Personalised imaging and biomechanical modelling of large vessels

Abstract

The large blood vessels are crucial for blood flow distribution in the body but they may be subjected to disease processes like atherosclerosis, and consequences thereof like aneurysm formation, stroke, and myocardial infarction. These diseases are associated to a majority of the mortality of cardiovascular disease, which may be as high as 33% of overall disease related mortality. The function of these blood vessels has successfully been studied in the framework of biology, physics, and imaging. While a decade ago vessel function was merely described in terms of average blood flow, overall compliance and distensibility, the turbulent development of computational resources and numerical modelling has enabled calculations of local wall stress, local blood flow, and local wall deformation. Especially the methods to solve the non-linear NavierStokes equations and the equations that describe non-linear solid mechanics have evolved over the last decade and currently enable shear stress distributions in complex vessel geometries. Furthermore, the development of invasive and non-invasive imaging enables imaging the 3D geometry of blood vessels and thereby to develop personalised and segmental calculations of the wall stress and shear stress fields. This Special Issue is focussed upon the development and improvement of methods to obtain personalised information of the arterial tree in terms of vascular geometry, pressure distribution, shear stress distribution and wall stress distribution, in order to predict better interventions for individual patients.The first paper in this issue [9] gives an overview of developments in diagnostic tests for carotid and coronary disease, and aortic aneurysms and dissection. It is concluded that improved diagnostics by applying biophysics based mathematical model eventually will lead to improved patient management.In the second series of papers the technical description of automated methods for image reconstruction is presented. In the first of the series, Peiro [8] describe methods to obtain high quality reconstructions of images of blood vessels and the consequences for mesh-generation and CFD quality. Two other papers [1, 2] describe methods to develop a cascade of methods to start from an image and end with a wall stress or shear stress field in either the carotid artery [1] and aortas [2]. These methods are essential for obtaining patient specific information in the clinical environment.In the next series of papers, the pathophysiology of diseases is deepened by showing that haemodynamics contributes factors to the formation of brain aneurysm [3], aneurysm expansion [4] and stent-graft vessel wall interaction [5]. Chien et al. [3] show that in ruptured aneurysm the flow field is different compared to flow fields in aneurysm without rupture. The question is whether this difference could have been detected before rupture occurred. Helderman et al. [4] develop a general method to predict aneurysm expansion, while Lam et al. [5] describe the parameters that will help to better design...

Modeling effects of axial extension on arterial growth and remodeling

“…Nevertheless, the present results are encouraging and suggest that a single theory of arterial growth and remodeling, containing a single set of material parameters, should be able to describe and predict responses to diverse perturbations in the chemomechan-ical environment once we have refined the requisite constitutive relations and material parameters based on improved data, particularly on stress-mediated constituent turnover rates. Together, therefore, continued parallel advances in vascular mechanobiology, medical imaging, biomechanical modeling, and computational methods promise to increase significantly our understanding of vascular physiology, pathophysiology, injury, and clinical intervention, and thus to improve clinical care via more personalized and pre-emptive treatments [14, 18]. …”

The Nightingale Award 2008

“…Then, the problem remained to reorder that short list of 14 papers according to the judgment of the editors. The invited papers from Special Issues [ 9 , 15 ], as well as review papers where excluded. We cite these papers in this editorial as to provide credit to the authors who submitted excellent work to the journal.…”