From the Department of Radiology, Radio-Oncology and Nuclear Medicine, and Institute of Biomedical Engineering, Université de Montréal, Montreal, Quebec, Canada (E.S., A.B., C.K., E.T., G.C., G.S.); Department of Radiology, Centre Hospitalier de l'Université de Montréal, Montreal, Quebec, Canada (E.T., G.S.); Centre de Recherche de l'Université de Montréal, 900 rue Saint-Denis, Montreal, QC, Canada H2X 0A9 (E.S., A.B., S.L., C.K., H.H., E.T., I.S., M.H.R.C., G.C., G.S.); Laboratory of Biorheology and Medical Ultrasonics (E.S., A.B., M.H.R.C., G.C.) and Clinical Image Processing Laboratory (E.S., A.B., C.K., G.S.), Centre de Recherche de l'Université de Montréal, Montreal, Quebec, Canada; and Department of Mechanical Engineering, École de Technologie Supérieure, Montreal, Quebec, Canada (S.L.).
Radiology. 2016 May;279(2):410-9. doi: 10.1148/radiol.2015142098. Epub 2015 Dec 21.
To assess the ability of noninvasive vascular elastography (NIVE) to help characterize endoleaks and thrombus organization in a canine model of abdominal aortic aneurysm after endovascular aneurysm repair with stent-grafts, in comparison with computed tomography (CT) and pathologic examination findings.
All protocols were approved by the Animal Care Committee in accordance with the guidelines of the Canadian Council of Animal Care. Stent-grafts were implanted in a group of 18 dogs with aneurysms created in the abdominal aorta. Type I endoleak was created in four aneurysms; type II endoleak, in 13 aneurysms; and no endoleak, in one aneurysm. Doppler ultrasonography and NIVE examinations were performed at baseline and at 1-week, 1-month, 3-month, and 6-month follow-up. Angiography, CT, and macroscopic tissue examination were performed at sacrifice. Strain values were computed by using the Lagrangian speckle model estimator. Areas of endoleak, solid organized thrombus, and fresh thrombus were identified and segmented by comparing the results of CT and macroscopic tissue examination. Strain values were compared by using the Wilcoxon rank-sum and Kruskal-Wallis tests.
All stent-grafts were successfully deployed, and endoleaks were clearly depicted in the last follow-up elastography examinations. Maximal axial strains over consecutive heart cycles in endoleak, organized thrombus, and fresh thrombus areas were 0.78% ± 0.22, 0.23% ± 0.02, 0.10% ± 0.04, respectively. Strain values were significantly different between endoleak and organized or fresh thrombus areas (P < .000) and between organized and fresh thrombus areas (P < .0002). No correlation was found between strain values and type of endoleak, sac pressure, endoleak size, and aneurysm size.
NIVE may be able to help characterize endoleak and thrombus organization, regardless of the size, pressure, and type of endoleak.
通过与计算机断层扫描（CT）和病理检查结果进行比较，评估无创血管弹性成像（NIVE）在犬腹主动脉瘤血管内修复后帮助表征内漏和血栓形成的能力。
所有方案均经动物护理委员会批准，符合加拿大动物护理委员会的准则。在一组 18 只患有腹主动脉瘤的狗中植入了支架移植物。在 4 个动脉瘤中创建了 I 型内漏；在 13 个动脉瘤中创建了 II 型内漏；在一个动脉瘤中没有内漏。在基线和 1 周、1 个月、3 个月和 6 个月的随访时进行了多普勒超声和 NIVE 检查。在牺牲时进行了血管造影、CT 和大体组织检查。通过使用拉格朗日散斑模型估计器计算应变值。通过比较 CT 和大体组织检查的结果来识别和分割内漏、固体组织血栓和新鲜血栓的区域。通过使用 Wilcoxon 秩和检验和 Kruskal-Wallis 检验比较应变值。
所有支架移植物均成功植入，最后一次随访弹性成像检查中清楚地描绘了内漏。在连续的心动周期中，内漏、组织化血栓和新鲜血栓区域的最大轴向应变分别为 0.78%±0.22、0.23%±0.02、0.10%±0.04。内漏和组织化或新鲜血栓区域之间的应变值存在显著差异（P<0.000），组织化和新鲜血栓区域之间的应变值也存在显著差异（P<0.0002）。应变值与内漏类型、囊内压、内漏大小和动脉瘤大小之间无相关性。
NIVE 可能能够帮助表征内漏和血栓形成，而与内漏的大小、压力和类型无关。
