3D Motion Compensated Tomographic Reconstruction of Coronary Stents from X-ray Rotational Sequence : An Experimental Study

Percutaneous transluminal coronary angioplasty consists in conducting a balloon and a stent through a coronary lesion and deploying the stent by balloon inflation. A coronary stent is a 3D complex mesh hardly visible in X-Ray images. The control of stent deployment is difficult from the 2D projection images inspection although insufficient deployment of the stent may lead to post intervention complications. In previous works, we have proposed a way to improve the clinical control of the intervention in the continuity of the angiographic procedure. We suggest to reconstruct 3D stent images from a set of 2D cone-beam projections acquired in rotational acquisition mode, using a motion compensation technique. In this paper, we investigate the feasibility of this method on coronary stents in-vivo. We first introduce one synthetic realistic case to illustrate the incorrect deployment problematic and control requirements. In-vivo experiments have been carried out on ten pigs, the porcine model is known to get anatomical and physiological similarities with humans. The cross-sectional area and the diameter along the motion compensated reconstructed deployed stent are measured in 3D slices (parallel or orthogonal to the axis of the stent). This feasibility study shows that a three-dimensional stent tomographic reconstruction can be obtained in a conventional interventional suite from a rotational X-ray sequence. So 3D quantitative measurements not available from the actual angiographic procedure are provided to the physician and help him to assess the quality of his intervention.