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European Radiology

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01-03-2015 | Vascular-Interventional

Reduction of CT beam hardening artefacts of ethylene vinyl alcohol copolymer by variation of the tantalum content: evaluation in a standardized aortic endoleak phantom

Authors: Karla M. Treitl, Michael Scherr, Monika Förth, Franziska Braun, Daniel Maxien, Marcus Treitl

Published in: European Radiology | Issue 3/2015

Abstract

Objectives

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.

Methods

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.

Results

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.

Conclusions

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.

Key Points

• Standard Tantalum-ethylene-vinyl-alcohol-copolymer causes severe beam hardening artefacts, limiting cross-sectional imaging.

• Increased peripheral use of Tantalum-ethylene-vinyl-alcohol-copolymer requires a formulation causing fewer artefacts.

• Treatment of endoleaks can be simulated with an aortic stent graft phantom.

• Tantalum contents of 45–50 % exhibit sufficient visualization and tolerable low artefacts.

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Title: Reduction of CT beam hardening artefacts of ethylene vinyl alcohol copolymer by variation of the tantalum content: evaluation in a standardized aortic endoleak phantom
Authors: Karla M. Treitl
Michael Scherr
Monika Förth
Franziska Braun
Daniel Maxien
Marcus Treitl
Publication date: 01-03-2015
Publisher: Springer Berlin Heidelberg
Published in: European Radiology / Issue 3/2015
Print ISSN: 0938-7994
Electronic ISSN: 1432-1084
DOI: https://doi.org/10.1007/s00330-014-3438-9

At a glance: The STEP trials

Springer Medicine

Reduction of CT beam hardening artefacts of ethylene vinyl alcohol copolymer by variation of the tantalum content: evaluation in a standardized aortic endoleak phantom

Abstract

Objectives

Methods

Results

Conclusions

Key Points

At a glance: The STEP trials

Springer Medicine

Abstract

Objectives

Methods

Results

Conclusions

Key Points

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