A geometric index to differentiate abnormal from normal septal wall motion on cardiac MRI.

BackgroundThe definition of abnormal septal wall motion (SWM) is usually performed on a subjective visual assessment with cardiac MR (CMR).PurposeTo quantify SWM using a geometric index and to compare this index to the visual inspection in patients with or without abnormal SWM.Material and MethodsCine CMR images of 100 consecutive patients were retrospectively assessed for visual evaluation of SWM and calculation of a convexity septal index (CSI) on mid-ventricular short-axis images, defined as b/a (a = minimal distance from anterior to posterior ventricular junctions; b = maximal distance from septum to a), obtained in end-systole (ES) and end-diastole (ED). Cohen κ, Bland-Altman method, Kruskall-Wallis, Mann-Whitney U, Jonckheere-Terpstra, and Spearman statistics were used to compare the two methods.ResultsAt visual evaluation, 73 patients had normal SWM (group A), nine abnormal SWM at ES (group B), and 18 at ES and ED (group C). Median CSI for group A was significantly higher (ES = 0.23, ED = 0.25) tha...