Dual-source CT Coronary Stent Imaging With Iterative Reconstruction

Objective:To evaluate the improvement of Iterative Reconstruction in Image Space (IRIS) technique in computed tomography (CT) coronary stent imaging with sharp kernel, and make a trade-off analysis.Materials and methods:56patients with105stents were examined by128-slice dual-source CT coronary angiography (CTCA). Images were reconstructed using standard filter back projection (FBP) and IRIS with both medium kernel and sharp kernel applied. Image noise and the stent diameter were investigated. Image noise was measured both in background vessel and in-stent lumen as objective image evaluation. Image noise score and stent score were performed as subjective image evaluation.Results:The CTCA images reconstructed with IRIS were associated with significant reduction in noise compared to that of CTCA images reconstructed using FBP technique in both of background vessel and in-stent lumen (the background noise decreased about25.4±8.2%in medium kernel (p<0.0001), and30.3±3.4%in sharp kernel (p<0.0001); the in-stent lumen noise decreased about14.2±19.2%%in medium kernel (p<0.0001), and27.0±17.8%in sharp kernel (p<0.0001)). Subjective image assessment showed that the noise of the images reconstructed with IRIS decreased compared to that with FBP. Moreover, the images with sharp kernel showed better visualization of the stent struts and in-stent lumen than that with medium kernel.Conclusions:IRIS reconstruction can effectively reduce the image noise and improve image quality. The sharp kernel images constructed with iterative reconstruction are considered as the optimal images to observe coronary stents in this study.