Objectives
To evaluate the imaging features of isocitrate dehydrogenase (IDH) mutant glioma and to assess the diagnostic performance of magnetic resonance imaging (MRI) for prediction of IDH mutation ...in patients with glioma.
Methods
A systematic search of Ovid-MEDLINE and EMBASE up to 10 October 2017 was conducted to find relevant studies. The search terms combined synonyms for ‘glioma’, ‘IDH mutation’ and ‘MRI’. Studies evaluating the imaging features of IDH mutant glioma and the diagnostic performance of MRI for prediction of IDH mutation in patients with glioma were selected. The pooled summary estimates of sensitivity and specificity and their 95% confidence intervals (CIs) were calculated using a bivariate random-effects model. The results of multiple subgroup analyses are reported.
Results
Twenty-eight original articles in a total of 2,146 patients with glioma were included. IDH mutant glioma showed frontal lobe predominance, less contrast enhancement, well-defined border, high apparent diffusion coefficient (ADC) value and low relative cerebral blood volume (rCBV) value. For the meta-analysis that included 18 original articles, the summary sensitivity was 86% (95% CI, 79%–91%) and the summary specificity was 87% (95% CI, 78–92%). In a subgroup analysis, the summary sensitivity of 2-hydroxyglutarate magnetic resonance spectroscopy (MRS) 96% (95% CI, 91–100%) was higher than the summary sensitivities of other imaging modalities.
Conclusions
IDH mutant glioma consistently demonstrated less aggressive imaging features than IDH wild-type glioma. Despite the variety of different MRI techniques used, MRI showed the potential to non-invasively predict IDH mutation in patients with glioma. 2-Hydroxyglutarate MRS shows higher pooled sensitivity than other imaging modalities.
Key Points
• IDH mutant glioma showed frontal lobe predominance, less contrast enhancement, well-defined border, high ADC value, and low rCBV value.
• The diagnostic performance of MRI for prediction of IDH mutation in patients with glioma is within a clinically acceptable range, the summary sensitivity was 86% (95% CI, 79–91%) and the summary specificity was 87% (95% CI, 78–92%).
• In a subgroup analysis, the summary sensitivity of 2-hydroxyglutarate MRS 96% (95% CI, 91–100%) was higher than the summary sensitivities of other imaging modalities.
Porcine parvoviruses (PPVs) are small, nonenveloped DNA viruses that are widespread in the global pig population. PPV type 1 (PPV1) is a major causative agent of reproductive failure and has been ...recognized since the 1960s. In recent decades, novel PPVs have been identified and designated as PPVs 2 through 7 (PPV2~PPV7). Although the epidemiological impacts of these newly recognized parvoviruses on pigs are largely unknown, continuous surveillance of these PPVs is needed. The aim of this study was to develop an improved and efficient detection tool for these PPVs and to assess the developed method with field samples. Using 7 sets of newly designed primers, a multiplex polymerase chain reaction (mPCR) protocol was developed for the simultaneous detection of the seven genotypes of PPV (PPV1~PPV7). The sensitivity of the mPCR assay was analyzed, and the detection limit was determined to be 3×103 viral copies. The assay was highly specific in detecting one or more of the viruses in various combinations in specimens. The mPCR method was evaluated with 80 serum samples, 40 lung or lymph node samples and 40 intestine or fecal samples. When applied to these samples, the mPCR method could detect the 7 viruses simultaneously, providing rapid results regarding infection and coinfection status. In conclusion, the developed mPCR assay can be utilized as an effective and accurate diagnostic tool for rapid differential detection and epidemiological surveillance of various PPVs in numerous types of field samples.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
This paper proposes the design process of a 2.62-kW 150-krpm high-speed surface-mounted permanent-magnet synchronous motor. To meet the required specifications, the numbers of poles and slots were ...determined by considering the maximum speed and the rotary stability affected by the vibration of the rotor. In addition, this paper describes not only the appropriate material selection method but also the appropriate geometry design method based on analytic approaches. Furthermore, to precisely evaluate the bearing and windage losses at a high speed, a method that combines the finite-element method and the experiment results of the prototype was used. As a result, an improved motor was designed, which had higher maximum power and speed than the prototype and a lower mass moment of inertia. Finally, tests were conducted to verify the validity of the proposed design process and the effectiveness of the motor.
Objectives
To investigate whether clinical condition, imaging session, and locations affect repeatability of amide proton transfer–weighted (APTw) magnetic resonance imaging (MRI) in the brain.
...Materials and methods
Three APTw MRI data sets were acquired, involving two intrasession scans and one intersession scan for 19 healthy, 15 glioma, and 12 acute stroke adult participants (mean age 53.8, 54.6, and 68.5, respectively) on a 3T MR scanner. The mean APTw signals from five locations in healthy brain (supratentorial and infratentorial locations) and from entire tumor and stroke lesions (supratentorial location) were calculated. The within-subject coefficient of variation (wCV) and intraclass correlation coefficient (ICC) were calculated for each clinical conditions, image sessions, and anatomic locations. Differences in APTw signals between sessions were analyzed using repeated-measures analysis of variance.
Results
The ICC and wCV were 0.96 (95% confidence interval CI, 0.91–0.99) and 16.1 (12.6–21.3) in glioma, 0.93 (0.82–0.98) and 15.0 (11.4–20.6) in stroke, and 0.84 (0.72–0.91) and 34.0 (28.7–41.0) in healthy brain. There were no significant differences in APTw signal between three sessions, irrespective of disease condition and location. The ICC and wCV were 0.85 (0.68–0.94) and 27.4 (21.8–35.6) in supratentorial, and 0.44 (− 0.18 to 0.76) and 32.7 (25.9 to 42.9) in infratentorial locations. There were significant differences in APTw signal between supra- (mean, 0.49%; 95% CI, 0.38–0.61) and infratentorial locations (1.09%, 0.98–1.20;
p
< 0.001).
Conclusion
The repeatability of APTw signal was excellent in supratentorial locations, while it was poor in infratentorial locations due to severe B0 inhomogeneity and susceptibility which affects MTR asymmetry.
Key Points
• In supratentorial locations, APTw MRI showed excellent intrasession and intersession repeatability in brains of healthy controls and patients with glioma, as well as in stroke-affected regions.
• APTw MRI showed excellent repeatability in supratentorial locations, but poor repeatability in infratentorial locations.
• Considering poor repeatability in the infratentorial locations, the use of APTw MRI in longitudinal assessment in infratentorial locations is not indicated.
Abstract
Background
Noninvasive and accurate modality to predict isocitrate dehydrogenase (IDH) mutant glioma may have great potential in routine clinical practice. We aimed to investigate the ...diagnostic performance of 2-hydroxyglutarate (2HG) magnetic resonance spectroscopy (MRS) for prediction of IDH mutant glioma and provide an optimal cutoff value for 2HG.
Methods
A systematic literature search of Ovid-MEDLINE and EMBASE was performed to identify original articles investigating the diagnostic performance of 2HG MRS up to March 20, 2018. Pooled sensitivity and specificity were calculated using a bivariate random-effects model. Subgroup analysis and meta-regression were performed to explain heterogeneity effects. An optimal cutoff value for 2HG was calculated from studies providing individual patient data.
Results
Fourteen original articles with 460 patients were included. The pooled sensitivity and specificity for the diagnostic performance of 2HG MRS for prediction of IDH mutant glioma were 95% (95% CI, 85–98%) and 91% (95% CI, 83–96%), respectively. The Higgins I2 statistic demonstrated that heterogeneity was present in the sensitivity (I2 = 50.69%), but not in the specificity (I2 = 30.37%). In the meta-regression, echo time (TE) was associated with study heterogeneity. Among the studies using point-resolved spectroscopy (PRESS), a long TE (97 ms) resulted in higher sensitivity (92%) and specificity (97%) than a short TE (30–35 ms; sensitivity of 90%, specificity of 88%; P < 0.01). The optimal 2HG cutoff value of 2HG using individual patient data was 1.76 mM.
Conclusion
2HG MRS demonstrated excellent specificity for prediction of IDH mutant glioma, with TE being associated with heterogeneity in the sensitivity.
Key Points
1. HG MRS has excellent diagnostic performance in the prediction of IDH mutant glioma.
2. The pooled sensitivity was 95% and the pooled specificity was 91%.
3. Echo time was associated with study heterogeneity in the meta-regression.
Objective
To evaluate the value of multiparametric MRI for determination of early treatment response following concurrent chemoradiotherapy in patients with newly diagnosed glioblastoma.
Methods
A ...computerized search of Ovid-MEDLINE and EMBASE up to 1 October 2017 was performed to find studies on the diagnostic performance of multiparametric MRI for differentiating true progression from pseudoprogression. The beginning search date was not specified. Pooled estimates of sensitivity and specificity were obtained using hierarchical logistic regression modeling. We performed meta-regression and sensitivity analyses to explain the effects of the study heterogeneity.
Results
Nine studies including 456 patients were included. Pooled sensitivity and specificity were 84 % (95 % CI 74–91) and 95 % (95 % CI 83–99), respectively. Area under the hierarchical summary receiver operating characteristic curve was 0.95 (95 % CI 0.92–0.96). Meta-regression showed true progression in the study population, the mean age and the reference standard were significant factors affecting heterogeneity.
Conclusion
Multiparametric MRI may be used as a potential surrogate endpoint for assessment of early treatment response, especially in the differentiation of true progression from pseudoprogression. However, based on the current evidence, monoparametric and multiparametric MRI perform equally in the clinical context. Further evaluation will be needed.
Key Points
•
Multiparametric MRI shows high diagnostic performance for early treatment response in glioblastoma.
•
Multiparametric MRI could differentiate true progression from pseudoprogression in newly diagnosed glioblastoma.
•
The normalized rCBV derived from DSC was the most commonly used parameter.
The effect of subclinical leaflet thrombosis, characterised by hypoattenuated leaflet thickening (HALT), on the valve haemodynamic function and durability of the bioprosthetic valve, is not yet ...determined. We determined the impact of HALT on valve haemodynamics after transcatheter aortic valve replacement (TAVR) and the predictors of haemodynamic structural valve deterioration (SVD).
The Anticoagulation vs Dual Antiplatelet Therapy for Prevention of Leaflet Thrombosis and Cerebral Embolization after Transcatheter Aortic Valve Replacement(ADAPT-TAVR) trial is a multicenter, randomised trial that compared edoxaban and dual antiplatelet therapy in patients who had undergone successful TAVR. The presence of HALT was evaluated by four-dimensional CT at 6 months and serial echocardiography performed at baseline, immediately post-TAVR and after 6 months. SVD was defined as at least one of the following: (1) mean transprosthetic gradient ≥20 mm Hg, (2) change in the mean gradient ≥10 mm Hg from baseline, or (3) new or increase in intraprosthetic aortic regurgitation of at least ≥1 grade, resulting in moderate or greater regurgitation.
At 6 months, HALT was found in 30 of 211 (14.2%) patients. The presence of HALT did not significantly affect aortic valve mean gradients (with vs without HALT; 14.0±4.8 mm Hg vs 13.7±5.5 mm Hg; p=0.74) at 6 months. SVD was reported in 30 of 206 patients (14.6%) at 6-month follow-up echocardiography. Older age (OR: 1.138; 95% CI: 1.019 to 1.293; p=0.033), use of aortic valve size ≤23 mm (OR: 6.254; 95% CI: 2.230 to 20.569; p=0.001) and mean post-TAVR pressure gradient (OR: 1.233; 95% CI: 1.123 to 1.371; p<0.001) were independent predictors of haemodynamic SVD; however, the presence of HALT was not identified as a predictor of SVD.
In patients who had undergone successful TAVR, aortic valve haemodynamic status was not influenced by the presence of HALT. Although HALT was not a predictor of haemodynamic SVD at 6 months, it warrants further longer-term follow-up to evaluate the effect on long-term valve durability.
NCT03284827 (https://www.
gov).
Abstract
From May 2015 to June 2016, data on 296 patients undergoing 1.5-Tesla MRI for symptoms of acute ischemic stroke were retrospectively collected. Conventional, echo-planar imaging (EPI) and ...echo train length (ETL)-T2-FLAIR were simultaneously obtained in 118 patients (first group), and conventional, ETL-, and repetition time (TR)-T2-FLAIR were simultaneously obtained in 178 patients (second group). A total of 595 radiomics features were extracted from one region-of-interest (ROI) reflecting the acute and chronic ischemic hyperintensity, and concordance correlation coefficients (CCC) of the radiomics features were calculated between the fast scanned and conventional T2-FLAIR for paired patients (1st group and 2nd group). Stabilities of the radiomics features were compared with the proportions of features with a CCC higher than 0.85, which were considered to be stable in the fast scanned T2-FLAIR. EPI-T2-FLAIR showed higher proportions of stable features than ETL-T2-FLAIR, and TR-T2-FLAIR also showed higher proportions of stable features than ETL-T2-FLAIR, both in acute and chronic ischemic hyperintensities of whole- and intersection masks (p < .002). Radiomics features in fast scanned T2-FLAIR showed variable stabilities according to the sequences compared with conventional T2-FLAIR. Therefore, radiomics features may be used cautiously in applications for feature analysis as their stability and robustness can be variable.
It is unknown whether edoxaban versus dual antiplatelet therapy (DAPT) has differential treatment effects on leaflet thrombosis, cerebral thromboembolism, and neurologic or neurocognitive dysfunction ...according to clinical and anatomic factors after transcatheter aortic valve implantation.
To investigate the relative effects of edoxaban and DAPT on leaflet and cerebral thromboembolism in patients with major risk factors.
The primary end point of this study was the incidence of leaflet thrombosis on computed tomography at 6 months. The secondary end points were new cerebral lesions on brain magnetic resonance imaging and neurologic and neurocognitive dysfunction between baseline and 6-month follow-up. Cox regression models assessed the consistency of the treatment effects in the prespecified subgroups.
The favorable effect of edoxaban versus DAPT on the leaflet thrombosis was consistent across multiple clinical or anatomic subgroups, without significant interaction between the drug effect and each subgroup (p for interaction for age = 0.597, gender = 0.557, body mass index = 0.866, Society of Thoracic Surgeons score = 0.307, valve type = 0.702, edoxaban reduction criteria = 0.604, and valve morphology = 0.688). However, the incidence of new cerebral lesions on brain magnetic resonance imaging and worsening of neurologic and neurocognitive function were not significantly different between the groups among the various key subgroups.
The relative effects of edoxaban and DAPT on the risk of leaflet thrombosis, cerebral thromboembolism, and neurologic dysfunction were consistent across a diverse spectrum of clinical or anatomical factors. Further studies are required to define tailored antithrombotic therapy for high-risk groups with specific clinical or anatomic characteristics.
Objectives
Differentiation of glioma from brain metastasis is clinically crucial because it affects the clinical outcome of patients and alters patient management. Here, we present a systematic ...review and meta-analysis of the currently available data on perfusion magnetic resonance imaging (MRI) for differentiating glioma from brain metastasis, assessing MRI protocols and parameters.
Methods
A computerised search of Ovid-MEDLINE and EMBASE databases was performed up to 3 October 2017, to find studies on the diagnostic performance of perfusion MRI for differentiating glioma from brain metastasis. Pooled summary estimates of sensitivity and specificity were obtained using hierarchical logistic regression modelling. We conducted meta-regression and subgroup analyses to explain the effects of the study heterogeneity.
Results
Eighteen studies with 900 patients were included. The pooled sensitivity and specificity were 90% (95% CI, 84–94%) and 91% (95% CI, 84–95%), respectively. The area under the hierarchical summary receiver operating characteristic curve was 0.96 (95% CI, 0.94–0.98). The meta-regression showed that the percentage of glioma in the study population and the study design were significant factors affecting study heterogeneity. In a subgroup analysis including patients with glioblastoma only, the pooled sensitivity was 92% (95% CI, 84–97%) and the pooled specificity was 94% (95% CI, 85–98%).
Conclusions
Although various perfusion MRI techniques were used, the current evidence supports the use of perfusion MRI to differentiate glioma from brain metastasis. In particular, perfusion MRI showed excellent diagnostic performance for differentiating glioblastoma from brain metastasis.
Key Points
• Perfusion MRI shows high diagnostic performance for differentiating glioma from brain metastasis.
• The pooled sensitivity was 90% and pooled specificity was 91%.
• Peritumoral rCBV derived from DSC is a relatively well-validated.
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