Values of computed tomographic axial images and three-dimensional reconstructed images in evaluation of aortic dissection and aortic aneurysm before endovascular aortic repair

Objective: To compare the accuracy of measurements between computed tomographic (CT) axial images and three-dimensional reconstructed images (3D) in evaluation of aortic dissection of aortic aneurysm before endovascular aortic repair. Methods: Aortic axial images were got from thin-slices scanning in 20 patients with aortic dissection and 12 patients with abdominal aortic aneurysm. Multi-planar reconstruction and maximal intensity projection were used for 3D images. Parameters related to aortic dissection and aneurysm were measured from CT axial and 3D images and compared with those from aortography. Results: Diameters of arch, lengths of neck and aneurysm were smaller measured on CT axial images than those by 3D and aortographic images. The proximal aortic diameters of dissection or aneurysm, middle aortic diameter and diameters of bilateral iliac arteries were greater measured by CT axial images than by those of 3D images and aortography. There were no remarkable differences between the measurements from 3D images and aortographies. The breakage of dissection can be easily demonstrated by 3D images and aortographies but not by CT axial images. However, CT axial and 3D images revealed more accuracy than aortographice in detecting thrombi and measuring the maximal diameters of aneurysm. Endovascular grafts were chosen according to measurements by CT 3D images and outcoming with successful closure of all the dissections and aneurysms. Conclusions: Combined CT axial and 3D images can provide accurate evaluation of aortic dissection and aneurysm before endovascular aortic repair, especialy CT 3D images was strongly recommended to determine size of endovascular grafts. (authors)