Increased accuracy in computed tomography coronary angiography; a new body surface area adapted protocol

Vascular Biology and Interventio

Mitral regurgitation quantification by cardiac magnetic resonance imaging (MRI) remains reproducible between software solutions

Background: The reproducibility of mitral regurgitation (MR) quantification by cardiovascular magnetic resonance (CMR) imaging using different software solutions remains unclear. This research aimed to investigate the reproducibility of MR quantification between two software solutions: MASS (version 2019 EXP, LUMC, Netherlands) and CAAS (version 5.2, Pie Medical Imaging). Methods: CMR data of 35 patients with MR (12 primary MR, 13 mitral valve repair/replacement, and ten secondary MR) was used. Four methods of MR volume quantification were studied, including two 4D-flow CMR methods (MRMVAV and MRJet) and two non-4D-flow techniques (MRStandard and MRLVRV). We conducted within-software and inter-software correlation and agreement analyses. Results: All methods demonstrated significant correlation between the two software solutions: MRStandard (r=0.92, p<0.001), MRLVRV (r=0.95, p<0.001), MRJet (r=0.86, p<0.001), and MRMVAV (r=0.91, p<0.001). Between CAAS and MASS, MRJet and MRMVAV, compared to each of the four methods, were the only methods not to be associated with significant bias. Conclusions: We conclude that 4D-flow CMR methods demonstrate equivalent reproducibility to non-4D-flow methods but greater levels of agreement between software solutions

Mitral regurgitation quantification by cardiac magnetic resonance imaging (MRI) remains reproducible between software solutions [version 2; peer review: 1 approved]

BACKGROUND: The reproducibility of mitral regurgitation (MR) quantification by cardiovascular magnetic resonance (CMR) imaging using different software solutions remains unclear. This research aimed to investigate the reproducibility of MR quantification between two software solutions: MASS (version 2019 EXP, LUMC, Netherlands) and CAAS (version 5.2, Pie Medical Imaging). METHODS: CMR data of 35 patients with MR (12 primary MR, 13 mitral valve repair/replacement, and ten secondary MR) was used. Four methods of MR volume quantification were studied, including two 4D-flow CMR methods (MRMVAV and MRJet) and two non-4D-flow techniques (MRStandard and MRLVRV). We conducted within-software and inter-software correlation and agreement analyses. RESULTS: All methods demonstrated significant correlation between the two software solutions: MR_{Standard} (r=0.92, p<0.001), MR_{LVRV} (r=0.95, p<0.001), MR_{Jet} (r=0.86, p<0.001), and MR_{MVAV} (r=0.91, p<0.001). Between CAAS and MASS, MR_{Jet} and MR_{MVAV}, compared to each of the four methods, were the only methods not to be associated with significant bias. CONCLUSIONS: We conclude that 4D-flow CMR methods demonstrate equivalent reproducibility to non-4D-flow methods but greater levels of agreement between software solutions

Deep Learning-based Method for Fully Automatic Quantification of Left Ventricle Function from Cine MR Images: A Multivendor, Multicenter Study

Purpose: To develop a deep learning–based method for fully automated quantification of left ventricular (LV) function from short-axis cine MR images and to evaluate its performance in a multivendor and multicenter setting. Materials and Methods: This retrospective study included cine MRI data sets obtained from three major MRI vendors in four medical centers from 2008 to 2016. Three convolutional neural networks (CNNs) with the U-NET architecture were trained on data sets of increasing variability: (a) a single-vendor, single-center, homogeneous cohort of 100 patients (CNN1); (b) a single-vendor, multicenter, heterogeneous cohort of 200 patients (CNN2); and (c) a multivendor, multicenter, heterogeneous cohort of 400 patients (CNN3). All CNNs were tested on an independent multivendor, multicenter data set of 196 patients. CNN performance was evaluated with respect to the manual annotations from three experienced observers in terms of (a) LV detection accuracy, (b) LV segmentation accuracy, and (c) LV functional parameter accuracy. Automatic and manual results were compared with the paired Wilcoxon test, Pearson correlation, and Bland-Altman analysis. Results: CNN3 achieved the highest performance on the independent testing data set. The average perpendicular distance compared with manual analysis was 1.1 mm ± 0.3 for CNN3, compared with 1.5 mm ± 1.0 for CNN1 (P < .05) and 1.3 mm ± 0.6 for CNN2 (P < .05). The LV function parameters derived from CNN3 showed a high correlation (r2 ≥ 0.98) and agreement with those obtained by experts for data sets from different vendors and centers. Conclusion: A deep learning–based method trained on a data set with high variability can achieve fully automated and accurate cine MRI analysis on multivendor, multicenter cine MRI data

Bycatch weight, composition and preliminary estimates of the impact of bycatch reduction devices in Queensland's trawl fishery

This report provides quantitative information on the effects of turtle excluder devices (TEDs) and bycatch reduction devices (BRDs) on the catch rates of bycatch, prawns, scallops and byproduct species, such as Moreton Bay bugs and Balmain bugs, in Queensland’s major trawl fishing sectors. It also provides biological information on, and management advice for several species referred to in the Fishery Management Plan as the permitted species. Several recommendations are included for reducing bycatch in the trawl fishery and for sustaining stocks of the permitted species

Posterior left atrial adipose tissue attenuation assessed by computed tomography and recurrence of atrial fibrillation after catheter ablation

BACKGROUND: Atrial fibrillation (AF) recurrence following catheter ablation remains high. Recent studies have shown a relation between epicardial adipose tissue and AF. epicardial adipose tissue secretes several proinflammatory and anti-inflammatory adipokines that directly interact with the adjacent myocardium. The aim of the current study was to evaluate whether posterior left atrial (LA) adipose tissue attenuation, as marker of inflammation, is related to AF recurrences after catheter ablation.METHODS: Consecutive patients with symptomatic AF referred for first AF catheter ablation who underwent computed tomography were included. The total epicardial adipose tissue and posterior LA adipose tissue were manually traced and adipose tissue was automatically recognized as tissue with Hounsfield units (HU) between -195 and -45. The attenuation value of the posterior LA adipose tissue was assessed, and the population was divided according to the mean HU value (-96.4 HU).RESULTS: In total, 460 patients (66% male, age 61 +/- 10 years) were included in the analysis. After a median follow-up of 18 months (interquartile range, 6-32), 168 (37%) patients had AF recurrence. Patients with higher attenuation (>=-96.4 HU) of the posterior LA adipose tissue showed higher AF recurrence rates compared with patients with lower attenuation (P=0.046). Univariate analysis showed an association between AF recurrence and higher posterior LA adipose tissue attenuation (>=-96.4 HU; P<0.05). On multivariable analysis, posterior LA adipose tissue attenuation (hazard ratio, 1.26 [95% CI, 0.90-1.76]; P=0.181) remained a promising predictor of AF recurrence following catheter ablation.CONCLUSIONS: Posterior LA adipose tissue attenuation is a promising predictor of AF recurrence in patients who undergo catheter ablation. Higher adipose tissue attenuation might signal increased local inflammation and serve as an imaging biomarker of increased risk of AF recurrence.GRAPHIC ABSTRACT: A is available for this article.Cardiovascular Aspects of Radiolog

Do health systems delay the treatment of poor children? A qualitative study of child deaths in rural Tanzania.

Child mortality remains one of the major public-health problems in Tanzania. Delays in receiving and accessing adequate care contribute to these high rates. The literature on public health often focuses on the role of mothers in delaying treatment, suggesting that they contact the health system too late and that they prefer to treat their children at home, a perspective often echoed by health workers. Using the three-delay methodology, this study focus on the third phase of the model, exploring the delays experienced in receiving adequate care when mothers with a sick child contact a health-care facility. The overall objective is to analyse specific structural factors embedded in everyday practices at health facilities in a district in Tanzania which cause delays in the treatment of poor children and to discuss possible changes to institutions and social technologies. The study is based on qualitative fieldwork, including in-depth interviews with sixteen mothers who have lost a child, case studies in which patients were followed through the health system, and observations of more than a hundred consultations at all three levels of the health-care system. Data analysis took the form of thematic analysis. Focusing on the third phase of the three-delay model, four main obstacles have been identified: confusions over payment, inadequate referral systems, the inefficient organization of health services and the culture of communication. These impediments strike the poorest segment of the mothers particularly hard. It is argued that these delaying factors function as 'technologies of social exclusion', as they are embedded in the everyday practices of the health facilities in systematic ways. The interviews, case studies and observations show that it is especially families with low social and cultural capital that experience delays after having contacted the health-care system. Reductions of the various types of uncertainty concerning payment, improved referral practices and improved communication between health staff and patients would reduce some of the delays within health facilities, which might feedback positively into the other two phases of delay

Highly potent bispecific sybodies neutralize SARS-CoV-2

The ongoing COVID-19 pandemic represents an unprecedented global health crisis. Here, we report the identification of a synthetic nanobody (sybody) pair (Sb#15 and Sb#68) that can bind simultaneously to the SARS-CoV-2 spike-RBD and efficiently neutralize pseudotyped and live-viruses by interfering with ACE2 interaction. Two spatially-discrete epitopes identified by cryo-EM translated into the rational design of bispecific and tri-bispecific fusions constructs, exhibiting up to 100- and 1000-fold increase in neutralization potency. Cryo-EM of the sybody-spike complex further revealed a novel up-out RBD conformation. While resistant viruses emerged rapidly in the presence of single binders, no escape variants were observed in presence of the bispecific sybody. The multivalent bispecific constructs further increased the neutralization potency against globally-circulating SARS-CoV-2 variants of concern. Our study illustrates the power of multivalency and biparatopic nanobody fusions for the development of clinically relevant therapeutic strategies that mitigate the emergence of new SARS-CoV-2 escape mutants