Fei Hao, Presenter: Nothing to Disclose

Ning Guo PhD, Abstract Co-Author: Nothing to Disclose

Spectral CT imaging with fast kVp switching dual energy system is capable to create monochromic images so that high keV images with small small blooming artifact can be used for artery stent assessment. Also density of contrast material (iodine) is one important factor to effect coronary stent diagnosis. In this study, we compare the measured in-stent luminal diameter (ISLA) using monochromic images with the measured ISLA using 140kVp image on the different iodine density.

A coronary artery stent phantom (Cypher-3.0mm) filled with different contrast fluid (Iodine density: water, 2:9mg/ml: 85HU, 5.8mg/ml: 154HU and 11:6mg/ml: 292HU at 140kVp) and surrounded by water was scanned using a high definition CT (Discovery CT750HD, GE) in GSI scan mode. Six monochromatic images (40 - 140keV, 20keV increment) and one 140kVp were reconstructed. The in-stent luminal diameter (ISLA) was measured as the full width half maximum (FWHM) of the attenuation profile across the stent at three different stent locations. The measurement accuracy was estimated by FWHM/stent physical size. The Mann-Whitney test was used for this study.

The FWHM and accuracy of measured ISLA increased with the increase of keV in the monochromic images, and FWHM and accuracy of stent on the small contrast density get higher. The accuracy of measured ISLA on the 60keV monochromic images was 57.0+0.4% on waterp; 52.1+0.8% on 2.9mg/ml iodine density; 50.1+0.9% on 5.8mg/ml; 47.2+1.1% on 11.8mg/ml, respectively. There have statistical difference (p < 0.05) between each different iodine group on the 60keV. The measurement average accuracy on the different iodine density (0, 2.9, 5.8 & 11.6mg/ml) was 50.0+3.3% on 140kVp; 48.7+5.1% on 40keV; 51.6+4.1% on 60keV; 55.2+3.2% on 80keV; 57.8+1.2% on 100keV; 60.8+3.1% on 120keV; 62.6+2.9% on 140keV, respectively. The statistical significantly (p < 0.05) better results were obtained at high keV images (100keV, 120keV and 140keV) than high keV images (40keV, 60keV and 80keV).

The accuracy of the artery stent assessment can be improved using monochromic images (keV) in spectral CT imaging with fast kVp switching dual energy technology.

The monochromic images (keV) in spectral CT imaging with fast kVp switching dual energy technology can improve stent diagnosis performance.

Hao, F, Guo, N, Application of Monochromatic Images in Artery Stent Assessment using CT Spectral Imaging with Fast kVp Switching Dual Energy System: Effect of Iodine Density on the Stent Phantom Study.  Radiological Society of North America 2012 Scientific Assembly and Annual Meeting, November 25 - November 30, 2012 ,Chicago IL. http://archive.rsna.org/2012/12043760.html