Assessment of Coronary Stents Using 40-Detector Row CT

Objective: To evaluate the performance of 40-detector row computed tomography (CT) in the assessment of coronary stents in comparison with 16-detector row CT. Methods: A total of 6 vascular models (3 models without stenosis and 3 with stenosis) using 3 types of stent (Bx-Velocity, Express2, and Driver) with an approximately 3.5-mm inner diameter filled with contrast material (450 Hounsfield units) were scanned with 2 computed tomographic scanners (collimation, 16 x 0.75 and 40 x 0.625 mm). We evaluated the in-stent stenosis visually for the 6 vascular models in 4 orientations (0, 30, 60, and 90 degrees) to the z-axis of the scanner. We evaluated attenuation values of the stent lumen of the 3 patent models in the 4 orientations. The average and standard deviation of the luminal attenuation values were assessed to evaluate the degree of blooming and streak artifacts. Results: The visualization of the stent lumen of the vascular models at 90 degrees was improved using 40-detector row CT. For all the 3 stents, the average luminal attenuations values using 40-detector row CT were significantly lower than those using 16-detector row CT in all orientations. For all the 3 stents, the standard deviations of the luminal computed tomographic attenuation using 40-detector row CT were significantly smaller than those using 16-detector row CT in the 4 orientations to the z-axis except for Express2 at 0 degrees. Conclusions: The visualization of coronary stents is improved by the use of 40-detector row CT with reduced blooming and streak artifacts.