The novel coronavirus disease 2019(COVID-19)was firstly reported in Wuhan,China,and eventually identified on December 31,2019 and remains as an ongoing worldwide pandemic.Severe acute respiratory syndrome coronavirus ...The novel coronavirus disease 2019(COVID-19)was firstly reported in Wuhan,China,and eventually identified on December 31,2019 and remains as an ongoing worldwide pandemic.Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)invades human alveolar epithelial cells in the nose and throat mainly through angiotensin-converting enzyme 2(ACE2),[1]inducing innate inflammation in the lungs largely mediated by pro-inflammatory macrophages and granulocytes.展开更多
Background:Hemodynamic parameters derived from computed tomography angiography–based computational fluid dynamics(CFD)analysis have been widely used for clinical decision-making and researches to assess the vulnerabi...Background:Hemodynamic parameters derived from computed tomography angiography–based computational fluid dynamics(CFD)analysis have been widely used for clinical decision-making and researches to assess the vulnerability of atherosclerotic plaques and explain the initialization and development of atherosclerosis.Subbranches in the CFD model might affect the accuracy of hemodynamic parameters,but the effectiveness has been least quantified.Methods:A coronary artery baseline model was generated with focal stenosis at the proximal left anterior descending artery.Nineteen comparing models were created by systematically removing various subbranches to examine the changes in hemodynamic parameters,including time-averaged pressure(TAP),time-averaged wall shear stress(TAWSS),oscillatory shear index(OSI),and particle relative residence time(RRT).Changes in these parameters were assessed quantitatively around the stenosis and near the region where subbranches were removed.Results:The removal of subbranches caused a significant change in outflow rate,and there was generally a decrease in all CFD parameters in the regions of interest with a decrease in outflow rate.The subbranch removal had a significant impact on the calculation of TAWSS,OSI,and RRT,whereas TAP was insensitive to the removal with approximately 0.25%variation in all 19 models.The local effect from removing branch segments generally became negligible after 5 diameters away from the cutting-off position,but the decrease could be affected by other factors,such as a large curvature.Conclusion:The outflow rate is a dominant factor for the calculation of TAP,TAWSS,OSI,and RRT.Removal of subbranches has a minor effect on the TAP calculation,but its effect is considerable on the TAWSS,OSI,and RRT.The effect of subbranch removal is limited in a region with 5 local diameters.展开更多
基金This work is partially supported by British Heart Foundation(PG/18/14/33562)National Institute for Health Research Cambridge Biomedical Research Centre,National Natural Science Foundation of China(81871354,81571672)the Taishan Scholar Projection,and Academic Promotion Programme of Shandong First Medical University(2019QL023).
文摘The novel coronavirus disease 2019(COVID-19)was firstly reported in Wuhan,China,and eventually identified on December 31,2019 and remains as an ongoing worldwide pandemic.Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)invades human alveolar epithelial cells in the nose and throat mainly through angiotensin-converting enzyme 2(ACE2),[1]inducing innate inflammation in the lungs largely mediated by pro-inflammatory macrophages and granulocytes.
基金Bureau of Science and Technology,Xuzhou,People’s Republic of China(KC19176)the NIHR Cambridge Biomedical Research Centre(BRC-1215-20014).
文摘Background:Hemodynamic parameters derived from computed tomography angiography–based computational fluid dynamics(CFD)analysis have been widely used for clinical decision-making and researches to assess the vulnerability of atherosclerotic plaques and explain the initialization and development of atherosclerosis.Subbranches in the CFD model might affect the accuracy of hemodynamic parameters,but the effectiveness has been least quantified.Methods:A coronary artery baseline model was generated with focal stenosis at the proximal left anterior descending artery.Nineteen comparing models were created by systematically removing various subbranches to examine the changes in hemodynamic parameters,including time-averaged pressure(TAP),time-averaged wall shear stress(TAWSS),oscillatory shear index(OSI),and particle relative residence time(RRT).Changes in these parameters were assessed quantitatively around the stenosis and near the region where subbranches were removed.Results:The removal of subbranches caused a significant change in outflow rate,and there was generally a decrease in all CFD parameters in the regions of interest with a decrease in outflow rate.The subbranch removal had a significant impact on the calculation of TAWSS,OSI,and RRT,whereas TAP was insensitive to the removal with approximately 0.25%variation in all 19 models.The local effect from removing branch segments generally became negligible after 5 diameters away from the cutting-off position,but the decrease could be affected by other factors,such as a large curvature.Conclusion:The outflow rate is a dominant factor for the calculation of TAP,TAWSS,OSI,and RRT.Removal of subbranches has a minor effect on the TAP calculation,but its effect is considerable on the TAWSS,OSI,and RRT.The effect of subbranch removal is limited in a region with 5 local diameters.