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41 result(s) for "Nihashi, Takashi"
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Prevalence of incidental findings requiring interventions in CT for trauma patients in the emergency department: a systematic review and meta-analysis
ObjectiveTo systematically review and meta-analyse the prevalence of incidental findings (IFs) requiring interventions identified in CT performed for patients with traumatic injuries in the emergency department, including pathologically confirmed cancers and emergent non-traumatic vascular pathologies.DesignSystematic review and meta-analysis.Data sourcesPubMed, EMBASE and Cochrane CENTRAL databases from database inception to 22 November 2024.Eligibility criteria for selecting studiesProspective or retrospective studies involving traumatic injury patients presented at the emergency department reporting IFs of clinical significance detected through CT with any interventions proposed were included. Studies that exclusively included paediatric populations were excluded. The systematic review methods included double-screening, dual assessment of eligibility and study validity, dual data extraction, Bayesian multivariate random-effects meta-analysis of prevalence and employing the Grading of Recommendations, Assessment, Development and Evaluations’ rating for the certainty of evidence. The primary outcomes were IFs requiring any interventions, and subset IFs requiring urgent interventions. Secondary outcomes were histologically confirmed cancers and emergent non-traumatic vascular pathologies.Results22 studies (1 with a prospective and 21 with a retrospective design) mainly from high-income countries using limited-quality data based on clinical practice involving 18 538 patients were included. 9 studies evaluated the whole body, while 13 evaluated selective body regions. The grading criteria for IFs were non-uniform, and the image interpreters involved had diverse experience and expertise. The summary prevalence estimates for IFs requiring any interventions, urgent interventions, pathologically confirmed cancers and emergent non-traumatic vascular pathologies detected in the whole body were 29.8% (95% credible interval (CrI) 20.4% to 42.9%; very low certainty), 7.6% (95% CrI 4.5% to 14.8%; low certainty), 0.6% (95% CrI 0.3% to 1.6%; moderate certainty) and 0.3% (95% CrI 0.1% to 0.9%; moderate certainty), respectively. These findings were largely identified in the chest or abdomen and pelvis, with the overall detection frequency reduced with the scanned body regions narrowed (very low to moderate certainty). Sparse data on the head, neck and spine resulted in limited results.ConclusionsIFs identified in trauma whole-body CT requiring intervention are prevalent and can lead to substantial medical costs. The widely reported prevalence range suggests variations in radiologist recommendations and reporting in clinical practice and calls for standardisations. IFs requiring urgent intervention are not rare, which leads to a diagnosis of significant diseases including cancers and urgent vascular pathologies. Future studies should report long-term, patient-relevant results based on standardised classification and reporting systems.PROSPERO registration numberCRD42020187852.
Diagnostic accuracy of DAT-SPECT and MIBG scintigraphy for dementia with Lewy bodies: an updated systematic review and Bayesian latent class model meta-analysis
PurposeImperfect clinical reference standards can preclude accurately estimating the diagnostic accuracy of DAT-SPECT and MIBG myocardial scintigraphy for diagnosing DLB. To investigate the validity of unadjusted accuracy, we updated our previous meta-analysis.MethodsLiterature search was updated to March 18, 2018. We also examined published systematic review reports. Two investigators extracted data and rated study validity using the QUADAS-2 tool. We performed a Bayesian latent class model meta-analysis accounting for imperfect reference standards.ResultsWe evaluated 27 studies including 2236 patients. With the exception of two DAT-SPECT studies that involved postmortem neuropathological verification, studies were susceptible to bias from imperfect reference standards. Compared with the unadjusted accuracy estimates, the adjusted sensitivity values were similar, whereas the adjusted specificity values were generally lower for detecting α-synuclein pathology in the brain. The adjusted summary sensitivity and specificity were 0.86 (95% credible interval [CrI], 0.76–0.95) and 0.81 (CrI, 0.70–0.92), and 0.93 (CrI, 0.74–1.00) and 0.75 (CI, 0.47–0.94) for visual and semi-quantitative assessments of DAT-SPECT, respectively; 0.92 (CrI, 0.81–0.99) and 0.80 (CrI, 0.67–0.93), and 0.87 (CrI, 0.74–0.98) and 0.80 (CrI, 0.69–0.93), for delayed- and early-phase scans of MIBG scintigraphy, respectively. When diagnosing the typical clinical syndrome, the adjusted accuracy values were similar to the unadjusted estimates. The adjusted sensitivity and specificity were 0.89 (CrI, 0.75–0.98) and 0.87 (CrI, 0.72–0.97), and 0.97 (CrI, 0.78–1.0) and 0.70 (CrI, 0.43–0.92) for visual and semi-quantitative assessments of DAT-SPECT, respectively; and 0.93 (CrI, 0.81–0.98) and 0.90 (CrI, 0.73–0.97), and 0.85 (CrI, 0.66–0.96) and 0.96 (95% CI, 0.83–1.0) for delayed- and early-phase scans of MIBG scintigraphy, respectively.ConclusionsIn our adjusted analyses, both imaging biomarkers had high diagnostic accuracy for detecting the hallmark pathology in the brain and for diagnosing the typical clinical syndrome.
Interrater agreement and variability in visual reading of 18F flutemetamol PET images
Objective The purpose of this study was to validate the concordance of visual ratings of [18F] flutemetamol amyloid positron emission tomography (PET) images and to investigate the correlation between the agreement of each rater and the Centiloid (CL) scale. Methods A total of 192 participants, clinically classified as cognitively normal (CN) ( n  = 59), mild cognitive impairment (MCI) ( n  = 65), Alzheimer’s disease (AD) ( n  = 55), or non-AD dementia ( n  = 13), participated in this study. Three experts conducted visual ratings of the amyloid PET images for all 192 patients, assigning a confidence level to each rating on a three-point scale (certain, probable, or neither). The positive or negative determination of amyloid PET results was made by majority vote. The CL value was calculated using the CapAIBL pipeline. Results Overall, 101 images were determined to be positive, and 91 images were negative. Of the 101 positive images, the three raters were in complete agreement for 92 images and in disagreement for 9 images. Of the 91 negative images, the three raters were in complete agreement for 75 images and in disagreement for 16 images. Interrater reliability among the three experts was particularly high, with both Fleiss’ kappa and Conger’s kappa measuring 0.83 (0.76–0.89). The CL values of the unanimous positive group were significantly greater than those of the other groups, whereas the CL values of the unanimous negative group were significantly lower than those of the other groups. Images with rater disagreement had intermediate CLs. In cases with a high confidence level, the positive or negative visual ratings were in almost complete agreement. However, as confidence levels decreased, experts’ visual ratings became more variable. The lower the confidence level was, the greater the number of cases with disagreement in the visual ratings. Conclusion Three experts independently rated 192 amyloid PET images, achieving a high level of interrater agreement. However, in patients with intermediate amyloid accumulation, visual ratings varied. Therefore, determining positive and negative decisions in these patients should be performed with caution.
Comparison of consistency in centiloid scale among different analytical methods in amyloid PET: the CapAIBL, VIZCalc, and Amyquant methods
Objective The Centiloid (CL) scale is a standardized measure for quantifying amyloid deposition in amyloid positron emission tomography (PET) imaging. We aimed to assess the agreement among 3 CL calculation methods: CapAIBL, VIZCalc, and Amyquant. Methods This study included 192 participants (mean age: 71.5 years, range: 50–87 years), comprising 55 with Alzheimer’s disease, 65 with mild cognitive impairment, 13 with non-Alzheimer's dementia, and 59 cognitively normal participants. All the participants were assessed using the three CL calculation methods. Spearman’s rank correlation, linear regression, Friedman tests, Wilcoxon signed-rank tests, and Bland–Altman analysis were employed to assess data correlations, linear associations, method differences, and systematic bias, respectively. Results Strong correlations (rho = 0.99, p  < .001) were observed among the CL values calculated using the three methods. Scatter plots and regression lines visually confirmed these strong correlations and met the validation criteria. Despite the robust correlations, a significant difference in CL value between CapAIBL and Amyquant was observed (36.1 ± 39.7 vs. 34.9 ± 39.4; p  < .001). In contrast, no significant differences were found between CapAIBL and VIZCalc or between VIZCalc and Amyquant. The Bland–Altman analysis showed no observable systematic bias between the methods. Conclusions The study demonstrated strong agreement among the three methods for calculating CL values. Despite minor variations in the absolute values of the Centiloid scores obtained using these methods, the overall agreement suggests that they are interchangeable.
Age-related increase of monoamine oxidase B in amyloid-negative cognitively unimpaired elderly subjects
ObjectiveMonoamine oxidase B (MAO-B) is highly abundant in reactive astrocytes and upregulated in neuroinflammatory processes. However, the age-related change of MAO-B in amyloid-negative cognitively unimpaired elderly subjects has not yet been sufficiently evaluated on positron emission tomography (PET). 18F-THK5351 is a radiotracer with high affinity to MAO-B, which may potentially serve as an imaging biomarker for detecting neuroinflammation. The purpose of this study was to investigate the age-related topographic change of 18F-THK5351 PET in amyloid-negative cognitively unimpaired elderly subjects.MethodsThe age-related change of 18F-THK5351 retention was evaluated on the visual analysis, voxel and region of interest (ROI)-based analyses using Statistical Parametric Mapping and PETSurfer tool of FreeSurfer in 31 amyloid-negative cognitively unimpaired elderly subjects.ResultsOn visual inspection, elderly groups showed the spread of 18F-THK5351 accumulation from the medial to inferolateral temporal and basal frontal lobes, and cingulate gyrus. Additionally, voxel- and ROI-based analysis demonstrated the correlation between 18F-THK5351 accumulation and participants’ age, especially in the inferior temporal lobes.ConclusionsThis study demonstrated age-dependent increase of 18F-THK5351 retention in amyloid-negative cognitively unimpaired subjects, which suggests an increase in MAO-B positive reactive astrocytes with aging.
Monitoring of fatigue in radiologists during prolonged image interpretation using fNIRS
PurposeTo determine whether functional near-infrared spectroscopy (fNIRS) allows monitoring fatigue in radiologists during prolonged image interpretation.Materials and methodsNine radiologists participated as subjects in the present study and continuously interpreted medical images and generated reports for cases for more than 4 h under real clinical work conditions. We measured changes in oxygenated hemoglobin concentrations [oxy-Hb] in the prefrontal cortex using 16-channel fNIRS (OEG16ME, Spectratech) every hour during the Stroop task to evaluate fatigue of radiologists and recorded fatigue scale (FS) as a behavior data.ResultsTwo subjects showed a subjective feeling of fatigue and an apparent decrease in brain activity after 4 h, so the experiment was completed in 4 h. The remaining seven subjects continued the experiment up to 5 h. FS decreased with time, and a significant reduction was observed between before and the end of image interpretation. Seven out of nine subjects showed a minimum [oxy-Hb] change at the end of prolonged image interpretation. The mean change of [oxy-Hb] at the end of all nine subjects was significantly less than the maximum during image interpretation.ConclusionfNIRS using the change of [oxy-Hb] may be useful for monitoring fatigue in radiologists during image interpretation.
Blood levels of glial fibrillary acidic protein for predicting clinical progression to Alzheimer’s disease in adults without dementia: a systematic review and meta-analysis protocol
Background There is urgent clinical need to identify reliable prognostic biomarkers that predict the progression of dementia symptoms in individuals with early-phase Alzheimer’s disease (AD) especially given the research on and predicted applications of amyloid-beta (Aβ)-directed immunotherapies to remove Aβ from the brain. Cross-sectional studies have reported higher levels of cerebrospinal fluid and blood glial fibrillary acidic protein (GFAP) in individuals with AD-associated dementia than in cognitively unimpaired individuals. Further, recent longitudinal studies have assessed the prognostic potential of baseline blood GFAP levels as a predictor of future cognitive decline in cognitively unimpaired individuals and in those with mild cognitive impairment (MCI) due to AD. In this systematic review and meta-analysis, we propose analyzing longitudinal studies on blood GFAP levels to predict future cognitive decline. Methods This study will include prospective and retrospective cohort studies that assessed blood GFAP levels as a prognostic factor and any prediction models that incorporated blood GFAP levels in cognitively unimpaired individuals or those with MCI. The primary outcome will be conversion to MCI or AD in cognitively unimpaired individuals or conversion to AD in individuals with MCI. Articles from PubMed and Embase will be extracted up to December 31, 2023, without language restrictions. An independent dual screening of abstracts and potentially eligible full-text reports will be conducted. Data will be dual-extracted using the CHeck list for critical appraisal, data extraction for systematic Reviews of prediction Modeling Studies (CHARMS)-prognostic factor, and CHARMS checklists, and we will dual-rate the risk of bias and applicability using the Quality In Prognosis Studies and Prediction Study Risk-of-Bias Assessment tools. We will qualitatively synthesize the study data, participants, index biomarkers, predictive model characteristics, and clinical outcomes. If appropriate, random-effects meta-analyses will be performed to obtain summary estimates. Finally, we will assess the body of evidence using the Grading of Recommendation, Assessment, Development, and Evaluation Approach. Discussion This systematic review and meta-analysis will comprehensively evaluate and synthesize existing evidence on blood GFAP levels for prognosticating presymptomatic individuals and those with MCI to help advance risk-stratified treatment strategies for early-phase AD. Trial registration PROSPERO CRD42023481200.
Smoking results in accumulation of ectopic fat in the liver
An association between smoking and nonalcoholic fatty liver disease has been reported. However, objective quantification of intrahepatic fat via magnetic resonance spectroscopy (MRS) in relation to smoking has rarely been performed in previous studies. Moreover, the possible pathways via which smoking could induce ectopic fat accumulation have not yet been addressed. The current study aimed to examine the association between smoking status and intrahepatic fat quantity and explore the possible mediating effects of triglycerides (TG) and adiponectin. Magnetic resonance imager (MRI) spectra were analyzed to quantify intrahepatic fat in 45 men who were on average 62.3 years of age. Smoking status and alcohol intake were self-reported. Accelerometers were used to record daily total physical activity. Fasting blood TG and adiponectin levels were measured enzymatically. Differences in mean intrahepatic fat values according to smoking status were assessed using analysis of covariance. A stepwise increase in mean intrahepatic fat was observed between never, former, and current smokers, respectively, independent of age, physical activity, alcohol intake, and body mass index (BMI) ( =0.005). Adjustment for TG and adiponectin significantly attenuated this association ( =0.074). Current smoking was significantly associated with increased intrahepatic fat, which may be a result of adipocyte dysfunction, manifested as high circulating TG concentrations and low adiponectin levels.
MRI and FDG-PET for Assessment of Response to Neoadjuvant Chemotherapy in Locally Advanced Rectal Cancer
Background The purpose of this study was to assess the value of magnetic resonance imaging (MRI) and additional 18 F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) for tumor response to neoadjuvant chemotherapy (NAC) in patients with locally advanced rectal cancer (LARC). Methods Data on 40 patients with LARC, who were treated with NAC and underwent MRI and FDG-PET/CT before and after NAC, were analyzed retrospectively. Surgery was performed at a median of 6 weeks after NAC and the images were compared with the histological findings. The tumor regression grade 3/4 was classified as a responder. Results Sixteen patients were pathological responders. Receiver operating characteristic (ROC) analysis revealed that MRI total volume after NAC (MRI-TV2) and ΔMRI-TV had the highest performance to assess responders (area under the ROC curve [AUC] 0.849 and AUC 0.853, respectively). The reduction rate of the maximum standardized uptake value (ΔSUVmax) was also an informative factor (AUC 0.719). There seems no added value of adding FDG-PET/CT to MRI-TV2 and ΔMRI-TV in assessment of NAC responders judging from changes in AUC (AUC of ΔSUVmax and MRI-TV2 was 0.844, and AUC of ΔSUVmax and ΔMRI-TV was 0.846). Conclusions MRI-TV2 and ΔMRI-TV were the most accurate factors to assess pathological response to NAC. Although ΔSUVmax by itself was also informative, the addition of FDG-PET/CT to MRI did not improve performance. Patients with LARC who were treated by induction chemotherapy should receive an MRI examination before and after NAC to assess treatment response. A more than 70 % volume reduction shown by MRI volumetry may justify the omission of subsequent radiotherapy.
Positron emission tomography (PET) for prediction of glioma histology: protocol for an individual-level data meta-analysis of test performance
IntroductionGliomas, the most commonly diagnosed primary brain tumours, are associated with varied survivals based, in part, on their histological subtype. Therefore, accurate pretreatment tumour grading is essential for patient care and clinical trial design.Methods and analysisWe will perform an individual-level data meta-analysis of published studies to evaluate the ability of different types of positron emission tomography (PET) to differentiate high from low-grade gliomas. We will search PubMed and Scopus from inception through 30 July 2017 with no language restriction and full-text evaluation of potentially relevant articles. We will choose studies that assess PET using 18-Fludeoxyglucose (18F-FDG), l-[Methyl-()11C]Methionine (11C-MET), 18F-Fluoro-Ethyl-Tyrosine (18F-FET) or (18)F-Fluorothymidine (18F-FLT)for grading, verified with histological confirmation. We will include both prospective and retrospective studies. Bias will be assessed by two reviewers with the Quality Assessment of Diagnostic Accuracy Studies-2 tool and as per method described by Deeks et al.Ethics and disseminationEthics approval was not applicable, as this is a meta-analytic study. Results of the analysis will be submitted for publication in a peer-reviewed journal.PROSPERO registration number CRD42017078649.