High-Pitch 128-Slice Dual-Source CT for the Assessment of Coronary Stents in a Phantom Model

In Vitro Comparison of Second- and Third-generation Dual-source CT for Coronary Stent Visualization at Different Tube Potentials

“…A previous study on the third-generation dual-source CT system showed that, depending on the stent's orientation, up to 80% lumen visibility on average can be achieved in 3.0-mm metal stents when applying new iterative reconstruction kernels (14). However, comparison of these results to former studies is limited because of the differences in CT systems, reconstruction kernels, and especially the selection of coronary stents (4,9,12). Therefore, the exact degree of diagnostic improvement deriving from the use of third-generation dualsource CT systems remained unclear, generating a need for this comparison study.…”

“…The finding of reduced visible stent lumen diameter at 100 kVp is presumably based on the increase of beam hardening or, rather, effects that have been described before as blooming and "halo effect" (9,12). These effects are caused by very dense materials like coronary calcification or metallic stent struts and limit the evaluation of the stent's lumen in the vicinity thereof (15).…”

“…However, previous studies have indicated that there is a certain correlation between stent orientation and visible lumen diameter (9,14,19).…”

“…With the increasing technical capabilities of new CT scanner generations, including the introduction of dual-source CT and new reconstruction algorithms, various studies have shown a marked improvement in coronary stent visualization by CTA over the last years (8)(9)(10)(11)(12). These advances were accompanied by reduced radiation exposure, eventually leading to lowdose coronary CTA with still acceptable image quality and sufficient predictive values even for the detection of in-stent stenosis (13).…”

Influence of cardiac motion on stent lumen visualization in third generation dual-source CT employing a pulsatile heart model

“…4,5 However, through increasing number of detector rows, increasing temporal resolution and improved reconstruction kernels, the image quality has been substantially improved. [6][7][8][9][10][11][12][13][14][15][16] A previous study revealed that a third-generation dual-source CT scanner (SOMATOM Force; Siemens Healthcare, Forchheim, Germany) enabled a lumen visibility of up to 80% in metal stents while the stents were at rest. 17 To evaluate the influence of cardiac motion on stent lumen visualization in the same third-generation dual-source CT scanner, we employed a pulsatile heart model (CoroSim®; Mecora, Aachen, Germany) (Figures 1 and 2) to evaluate differences in visible stent lumen diameter between motion and standstill.…”