The Patient-specific Computational Model Of Risk Prediction Of Carotid Atherosclerotic Plaque Rupture: Preliminary Research

Objectives: To explore a method to predict the risk of carotid atherosclerotic plaquerupture using a patient-specific computational model.Methods: A3D finite element computational model with fluid structure interactionsbased on in vivo high resolution MRI combined specific material properties andboundary conditions is introduced to perform biomechanical analysis which may berelated to plaque rupture.1. The collection and processing of high resolution MRI data57patients with carotid atherosclerosis undergone high resolution MRI scan.3.0Tnuclear magnetic resonane scanner was adopted（GE Signa Excite，GE MedicalSystem, MilwaukeeUS）. Choose one patient from them by analysis the scan result.Including criteria of patient of interest was:（1）thin or incomplete fibrous cap;(2)large lipid necrosis core;(3) hemorrhage within plaques;(4)Calcification developedon the lumen side of the plaques.2. Materials Propertiesa) Blood density and viscosity: The blood sample was drawed from the patientof interest for a hemorheology test.b) The elastic mudulus of carotid artery: ALOKA SSD-5500Doppler ultrasonicdiagnosis scanner was used to measure the in vivo presure-strain elasticmudulus (Ep) of carotid artery. Echo-traching technique with e-DMS systemwas deployed.c) The elastic mudulus of plaques: AixPlorer ultrasonic diagnosis scanner wasused to measure the elastic mudulus (E) of plaques，including the fibrous capand lipid pool. 3. Boundary conditionsa) Blood pressure: DynaPulse (DP2000A) electronic sphygmomanometer wasdeployed to measure the blood pressure of brachial artery. The bloodpressure of carotid artery was then calculated.b) Blood velosity: Doppler ultrasonic scanner was used to measure the bloodvelosity in carotid artery4. Statistic methods: All statistic data was analysised by SPSS17.0sofeware.5. Geometric modelling6. Computational simulationResults:1. Data of high resolution MRI of carotid bifurcation was achieved.2. The elastic modulus of carotid atherosclerotic artery was measured noninvasively.3. The elastic modulus of carotid atherosclerotic plaques was measured noninvasively.4. Simple geometric model construction and computational simulation wasaccomplished.5. The blood velocity, high wall shear stress and pressure of the stenosis artery maybe the biomechanical reason of plaque rupture from our preliminary result ofnumerical simulation.Conclusions:1. High solution MRI is a commendable method which can be used to measure thesize and components of the plaques quantitatively.2. Techniques of in vivo measurement of elastic modulus need to be further improved.3. Distinct variances presented in different plagues of a particular individual and alsoamong different cases.4. Computational simulation could explicitly display the biomechanical changes inand around the plaque indicating that the biomechanical reason of plaque rupture 5. Material properties and boundary restrictions should be measured specifically whenconstructing3D finite element computational model in order to ensure the validityand specificity of the numerical simulation.