Multidetector computed tomography in transcatheter aortic valve implantation. Where we stand.

Degenerative calcific aortic stenosis represents the most common valve abnormality with increasing incidence in the elderly. Studies have shown that aortic stenosis is a fatal disease with a high cardiovascular death rate if untreated. However, many patients are encumbered with multiple comorbidities making them high-risk candidates for surgical aortic valve replacement, which is the hitorical treatment of choice. Transcatheter aortic valve implantation (TAVI) has seen rapid advancements over the last number of years with over 50000 TAVI procedures being performed in 40 countries with excellent prognosis proving TAVI to be a feasible alternative therapy to traditional surgical aortic valve replacement to treat high-risk patients. In addition to clinical suitability, imaging plays an essential role for optimal patient selection and to help select the appropriate prosthesis and to help reduce the likelihood of complications and adverse events. Fundamental to the procedure success, is the non-invasive assessment of the aortic annulus, the evaluation of the aortic root and the determination of the access to the aortic annulus. Among different imaging modalities that have been employed, multidetector computed tomography (MDCT) is increasingly used because of its capability of 3-dimentional (3D) determination of the non-circular nature of the aortic annulus as well as the complex aortic root anatomy. Additionally, MDCT provides a deep understanding of the structural integrity of the transcatheter aortic valve and enables the evaluation of the prosthesis location after TAVI and identification of post procedure complications. In this article, we discuss the current role of MDCT in pre-TAVI evaluation but also in the guidance of the procedure and in post-procedure follow-up.