In vitro Evaluation of Metallic Coronary Artery Stents with Sub-Millimeter Multi-Slice Computed Tomography Using an ECG-Gated Cardiac Phantom: Relationship between In-Stent Visualization and Stent Type

Abstract

The aim of this experimental study was to investigate visualization of various coronary artery stents with sub-millimeter multi-slice spiral computed tomography (MSCT) using a cardiac physical phantom. Four 3-mm stents of various designs were implanted in tubes with an inner diameter of 3 mm to simulate coronary artery. Stents were placed on a cardiac phantom and scanned at different heart rates. Retrospective ECG-gated adaptive segmental reconstruction technique was employed. Profile curves across longitudinal curved planar reconstruction images of the stents were generated. From the profile curve, the full width at half maximum was defined as the stent lumen index. The effect of heart rate and stent type on the stent lumen index was evaluated. Visual evaluation for each stent at various heart rates was also performed. The heart rate had no significant effect on in-stent visualization. However, in-stent visualization differed significantly for the various stent types for both profile curve analysis and visual evaluation (the Tukey-Kramer multiple comparisons test). Multiple regression analysis indicated that strut thickness, especially minimal strut thickness, was the significant influencing factor for the in-stent visualization. On the basis of four stent models examined it would appear that visualization of the coronary stent lumen varies depending on the stent type, but not on the heart rate. Stents with slim struts are preferable for in-stent evaluation with multi-slice spiral computed tomography.

Diagnostic accuracy of in-stent coronary restenosis detection with multislice spiral computed tomography: a meta-analysis

“…Imaging coronary stents using CT is a technically more demanding task than imaging native coronary arteries. The degree of metal artifacts of stents, including partial volume effects is related to stent material, the size of the diameter, the thickness and strut design [6,[31][32][33][34]. The metal artifact of tantalum is so severe in comparison with other materials that it is considered to be impossible to assess the lumens of the stents made of tantalum by MSCT.…”

Role of cardiac computed tomography in patients with suspected coronary artery disease: interaction with nuclear cardiology

“…High spatial resolution (slice thickness 0.50-0.75 mm) and the dedicated sharp convolution kernel can optimize in-stent visualization. 22,23 Second, cardiac and respiratory motions may adversely affect the diagnostic accuracy of coronary CTA. It has been reported that coronary CTA tends to overestimate the degree of stenosis.…”