Objective To investigate the clinical applications of 64-MSCTA for the follow-up of endovascular stent-graft exclusion (EVE). Methods Between Oct 2006 and Feb 2008, forty-four 64-MSCTA examinations were performed in 30 patients with aortic dissection (AD) and 5 patients with abdominal aortic aneurysm (AAA) who underwent EVE. Imaging reconstruction including MPR, MIP and VR were finished on workstation. The outcomes and complications after EVE of aortic dissection and aortic aneurysm were evaluated. Results (1) Of 30 patients with aortic dissection, large thrombosis in false lumen was observed in 28 cases and small thrombosis in 2 cases. The cavity of aortic aneurysm outside the stent was thrombosed completely in 5 patients with AAA. (2) Thrombosis in the innominate artery on follow-up CTA after EVE was found in 1 AD patient with the innominate artery involved, Thrombosis in the superior mesenteric artery was observed on 15 days follow-up CTA but thrombolysis on 3 months after EVE in 1 case, lntimal tear in right common iliac artery was found in 1 case. Of 5 patients with AAA, occlusion of right inner iliac artery was observed in 1 case, and instent thrombosis in distal right common iliac artery was found in 1 case. (3) Endoleak was found in 14 patients with AD, including 8 with type Ⅰ and 6 with type Ⅲ endoleaks, one type Ⅲ endoleak was disappeared on follow-up CTA after 3 months. Conclusions 64-MSCTA with fast, non-invasive and effective merits, combining multiple reconstructive methods, has become one of preferred imaging methods in post-operative evaluation of EVE.

Objective:To explore the feasibility of the clinical implementation of intensity-modulated radiation therapy (IMRT) and volumetric-modulated arc therapy (VMAT) plans with 6MV photon on two Elekta Linacs (Versa HD and Synergy) after beam matching.Methods:The images of 12 patients with nasopharyngeal carcinoma, central lung cancer and prostate cancer were randomly selected, and the IMRT and VMAT plans were designed. Two different dose tools of ionization chamber and three-dimensional detector ArcCheck were used to verify the individualized radiation treatment of 6MV photon beams on two Linacs and compare the differences.Results:The deviations between the doses of two Linacs (Versa HD and Synergy) measured by the ion chamber and treatment planning system were (0.32±1.32)% and (0.54±1.29)%. The differences of all plans were within the range of ±3%, and the deviations of the point dose between two Linacs were within the range of ±2% with no statistical significance (both P>0.05). The γ analysis of verification using ArcCheck showed that the passing rates of all plans under the 2mm/3% and 3mm/3% with 10% threshold conditions were over 95%, respectively. The average differences between two Linacs were 0.19%(2mm/3%) and 0.09%(3mm/3%). Conclusions:The results of performing IMRT/VMAT plans on two Linacs meet the clinical requirements and the differences between two Linacs are small. Hence, the same plans can be implemented interchangeably on different Linacs.