From the Division of Cardiovascular Imaging, Department of Radiology and Radiological Science (L.L.G., G.R.G., C.N.D.C., M.V.H., J.R.S., A.W.K., J.M.K., A.B., U.E., P.C., U.J.S.), and Division of Cardiology, Department of Medicine (U.J.S.), Medical University of South Carolina, Heart & Vascular Center, Ashley River Tower, 25 Courtenay Dr, Charleston, SC 29425-2260; Department of Clinical Radiology, University Hospitals LMU Munich, Munich, Germany (L.L.G., F.B.); Siemens Medical Solutions, CT Division, Malvern, Pa (C.C.); Department of Cardiology and Intensive Care Medicine, Heart Center Munich-Bogenhausen, Munich, Germany (U.E.); and Department of Radiology, University of Tuebingen, Tuebingen, Germany (F.B.).
Radiology. 2015 Sep;276(3):706-14. doi: 10.1148/radiol.15140427. Epub 2015 Mar 17.
To use suitable objective methods of analysis to assess the influence of the combination of an integrated-circuit computed tomographic (CT) detector and iterative reconstruction (IR) algorithms on the visualization of small (≤3-mm) coronary artery stents.
By using a moving heart phantom, 18 data sets obtained from three coronary artery stents with small diameters were investigated. A second-generation dual-source CT system equipped with an integrated-circuit detector was used. Images were reconstructed with filtered back-projection (FBP) and IR at a section thickness of 0.75 mm (FBP75 and IR75, respectively) and IR at a section thickness of 0.50 mm (IR50). Multirow intensity profiles in Hounsfield units were modeled by using a sum-of-Gaussians fit to analyze in-plane image characteristics. Out-of-plane image characteristics were analyzed with z upslope of multicolumn intensity profiles in Hounsfield units. Statistical analysis was conducted with one-way analysis of variance and the Student t test.
Independent of stent diameter and heart rate, IR75 resulted in significantly increased xy sharpness, signal-to-noise ratio, and contrast-to-noise ratio, as well as decreased blurring and noise compared with FBP75 (eg, 2.25-mm stent, 0 beats per minute; xy sharpness, 278.2 vs 252.3; signal-to-noise ratio, 46.6 vs 33.5; contrast-to-noise ratio, 26.0 vs 16.8; blurring, 1.4 vs 1.5; noise, 15.4 vs 21.2; all P < .001). In the z direction, the upslopes were substantially higher in the IR50 reconstructions (2.25-mm stent: IR50, 94.0; IR75, 53.1; and FBP75, 48.1; P < .001).
The implementation of an integrated-circuit CT detector provides substantially sharper out-of-plane resolution of coronary artery stents at 0.5-mm section thickness, while the use of iterative image reconstruction mostly improves in-plane stent visualization.
使用合适的客观分析方法来评估集成电路计算机断层扫描（CT）探测器与迭代重建（IR）算法相结合对小直径（≤3mm）冠状动脉支架可视化的影响。
通过使用心脏运动体模，对三个小直径冠状动脉支架的 18 个数据集进行了研究。使用配备集成电路探测器的第二代双源 CT 系统。图像以层厚 0.75mm 进行滤波反投影（FBP）和 IR 重建（FBP75 和 IR75），以及以层厚 0.50mm 进行 IR 重建（IR50）。使用高斯和拟合对多排强度曲线进行建模，以分析平面内图像特征。通过柱形强度曲线在 z 方向上的斜率分析平面外图像特征。采用单因素方差分析和学生 t 检验进行统计学分析。
与 FBP75 相比，IR75 独立于支架直径和心率，可显著提高 xy 锐利度、信噪比和对比噪声比，并降低模糊度和噪声（例如，2.25mm 支架，0 次/分钟；xy 锐利度，278.2 比 252.3；信噪比，46.6 比 33.5；对比噪声比，26.0 比 16.8；模糊度，1.4 比 1.5；噪声，15.4 比 21.2；所有 P<0.001）。在 z 方向上，IR50 重建的斜率明显更高（2.25mm 支架：IR50，94.0；IR75，53.1；FBP75，48.1；P<0.001）。
集成电路 CT 探测器的应用可在 0.5mm 层厚时显著提高冠状动脉支架的平面外分辨率，而迭代图像重建主要改善平面内支架可视化。
