CTMS in the study of post-EVAR endoleak in the treatment of aneurysmal dilations

Abstract

Computed tomography angiography (CTA) has been widely used in diagnostic evaluation of many aortic diseases, but there are not standardized techniques for aortic CTA. The purpose of this study is to compare two methods: biphasic technique and split bolus. A 64-slice CT scanner has been used. There were a total of 28 patients involved in the study. The patients have been divided in two groups: - Group A: 18 patients - Group B: 10 patients The biphasic technique has been used on 18 patients in group A. In this protocol was used a low dose acquisition without contrast medium (CM) and two contrastographic phases with CM. The split bolus technique was performed on 10 patients of group B. 120-140 ml of CM are divided in two boluses. The first bolus of 55-90 ml of CM was injected at a flow of 1,5-2 ml/s, followed by 20ml of physiological solution at a flow of 1,5-2ml/s. After physiological solution the second bolus of 35-60 ml was injected at a flow of 3,5ml/s followed by 20ml of Nacl at a flow of 3,5ml/s. In group A 6 patients had endoleak type I, n=2 endoleak type II, n=8 endoleak type III, n=2 endoleak type IV. (dose of 43.2 mSv). In group B 2 patients had endoleak type I, n= 4 endoleak type II, n=3 endoleak type III and n=1 endoleak type IV. (dose of 16,39 mSv). The biphasic technique has high spatial resolution and contrast resolution, reduction of acquisition times and reduction of artifacts, but an unacceptable a great amount of radiation is involved. The split bolus technique provides results comparable to the biphasic technique but with a lower dose of radiation.