The Feasibility of Accurate Stent Visualization With Photon-Counting Detector CT and K-Edge Imaging

Abstract

CT stent imaging suffers from blooming and metal artifacts, reducing the diagnostic quality of images in the areas around stents. Photon-counting detectors (PCDs) have been shown to reduce these artifacts. Two clinical scanners, a GE Optima 580 and Discovery IQ, were compared to a bench-top PCD-CT system for stent imaging with three stents: Medtronic Protégé, Cordis Precise, and Cordis S.M.A.R.T. Control. The apparent strut thickness, lumen diameter, and lumen attenuation of the stents were evaluated in reconstructed images. K-edge images were also reconstructed to demonstrate more accurate delineation of the tantalum radiopaque markers. PCD-CT offered lower percent differences for strut thickness for all three stents (p < 0.001) and for lumen diameter for the Protégé and Precise stents (p < 0.01). The lumen attenuation was more accurate with PCD-CT as well (p < 0.01), excluding the comparisons between the Optima 580 and PCD-CT for the Protégé and Precise stents. The PCD-CT system was better able to delineate stents, specifically strut thickness. The stents were more easily distinguished in PCD-CT images and in 3D volume renderings than the clinical systems. The tantalum radiopaque markers were clearly visible in K-edge images due to reduced metal artifacts.