Abstract 5800: Improvement of In-Stent Lumen Visualization with prototype Fine-cell Detector CT: Comparison with 64-slice CT
PURPOSE The purpose of this study was to evaluate improvement of in-stent lumen visualization using coronary stent phantoms on the prototype Fine-cell Detector CT (FDCT; 0.3mm collimation) compared with 64-slice CT.
METHOD AND MATERIALS The prototype FDCT has 1824-ch * 32-row * 0.3125mm (10mm for z-coverage) detector, and the X-ray tube small focal spot size was 0.35mm width with 335mA at 120kVp (40kW). We developed five types of coronary stent phantom, which have 3mm-diameter with three different types of stent (Driver: Medotronic, Bx Velocity: Johnson&Johnson, Multilink Penta: Guidant), and 2.75mm-diameter with two different types of stent (Express2, Liberte: Boston Scientific). Those coronary vessels were made by Acrylic or Acrylonitrile-Butadiene-Styrene (ABS) resin and filled with diluted Iodine (350HU in 120kVp), and each stent was fixed inside of those vessels. Those phantoms in the water tank were scanned by both 64-slice CT (LightSpeed VCT, GE Healthcare) and FDCT with 120kVp, 200mAs, 16-row * 0.625mm in 64-slice CT, 32-row * 0.3125mm in FDCT, and those images were reconstructed with 96mm Display Field of View and Standard kernel. Histogram was calculated from ROIs automatically enclosed each phantom in eight consecutive slice images. Quantitative analysis of lumen area and stent peak was performed using CT value histogram.
RESULTS FDCT improved lumen area 26.4% in 3mm-Driver, 26.4% in 3mm-Bx Velocity, 22.3% in 3mm-Multilink Penta, 25.1% in 2.75mm-Leberte and 20.1% in 2.75mm-Express2, respectively, comparing with 64-slice CT. The three times repeatable tests were performed for 2.75mm-Express2, and the result was 20.1+/−1.1%. And then, CT value of each stent peak was 1150 –1450HU in 64-slice CT and 1600 –2050HU in FDCT, and showed FDCT had less partial volume effect than 64-slice CT. These results were corresponded by visual assessments in short and long axes images of them.
CONCLUSION FDCT improved more than 20% in-stent lumen visualization quantitatively compared with 64-slice CT, and also, we confirmed those improvements by visually for small-sized stent.
CLINICAL RELEVANCE/APPLICATION This FDCT improves coronary artery visualization, and has possibility to improve the detection in-stent restenosis compared with 64-slice CT.