64-slice spiral CT angiography in the diagnosis of aortic dissection

Objective:To investigate the clinical value of multi-slice spiral CT angiography(MSCTA) in the diagnosis and preoperative assessment of aortic dissection(AD).Methods:Fifty-eighty consecutive patients with AD underwent 64-slice spiral CT angiography.The original data were post-processed with MPR,MIP and VR techniques and the results were analyzed.Results:Based on Debakey classification,the MSCTA results of these fifty-eight patients were classified as TypeⅠ(14 patients),TypeⅡ(2 patients) and Type Ⅲ(42 patients).True and false lumen and intimal flap tearing could be clearly revealed in all of these 58 patients.Furthermore,the mean CT value after enhancement in true lumen is higher than that in false lumen in arterial phase,with significant statistical difference(P=0.0000.05).Initial entry sites were well defined in all patients,and one or multiple re-entry sites were shown in 55 patients,but did not showed in 3 patients with Type Ⅲ dissection.In 39 patients with Type Ⅲ dissection,the initial entry site located in descendent part of aortic arch or proximal part of thoracic aorta,the length and the width of proximal neck of aortic aneurysm were ranged from 0.4cm to 10.8cm(mean,3.5cm) and ranged from 2.2cm to 3.6cm(mean,2.8cm) respectively,and the maximum diameter of aortic aneurysm was between 3.2cm and 9.2cm(mean 5.4cm).All of the main branches of aorta involved by dissection and the thrombus within false lumen were accurately showed by MSCTA Conclusion:The advantages of 64-slice spiral CT angiography are fast,non-invasive and highly effective which is one of the reliable imaging methods in the diagnosis and preoperative evaluation of aortic dissection.