0000000000351531
AUTHOR
Yufei Wang
The compliance modelling of the pathology aorta of the type of aneurism
The Abdominal Aorta Aneurysm (AAA) is a pathology that is defined by a localized and permanent dilation of the artery and which involves over 8.8% of the seniors. Currently, when a patient has a dilatation of the aorta leading to a surgery because of the rupture risk, the therapeutic decision is made depending on the diameter of the aneurysm. To determine this diameter, it is usually conducted an examination by medical imaging (ultrasound, CT, MRI...). However, it notes that the diagnosis can’t be satisfied with a single dimensional measurement face to induced risks: first of all, when the diameter exceed a certain growth, the risk of rupture can reach 50% but more than 5% of surgical proce…
Strain fields measurement of non-rigid solid by scanning laser coupled with camera
International audience; Abstract. Today, the techniques of measurement without contact by scanning laser are increasingly used. These techniques allow to measure 3D objects without contact and the measurement rates can reach few thousand points by second that is very adapted to complex shapes. To measure displacements and deformations, it is necessary to follow a solid particle in its motion between two configurations of the body before and after displacement. The method of stereovision based on grayscale patterns, obtained by applying a spray, is generally used. The results are obtained by two correlations: spatial and temporal correlations. An alternative method consists to use a scanner …
Intercomparison between MRI and stereovision/PIV measurements for diagnosis of aorta pathologies
International audience; The objective of the study is to validate the ability of magnetic resonance imaging (MRI) to perform measurements of deformations and internal flow of an aortic phantom with aneurysm. An in-vitro measurement experimental device to simulate blood flow was developed. It was tested within MRI and within stereovision and particle image velocimetry (PIV) devices. The measurement results are well correlated and can be used to establish a preoperative diagnosis based on computed parietal stresses with a finite element model (FEM).
Effective orifice area assessment in BI-leaflet mechanical valves by MRI,
International audience; Effective orifice area (EOA) and mean pressure gradientare routine echocardiographic measurements of valvularprosthesis function in both the mitral and aortic position.EOA computation is based on the continuity equationand is used to describe the “effective” orifice formed bythe flow traversing a geometrical orifice. In the case ofbi-leaflet biomechanical valvular prosthesis (BMHV),the orifice of the valve is divided into 3 zones. BMHVperformance assessment by MRI have been described inthe in-vitro setting in [1] using the maximum pressuregradient. Additionally, a method using jet layer has beenused to detect EOA dynamically [2]. 4D-PC flowsequences enable measuremen…
Comparison of the strain field of abdominal aortic aneurysm measured by magnetic resonance imaging and stereovision: a feasibility study for prediction of the risk of rupture of aortic abdominal aneurysm
International audience; The prediction of the risk of rupture of abdominal aortic aneurysm (AAA) is a complex problem. Currently the criteria to predict rupture of abdominal aortic aneurysms are aneurysm diameter and growth rates. It is generally believed that study of the wall strain distribution could be helpful to find a better decision criterion for surgery of aortic aneurysms before their rupture. The wall strain distribution depends on many biological and biomechanical factors such as elastic properties of the aorta, turbulent blood flow, anatomy of the aorta, presence of thrombus or not and so on. Recently, numerical simulations to estimate rupture-potential have received many attent…
Validation of the Strain Assessment of a Phantom of Abdominal Aortic Aneurysm: Comparison of Results Obtained From Magnetic Resonance Imaging and Stereovision Measurements
Predicting aortic aneurysm ruptures is a complex problem that has been investigated by many research teams over several decades. Work on this issue is notably complex and involves both the mechanical behavior of the artery and the blood flow. Magnetic resonance imaging (MRI) can provide measurements concerning the shape of an organ and the blood that flows through it. Measuring local distortion of the artery wall is the first essential factor to evaluate in a ruptured artery. This paper aims to demonstrate the feasibility of this measure using MRI on a phantom of an abdominal aortic aneurysm (AAA) with realistic shape. The aortic geometry is obtained from a series of cine-MR images and reco…