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Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) is a promising approach to assess microvascular blood flow (perfusion) within the myocardium, and the Fermi microvascular perfusion model is widely applied to extract estimates of the myocardial blood flow (MBF) from DCE-MRI data sets. The classification of myocardial tissues into normal (healthy) and hypoperfused (lesion) regions provides new opportunities for the diagnosis of coronary heart disease and for advancing our understanding of the aetiology of this highly prevalent disease. In the present paper, the Fermi model is combined with a hierarchical Bayesian model (HBM) and a Markov random fields prior to automate this classification. The proposed model exploits spatial context information to smooth the MBF estimates while sharpening the edges between lesions and healthy tissues. The model parameters are approximately sampled from the posterior distribution with Markov chain Monte Carlo (MCMC), and we demonstrate that this enables robust classification of myocardial tissue elements based on estimated MBF, along with sound uncertainty quantification. A well-established traditional method, based on a Gaussian mixture model (GMM) trained with the expectation–maximisation algorithm, is used as a benchmark for comparison.

Objectives:\ud Studies have suggested phosphodiesterase 4 (PDE4) inhibition may be associated with weight loss and other cardiometabolic benefits. We evaluated the effect of the PDE4 inhibitor apremilast on body weight and composition, glucose homeostasis, lipid profiles, and vascular function in psoriatic disease, and whether weight change correlated with therapeutic response.\ud \ud Methods:\ud We conducted a prospective, open label study (Immune Metabolic Associations in Psoriatic Arthritis, IMAPA) of adults receiving apremilast 30 mg as part of routine care for psoriatic arthritis and/or psoriasis. Cardiometabolic, anthropometric, and disease activity assessments were performed at baseline (pre-apremilast) and at months 1, 3, and 6 of apremilast treatment in 60 patients. A subgroup underwent further assessment of endothelial function, body composition, and adipocyte morphology.\ud \ud Results:\ud In patients (median age 54.5 years, 63% women, median BMI 33.2 kg/m2) apremilast was associated with a mean weight loss of 2.2 kg (95% CI 1.4–3.0 kg, p< 0.001) and mean BMI decrease of 0.8 kg/m2 (95% CI 0.5–1.2 kg/m2, p< 0.001) after 6 months treatment. Body composition analysis demonstrated a reduction in total abdominal fat (mean decrease 0.52 L, 95% CI 0.08–0.96L, p= 0.022), principally subcutaneous adipose tissue (mean decrease 0.37 L, 95% CI 0.05–0.68L, p= 0.022). There was no change in adipocyte diameter, HbA1c, lipid, GLP-1, or vascular function. Psoriatic disease activity improved with apremilast, although this was not correlated with weight change.\ud \ud Conclusion:\ud Following apremilast treatment, we observed weight loss, principally abdominal subcutaneous fat, and improvement in psoriatic disease activity. The latter was independent of weight change, suggesting apremilast likely acts through direct immunological mechanisms.

Additional file 1. Supplementary material: S1. Baseline characteristics of participants. S2. Summary of clinically significant incidental findings. S3. Intra- and inter-observer reproducibility for cardiovascular MRI parameters. S4. Determinants of blood pool native T1. S5. Analyses exploring the potential influence of intravenous iron therapy on native T1.

Additional file 2. Sensitivity Analysis (with 3 outliers excluded) Results and Scatterplot.

Additional file 1. Flowchart of cardiovascular magnetic resonance (CMR) and computed tomography (CT) scans available for analysis.

Additional file 3. Sensitivity Analysis Bland-Altman plot.

Ferumoxytol-enhanced68 MR angiography was superior to duplex US in the detection of central vein stenosis and arterial disease that correlated with outcomes of arteriovenous fistula surgery for hemodialysis.\ud \ud Background:\ud Duplex US is performed routinely for vascular mapping prior to arteriovenous fistula (AVF) creation for hemodialysis but cannot demonstrate the central vasculature. Ferumoxytol, an iron oxide nanoparticle, provides an alternative to gadolinium contrast material for MR angiography for safe use in chronic kidney disease (CKD).\ud \ud Purpose:\ud To assess the clinical utility of ferumoxytol-enhanced MR angiography compared with duplex US for vascular mapping before upper limb AVF creation in participants with CKD.\ud \ud Materials and Methods:\ud In a prospective comparative study (ClinicalTrials.gov: NCT02997046) from December 2016 to August 2018, participants with CKD underwent ferumoxytol-enhanced MR angiography and duplex US. Two independent readers evaluated vessels for diameter, stenosis or occlusion, arterial disease, and central stenosis. Intraclass correlation coefficients (ICCs) and Bland-Altman plots were used to assess intra- and interreader variability. On the basis of accepted standards for AVF creation, an algorithm was developed to predict AVF outcome based on imaging findings. Multivariable regression models used AVF success as the dependent variable and age, sex, and duplex US or ferumoxytol-enhanced MR angiography findings as independent variables.\ud \ud Results:\ud Fifty-nine participants with CKD (mean age, 59 years ± 13 [standard deviation]; 30 women) were evaluated. A total of 51 fistulas were created, of which 24 (47%) were successful. Ferumoxytol-enhanced MR angiography showed excellent inter- and intrareader repeatability (ICC, 0.84–0.99) for all variables assessed. In addition to revealing 15 central vasculature stenoses, ferumoxytol-enhanced MR angiography resulted in characterization of 88 of 236 (37%) of the arterial sections examined as unsuitable for AVF creation compared with 61 of 236 (26%) sections with duplex US (P = .01). Ferumoxytol-enhanced MR angiography independently predicted AVF success in models including (odds ratio, 6.5; 95% confidence interval: 1.7, 25; P = .006) and those excluding (odds ratio, 4.6; 95% confidence interval: 1.3, 17; P = .02) the central vasculature.\ud \ud Conclusion:\ud In addition to enabling identification of central vessel pathologic features, ferumoxytol-enhanced MR angiography revealed peripheral arterial disease not recognized with duplex US and was more predictive than duplex US of the outcome of arteriovenous fistula surgery.

No abstract available.