Medical Image-base Anatomic And Functional Assessment Of The Cardiovascular Diseases By 3D Printing And Hemodynamics Analysis

BackgroundCardiovascular disease(CVD)has been accounted for the major cause of death in developing countries.The atherosclerosis in the arteries lead to the initiation of the stenotic plaque,which causes stroke,myocardial infarction and other major adverse cardiovascular events(MACE).Ischemic risk assessments of the arterial stenosis are commonly determined by invasive procedures,such as invasive angiography and invasive fractional flow reserve(FFR)measurements.These procedures are side with invasive complications and economic burden,which hindered the clinical application of the CVD screening in the high-risk cohort.Therefore,there is a need to develop effective methods for noninvasive assessment of the ischemic risk.On the purpose of providing a further understanding of the noninvasive cardiovascular functional assessment,studies were conducted to investigate the correlation between anatomic and hemodynamic parameters in the patient-specific arterial geometries.Method1.Twenty cases of CTA images from patients with coronary stenosis were retrospectively collected.An automatic three-dimensional reconstruction algorithem was developed for patient-speicfic coronary arterial geometric reconstruction and hemodynamic analysis were performed.FFRCT retracted curve was proposed for hemodynamic analysis of the serial stenosis.Based on the calcualtions,virtual revascularization was performed for predicting the post-operational outcomes.2.Eight cases of CTA images from the patients with left coronary stenosis were rectrospectively collected.Three-dimensional coronary arterial geometries were reconstructed for correlation analysis between anatomic and hemodynamic characteristics.We also compared the technical detail among common 3D printing methods to explore the application to the small-scale arteries,such as coronary artery.3.Nineteen cases of MRA images from patients with carotid arterial stenosis were rectrospectively collected.Three-dimensional carotid arterial geometries were reconstructed for anatomic and hemodynamic analysis.Based on the calcuations,we proposed a quantitative index for functional assessment of the stenotic carotid artery.Results1.Hemodynamics analysis of the serial stenotic coronary arteries proved that noninvasive FFRCT pull back curve and wall shear stress distribution was capable to predict the fluctuation of the blood pressure due to the serial stenoses.On the other hand,virtual surgery was performed and validated by comparing the FFRCT pull-back curve to the FFR measurement from actual revascularization and consistency was found compared to actual revascularizations.2.Hemodynamics analysis was performed in the left coronary artery with stenosis to evaluated the correlation between anatomic and functional assessments.Results indicated that severity of stenosis was a determinate factor to the translesion pressure drop,and the joint effect of arterial curvature and angle culprit vessel on the maximum flow velocity over the stenosis could serve as indicator to predict the vulnerability of the lesion(r=-0.673,p=0.033).This study validated the usefulness of coronary visualization by using Stereolithography(SLA)based 3D printing device for the first time(r=0.987,p<0.01)3.A pressure gradient index was first proposed and the diagnostic performance on functional assessment was tested.The threshold value for determining the functionally significant stenosis was established and the impacts of carotid anatomic parameters on the pressure gradient was evaluated(vPG<0.88).Results showed that diagnostic performance on the carotid functional assessment could be potentially benefited from the quantitative pressure gradient index.ConclusionThe non-invasive ischemic-risk assessment has been a important advance for screening CVD.By further investigating the correlation between anatomic significance and hemodynamic significance,the diagnostic accuracy,efficiency of the non-invasive functional assessment methods could be improved.In additional,the accuracy of the application of 3D printing for the small arteries had been evluated in present study.The value of 3D printing for small scale vessel was therefore validated.