Carsten Rist MD, Presenter: Nothing to Disclose

Christoph Richard F. Becker MD, Abstract Co-Author: Nothing to Disclose

Miles A. Kirchin PhD, Abstract Co-Author: Employee, Bracco Group

Thorsten R.C. Johnson MD, Abstract Co-Author: Speakers Bureau, Siemens AG

Maximilian F. Reiser MD, Abstract Co-Author: Nothing to Disclose

Konstantin Nikolaou MD, Abstract Co-Author: Nothing to Disclose

Our aim was to evaluate the potential clinical value of Dual-Source Computed Tomography (DSCT) for the assessment of coronary artery stent patency and stenosis.

In an ongoing study, twenty patients underwent both DSCT (Somatom Definition, Siemens Medical Solutions, Forchheim, Germany) of the coronary arteries and quantitative X-ray coronary angiography (QCA) after coronary artery stent placement. DSCT coronary angiography was performed with the following parameters: spatial resolution = 0.75x0.4x0.4mm; temporal resolution=83ms. The contrast medium (Iomeprol 400®, Bracco Imaging SpA, Milan, Italy) volume and flow rate was adapted to the patient’s body weight. The DSCT scans were evaluated for image quality and for the presence of significant in-stent stenoses assessing the sensitivity, specificity and diagnostic accuracy of DSCT for the detection or exclusion of significant in-stent stenoses.

A total of 29 stents were evaluated, of which 28 were assessed to be of diagnostic image quality (97%). Mean heart rate during the CT examination was 72±12 bpm (range, 48-93). Significant in-stent restenosis or occlusion was detected on QCA in 5/28 cases (≥50% stenosis = 3; occlusion = 2). The sensitivity for the detection of high-grade stenosis or stent occlusion was 80% (4/5). Both stent occlusions were correctly identified, however, one of three significant stenoses was underestimated. The specificity and diagnostic accuracy were 91% (21/23) and 89% (25/28), respectively.

In this ongoing study, initial results comparing coronary DSCT with QCA showed a very robust image quality and a high diagnostic accuracy in the detection of stent occlusion or in-stent restenosis, although grading of in-stent stenosis remains difficult.

Restenosis remains a major limitation of coronary artery stent placement. Therefore, a reliable non-invasive diagnostic tool to evaluate patency of coronary stents would be highly desirable.

Rist, C, Becker, C, Kirchin, M, Johnson, T, Reiser, M, Nikolaou, K, Assessment of Coronary Artery Stent Patency and Restenosis Using Dual Source Computed Tomography.  Radiological Society of North America 2007 Scientific Assembly and Annual Meeting, November 25 - November 30, 2007 ,Chicago IL. http://archive.rsna.org/2007/5011187.html