The Role Of Multi-Detector Spiral Computed Tomography Angiography In The Diagnosis And Evaluating The Aortic Arch Vessels In Type A Aortic Dissection

Objective:(1)To analyze the features of multi-detector spiral computed Tomography Angiography(MDCTA)in type A aortic dissection,and to study the diagnostic value of MDCTA in type A aortic dissection(2)To evaluate the clinical value of MDCTA in the preoperative aortic arch injury in type A aortic dissection.(3)To explore the appropriate surgical procedure for type A aortic dissection.Methods:From September 2017 to February 2020,78 patients(case group)with type A aortic dissection and 50 patients(control group)with hypertension without aortic dissection were analyzed retrospectively.The original CT scanning image is reconstructed on the post-processing machine.The main reconstruction methods are MPR,CPR,MIP,VR,and then image analysis and diagnosis.On the examination image,the related parameters of the aortic dissection were recorded,including the diameter of the aorta at the junction of the aortic sinus,the diameter of the aorta at the first branch of the aortic arch,the diameter of the proximal aorta(between the brachiocephalic artery and the left common carotid artery),the diameter of the distal aorta(between the left common carotid artery and the left subclavian artery),the diameter of the descending aorta,the diameter of the brachiocephalic artery and the left common carotid artery Distance,distance between left common carotid artery and left subclavian artery,diameter of brachiocephalic artery,diameter of left common carotid artery,and diameter of left subclavian artery.The differences of aortic dissection parameters among the groups were analyzed.Results:In this study,the diagnostic accuracy of MDCTA in 78 patients was 100%.78 patients showed true and false lumen of aortic dissection and intima separating true and false lumen.The original axial images of MDCTA can show all the information of the lesions,the size and density difference of the true and false lumen of the aorta,the sign of intimal slice,the position of the breach,and the sign of thrombus.The method of image post reconstruction has different advantages in displaying lesions.The site of intimal tear was identified in all patients,including ascending aorta(n = 46 cases),aortic arch(n = 22 cases)and other sites(n = 10 cases).There was significant difference in aortic arch anatomy between type A aortic dissection and control group.The distance between brachiocephalic artery and left common carotid artery was statistically significant between type A aortic dissection patients and the control group.Conclusions:(1)MDCTA has the advantages of fast scanning speed,high image resolution,rich image post-processing function,comprehensive utilization of the original image and post-processing method,which can understand the anatomy of aortic dissection,comprehensively evaluate the conditions inside and outside the vessel,and has significant significance for the diagnosis and classification of aortic dissection.(2)MDCTA plays an important role in the preoperative evaluation of aortic arch injury in determining the location of intimal tear and the variation of branch vessels,and guides the formulation of clinical reasonable operation plan.(3)It is necessary to evaluate the structure of aortic arch and branch vessels before operation.According to the information of MDCTA before operation,we can make the appropriate surgical plan,especially the three branch stent implantation technology.