3-D Registration on Carotid Artery imaging data: MRI for different timesteps

A common problem which is faced by the researchers when dealing with arterial carotid imaging data is the registration of the geometrical structures between different imaging modalities or different timesteps. The use of the "Patient Position" DICOM field is not adequate to achieve accurate results due to the fact that the carotid artery is a relatively small structure and even imperceptible changes in patient position and/or direction make it difficult. While there is a wide range of simple/advanced registration techniques in the literature, there is a considerable number of studies which address the geometrical structure of the carotid artery without using any registration technique. On the other hand the existence of various registration techniques prohibits an objective comparison of the results using different registration techniques. In this paper we present a method for estimating the statistical significance that the choice of the registration technique has on the carotid geometry. One-Way Analysis of Variance(ANOVA) showed that the p-values were <0.0001 for the distances of the lumen from the centerline for both right and left carotids of the patient case that was studied.Comment: 4 pages, 4 figures, 1 table, preprint submitted to IEEE-EMBC 201

Staged Percutaneous Coronary Intervention (PCI) for Multivessel STEMI Patients?

Primary percutaneous coronary intervention (PCI) is the treatment of choice for patients with ST-elevation myocardial infarction (STEMI) since it results in greater patency of the infarct-related artery (IRA) and lower rates of re-infarction, stroke and death when compared with fibrinolysis alone. Multivessel disease (MVD) occurs in 40% to 65% of patients with STEMI. Is it possible for an aggressive multivessel percutaneous revascularization strategy to afford advantages in greater myocardial salvage and avoidance of staged procedures, with subsequent savings in compounded procedural risks? ...(excerpt

Lack of effects of pioglitazone on cardiac function in patients with type 2 diabetes and evidence of left ventricular diastolic dysfunction: a tissue doppler imaging study

<p>Abstract</p> <p>Background</p> <p>Thiazolidinediones, used for the treatment of patients with type 2 diabetes mellitus (DM2), are associated with an increased incidence of heart failure. We sought to investigate the effects of pioglitazone on novel echocardiographic indices of left ventricular (LV) diastolic function in DM2 patients with LV diastolic dysfunction (LVDD).</p> <p>Methods</p> <p>Eighty-eight asymptomatic DM2 patients on metformin and/or sulfonylureas, aged 64.5 ± 7.7 years, without known cardiovascular disease, with normal LV systolic function and evidence of LVDD were randomly assigned to pioglitazone 30 mg/day (n = 42) or an increase in dose of other oral agents (n = 39) for 6 months. All patients underwent transthoracic conventional and Tissue Doppler Imaging echocardiography at baseline and follow-up. The primary end-point was change in early diastolic velocity of the mitral annulus (E').</p> <p>Results</p> <p>Improvement of glycaemic control was similar in the 2 groups. A significant difference (p < 0.05) between the 2 groups was found in the treatment-induced changes in fasting insulin, the insulin resistance index HOMA, HDL cholesterol, triglycerides, diastolic blood pressure (all in favor of pioglitazone) and in body weight (increase with pioglitazone). No significant changes were observed in any echocardiographic parameter in either group and did not differ between groups (p = NS for all). E' increased non-significantly and to a similar extent in both groups (p = NS).</p> <p>Conclusions</p> <p>In asymptomatic DM2 patients with LVDD, the addition of pioglitazone to oral conventional treatment for 6 months does not induce any adverse or favorable changes in LV diastolic or systolic function despite improvements in glycaemic control, insulin sensitivity, lipid profile, and blood pressure.</p

Patient-specific computational modeling of subendothelial LDL accumulation in a stenosed right coronary artery: effect of hemodynamic and biological factors

Patient-specific computational modeling of subendothelial LDL accumulation in a stenosed right coronary artery: effect of hemodynamic and biological factors. Am J Physiol Heart Circ Physiol 304: H1455-H1470, 2013. First published March 15, 2013; doi:10.1152/ajpheart.00539.2012.-Atherosclerosis is a systemic disease with local manifestations. Low-density lipoprotein (LDL) accumulation in the subendothelial layer is one of the hallmarks of atherosclerosis onset and ignites plaque development and progression. Blood flow-induced endothelial shear stress (ESS) is causally related to the heterogenic distribution of atherosclerotic lesions and critically affects LDL deposition in the vessel wall. In this work we modeled blood flow and LDL transport in the coronary arterial wall and investigated the influence of several hemodynamic and biological factors that may regulate LDL accumulation. We used a three-dimensional model of a stenosed right coronary artery reconstructed from angiographic and intravascular ultrasound patient data. We also reconstructed a second model after restoring the patency of the stenosed lumen to its nondiseased state to assess the effect of the stenosis on LDL accumulation

Simulation of atherosclerotic plaque growth using computational biomechanics and patient-specific data

Atherosclerosis is the one of the major causes of mortality worldwide, urging the need for prevention strategies. In this work, a novel computational model is developed, which is used for simulation of plaque growth to 94 realistic 3D reconstructed coronary arteries. This model considers several factors of the atherosclerotic process even mechanical factors such as the effect of endothelial shear stress, responsible for the initiation of atherosclerosis, and biological factors such as the accumulation of low and high density lipoproteins (LDL and HDL), monocytes, macrophages, cytokines, nitric oxide and formation of foams cells or proliferation of contractile and synthetic smooth muscle cells (SMCs). The model is validated using the serial imaging of CTCA comparing the simulated geometries with the real follow-up arteries. Additionally, we examine the predictive capability of the model to identify regions prone of disease progression. The results presented good correlation between the simulated lumen area (P<0.0001), plaque area (P<0.0001) and plaque burden (P<0.0001) with the realistic ones. Finally, disease progression is achieved with 80% accuracy with many of the computational results being independent predictors

Patient-specific simulation of coronary artery pressure measurements: An in vivo three-dimensional validation study in humans

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Non-Invasive Prediction of Site-Specific Coronary Atherosclerotic Plaque Progression using Lipidomics, Blood Flow, and LDL Transport Modeling

Background: coronary computed tomography angiography (CCTA) is a first line non-invasive imaging modality for detection of coronary atherosclerosis. Computational modeling with lipidomics analysis can be used for prediction of coronary atherosclerotic plaque progression. Methods: 187 patients (480 vessels) with stable coronary artery disease (CAD) undergoing CCTA scan at baseline and after 6.2 +/- 1.4 years were selected from the SMARTool clinical study cohort (Clinicaltrial.gov Identifiers NCT04448691) according to a computed tomography (CT) scan image quality suitable for three-dimensional (3D) reconstruction of coronary arteries and the absence of implanted coronary stents. Clinical and biohumoral data were collected, and plasma lipidomics analysis was performed. Blood flow and low-density lipoprotein (LDL) transport were modeled using patient-specific data to estimate endothelial shear stress (ESS) and LDL accumulation based on a previously developed methodology. Additionally, non-invasive Fractional Flow Reserve (FFR) was calculated (SmartFFR). Plaque progression was defined as significant change of at least two of the morphological metrics: lumen area, plaque area, plaque burden. Results: a multi-parametric predictive model, including traditional risk factors, plasma lipids, 3D imaging parameters, and computational data demonstrated 88% accuracy to predict site-specific plaque progression, outperforming current computational models. Conclusions: Low ESS and LDL accumulation, estimated by computational modeling of CCTA imaging, can be used to predict site-specific progression of coronary atherosclerotic plaques.</div

Focus on the research utility of intravascular ultrasound - comparison with other invasive modalities

Intravascular ultrasound (IVUS) is an invasive modality which provides cross-sectional images of a coronary artery. In these images both the lumen and outer vessel wall can be identified and accurate estimations of their dimensions and of the plaque burden can be obtained. In addition, further processing of the IVUS backscatter signal helps in the characterization of the type of the plaque and thus it has been used to study the natural history of the atherosclerotic evolution. On the other hand its indigenous limitations do not allow IVUS to assess accurately stent struts coverage, existence of thrombus or exact site of plaque rupture and to identify some of the features associated with increased plaque vulnerability. In order this information to be obtained, other modalities such as optical coherence tomography, angioscopy, near infrared spectroscopy and intravascular magnetic resonance imaging have either been utilized or are under evaluation. The aim of this review article is to present the current utilities of IVUS in research and to discuss its advantages and disadvantages over the other imaging techniques