Quantification of myocardial deformation by deformable registration–based analysis of cine MRI: validation with tagged CMR

ObjectivesTo validate deformable registration algorithms (DRAs) for cine balanced steady-state free precession (bSSFP) assessment of global longitudinal strain (GLS) and global circumferential strain (GCS) using harmonic phase (HARP) cardiovascular magnetic resonance as standard of reference (SoR).MethodsSeventeen patients and 17 volunteers underwent short axis stack and 2-/4-chamber cine bSSFP imaging with matching slice long-axis and mid-ventricular spatial modulation of magnetization (SPAMM) myocardial tagging. Inverse DRA was applied on bSSFP data for assessment of GLS and GCS while myocardial tagging was processed using HARP. Intra- and inter-observer variability assessment was based on repeated analysis by a single observer and analysis by a second observer, respectively. Standard semi-automated short axis stack segmentation was performed for analysis of left ventricular (LV) volumes and ejection fraction (EF).ResultsDRA demonstrated strong relationships to HARP for myocardial GLS (R2 = 0.75; p < 0.0001) and endocardial GLS (R2 = 0.61; p < 0.0001). GCS result comparison also demonstrated significant relationships between DRA and HARP for myocardial strain (R2 = 0.61; p < 0.0001) and endocardial strain (R2 = 0.51; p < 0.0001). Both methods demonstrated small systematic errors for intra- and inter-observer variability but DRA demonstrated consistently lower CV. Global LVEF was significantly lower (p = 0.0099) in patients (53.7%; IQR 43.9/64.0%) than in healthy volunteers (62.6%; IQR 61.1/66.2%). DRA and HARP strain data demonstrated significant relationships to LVEF.ConclusionsNon-rigid deformation method–based DRA provides a reliable measure of peak systolic GCS and GLS based on cine bSSFP with superior intra- and inter-observer reproducibility compared to HARP.Key Point• Myocardial strain can be reliably analyzed using inverse deformable registration algorithms (DRAs) on cine CMR.• Inverse DRA-derived strain shows higher reproducibility than tagged CMR.• DRA and tagged CMR-based myocardial strain demonstrate strong relationships to global left ventricular function.