【摘要】： 目的 結合醫(yī)學圖像三維重構技術和計算流體力學(CFD)研究方法對人體胸主動脈內血液流動進行三維數(shù)值模擬并獲取相應的血流動力學參數(shù),通過對不同個體(包括正常和異�；颊�)胸主動脈內血液流動分析來探討血流動力學參數(shù)對主動脈脈管疾病如動脈粥樣硬化、動脈夾層等疾病的影響,為其各種脈管疾病的發(fā)病機理提供理論依據以及對脈管疾病臨床預防提供幫助。 方法 應用醫(yī)學圖像后處理軟件MIMICS10.01對臨床通過增強CT獲得的二維醫(yī)學圖像數(shù)據進行處理,得到包括升主動脈、主動脈弓、降主動脈及主動脈弓上部的頭臂干、左頸總動脈和左鎖骨下動脈的胸主動脈的整體三維重構模型。借助軟件ANSYS-CFX對主動脈弓內的血液進行血流動力學數(shù)值模擬并得到可視化結果,獲取正常胸主動脈弓和患有降主動脈夾層疾病胸主動脈弓內相關血流動力學的各種參數(shù)。通過對比不同個體主動脈弓內血流動力學參數(shù)的異同,及正常胸主動脈弓和患有降主動脈夾層疾病胸主動脈弓內血流動力學參數(shù)的異同來討論血流動力學參數(shù)對脈管疾病的影響。 結果 通過三維重構方法建立了真實的人體主動脈弓解剖系統(tǒng)三維幾何模型,實現(xiàn)了基于人體主動脈弓真實解剖模型進行的血流動力學數(shù)值模擬分析。通過應用計算流體力學方法獲得了主動脈弓內血流在心動周期內不同時刻的壁面壓力、流線分布、壁面切應力等血流動力學參數(shù)。并且通過對不同個體的主動脈弓內的血流動力學參數(shù)的比較分析確定心臟收縮期的血管壁壓力及壓力變化比舒張期更大；在整個心動收縮期,主動脈外側壁的壓力明顯地高于內側壁的壓力；在主動脈弓和降主動脈連接的彎曲部位處存在明顯的壓力變化；在主動脈弓內側壁的壁面剪應力比主動脈弓外側壁的壁面剪應力具有更大的量值和變化幅度；在心動收縮期主動脈弓處出現(xiàn)二次流現(xiàn)象,且在心動收縮期出現(xiàn)明顯的漩渦現(xiàn)象。 結論 計算流體力學數(shù)值模擬的方法是目前研究脈管疾病血流動力學的一種可靠方法。通過三維重構方法獲得了個體化仿真的包括主動脈弓及分叉的正常胸主動脈、患有降主動脈夾層的病態(tài)胸主動脈的三維模型,并確定相關關鍵技術方法,為進一步進行血流動力學研究分析確定基礎。通過模擬對比分析,明確血管的彎曲及分叉導致局部壓力變化可能與脈管疾病的形成有一定的關系。
[Abstract]:Objective to simulate the blood flow in human thoracic aorta by 3D reconstruction of medical images and computational fluid dynamics (CFD) and to obtain the corresponding hemodynamic parameters. The effects of hemodynamic parameters on aortic vascular diseases such as atherosclerosis, dissection and other diseases were investigated by analyzing the blood flow in thoracic aorta of different individuals (including normal and abnormal patients). To provide theoretical basis for the pathogenesis of various vascular diseases and to provide help for clinical prevention of vascular diseases. Methods Medical image post-processing software (MIMICS10.01) was used to process the two-dimensional medical image data obtained by enhanced CT. The ascending aorta, aortic arch, descending aorta and upper arm trunk of aortic arch were obtained, which included ascending aorta, aortic arch, descending aorta and upper part of aortic arch. Three-dimensional reconstruction model of thoracic aorta of left common carotid artery and left subclavian artery. The hemodynamic parameters of the normal aortic arch and the aortic arch with descending aortic dissection were obtained by using the software ANSYS-CFX to simulate the hemodynamics of the blood in the aortic arch and obtain the visual results. By comparing the hemodynamic parameters of different individuals in the aortic arch, The influence of hemodynamic parameters on vascular diseases was discussed by comparing the hemodynamic parameters of thoracic aortic arch with that of normal aortic arch and descending aortic dissection. Results Three-dimensional geometric model of human aortic arch anatomy system was established by three-dimensional reconstruction method, and hemodynamic numerical simulation analysis based on real anatomy model of human aortic arch was realized. The wall pressure, streamline distribution, wall shear stress and other hemodynamic parameters of the aortic arch blood flow at different times in the cardiac cycle were obtained by using computational fluid dynamics (CFD). By comparing and analyzing the hemodynamic parameters of different individuals in aortic arch, it was found that the changes of vessel wall pressure and pressure in systolic period were greater than that in diastolic phase. The pressure on the lateral wall of the aorta was significantly higher than that on the medial wall during the whole systolic period, and there was a significant change in the pressure at the bend of the aortic arch and descending aorta junction. The wall shear stress of the medial wall of the aortic arch is larger than that of the lateral wall of the aortic arch, and the secondary flow occurs at the aortic arch during the systolic period, and the vortex phenomenon appears during the contraction phase of the aortic arch, and the wall shear stress of the inner wall of the aortic arch is larger than the wall shear stress of the lateral wall of the aortic arch. Conclusion Computational fluid dynamics numerical simulation is a reliable method to study hemodynamics of vascular diseases. The three-dimensional model of the normal thoracic aorta with aortic arch and bifurcation and the diseased thoracic aorta with descending aortic dissection were obtained by three-dimensional reconstruction method, and the relevant key techniques were determined. To determine the basis for further hemodynamic analysis. By simulation and contrast analysis, it is clear that the variation of local pressure caused by the bending and bifurcation of blood vessels may be related to the formation of vascular diseases.
【學位授予單位】：中國醫(yī)科大學
【學位級別】：碩士
【學位授予年份】：2010
【分類號】：R312

【引證文獻】

相關博士學位論文 前1條

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相關碩士學位論文 前2條

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本文編號：2367692