 Riccardo Faletti riccardo.faletti@unito.it 1 Department of Surgical Sciences, Radiology Institute, University of Turin, Via Genova 3, 10126 Turin, Italy 2 Division of Cardiac Surgery, Department of Surgical Sciences, University of Turin, Turin, Italy 3 Department of Surgical Sciences, University of Turin, Turin, Italy 4 Department of Radiodiagnostic, S.C. Radiodiagnostica Ospedaliera, Turin, Italy 5 Division of Cardiology, Department of Medical Sciences,, University of Turin, Turin, Italy Received: 29 February 2016 / Accepted: 16 April 2016 © Springer Science +Business Media Dordrecht 2016                   1   1   2             2       1   2 Int J Cardiovasc Imaging DOI 10.1007/s10554-016-0899-8 variables were studied with Fisher’s exact test. The intr and inter-operator reliability was satisfying. There wer no signifcant differences between the annulus dimensions measured by CMR and either one of the three references. Valve sizing for CoreValve by CMR had the same good agreement with CCT and TEE, with a 78 % match rate; for SAPIEN XT the agreement was slightly better (82 %) for CCT than for TEE (66 %). MR performs well when com - pared to the surgical reference of intra-operative sizin stands up to the level of the most used imaging referenc (CCT and TEE). Aortic stenosis · Transcatheter aortic valv implantation · Transesophageal echocardiography · Cardiovascular computed tomography · Cardiovascular magnetic resonance Aortic stenosis (AS) is the most frequent degenerative - vular heart disease in western countries and its prevale keeps increasing with the progressive ageing of the popu - tion [ 1]. Transcatheter aortic valve implantation (TAVI) in patients with severe symptomatic AS was recently approv as a therapeutic alternative for patients who are not su to undergo conventional aortic valve replacement (AV [ 2, 3]. Standard TAVI workup includes clinical assessment, surgical and frailty risk scoring, blood investigations, ec - cardiography, pulmonary function tests, cardiovascu computed tomography (CCT), angiography and cardiac catheterisation [ 4]. The choice of the correct valve size is based on the aor root structures and the aortic annulus dimensions, and e To assess the accuracy and reproducibly of cardiovascular magnetic resonance (CMR) in the measure - ment of the aortic annulus and in process of valve sizing as compared to intra-operative sizing, cardiovascular com - puted tomography (CCT) and transesophageal echocar - diography (TEE). Retrospective study on 42 patients who underwent aortic valve replacement from September 2010 to September 2015, with available records of pre surgery annulus assessment by CMR, CCT and TEE and of peri- operative assessment. In CCT and CMR, the annular plane was considered a virtual ring formed by the lowest hinge points of the valvular attachments to the aorta. In TEE the annulus was measured at the base of leafet insertion in the mid-esophageal long-axis view using the X-plane technique. Two double-blinded operators performed the assessments for each imaging technique. Intra-operative evaluation was performed using Hegar dilators. Continu - ous variables were studied with within-subject ANOVA, Bland–Altman (BA) plots, Wilcoxon’s and Friedman’s tests; trends were explored with scatter plots. Categorical 1 3