Research On The Fractional Flow Reserve Calculation Based On CT Image Three-dimensional Reconstruction

With the improvement of living standard and the rapidly widespread of the health education,curing the disease and minimize the risks of side effects are both our goals.Our country have many patients who have the coronary heart disease,and the morbidity and mortality of coronary heart disease increases every year with the younger trend.So coronary artery stenosis detection is very important in the treatment of coronary heart disease.As a "gold standard" of the diagnosis of coronary heart disease,coronary angiography techniques provide anatomical information for us,but it can be effected by the subjective factors easily.So it can not quantify the degree of stenosis.Fractional flow reserve(FFR)can make the functional evaluation for the degree of vascular stenosis sufficiently,which can make up for deficiencies in the diagnosis of coronary angiography.Non-invasive fractional flow reserve,compared with the traditional method,had a small effect on the human health,which made a good impression to doctors.Most of the non-invasive fractional flow reserve calculations were based on CTA images for modeling and simulation,which are unfitted to people who are allergic to constrast agents,such as iodine reagent,and limited its application range.Therefore,this dissertation model the coronary artery and calculate fractional flow reserve.First of all,due to the complex structure of the tissue around the heart,the CT images in the coronary artery segmentation and reconstruction is not easy.For the medical images which contain a great amount of information,the semiautomatic interactive methods were used to segment the coronary artery typically.But the CT images of those people who are sensitive to contrast agents made the interactive segmentation was failure to identify vascular border clearly because it lost the contrast agent of vascular labeling.Therefore the semiautomatic interactive segmentation method was not segmented the images entirely.Based on this point,this dissertation would combine the segmentation method based on Clustering and the interactive segmentation method.This method could segment the coronary artery from two-dimensional slice CT coronary accurately.Secondly,the three-dimensional model of coronary was reconstructed the segmented two-dimensional coronary slices.Taking into account the limitations of software,hardware and other conditions,MC algorithm based on segmentation would be selected to reproduce the coronary artery.After simplifying the three-dimensional model of the grid,this dissertation made a calculation to get the WP by the ANSYS Workbench software,and then the fractional flow reserve requirements were got.Finally,the traditional method of FFR,the method of FFR+CTA and the method of FFR+CT were compared by the images from the first affiliated hospital of Harbin Medical University to the value of accuracy,sensitivity and specificity.The experimental results indicate that the method of FFR+CT is feasible.This method avoids the problems of patients who are sensitive to contrast agents effectively,the results made non-invasive application of fractional flow reserve more practical value.