Fig. 1

Method used to obtain the left-atrial focused long-axis cine images. Left atrial (LA)-focused 4- and 2-chamber long-axis cine images were planned from the standard long-axis cine images. Starting from the end-systolic standard 4-chamber cine image (A1), the LA-focused 2-chamber image (B) was obtained, oriented parallel to the interatrial septum, by selecting a perpendicular plane passing through the roof of the LA and the center of the mitral annulus. From the cine image in panel B, a perpendicular plane was selected, again intercepting the roof of the LA and the center of the mitral annulus, to obtain the LA-focused 4-chamber cine image (C). Before acquisition, the plane orientation to obtain LA-focused cine images was cross-checked in the standard 3-chamber cine image (A2), to avoid the inclusion of the adjacent aortic root in the final images