Role of Computed Tomography in Transcatheter Aortic Valve Implantation

Computed tomography (CT) has emerged as the standard of care for preprocedural planning of transcatheter aortic valve implantation (TAVI). Because of the submillimeter isotropic 3D imaging capability and the unique ability of imaging calcification and vessel tortuosity in 3D, multi-detector row CT imaging has been routinely used in clinic to perform patient screening, annulus sizing, transcatheter heart valve selection, and access route evaluation before the TAVI procedure. CT-based annular sizing has been shown to be superior to 2D echocardiography in predicting the occurrence of paravalvular leak post TAVI. In this chapter, we reviewed the role of CT imaging in TAVI using the most commonly used self-expandable and balloon-expandable TAVI valves as examples and discussed the CT acquisition protocols and the image processing and evaluation techniques of the CT images. Specifically, we gave detailed descriptions of a number of important CT analysis techniques for the purpose of preprocedural planning, including the measurement of the aortic annulus and the aortic root, the characterization of calcification, the calculation of the angiographic projection angles, and the assessment of the access route. The utility of CT post TAVI was also discussed.