Comparison of cardiac MR feature tracking and myocardial MR tagging for assessment of regional ventricular function

Background Quantification of regional myocardial function allows risk stratification in heart disease. CMR tagging (TAG) enables the evaluation of segmental cardiac deformation, but it has not reached clinical routine due to the long acquisition and post-processing times. Conversely, CMR feature-tracking (FT) is a post-processing method based on standard cine-MR imaging. Purpose To compare myocardial strain and torsion obtained with CMR-TAG and CMR-FT in healthy volunteers and myocardial infarction (MI). Methods 42 subjects (18 healthy; 24 MI) underwent CMR (1.5T, cine/TAG sequences). Global and segmental (16-segment) circumferential strain (CS), and torsion were measured using FT (CVI42, Canada) and tagging (InTag, France). Inter-method agreement was assessed using 2-way-mixed intraclass correlation coefficient (ICC). Results The agreement for segmental and global CS measurements was good to excellent in both groups (Table). Torsion angle showed excellent (0.763) and good (0.697) agreement for healthy and MI. Conclusion CMR-FT strain and torsion measurements showed high agreement with CMR-tagging. Thus, CMR-FT provides a potential clinical alternative in the assessment of regional ventricular function. Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): Carlos III Health Institute, Spanish Ministry of Economy and Competiveness; Agencia Valenciana de la Innovaciόn, Generalitat Valenciana

CMR—basic principles

Recent advances have enabled CMR to come close to the goal of a complete examination of the cardiovascular system by a single modality. It can provide relevant information on most aspects of heart structure, global and regional ventricular function, valve function, flow patterns, myocardial perfusion, coronary anatomy, and myocardial viability, all obtained non-invasively in a single study in 30–60 min. The aim of this chapter is to describe the physics and practical aspects of CMR and then explore the available pulse sequences, so that the clinical utility of CMR can be maximized.