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:

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.

• Authors: Karla M Treitl, Michael Scherr, Monika Förth, Franziska Braun, Daniel Maxien, Marcus Treitl
• Journal: European radiology (Eur Radiol) Vol. 25 Issue 3 Pg. 597-605 (Mar 2015) ISSN: 1432-1084 [Electronic] Germany
• PMID: 25319348 (Publication Type: Evaluation Study, Journal Article)

Chemical References

• Polyvinyls
• ethylene-vinyl alcohol copolymer
• Tantalum

Topics

• Aortic Aneurysm, Abdominal (diagnostic imaging)
• Artifacts
• Embolization, Therapeutic (methods)
• Endoleak (diagnostic imaging)
• Fluoroscopy
• Humans
• Phantoms, Imaging
• Polyvinyls (chemistry)
• Stents
• Tantalum (chemistry)
• Tomography, X-Ray Computed (instrumentation, methods)