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4D phase contrast magnetic resonance imaging (PC-MRI) allows for the visualization and quantification of the cerebral blood flow. A drawback of software that is used to quantify the cerebral blood flow is that it oftentimes assumes a static arterial luminal area over the cardiac cycle. Quantifying the lumen area pulsatility index (aPI), i.e. the change in lumen area due to an increase in distending pressure over the cardiac cycle, can provide insight in the stiffness of the arteries. Arterial stiffness has received increased attention as a predictor in the development of cerebrovascular disease. In this study, we introduce software that allows for measurement of the aPI as well as the blood flow velocity pulsatility index (vPI) from 4D PC-MRI. The internal carotid arteries of seven volunteers were imaged using 7 T MRI. The aPI and vPI measurements from 4D PC-MRI were validated against measurements from 2D PC-MRI at two levels of the internal carotid arteries (C3 and C7). The aPI and vPI computed from 4D PC-MRI were comparable to those measured from 2D PC-MRI (aPI: mean difference: 0.03 (limits of agreement: −0.14 – 0.23); vPI: 0.03 (−0.17–0.23)). The measured blood flow rate for the C3 and C7 segments was similar, indicating that our proposed software correctly captures the variation in arterial lumen area and blood flow velocity that exists along the distal end of the carotid artery. Our software may potentially aid in identifying changes in arterial stiffness of the intracranial arteries caused by pathological changes to the vessel wall.

Some of the detachable microcoils are associated with the prominent metallic artifact. We have applied Silent MRA to reduce the artifact. In this study, we present a retrospective study in which Silent MRA is used for cases showing prominent metallic artifact on conventional TOF-MRA due to a detachable bare platinum microcoil (Barricade coil). Fifteen patients, who had undergone endosaccular embolization using Barricade coil and other detachable microcoils up to 3 days previously, were scanned with TOF-MRA and silent MRA at the same time. The treatment DSA and follow-up MRA images were graded by two experienced neuroradiologists, focusing on the visibility of residual aneurysm and parent arterial lumen. DSA images showed residual aneurysm (RA) in four, residual neck (RN) in six, and complete occlusion (CO) in five patients. TOF-MRA images showed RN in five, CO in four, mild defect (MD) in one, severe defect (SD) in three, and complete defect in two. In contrast, on Silent MRA, the grades were RA in two, RN in five, CO in five, and MD in three. Barricade coils are associated with prominent metallic artifact on TOF-MRA. Silent MRA is useful for follow-up MRA after embolization using Barricade coils. The metallic artifacts were compared between TOF-MRA and Silent MRA in patients treated by using Barricade coils. Barricade coils are associated with more metallic artifact on TOF-MRA than Silent MRA. Silent MRA is useful for follow-up MRA after embolization using Barricade coils.

Cardiovascular disease (CVD) is a leading cause of mortality and morbidity in developed\ud countries. CVD is produced by atherosclerotic lesions that reduce arterial lumen size through\ud plaque formation and arterial thickening. This decreases blood flow to the heart and frequently\ud manifests in severe hemodynamic complications like myocardial infarction or angina pectoris. A\ud drug delivery system (DDS) is a clinical methodology (formulation or device) which enables the\ud introduction of a therapeutic substance into the body and improves its efficacy and safety by\ud controlling the rate, time, and place of release of drugs in the body. Drug delivery technologies\ud modify drug release profile, absorption, distribution and elimination for the benefit of improving\ud product effectiveness and patient convenience and compliance. The review explores extensively\ud hemodynamic aspects of the cardiovascular system and diseases which can be treated via nanodrug delivery with a comprehensive overview of research efforts in these areas. Nanomedicine is\ud an expeditiously growing science in which biomaterials (drugs) engineered at the nanoscale are\ud implemented to enhance therapeutic performance and improve patient treatments. Among the\ud many other diverse applications of nanomaterials in medicine (e.g. bio-UIRtribology, tissue repair,\ud orthopaedic implants etc), nano-drug delivery systems have emerged as among the most\ud promising. This technology has evolved into a significant platform for delivering successfully\ud remedial agents to diseased sites with substantially greater target control, precision and\ud sophistication. By greatly increasing site specificity, lowering toxicity and target-oriented \ud 2\ud delivery, nanotechnological drug delivery (“nano-pharmacodynamics”) has consistently achieved\ud very impressive consistency, benefits and has aided massively in the fight against potentially lethal\ud haemotological diseases. Recently, nanomedicine has embraced an even wider range of\ud applications including the administration of chemotherapeutic agents, biological agents, diabetes\ud regulation, sterilization, cancer and tumour inhibition, rheumatic fever mitigation etc. The current\ud review presents a comprehensive appraisal of nano-drug delivery systems, simulation with\ud engineering methods, types of nanodrugs and their effectiveness. The excellent targeting properties\ud attainable with magnetic nanoparticles as engineering pharmacodynamic agents, in particular,\ud offers huge potential in the treatment of many complex hemodynamic disorders. Furthermore, the\ud present review summarizes the efficiency of drug carrier nanoparticles in mitigating the adverse\ud effects of stenosed blood vessels and outlines other future potential uses for nano-drugs in\ud biomedical applications.

The rupture of unstable or vulnerable atherosclerotic plaque is the major cause of ischemic stroke. Manual analysis of the vessel wall and plaque is labor-intensive and experience-dependent. The purpose of this study is to develop an automatic method to segment the vessel wall and lumen contour for quantitative measurement. In this work, a CNN architecture for fully automated segmentation of arterial lumen and vessel wall on MR vessel wall images was developed and evaluated on ischemic stroke patients. In conclusion, we proposed a good performance automatic analysis method for the vessel wall and is important for plaque analysis.

We present a multiphysical model to understand atheromatous plaque growth. The model was based on the physics of blood flow in the arterial lumen (Navier–Stokes equations and Darcy's law) coupled to a convection-diffusion-reaction equation to model exchange between lumen and arterial wall. The Kedem-Katchalsky theory was used to model intercellular coupling via the membranes.

This paper reports on modelling and simulation of the coupled mass and momentum transport through the arterial lumen and the porous arterial wall of an abdominal aortic aneurysm (AAA). The effect of porous structure and intramural flow, which is usually neglected, is essential to quantify the oxygen concentration in the aneurysmal wall and will be addressed in this work via a novel coupled fluid-porous structure-mass transport model for AAA. The computational solver provides a prediction of the filtration velocity and oxygen concentration in the artery and further simulations are used to investigate the relation between the wall oxygen concentration and permeability. The results demonstrate the essential coupling between blood and filtration flow and specifically how their interactions affect oxygen transport.

The drug-eluting stents (DESs) have been considered as an effective technique to reduce the severity of atherosclerotic stenosis. Recent technological advances have opened the door for developing new and innovative smart cardiovascular stents by integrating various electronics components and sensors to improve health monitoring and diagnosis. Rupture of atherosclerotic plaque represents the major cause of cardiovascular disease (CVD) such as heart attacks due to blockages of the arterial lumen. Pentraxin-3 (PTX3) is a novel localized inflammatory biomarker associated with the development of atherosclerosis and plaque vulnerability. In this paper, we propose a biosensor interface platform for monitoring the plaque vulnerability via detection and prediction of the inflammatory biomarker (PTX3). We propose mathematical and stochastic models using molecular communication paradigm for detection of Pentraxin-3 (PTX3) molecules in the atherosclerotic arterial wall using biosensor attached to a vascular stent inside the artery. The proposed platform and models can help in the localized sensing of the atherosclerotic biomarkers for monitoring of the plaque progression and for early warning of certain disorders such as heart attack.

Coronary angiography remains the gold standard imaging method for the detection of coronary artery disease (CAD) and its widespread clinical application has steered patients to a host of beneficial interventional medical therapies. Nonetheless, this approach only provides a two-dimensional image of the contrast-filled arterial lumen and does not visualize the arterial wall where largest atherosclerotic plaques are located. Consequently, angiography often underestimates the degree of intraluminal stenosis and does not gauge the size of the plaque burden itself (Topol and Nissen, 1995).

BACKGROUND: Trapping of apoB lipoprotein particles within the arterial wall initiates and drives the atherosclerotic process from beginning to end. Very low-density lipoprotein particles (VLDL) contain most of the triglyceride in plasma whereas low-density lipoprotein particles (LDL) particles contain most of the cholesterol. Smaller numbers of chylomicron and Lp(a) particles are also present in plasma. All these particles have one molecule of apoB. Therefore, plasma apoB equals the total number of apoB particles. Because the lipid content of apoB particles is variable, plasma triglyceride and cholesterol are not always accurate-measures of the number of apoB particles. THE CHOLESTEROL MODEL OF ATHEROSCLEROSIS: The conventional model of atherosclerosis presumes that the mass of cholesterol within VLDL and LDL particles is the principal determinant of the mass of cholesterol that will be deposited within the arterial wall and will drive atherogenesis. But cholesterol can only enter the arterial wall within apoB particles and the mass of cholesterol that will be deposited is determined by the rate at which apoB particles are trapped within the arterial wall rather than passing harmless through. THE APOB PARTICLE MODEL OF ATHEROGENESIS: The number of apoB particles that enter and are trapped within the arterial wall is determined primarily by the number of apoB particles within the arterial lumen. However, once within the arterial wall, smaller cholesterol-depleted apoB particles have a greater tendency to be trapped than larger cholesterol-enriched apoB particles because they bind more avidly to the glycosaminoglycans within the subintimal space of the arterial wall. If so, a cholesterol-enriched particle would deposit more cholesterol than a cholesterol-depleted apoB particle. By contrast, more smaller apoB particles that enter the arterial wall will be trapped than larger apoB particles. The net result is, with the exceptions of the abnormal chylomicron remnants in type III hyperlipoproteinemia and Lp(a), all apoB particles are equally atherogenic. ApoB, therefore, unifies, amplifies, and simplifies the information from the conventional lipid markers as to the atherogenic risk attributable to the apoB lipoproteins.

Blood flow rate ([Formula: see text]) in relation to arterial lumen radius (r(i)) is commonly modelled according to theoretical equations and paradigms, including Murray’s Law ([Formula: see text] ∝ [Formula: see text]) and da Vinci’s Rule ([Formula: see text] ∝ [Formula: see text]). Wall shear stress (τ) is independent of r(i) with Murray’s Law (τ ∝ [Formula: see text]) and decreases with da Vinci’s Rule (τ ∝ [Formula: see text]). These paradigms are tested empirically with a meta‐analysis of the relationships between [Formula: see text] and r(i) in seven major arteries of the human cephalic circulation from 19 imaging studies in which both variables were presented. The analysis shows that [Formula: see text] ∝ [Formula: see text] and τ ∝ [Formula: see text] , more consistent with da Vinci’s Rule than Murray’s Law. This meta‐analysis provides standard values for [Formula: see text] , r(i) and τ in the human cephalic arteries that may be a useful baseline in future investigations. On average, the paired internal carotid arteries supply 75%, and the vertebral arteries supply 25%, of total brain blood flow. The internal carotid arteries contribute blood entirely to the anterior and middle cerebral arteries and also partly to the posterior cerebral arteries via the posterior communicating arteries of the circle of Willis. On average, the internal carotid arteries provide 88% of the blood flow to the cerebrum and the vertebral arteries only 12%.

Purpose The purpose of this study was to characterize the hemodynamics of peripheral artery stent grafts to guide intelligent stent redesign. Materials and methods Two surgically explanted porcine arteries were mounted in an ex vivo system with subsequent deployment of an Xpert self-expanding nitinol stent or Viabahn stent graft. The arteries were casted with radiopaque resin, and the cast then scanned using micro-computed tomography at 8 μm isotropic voxel resolution. The arterial lumen was segmented and a computational mesh grid surface generated. Computational fluid dynamics (CFD) analysis was subsequently performed using COMSOL Multiphysics 5.1. Results CFD analysis demonstrated low endothelial shear stress (ESS) involving 9.4 and 63.6% surface area of the central stent graft and bare metal stent, respectively. Recirculation zones were identified adjacent to the bare metal stent struts, while none were identified in the central stent graft. However, the stent graft demonstrated malapposition of the proximal stent graft edge with low velocity flow between the PTFE lining and arterial wall, which was associated with longitudinally and radially oriented recirculation zones and low ESS. Conclusion Computational hemodynamic analysis demonstrates that peripheral artery stent grafts have a superior central hemodynamic profile compared to bare metal stents. Stents grafts, however, suffer from malapposition at the proximal stent edge which is likely a major contributor to edge stenosis.

Cannulation of the shorter limb of an abdominal aortic endograft can be demanding. Confirmation of the accurate cannulation is equally challenging. Interventional cardiologists and cardiovascular surgeons may encounter certain difficulties during this procedure. In particular, cardiologists have a wide variety of experience in interventions from coronary practice. This novel method we describe herein consists of peripheral balloon usage in wiring the short limb of an aortic stent graft. In this method, an over-the-wire peripheral balloon is employed to centralize the wire at the gate of the short limb. The centralized wire in three-dimensional arterial lumen can cross the short limb of the graft easily.

Introduction It has not been reported how long the follow-up study after carotid artery stenting (CAS) should be continued. The purpose of the present study is to clarify the dynamic change of the in-stent neointimal layer and residual arterial lumen by two years following CAS using three-dimensional computed tomography angiography (3D CTA) with volume rendering. Methods Thirty-six stented carotid arteries in 34 consecutive patients were examined by 3D CTA with volume rendering at two weeks and 3, 6, 12, 24 months of follow-up. Results An in-stent hypodense area could be detected in 10 of 36 (27.8%) carotid arteries at two weeks after CAS. In-stent hypodense areas gradually declined thereafter by three months. In the course of longer follow-up, the layer of the in-stent hypodense area (neointimal hyperplasia) continued to grow in size for up to 24 months. Patients with an in-stent hypodense area at two weeks have a thicker layer of neointimal hyperplasia at 24 months than patients without in-stent hypodense area at two weeks’ follow-up. The predictive factors for growing neointimal hyperplasia at 24 months in multiple regression analysis are ulcer formation in pretreatment stenosis and the thickness of in-stent hypodense area at two weeks following CAS. Conclusion Our results suggest that follow-up study should be continued for a longer period even if in-stent restenosis could not be detected at one year following CAS. Especially in cases with ulcer formation in pretreatment stenosis and with a subacute in-stent hypodense area after CAS, longer follow-up is strongly recommended.

Preoperative evaluation of precise aneurysmal geometry is important for the treatment of intracranial aneurysms. We present two cases of unclippable side wall aneurysms due to their extremely low dome height, which appeared as saccular in the preoperative image because of a comparatively narrow atherosclerotic parent arterial lumen. In both cases, a calcified vessel wall was noted preoperatively. Lack of a definitive neck and abrupt discrepancy between the fragile aneurysmal wall and the atherosclerotic parent arterial wall was confirmed intraoperatively in both cases. This study describes an illustrative mechanism for the finding with emphasis on the importance of its preoperative diagnosis. Intracranial atherosclerosis associated with small side walled aneurysms may lead to overestimation of aneurysm height on preoperative imaging of the intravascular compartment.

Objective: Atherosclerosis is an inflammatory process that results in complex lesions or plaques that protrude into the arterial lumen. Carotid atherosclerotic plaque rupture, with distal atheromatous debris embolization, causes cerebrovascular events. This review aimed to explore research progress on the risk factors and outcomes of human carotid atherosclerotic plaques, and the molecular and cellular mechanisms of human carotid atherosclerotic plaque vulnerability for therapeutic intervention. Data Sources: We searched the PubMed database for recently published research articles up to June 2016, with the key words of "risk factors" , "outcomes" , "blood components" , "molecular mechanisms" , "cellular mechanisms" , and "human carotid atherosclerotic plaques" . Study Selection: The articles, regarding the latest developments related to the risk factors and outcomes, atherosclerotic plaque composition, blood components, and consequences of human carotid atherosclerotic plaques, and the molecular and cellular mechanisms of human carotid atherosclerotic plaque vulnerability for therapeutic intervention, were selected. Results: This review described the latest researches regarding the interactive effects of both traditional and novel risk factors for human carotid atherosclerotic plaques, novel insights into human carotid atherosclerotic plaque composition and blood components, and consequences of human carotid atherosclerotic plaque. Conclusion: Carotid plaque biology and serologic biomarkers of vulnerability can be used to predict the risk of cerebrovascular events. Furthermore, plaque composition, rather than lesion burden, seems to most predict rupture and subsequent thrombosis. Key words: Human Carotid Atherosclerosis; Outcomes; Plaques; Progress; Risk Factors

Accurate Blood Pressure (BP) estimation plays a crucial role in providing significant information about the patient’s cardiovascular health. In this paper, performance analysis of the various oscillometric BP estimation algorithms – Maximum Amplitude Algorithm (MAA), Maximum Minimum Slope Algorithm (MMSA), Arterial Lumen Area Algorithm (ALA) and Pulse Transit Time (PTT) algorithm has been performed. The analysis was carried out for a data set comprising 37 patients suffering from cardiac problems. The BP for each cardiac patient, estimated with the four oscillometric BP estimation algorithms, was compared with reference invasive BP measurements. The reference BP was estimated from the arterial pulse wave obtained by placing the pressure sensor inside the femoral or brachial arteries of the patients. The comparisons between the oscillometric BP estimation algorithms and the estimated reference BP are reported in terms of Mean Absolute Error (MAE), Standard Deviation of Error (SDE) and Bland-Altman plots analysis. It was found that the ALA followed by PTT are relatively accurate in estimation of BP with lowest MAE and SDE for cardiac patients, whereas MAA is the least accurate BP estimation technique. The results also emphasize the need to develop improved algorithms to estimate BP in cardiac patients.

Endofibrosis (EF) of the iliac arteries is a flow-limiting condition typically seen in highly trained endurance athletes. Thirty-seven athletes (74 limbs) were referred to our department with suspected EF. All patients had a pre- and postexercise color Doppler ultrasound (CDU) of the iliac arteries. Doppler waveform and peak systolic velocity (PSV) and end-diastolic velocity (EDV) were assessed pre- and postexercise. Endofibrosis was diagnosed with CDU in 24 athletes (29 limbs). Arterial wall and course abnormalities were detected at rest in 20 (67%) symptomatic limbs of athletes with and 4 (22%) symptomatic limbs of athletes without EF. Postexercise abnormal waveforms of the stenotic/damped type were seen in the iliac arteries in all 29 limbs of athletes diagnosed with EF. These waveform changes were accompanied by high PSV (>350 cm/s) and EDV (>150 cm/s), with (n = 10; 34%) or without (n = 19; 66%) the evidence of reduced arterial lumen caliber. Color Doppler ultrasound can be used to detect EF.

Smooth muscle contraction regulates the size of the blood vessel lumen which directly affects the mechanical response of the vessel. Folding in arteries has been observed in arteries during excessive contraction, known as a coronary artery spasm. The interplay of muscle contraction, geometry, and material responses and their effects on stability can be understood through mathematical models. Here, we consider a three-layer cross-sectional model of a coronary artery with anisotropic properties and intimal thickening, and perform a linear stability analysis to investigate the circumferential folding patterns that emerge due to muscle contraction. Our model shows that a critical level of contractile activity yields a uniform strain distribution across the arterial wall. When the muscle is contracted above this critical level, the tissue behaves isotropically and it is more prone to circumferential instability. This theoretical framework could serve as a valuable tool to understand the relationship between arterial lumen morphology and wall contraction in health and disease.

The most common reason of damage of extracranial carotid arteries is atherosclerosis. Atherosclerosis is a chronic disease, which develops in the result of disorder of lipid and protein metabolism. Elastic and muscular-elastic arteries get damaged following focal accretions of lipids and proteins in arterial intima and reactive growth of connective tissue. Arterial lumen consequently reduces, and thrombosis, which is customary for such condition, results in local or general circulatory disturbance.

Giant cell arteritis (GCA) is a primary systemic vasculitis present in subjects older than 50years with involvement of large- and medium-sized arteries. Early diagnosis for GCA is essential to prevent serious complications, such as permanent vision loss and/or cerebrovascular events. Elevated inflammatory cytokines, with acute phase and other proteins dominate large- and medium-sized arteries leading to stenosis or occlusion of arterial lumen. To date, there are no reliable serological markers for monitoring GCA. The review aims to provide concise overview of published GCA studies in order to: a) identify significantly changed serological biomarkers in GCA and compare the influences of techniques for marker evaluation and b) investigate most promising markers in GCA using analyte frequency and meta-analysis.

Coronary angiography has been the gold standard for assessment of coronary anatomy since first performed by Mason Sones in 1958. However, the coronary angiogram has many limitations; it gives information about the patency of the arterial lumen but no information about the vessel wall. Intravascular ultrasound (IVUS) is based upon the same principles used for ultrasound elsewhere in the body. It utilises a monorail catheter with an ultrasound transducer at its tip to generate a two-dimensional cross-sectional image of the coronary artery similar to a histologic cross section. Depending on the manufacturer, current IVUS catheters in use range from 20 to 60 MHz for coronary imaging and 10 to 20 MHz for peripheral imaging. The IVUS catheter has a single transducer element located at its tip that is rotated by an external motor drive attached to the proximal end of the catheter at 1800 rpm.

BackgroundAlthough renal sympathetic denervation therapy has shown promising results in patients with resistant hypertension, the human anatomy of peri-arterial renal nerves is poorly understood.ObjectivesThe aim of our study was to investigate the anatomic distribution of peri-arterial sympathetic nerves around human renal arteries.MethodsBilateral renal arteries were collected from human autopsy subjects, and peri-arterial renal nerve anatomy was examined by using morphometric software. The ratio of afferent to efferent nerve fibers was investigated by dual immunofluorescence staining using antibodies targeted for anti–tyrosine hydroxylase and anti–calcitonin gene–related peptide.ResultsA total of 10,329 nerves were identified from 20 (12 hypertensive and 8 nonhypertensive) patients. The mean individual number of nerves in the proximal and middle segments was similar (39.6 ± 16.7 per section and 39.9 ± 1 3.9 per section), whereas the distal segment showed fewer nerves (33.6 ± 13.1 per section) (p = 0.01). Mean subject-specific nerve distance to arterial lumen was greatest in proximal segments (3.40 ± 0.78 mm), followed by middle segments (3.10 ± 0.69 mm), and least in distal segments (2.60 ± 0.77 mm) (p < 0.001). The mean number of nerves in the ventral region (11.0 ± 3.5 per section) was greater compared with the dorsal region (6.2 ± 3.0 per section) (p < 0.001). Efferent nerve fibers were predominant (tyrosine hydroxylase/calcitonin gene–related peptide ratio 25.1 ± 33.4; p < 0.0001). Nerve anatomy in hypertensive patients was not considerably different compared with nonhypertensive patients.ConclusionsThe density of peri-arterial renal sympathetic nerve fibers is lower in distal segments and dorsal locations. There is a clear predominance of efferent nerve fibers, with decreasing prevalence of afferent nerves from proximal to distal peri-arterial and renal parenchyma. Understanding these anatomic patterns is important for refinement of renal denervation procedures.

Background: The aim was to evaluate the accuracy, precision and feasibility of semi-automatic border detection software (AMS) in comparison to manual electronic calipers (EC) in the analysis of arterial images obtained with transcutaneous very-high resolution vascular ultrasound (VHRU, 25-55 MHz). Methods: 100 images from central elastic and peripheral muscular arteries were obtained on two separate imaging occasions from 10 healthy subjects, and independently measured with AMS and EC. Results: No bias between AMS and EC was found. The intraobserver coefficients of variation (CV) for carotid lumen dimension (mean dimension 5.60 mm) was lower with AMS compared with EC (0.4 vs. 1.9%, p = 0.033; N = 20). No consistently significant differences in intra, inter or test-retest CVs were observed overall for muscular artery dimensions between AMS and EC. The intra CV for adventitial thickness (AT, mean 0.111 mm; 15.6 vs 24.8%, p = 0.011; N 41) and inter CV for intima-media thickness (IMT, mean 0.219 mm; 14.3 vs. 21.2%, p = 0.001; N = 58) obtained with AMS in higher quality thin muscular artery images was lower compared with EC. The mean reading time was significantly lower with AMS compared with EC (71.5 s vs. 156.6 s, p < 0.001). Conclusion: AMS is accurate, precise, and feasible in the analysis of arterial images obtained with VHRU. Minor, although statistically significant, differences in the precision of AMS and EC-systems were found. The precision of AMS was superior for AT and IMT in higher quality images likely related to a decrease in the technical variability imposed by the observer. (C) 2014 Elsevier Ireland Ltd. All rights reserved.

Atherosclerosis is a chronic inflammatory disease of the arterial wall where the accumulation of foam cells, lipids, calcium, and cellular debris leads to large fibrofatty atheromatous plaques narrowing the arterial lumen. As the principal cause of human deaths in the world, the pathogenesis of atherosclerosis has been extensively studied, as well as lipid and lipoprotein metabolism, across species. Important aspects of the disease were first investigated experimentally in a wide array of animal models, including laboratory avian and mammalian species also kept as companion pets. Although the disease is primarily a significant clinical entity in avian patients, the wealth of information obtained from companion exotic mammals is of interest to understand the complex comparative pathogenesis of atherosclerotic lesions. This review presents the current concepts of atherogenesis and lipoprotein metabolism followed by a brief overview of species peculiarities as it relates to the experimental reproduction of the disease. This overview should provide interesting insight on atherosclerosis, which spontaneously or experimentally affects many zoological companion species commonly seen by veterinarians.

[ES] Las enfermedades cardiovasculares se han convertido en la primera causa de fallecimientos en México y en el mundo. La medición de la íntima-media carotídea y del diámetro de la luz humeral en imágenes de ultrasonido, son la base de dos de las pruebas destacadas para el diagnóstico temprano de este tipo de enfermedades. En este trabajo se presenta una metodología completamente automática para la detección de la luz arterial en ultrasonografías, necesaria en las pruebas citadas; basada en grafos y detección de bordes. El grafo se crea con los puntos intermedios entre los bordes y, su árbol de expansión mínima, permite segmentar la luz arterial correcta, aplicando sobre las rutas internas del grafo un criterio de selección de longitud y otro de obscuridad. En 294 imágenes, se obtuvo un error promedio en la detección de la interfaz entre el lumen de la arteria humeral y la capa íntima de su pared cercana de 13.9 μm, con una desviación estándar de 12.3 μm; y, para la misma interfaz en la pared arterial lejana, de 15.4 μm, con una desviación estándar de 15.0 μm. La comparación del desempeño de nuestro algoritmo se realizó contra los resultados presentados en la literatura reciente para técnicas tanto automáticas como semi-automáticas en esta área, a las cuales supera en precisión., [EN] Cardiovascular diseases have become the first cause of dead in Mexico and the whole world. Intima-media thickness and brachial lumen diameter measurement in ultrasound images are the basis of two early diagnostic tests for this kind of illnesses. In this paper a methodology for automatic arterial lumen detection using ultrasound images, which is based on a graph and edge detection, is presented. The graph is created with middle points between edges and, its minimum spanning tree, is used together with decision criteria based on darkness and length, for the correct arterial lumen segmentation. In 294 images, a mean error in position detection of brachial lumen-intima interface on the near wall of 13.9 μm, with a standard deviation of 12.3 μm, was found; and, for same interface on the arterial far wall, mean error was of 15.4 μm with a standard deviation of 15.0 μm. Performance comparison of our algorithm was made against results presented in recent literature for automatic and semi-automatic techniques in this area, to whom it outperformed in accuracy.

Coronary artery disease (CAD) is the most common cause of death in the world, resulting in the loss of over 8 million lives in 2013 alone. During atherosclerotic CAD progression, localized inflammation causes plaque buildup, thickening of the arterial wall, and narrowing of the arterial lumen.

Arterial stiffness is increasingly recognized as an important determinant of cardiovascular risk and may be directly involved in the process of atherosclerosis. As atherosclerosis leads to increased arterial resistance and decrease the flow propagation speed within the arterial lumen, a similar decrease in aortic flow propagation with increased downstream resistance is detected, so aortic flow propagation velocity AVP was evaluated in many studies as a new parameter of aortic stiffness. Aim: To measure arterial stiffness using the new parameter AVP and compare it to flow mediated dilatation FMD as a parameter of endothelial dysfunction in patients with metabolic syndrome MS. Methods: AVP (assessed by transthoracic echocardiography) and FMD (assessed by brachial artery reactivity test) were measured in 100 patients with MS (Group 1) and were compared to 14 normal subjects (Group 2). Results: Patients with MS had significantly lower values of AVP as compared to the normal subjects; 36 ± 5 cm/s vs 57 ± 5, p

White blood and black blood magnetic resonance imaging methods are often used for lumenography and visualization of the arterial wall, respectively. However, the use of white blood imaging invariably obscures arterial wall boundaries, and thus, impedes precise measurement of arterial wall area. Conversely, black blood imaging imposes strict limits on sequence timing to suppress the arterial lumen, and by itself, precludes separation of superficial calcification from the hypointense arterial lumen. In this work, a three-dimensional arterial wall imaging methodology providing gray blood image contrast is described that remedies the above limitations. When applied to the carotid arteries, the described gray blood imaging method is found to clearly depict the inner and outer arterial wall boundaries as well as superficial and deep-seated vascular calcifications. A tailored phase-encoding schedule is also presented that enables concurrent gray and black blood, or “dual contrast,” imaging of the arterial wall with no increase in the acquisition time. Taken together, presented data demonstrate that gray and dual blood contrast magnetic resonance imaging provide an efficient means for viewing and characterizing the composition of atherosclerotic plaques. Magn Reson Med, 2013. © 2012 Wiley Periodicals, Inc.

The objective was to evaluate the efficacy of treatment of patients with large and giant cerebral arterial aneurysms using flow-diverting stents (FDSs).The treatment outcomes of 210 patients with large and giant intracranial aneurysms were analyzed. The study included patients with both asymptomatic and symptomatic aneurysms (manifested by SAH or pseudotumorous course). The rate of giant aneurysms was 62.3%.The technical success rate was 96%. In the perioperative period, the rate of clinically significant complications was 2.8%; the postoperative mortality was 3.3%. In the long-term period, total thrombosis of the aneurysm was observed in the majority of cases (80%) in the period from 4 to 12 months. Complete regression of clinical symptoms was observed in 26% of the cases, partial regression in 35%, and deterioration in 6% (of them, 4.9% of the cases were clinically significant). The long-term mortality was 2.5%.FDS is a highly efficient device for remodeling of the arterial lumen at the level of large, giant and fusiform intracranial aneurysms that significantly reduces the number of deconstructive operations and decreases the risk of ischemic complications of endovascular treatment for this complex vascular pathology.Цель - оценить эффективность лечения больных с крупными и гигантскими артериальными аневризмами головного мозга с использованием потокоперенаправляющих стентов (ППНС). Материал и методы. Анализируются результаты лечения 210 больных с крупными и гигантскими интракраниальными аневризмами. В исследование вошли пациенты как с симптомными, так и симптоматическими аневризмами (проявившимися САК или с псевдотуморозным течением). Доля гигантских аневризм составила 62,3%. Результаты. Технический успех составил 96%. В периоперационном периоде доля клинически значимых осложнений составила 2,8%, послеоперационная летальность - 3,3%. В отдаленном периоде в подавляющем большинстве (80%) случаев наблюдалось тотальное тромбирование аневризмы в сроки от 4 до 12 мес. Полный регресс клинических симптомов наблюдался в 26% случаев, частичный регресс - в 35%, ухудшение - в 6% (из них 4,9% - клинически значимые). Летальность в отдаленном периоде составила 2,5%. Заключение. ППНС является высокоэффективным устройством для ремоделирования просвета артерии на уровне крупных, гигантских и фузиформных интракраниальных аневризм, что позволяет существенно сократить количество деконструктивных операций и уменьшить риск ишемических осложнений при эндоваскулярном лечении этой сложной сосудистой патологии.

We deeply thank Drs. Vavuranakis, Kalogeras, and Tousoulis for their interest in our recent paper [(1)][1]. Any current intravessel optical coherence tomography (OCT) systems require injection of flushing medium, resulting in high pressure in the arterial lumen and consequently within the arterial

Objectives: The aim of this study was to evaluate a new fully automated lumen border tracing system based on a novel multifrequency processing algorithm. Background: We developed the multifrequency processing method to enhance arterial lumen detection by exploiting the differential scattering characteristics of blood and arterial tissue. The implementation of the method can be integrated into current intravascular ultrasound (IVUS) hardware. Methods: This study was performed in vivo with conventional 40-MHz IVUS catheters (Atlantis SR Pro™, Boston Scientific Corp, Natick, MA) in 43 clinical patients with coronary artery disease. A total of 522 frames were randomly selected, and lumen areas were measured after automatically tracing lumen borders with the new tracing system and a commercially available tracing system (TraceAssist™) referred to as the “conventional tracing system.” The data assessed by the two automated systems were compared with the results of manual tracings by experienced IVUS analysts. Results: New automated lumen measurements showed better agreement with manual lumen area tracings compared with those of the conventional tracing system (correlation coefficient: 0.819 vs. 0.509). When compared against manual tracings, the new algorithm also demonstrated improved systematic error (mean difference: 0.13 vs. −1.02 mm2) and random variability (standard deviation of difference: 2.21 vs. 4.02 mm2) compared with the conventional tracing system. Conclusions: This preliminary study showed that the novel fully automated tracing system based on the multifrequency processing algorithm can provide more accurate lumen border detection than current automated tracing systems and thus, offer a more reliable quantitative evaluation of lumen geometry. © 2011 Wiley Periodicals, Inc.

Numerous techniques have been described to treat intracranial vessel perforation during endovascular interventions. We describe a novel application of Onyx-18 for the treatment of intracranial catheter perforations by sealing the vessel from the outside while retracting the catheter into the arterial lumen.

Arteriosclerosis has accounted for three quarters of the deaths related to cardiovascular disease (CVD). Arteriosclerosis is a vascular disease that is characterized by a thickening of the arterial wall and subsequent decrease in the arterial lumen, eventually causing loss of circulation distal to the site of disease. Small diameter arteries (

The acute technical failure of endovascular treatment of chronic total occlusions is most often due to the inability to re-enter the true lumen after occlusion is crossed in a subintimal plane. True lumen re-entry catheters are very effective at gaining wire passage back to the true lumen and facilitating successful endovascular treatment of chronic total occlusions that would otherwise require open bypass. These case reports describe our initial experiences with a new catheter system (the Outback ⓡ LTD™ catheter) that is designed to allow fluoroscopically controlled re-entry of the true arterial lumen after subintimal guidewire passage during recanalization procedures of arterial occlusions.