Numerical Model Optimization Of Intracranial Aneurysms Based On CT And Analysis Of Rupture Factors

Objective To construct the numerical model of intracranial aneurysm,and optimize the numerical model,so as to provide good model parameters for the design of stent and stent implantation.To analyze the geometric appearance of aneurysm rupture and hemorrhage,and to provide some parameters for the risk assessment of aneurysm rupture.Method Three dimensional CT technique was used to establish the three-dimensional model of cerebral aneurysm,and the numerical model of aneurysm was constructed by using the computational fluid dynamics software ANSYS CFX15.0.The comparative analysis of different conditions,such as rigid and elastic wall,wall thickness and arterial aneurysm wall thickness is consistent or not,Newton and non Newton fluid,blood flow of artery entrance and exit of different length and different modulus under intra aneurysmal changes.For the geometric factors of aneurysm rupture,83 cases of CT patients were selected to establish the three-dimensional model,and the geometric appearance parameters were measured.Spss23.0 software was used to analyze the size of ruptured aneurysms and unruptured aneurysms.Result Compared with the rigid wall,the maximum deformation of the rigid wall accounts for about 13% of the diameter of the elastic wall,and the deformation of the elastic wall accounts for about 7.5% of the diameter.The deformation of the rigid wall is about 2.4 times that of the elastic wall.There is no difference between Newton and non-model of the blood flow,the maximum is about 2.19%.The difference between the thickness of the aneurysm and the thickness of the arterial wall is the same as that of the thickness of the artery.The difference between the two models is large,about 43%.The deformation of arterial wall decreases with the increase of Young’s modulus.When the outlet length of the aneurysm is unchanged,the inlet cavity length is too short,the eddy current in the tumor cavity is not obvious,and the vortex phenomenon increases with the increase of the inlet length,and finally stabilizes in a certain length.The inlet length is constant,the outlet length is not the same,the flow field of the two groups is not significant.The geometric appearance dimension of ruptured aneurysm and unruptured aneurysm was found,AR,the maximum height of the tumor,and the angle of the aneurysm,P<0.05,was statistically significant,other parameters were not statistically significant.On AR,tumor width,injection angle and aneurysms included angle of the receiver operating characteristic curve,ROC curve analysis,obtains the four best cut-off values were 1.4835(sensitivity 80%,specificity 41.9%)and 5.3(sensitivity 100%,specificity 18.6%)and 34.5(sensitivity 75%,specificity 37.2%).The analysis of the ROC curve of the angle of the tumor contained artery showed that the area under the curve,that is,AUC was 0.238 < 0.5,had no diagnostic significance.Finally,the tumor width,AR and injection angle were obtained,and the diagnostic efficiency of the three groups was tumor width > AR > injection angle.