CMR-FT

CMR-FT analysis was performed using Circle CVI42 5.12.1 software (Tissue Tracking, Circle Cardiovascular Imaging Inc., CVI42^® 5.12.1 software, Calgary, Alberta). Endocardial and epicardial contours of the functional RV were manually traced in long-axis and short-axis SSFP cine images at end-diastole. All contours were then automatically propagated through the cardiac cycle by applying the dedicated algorithm. If the automatic tracking was considered visually inadequate, SSFP cine images were retracked and the algorithm reapplied. Global peak systolic radial strain (GRS) and global peak systolic circumferential strain (GCS) were derived from short-axis images (basal, mid-ventricular, apical slices) while a 4-chamber cine image was used to quantify global peak systolic longitudinal strain (GLS). To determine the reproducibility of our measurements, CMR-FT analysis was evaluated twice by two blinded expert readers in a group of 10 randomly selected patients.