RESUMEN
The vessel-wall-volume (VWV) measured based on three-dimensional (3D) carotid artery (CA) ultrasound (US) images can help to assess carotid atherosclerosis and manage patients at risk for stroke. Manual involvement for measurement work is subjective and requires well-trained operators, and fully automatic measurement tools are not yet available. Thereby, we proposed a fully automatic VWV measurement framework (Auto-VWV) using a CA prior-knowledge embedded U-Net (CAP-UNet) to measure the VWV from 3D CA US images without manual intervention. The Auto-VWV framework is designed to improve the repeated VWV measuring consistency, which resulted in the first fully automatic framework for VWV measurement. CAP-UNet is developed to improve segmentation accuracy on the whole CA, which composed of a U-Net type backbone and three additional prior-knowledge learning modules. Specifically, a continuity learning module is used to learn the spatial continuity of the arteries in a sequence of image slices. A voxel evolution learning module was designed to learn the evolution of the artery in adjacent slices, and a topology learning module was used to learn the unique topology of the carotid artery. In two 3D CA US datasets, CAP-UNet architecture achieved state-of-the-art performance compared to eight competing models. Furthermore, CAP-UNet-based Auto-VWV achieved better accuracy and consistency than Auto-VWV based on competing models in the simulated repeated measurement. Finally, using 10 pairs of real repeatedly scanned samples, Auto-VWV achieved better VWV measurement reproducibility than intra- and inter-operator manual measurements.
RESUMEN
There have been recent advances in stroke prevention in nutrition, blood pressure control, antiplatelet therapy, anticoagulation, identification of high-risk asymptomatic carotid stenosis, and percutaneous closure of patent foramen ovale. There is evidence that the Mediterranean diet significantly reduces the risk of stroke and that B vitamins lower homocysteine, thus preventing stroke. The benefit of B vitamins to lower homocysteine was masked by harm from cyanocobalamin among study participants with impaired renal function; we should be using methylcobalamin instead of cyanocobalamin. Blood pressure control can be markedly improved by individualized therapy based on phenotyping by plasma renin and aldosterone. Loss of function mutations of CYP2D19 impair activation of clopidogrel and limits its efficacy; ticagrelor can avoid this problem. New oral anticoagulants that are not significantly more likely than aspirin to cause severe bleeding, and prolonged monitoring for atrial fibrillation (AF), have revolutionized the prevention of cardioembolic stroke. Most patients (~90%) with asymptomatic carotid stenosis are better treated with intensive medical therapy; the few that could benefit from stenting or endarterectomy can be identified by a number of approaches, the best validated of which is transcranial Doppler (TCD) embolus detection. Percutaneous closure of patent foramen ovale has been shown to be efficacious but should only be implemented in selected patients; they can be identified by clinical clues to paradoxical embolism and by TCD estimation of shunt grade. "Treating arteries instead of treating risk factors," and recent findings related to the intestinal microbiome and atherosclerosis point the way to promising advances in future.
RESUMEN
Recent recommendations that limits to dietary cholesterol be dropped were probably heavily influenced by propaganda from the egg industry. After conviction for false advertising, the industry has spent hundreds of millions of dollars to convince the public, physicians, and policy makers that dietary cholesterol and egg yolk are harmless. However, there are good reasons for longstanding recommendations that dietary cholesterol be limited to <200 mg/ day in persons at risk of vascular disease. It is seldom understood that this essentially means all people in developed countries who expect to attain an advanced age. There is abundant evidence that dietary cholesterol increases cardiovascular risk. The misdirection of the egg industry focuses on fasting levels of LDL cholesterol, which are only raised by ~ 10% by consumption of egg yolks. However, the main effect of diet is on the post-prandial state: for ~ 4 hours after a high fat/high cholesterol meal, there is oxidative stress, endothelial dysfunction, and arterial inflammation. One large (65 g) egg yolk contains 237 mg of cholesterol, well above the recommended limit-nearly as much as a 12-ounce hamburger. Besides the very high cholesterol content of egg yolk, the phosphatidylcholine in egg yolk leads, via action of the intestinal microbiome, to production of trimethylamine n-oxide (TMAO), which causes atherosclerosis in animal models. Levels of TMAO in the top quartile after a test dose of two egg yolks were associated with a 2.5-fold increase in the 3-year risk of stroke, death, or myocardial infarction among patients referred for coronary angiography. Persons at risk of cardiovascular disease should limit their intake of cholesterol and egg yolk.
