Keywords:
Arteries / Aorta, CT, Stents, Quality assurance
Authors:
A. M. den Harder, D. Suchá, J. Breur, J. Martens, R. P. J. Budde, C. Bos, T. Leiner; Utrecht/NL
Methods and Materials
Six different stents were expanded to an inner diameter of 20 mm using an atlas balloon and placed in a non-pulsatile anthropomorphic chest phantom and imaged using a 256-slice CT-scanner (Figure 1).
The following stents were used: Atrium V12 covered stent (stainless steel,
covering with PTFE),
Andramed AS-30 XL (cobalt-chromium),
CP covered stent (0.013” platinum / iridium),
CP stent (0.013” platinum / iridium),
EV3 LD Mega (stainless steel) and EV3 LD Max (stainless steel).
The stent lumen was filled with diluted contrast gel and the plastic holder was filled with gel without contrast.
All stents were scanned at normal dose (100 kV,
195 mAs) and low-dose (80 kV,
20 mAs).
Images were reconstructed with filtered back projection (FBP) and iterative reconstruction (IR,
iDose4 level 3).
At the center of the stents the inner stent diameter was measured using the area derived diameter (Figure 2).
At normal dose the diameter was measured twice by two observers and intra-rater and inter-rater variability was assessed with the intraclass correlation coefficient and Bland-Altman plots.