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CAD of Cardiovascular Diseases
Published in de Azevedo-Marques Paulo Mazzoncini, Mencattini Arianna, Salmeri Marcello, Rangayyan Rangaraj M., Medical Image Analysis and Informatics: Computer-Aided Diagnosis and Therapy, 2018
Marco A. Gutierrez, Marina S. Rebelo, Ramon A. Moreno, Anderson G. Santiago, Maysa M. G. Macedo
Fractional flow reserve (FFR) is the ratio of maximal coronary blood flow through a stenotic artery divided by the blood flow in the hypothetical case of a normal artery. It is performed during coronary angiography, an invasive procedure, and is an important tool for revealing the ischemic potential of individual lesions (Tu et al. 2014).
On inlet pressure boundary conditions for CT-based computation of fractional flow reserve: clinical measurement of aortic pressure
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2023
Jincheng Liu, Suqin Huang, Xue Wang, Bao Li, Junling Ma, Yutong Sun, Jian Liu, Youjun Liu
At present, the ‘gold standard’ for assessing the hemodynamic characteristics of coronary stenosis is fractional flow reserve (FFR) (Pijls et al. 1996; Michiels et al. 2012; Kakouros et al. 2013). FFR is defined as the ratio of the maximum blood flow in the myocardial region dominated by stenotic coronary arteries to the maximum blood flow in the same region without arterial blockage. Based on the concept that the myocardial blood flow is proportional to the perfusion pressure when the microcirculation resistance is constant and too small, its definition can be simplified as FFR = Pd/Pa, where Pd is the average pressure of the aortic root under the maximum hyperemia state (achieved by injecting coronary microcirculation dilatation drugs such as adenosine) (De Bruyne and Sarma 2008), namely the mean pressure of the coronary artery distal to the stenotic lesion. FFR > 0.8 indicates that the lesion does not cause severe stenosis and no intervention is required. In the Fame-1 and Fame-2 studies, FFR has been shown to be an efficient diagnostic criterion for determining suitability for stent therapy (Heyndrickx and Tóth 2016).
The influence of the elastic modulus of the plaque in carotid artery on the computed results of FFRCT
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2020
Kesong Xu, Long Yu, Jun Wan, Shengzhang Wang, Haiyan Lu
The carotid artery is one of the major blood vessels that supply the blood flow to the brain. Carotid artery stenosis is one of the most dangerous cardiovascular diseases and an important factor in causing cerebral infarction. Atherosclerosis is the leading cause of carotid artery stenosis in middle-aged and elderly people (Fabris et al. 1994; Stroud et al. 2002). However, currently there is a lack of effective means to evaluate the risk degree of carotid artery stenosis in clinical practice. Generally, the stenosis rate of carotid artery calculated by using medical image data is used to assess the risk degree of carotid artery stenosis (Augst et al. 2003). However, this method reflects hardly the actual blood supply from the carotid artery to the brain. To achieve functional assessment for carotid artery stenosis, the researchers managed to use the blood fraction flow reserve (FFR) (Huang et al. 2015). FFR is widely used clinically to evaluate the degree of coronary artery stenosis, which can reflect the ratio of the current blood flow that the artery can provide to the downstream compared to that it can provide when the artery is completely healthy. The flow ratio can be approximated by the ratio of the downstream pressure to the upstream pressure of the stenosis, and its approximate calculation formula is
Non-invasive imaging techniques to assess myocardial perfusion
Published in Expert Review of Medical Devices, 2020
Olivier Villemain, Jérôme Baranger, Zakaria Jalal, Christopher Lam, Jérémie Calais, Mathieu Pernot, Barbara Cifra, Mark K. Friedberg, Luc Mertens
Fractional flow reserve (FFR) is defined as the ratio of maximal MBF in the presence of the stenosis divided by the theoretically normal maximal MBF (i.e. in the absence of the stenosis). In other words, FFR reflects to what extent a coronary vessel stenosis limits coronary flow. Therefore, FFR reflects how a potential revascularization may improve myocardial perfusion [5]. In reality, the flows ratio can be extrapolated from the ratio of the distal pressure beyond the stenosis (Pd) divided by the proximal or aortic pressure (Pa) but this requires invasive pressure measurements with a coronary pressure wire.