Treitl Karla M, Scherr Michael, Förth Monika, Braun Franziska, Maxien Daniel, Treitl Marcus
Institute for Clinical Radiology, Hospitals of the Ludwig-Maximilians-University of Munich, Pettenkoferstr. 8a, D-80336, Munich, Germany,
Eur Radiol. 2015 Mar;25(3):597-605. doi: 10.1007/s00330-014-3438-9. Epub 2014 Oct 16.
Our aim was to develop an aortic stent graft phantom to simulate endoleak treatment and to find a tantalum content (TC) of ethylene-vinyl-alcohol-copolymer that causes fewer computed tomography (CT) beam hardening artefacts, but still allows for fluoroscopic visualization.
Ethylene-vinyl-alcohol-copolymer specimens of different TC (10-50 %, and 100 %) were injected in an aortic phantom bearing a stent graft and endoleak cavities with simulated re-perfusion. Fluoroscopic visibility of the ethylene-vinyl-alcohol-copolymer specimens was analyzed. In addition, six radiologists analyzed endoleak visibility, and artefact intensity of ethylene-vinyl-alcohol-copolymer in CT.
Reduction of TC significantly decreased CT artefact intensity of ethylene-vinyl-alcohol-copolymer and increased visibility of endoleak re-perfusion (p < 0.000). It also significantly decreased fluoroscopic visibility of ethylene-vinyl-alcohol-copolymer (R = 0.883, p ≤ 0.01), and increased the active embolic volumes prior to visualization (Δ ≥ 40 μl). Ethylene-vinyl-alcohol-copolymer specimens with a TC of 45-50 % exhibited reasonable visibility, a low active embolic volume and a tolerable CT artefact intensity.
The developed aortic stent graft phantom allows for a reproducible simulation of embolization of endoleaks. The data suggest a reduction of the TC of ethylene-vinyl-alcohol-copolymer to 45 -50 % of the original, to interfere less with diagnostic imaging in follow-up CT examinations, while still allowing for fluoroscopic visualization.
我们的目标是开发一种主动脉覆膜支架模型，以模拟内漏治疗，并找到一种乙烯-乙烯醇共聚物的钽含量（TC），使其在计算机断层扫描（CT）中产生较少的束硬化伪影，同时仍能实现荧光透视显影。
将不同钽含量（10%-50%和100%）的乙烯-乙烯醇共聚物标本注入带有覆膜支架和模拟再灌注内漏腔的主动脉模型中。分析乙烯-乙烯醇共聚物标本的荧光透视可见性。此外，六名放射科医生分析了内漏的可见性以及CT中乙烯-乙烯醇共聚物的伪影强度。
钽含量的降低显著降低了乙烯-乙烯醇共聚物的CT伪影强度，并提高了内漏再灌注的可见性（p<0.000）。它还显著降低了乙烯-乙烯醇共聚物的荧光透视可见性（R=0.883，p≤0.01），并增加了显影前的活性栓塞体积（Δ≥40μl）。钽含量为45%-50%的乙烯-乙烯醇共聚物标本表现出合理的可见性、较低的活性栓塞体积和可耐受的CT伪影强度。
所开发的主动脉覆膜支架模型能够可重复地模拟内漏栓塞。数据表明，将乙烯-乙烯醇共聚物的钽含量降低至原来的45%-50%，在后续CT检查中对诊断成像的干扰较小，同时仍能实现荧光透视显影。
