Three-dimensional imaging of the aortic valve and aortic root with computed tomography: new standards in an era of transcatheter valve repair/implantation.

Valvular heart disease is a significant, global cause of morbidity and mortality. In the ageing population of industrialized nations, degenerative aortic stenosis has become the most common native valve disorder. Although surgical aortic valve replacement is associated with excellent clinical outcomes, a large number of patients with severe aortic stenosis are not considered surgical candidates. These patients have poor prognosis with continued medical therapy. In this population, catheter-based approaches for valve replacement/insertion show promising initial results. In an era of expanding catheter-based approaches to valve disease, the requirements for peri-operative imaging are evolving. Because of the lack of direct exposure during the procedure, the operator has to rely increasingly on imaging data rather than direct inspection. Novel three-dimensional (3D) imaging modalities, including computed tomography, rapidly acquire volumetric data sets and allow subsequent 3D display and reconstruction in unlimited planes. Procedural planning based on 3D imaging has already become routine for other endovascular procedures including aortic stent grafts, but is in its infancy in the context of transcatheter valve insertion.