamus were associated with both cognition and affection abnormality. This review summarized the correspondence between white matter disconnections and behavioral disturbances such as cognition and affection, which provides a theoretical basis for the future diagnosis and treatment of AD.
PubMed: 37360170
DOI: 10.3389/fnins.2023.1209378 -
PloS One 2022The purpose of this study was to examine the values of fractional anisotropy (FA) and apparent diffusion coefficient (ADC) in diffusion tensor imaging (DTI) for... (Meta-Analysis)
Meta-Analysis
PURPOSE
The purpose of this study was to examine the values of fractional anisotropy (FA) and apparent diffusion coefficient (ADC) in diffusion tensor imaging (DTI) for diagnosing patients with nerve impairment due to lumbar disc herniation (LDH).
METHODS
A literature search of databases (PubMed, Web of Science, Cochrane Library and Embase) was systematically performed to identify articles published before September 2021 that were relevant to this study. FA and ADC estimates of compressed nerve roots due to LDH and healthy controls in the same segment were compared, with either fixed or random effects models selected according to I2 heterogeneity. Additionally, subgroup analysis, sensitivity analysis, potential publication bias analysis and meta-regression analysis were also performed.
RESULTS
A total of 369 patients with LDH from 11 publications were included in this meta-analysis. The results showed significantly lower FA values (Weighted Mean Difference (WMD): -0.08, 95% confidence interval (CI): -0.09 to -0.07, P ≤ 0.001, I2 = 87.6%) and significantly higher ADC values (WMD: 0.25, 95% CI: 0.20 to 0.30, P ≤ 0.001, I2 = 71.4%) of the nerve on the compressed side due to LDH compared to the healthy side. Subgroup analysis indicated that different countries and magnetic field strengths may be associated with higher heterogeneity. Furthermore, meta-regression analysis further revealed that segment and field strength did not have a significant effect on the results, regardless of the FA or ADC values. Contrastingly, in FA, the year of publication, country, b value and directions showed an effect on the results.
CONCLUSIONS
This meta-analysis showed a significant decrease in FA and a significant increase in ADC in patients with nerve damage due to LDH. The results favourably support the presence of nerve impairment in patients with LDH.
Topics: Humans; Diffusion Tensor Imaging; Intervertebral Disc Displacement; Lumbar Vertebrae; Spinal Nerve Roots; Diffusion Magnetic Resonance Imaging; Anisotropy
PubMed: 36574380
DOI: 10.1371/journal.pone.0279499 -
Frontiers in Neuroscience 2019This paper presents a systematic review of diffusion MRI (dMRI) and tractography of cranial nerves within the posterior fossa. We assess the effectiveness of the...
This paper presents a systematic review of diffusion MRI (dMRI) and tractography of cranial nerves within the posterior fossa. We assess the effectiveness of the diffusion imaging methods used and examine their clinical applications. The Pubmed, Web of Science and EMBASE databases were searched from January 1st 1997 to December 11th 2017 to identify relevant publications. Any study reporting the use of diffusion imaging and/or tractography in patients with confirmed cranial nerve pathology was eligible for selection. Study quality was assessed using the Methodological Index for Non-Randomized Studies (MINORS) tool. We included 41 studies comprising 16 studies of patients with trigeminal neuralgia (TN), 22 studies of patients with a posterior fossa tumor and three studies of patients with other pathologies. Most acquisition protocols used single-shot echo planar imaging (88%) with a single b-value of 1,000 s/mm (78%) but there was significant variation in the number of gradient directions, in-plane resolution, and slice thickness between studies. dMRI of the trigeminal nerve generated interpretable data in all cases. Analysis of diffusivity measurements found significantly lower fractional anisotropy (FA) values within the root entry zone of nerves affected by TN and FA values were significantly lower in patients with multiple sclerosis. Diffusivity values within the trigeminal nerve correlate with the effectiveness of surgical treatment and there is some evidence that pre-operative measurements may be predictive of treatment outcome. Fiber tractography was performed in 30 studies (73%). Most studies evaluating fiber tractography involved patients with a vestibular schwannoma (82%) and focused on generating tractography of the facial nerve to assist with surgical planning. Deterministic tractography using diffusion tensor imaging was performed in 93% of cases but the reported success rate and accuracy of generating fiber tracts from the acquired diffusion data varied considerably. dMRI has the potential to inform our understanding of the microstructural changes that occur within the cranial nerves in various pathologies. Cranial nerve tractography is a promising technique but new avenues of using dMRI should be explored to optimize and improve its reliability.
PubMed: 30809109
DOI: 10.3389/fnins.2019.00023 -
Annals of Translational Medicine Apr 2022Under the background that diffusion kurtosis imaging (DKI) has become a research hotspot of central nervous system diseases, there are no studies with large sample size...
BACKGROUND
Under the background that diffusion kurtosis imaging (DKI) has become a research hotspot of central nervous system diseases, there are no studies with large sample size evaluating the value of DKI in diagnosing Parkinson's disease (PD). Moreover, the diagnostic efficacy of DKI in PD is not consistent. Therefore, the main purpose of this study is to use the method of meta-analysis, to summarize and evaluate the diagnostic efficacy of DKI in the identification of PD, and to explore the value of its clinical application.
METHODS
We use PICOS principles for project design. The included patients were PD patients, and the control group were healthy volunteers. We hope to use DKI to make a differential diagnosis between the two, and this study is a diagnostic test. We performed a literature search of English (PubMed, Embase, Cochrane Library, etc.) and Chinese (China knowledge Network, Wanfang Data Knowledge Service platform, China Science and Technology Journal Database, China Biomedical Literature Service system) databases for related literatures on the efficacy of DKI in the differential diagnosis of PD published before March 29, 2022. We used Revman 5.3 software to assess the quality of the literature, Meta-Disc 1.4 software for summarizing sensitivity (Sen), specificity (Spe), diagnostic odds ratios, and heterogeneity tests, and for subgrouping, and Stata 16.0 software for publication bias analysis.
RESULTS
Fourteen articles were included through the literature search. The 14 studies included 535 patients with PD and 486 patients without PD. Most of the included literature had good clinical applicability and relatively low risk. By merging statistics, the results obtained were as follows: Sen =0.78 [95% confidence interval (CI): 0.74-0.81], Spe =0.83 (95% CI: 0.79-0.86), and the area under the summary receiver operating characteristic (SROC) curve was 0.8870.
DISCUSSION
The results of the meta-analysis showed that magnetic resonance DKI has comparable diagnostic accuracy in the diagnosis of PD. However, this study also has limitations, and the use of different diagnostic gold standards in the included studies may have some impact on the case selection in the study.
PubMed: 35571428
DOI: 10.21037/atm-22-1461 -
Frontiers in Oncology 2019The purpose of the present meta-analysis was to provide evident data about use of apparent diffusion coefficient (ADC) values for distinguishing malignant and benign...
The purpose of the present meta-analysis was to provide evident data about use of apparent diffusion coefficient (ADC) values for distinguishing malignant and benign lesions in the head and neck region. MEDLINE and Scopus databases were screened for associations between ADC and malignancy/benignancy of head and neck lesions up to December 2018. Overall, 22 studies met the inclusion criteria. The following data were extracted: authors, year of publication, study design, number of patients/lesions, lesion type, mean value, and standard deviation of ADC. The primary endpoint of the systematic review was the analysis of the association between lesion nature and ADC values. The methodological quality of the involved studies was checked according to the Quality Assessment of Diagnostic Accuracy Studies (QUADAS) instrument. The meta-analysis was undertaken by using RevMan 5.3 software. DerSimonian and Laird random-effects models with inverse-variance weights were used without further correction to account for the heterogeneity between the studies. Mean ADC values including 95% confidence intervals were calculated separately for benign and malignant lesions. The acquired 22 studies comprised 1,227 lesions. Different malignant lesions were diagnosed in 818 cases (66.7%) and benign lesions in 409 cases (33.3%). The mean ADC value of the malignant lesions was 1.04 × 10 mm/s, and the mean value of the benign lesions was 1.46 × 10 mm/s. Lymphomas and sarcomas showed the lowest calculated mean ADC values, 0.7 and 0.79 × 10 mm/s, respectively. Adenoid cystic carcinomas had the highest ADC values (1.5 × 10 mm/s). None of the analyzed malignant tumors had mean ADC values above 1.75 × 10 mm/s. ADC values play a limited role in distinguishing between malignant and benign lesions in the head and neck region. It may be only suggested that lesions with mean ADC values above 1.75 × 10 mm/s are probably benign. Further large studies are needed for the analysis of the role of diffusion-weighted imaging (DWI)/ADC in the discrimination of benign and malignant lesions in the head and neck region.
PubMed: 31970081
DOI: 10.3389/fonc.2019.01362 -
European Review For Medical and... Nov 2017Dry mouth (xerostomia), is a fairly common, well-researched condition, which is an indirect cause of oral malodour. This systematic literature review looked into another... (Review)
Review
Dry mouth (xerostomia), is a fairly common, well-researched condition, which is an indirect cause of oral malodour. This systematic literature review looked into another cause of bad breath: adverse drug reactions in the orofacial region causing halitosis. The study focused on extraoral halitosis, and its subdivisions, particularly blood borne halitosis in which malodourous compounds in the blood stream are carried to the lungs, passively diffused across the pulmonary alveolar membrane to enter the breath. An electronic search was conducted in various databases. Inclusion criteria were: editorials, case control studies, retrospective studies and randomized double-blind studies published in English between 1983 and March 2017. The search identified a total of 23 articles. According to these, drug-related halitosis may be caused by nine medications. Dimethyl sulfoxide, cysteamine and suplatast tosilate are metabolised to dimethyl sulfide, a malodourous compound that is stable in blood and is transported into the breath. Disulfiram is reduced to carbon disulfide, also a stable compound in blood. Nitric oxide reacts with foul-smelling volatile organosulfur compounds. The degradation of penicillamine raises the pH level, favouring the growth of gram-negative bacteria in the oral cavity producing halitosis. Chloral hydrate, phenothiazine, and paraldehyde could not be related to halitosis. The analysis showed that halitosis can be caused by medication but does not correlate to any specific disease or specific form of drug therapy. The pharmacological compounds identified as causes of halitosis are administered to treat a broad spectrum of diseases, or in therapeutic regimes.
Topics: Gram-Negative Bacteria; Halitosis; Humans; Hydrogen Sulfide; Penicillamine; Smell; Sulfhydryl Compounds; Sulfides
PubMed: 29164566
DOI: No ID Found