Xueying Huang¹, Chun Yang², Jie Zheng³, Pamela K. Woodard³, Dalin Tang¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.1, No.1, pp. 29-34, 2007, DOI:10.3970/icces.2007.001.029

Abstract Atherosclerotic plaques may rupture without warning and cause acute cardiovascular syndromes such as heart attack and stroke. Accurate identification of plaque components will improve the accuracy and reliability of computational models. In this article, we present a segmentation method using a cluster analysis technique to quantify and classify plaque components from magnetic resonance images (MRI). 3D in vivo and ex vivo multi-contrast (T1-, proton density-, and T2-weighted) MR Images were acquired from a patient of cardiovascular disease. Normal distribution Bayes classifier was performed on ex vivo and in vivo MR Images respectively. The resulting segmentation obtained from cluster analysis showed… More >

Caining Zhang¹, Huaguang Li², Xiaoya Guo³, David Molony⁴, Xiaopeng Guo², Habib Samady⁴, Don P. Giddens^4,5, Lambros Athanasiou⁶, Rencan Nie^2,*, Jinde Cao^3,*, Dalin Tang^1,*,7

Molecular & Cellular Biomechanics, Vol.16, No.2, pp. 153-161, 2019, DOI:10.32604/mcb.2019.06873

Abstract Cardiovascular diseases are closely associated with deteriorating atherosclerotic plaques. Optical coherence tomography (OCT) is a recently developed intravascular imaging technique with high resolution approximately 10 microns and could provide accurate quantification of coronary plaque morphology. However, tissue segmentation of OCT images in clinic is still mainly performed manually by physicians which is time consuming and subjective. To overcome these limitations, two automatic segmentation methods for intracoronary OCT image based on support vector machine (SVM) and convolutional neural network (CNN) were performed to identify the plaque region and characterize plaque components. In vivo IVUS and OCT coronary plaque data from 5… More >

Qingyu Wang¹, Dalin Tang^1,2,*, Gador Canton³, Zheyang Wu², Thomas S. Hatsukami⁴, Kristen L. Billiar⁵, Chun Yuan⁶

Molecular & Cellular Biomechanics, Vol.15, No.4, pp. 189-201, 2018, DOI:10.32604/mcb.2018.04572

Abstract Cardiovascular diseases are closely linked to atherosclerotic plaque development and rupture. Assessment of plaque vulnerability is of fundamental significance to cardiovascular research and disease diagnosis, prevention, treatment and management. Magnetic resonance image (MRI) data of carotid atherosclerotic plaques from 8 patients (5 male, 3 female; age: 62-83, mean=71) were acquired at the University of Washington (UW), Seattle by the Vascular Imaging Laboratory (VIL) with written informed consent obtained. Patient-specific vessel material properties were quantified using Cine MRI data for modeling use. 3D thin-layer models were used to obtain plaque stress and strain for plaque assessment. A stress-based plaque vulnerability index… More >

Yidan Chen^#,1, Kang Zhang^#,1, Juhui Qiu¹, Shicheng He¹, Junyang Huang², Lu Huang¹, Dongyu Jia³, Bo Ling¹, Da Sun⁴, Xiang Xie¹, Tieying Yin^*,1, Guixue Wang^*,1

Molecular & Cellular Biomechanics, Vol.14, No.2, pp. 83-100, 2017, DOI:10.3970/mcb.2017.014.081

Abstract Abnormal shear stress in the blood vessel is an important stimulating factor for the formation of angiogenesis and vulnerable plaques. This paper intended to explore the role of shear stress-regulated Id1 in angiogenesis. First, we applied a carotid artery ring ligation to create local stenosis in ApoE^-/- mice. Then, 3D geometry of the vessel network was reconstructed based on MRI, and our analysis of computational fluid dynamics revealed that wall shear stress of the proximal region was much higher than that of the distal region. In addition, results from histological staining of the proximal region found more vulnerable-probe plaques with… More >

Chunliu He¹, Jiaqiu Wang², Yuxiang Huang¹, Tongjing Zhu¹, Yuehong Miao¹, Zhiyong Li^1,2*

Molecular & Cellular Biomechanics, Vol.13, No.1, pp. 23-36, 2016, DOI:10.3970/mcb.2016.013.027

Abstract Fibrous cap thickness (FCT) is seen as critical to plaque vulnerability. Therefore, the development of automatic algorithms for the quantification of FCT is for estimating cardiovascular risk of patients. Intravascular optical coherence tomography (IVOCT) is currently the only in vivo imaging modality with which FCT, the critical component of plaque vulnerability, can be assessed accurately. This study was aimed to discussion the correlation between the texture features of OCT images and the FCT in lipid-rich atheroma. Methods: Firstly, a full automatic segmentation algorithm based on unsupervised fuzzy c means (FCM) clustering with geometric constrains was developed to segment the ROIs… More >

PoojaJhunjhunwala¹, P.M. Padole², S.B. Thombre³

Molecular & Cellular Biomechanics, Vol.13, No.1, pp. 1-21, 2016, DOI:10.3970/mcb.2016.013.001

Abstract This paper presents Computational fluid dynamic (CFD) analysis of blood flow in three different 3-D models of left coronary artery (LCA). A comparative study of flow parameters (pressure distribution, velocity distribution and wall shear stress) in each of the models is done for a non-Newtonian (Carreau) as well as the Newtonian nature of blood viscosity over a complete cardiac cycle. The difference between these two types of behavior of blood is studied for both transient and steady states of flow. Additionally, flow parameters are compared for steady and transient boundary conditions considering blood as non-Newtonian fluid. The study shows that… More >

Jianhang Du^1,2,3, Liang Wang⁴

Molecular & Cellular Biomechanics, Vol.12, No.4, pp. 249-263, 2015, DOI:10.3970/mcb.2015.012.249

Abstract Growing evidences suggest that long-term enhanced external counterpulsation (EECP) treatment can inhibit the initiation of atherosclerotic lesion by improving the hemodynamic environment in aortas. However, whether this kind procedure will intervene the progression of advanced atherosclerotic plaque remains elusive and causes great concern in its clinical application presently. In the current paper, a pilot study combining animal experiment and numerical simulation was conducted to investigate the acute mechanical stress variations during EECP intervention, and then to assess the possible chronic effects. An experimentally induced hypercholesterolemic porcine model was developed and the basic hemodynamic measurement was performed in vivo before and… More >

Hongjian Wang^*, Jie Zheng^†, LiangWang^‡, Akiko Maehara^§, Chun Yang^II, David Muccigrosso^†, Richard Bachk^II, Jian Zhu^**, Gary S. Mintz^§, Dalin Tang^*,‡,††

Molecular & Cellular Biomechanics, Vol.12, No.2, pp. 107-122, 2015, DOI:10.3970/mcb.2015.012.107

Abstract Computational modeling has been used extensively in cardiovascular and biological research, providing valuable information. However, 3D vulnerable plaque model construction with complex geometrical features and multicomponents is often very time consuming and not practical for clinical implementation. This paper investigated if 2D atherosclerotic plaque models could be used to replace 3D models to perform correlation analysis and achieve similar results. In vivo intravascular ultrasound (IVUS) coronary plaque data were acquired from a patient follow-up study to construct 2D structure-only and 3D FSI models to obtain plaque wall stress (PWS) and strain (PWSn) data. One hundred and twenty-seven (127) matched IVUS… More >

Molecular & Cellular Biomechanics, Vol.9, No.1, pp. 77-94, 2012, DOI:10.3970/mcb.2012.009.077

Abstract Image-based computational modeling has been introduced for vulnerable atherosclerotic plaques to identify critical mechanical conditions which may be used for better plaque assessment and rupture predictions. In vivo patient-specific coronary plaque models are lagging due to limitations on non-invasive image resolution, flow data, and vessel material properties. A framework is proposed to combine intravascular ultrasound (IVUS) imaging, biaxial mechanical testing and computational modeling with fluid-structure interactions and anisotropic material properties to acquire better and more complete plaque data and make more accurate plaque vulnerability assessment and predictions. Impact of pre-shrink-stretch process, vessel curvature and high blood pressure on stress, strain,… More >

Biyue Liu^∗, Dalin Tang^†

Molecular & Cellular Biomechanics, Vol.7, No.4, pp. 193-202, 2010, DOI:10.3970/mcb.2010.007.193

Abstract A three dimensional mathematical model with a linear plaque growth function was developed to investigate the geometrical adaptation of atherosclerotic plaques in coronary arteries and study the influences of flow wall shear stress (WSS), blood viscosity and the inlet flow rate on the growth of atherosclerotic plaques using computational plaque growth simulations. The simulation results indicated that the plaque wall thickness at the neck of the stenosis increased at a decreasing rate in the atherosclerosis progression. The simulation results also showed a strong dependence of the plaque wall thickness increase on the blood viscosity and the inlet flow rate. The… More >