Computer methods for follow-up study of hemodynamic and disease progression in the stented coronary artery by fusing IVUS and X-ray angiography

Abstract

Despite a lot of progress in the fields of medical imaging and modeling, problem of estimating the risk of in-stent restenosis and monitoring the progress of the therapy following stenting still remains. The principal aim of this paper was to propose architecture and implementation details of state of the art of computer methods for a follow-up study of disease progression in coronary arteries stented with bare-metal stents. The 3D reconstruction of coronary arteries was performed by fusing X-ray angiography and intravascular ultrasound (IVUS) as the most dominant modalities in interventional cardiology. The finite element simulation of plaque progression was performed by coupling the flow equations with the reaction-diffusion equation applying realistic boundary conditions at the wall. The alignment of baseline and follow-up data was performed automatically by temporal alignment of IVUS electrocardiogram-gated frames. The assessment was performed using three six-month follow-ups of right coronary artery. Simulation results were compared with the ground truth data measured by clinicians. In all three data sets, simulation results indicated the right places as critical. With the obtained difference of 5.89 ± ~4.5% between the clinical measurements and the results of computer simulations, we showed that presented framework is suitable for tracking the progress of coronary disease, especially for comparing face-to-face results and data of the same artery from distinct time periods.

Finite element analysis of uncommonly large renal arteriovenous malformation—Adjacent renal cyst complex

“…Consequently, as a disadvantage of this study we report the impossibility to perform in-vivo validation of the obtained results in the case of RAVM. However, since software tools used in this study have been previously validated and established as reliable in numerous examples [13][14][15][16]22,23], we assumed that calculated physical quantities were acceptable. To the best of our knowledge, there is no similar study in the literature that analyzed RAVM from the point of biomechanics.…”

“…The assumption was made about the cystic wall to be a linearly elastic, isotropic and homogenous. The blood was assumed to be incompressible, with a Newtonian behavior having density ρ ¼ 1050 ½kg=m 3 and viscosity μ ¼ 0:0035 ½Pa [13,14]. The governing equations for the viscous incompressible flow were the Navier-Stokes equation and the continuity equation:…”

“…In the recent literature, mechanical response and interaction of medical devices, human tissues and blood flow are commonly studied by using finite element method (FEM) or finite element analysis (FEA) [13][14][15][16]. FEA represents a cost-effective tool in situations where precise analysis and evaluation of physical quantities (such as stress, strain, displacements, velocity, temperature, etc.)…”

Simultaneous Registration of Location and Orientation in Intravascular Ultrasound Pullbacks Pairs Via 3D Graph-Based Optimization

“…Despite several methods reported [9]–[13], no perfect solution emerged delivering reliable registration results. The registration task is indeed very challenging [12], [13].…”

“…Despite several methods reported [9]–[13], no perfect solution emerged delivering reliable registration results. The registration task is indeed very challenging [12], [13]. The challenges associated with motion artifacts, longitudinal oscillations, artifactual angular twisting, stuck/accelerated IVUS catheter during pullback acquisitions, vessel-morphologic changes due to plaque progression/regression at follow-up, etc.…”