Cardiovascular magnetic resonance myocardial feature tracking detects quantitative wall motion during dobutamine stress

Abstract

BackgroundDobutamine stress cardiovascular magnetic resonance (DS-CMR) is an established tool to assess hibernating myocardium and ischemia. Analysis is typically based on visual assessment with considerable operator dependency. CMR myocardial feature tracking (CMR-FT) is a recently introduced technique for tissue voxel motion tracking on standard steady-state free precession (SSFP) images to derive circumferential and radial myocardial mechanics.We sought to determine the feasibility and reproducibility of CMR-FT for quantitative wall motion assessment during intermediate dose DS-CMR.Methods10 healthy subjects were studied at 1.5 Tesla. Myocardial strain parameters were derived from SSFP cine images using dedicated CMR-FT software (Diogenes MRI prototype; Tomtec; Germany). Right ventricular (RV) and left ventricular (LV) longitudinal strain (EllRV and EllLV) and LV long-axis radial strain (ErrLAX) were derived from a 4-chamber view at rest. LV short-axis circumferential strain (EccSAX) and ErrSAX; LV ejection fraction (EF) and volumes were analyzed at rest and during dobutamine stress (10 and 20 μg · kg-1· min-1).ResultsIn all volunteers strain parameters could be derived from the SSFP images at rest and stress. EccSAX values showed significantly increased contraction with DSMR (rest: -24.1 ± 6.7; 10 μg: -32.7 ± 11.4; 20 μg: -39.2 ± 15.2; p < 0.05). ErrSAX increased significantly with dobutamine (rest: 19.6 ± 14.6; 10 μg: 31.8 ± 20.9; 20 μg: 42.4 ± 25.5; p < 0.05). In parallel with these changes; EF increased significantly with dobutamine (rest: 56.9 ± 4.4%; 10 μg: 70.7 ± 8.1; 20 μg: 76.8 ± 4.6; p < 0.05). Observer variability was best for LV circumferential strain (EccSAX ) and worst for RV longitudinal strain (EllRV) as determined by 95% confidence intervals of the difference.ConclusionsCMR-FT reliably detects quantitative wall motion and strain derived from SSFP cine imaging that corresponds to inotropic stimulation. The current implementation may need improvement to reduce observer-induced variance. Within a given CMR lab; this novel technique holds promise of easy and fast quantification of wall mechanics and strain.

Myocardial strain in healthy adults across a broad age range as revealed by cardiac magnetic resonance imaging at 1.5 and 3.0T: Associations of myocardial strain with myocardial region, age, and sex

“…For feature tracking at 1.5T,16 an interobserver coefficient of variation between 5.48% and 17.3% was reported for longitudinal strain, and between 4.9% and 13.3% for circumferential strain. For feature tracking at 3.0T, an interobserver coefficient of variation between 16.3% and 26.4% for longitudinal strain and between 9.9% and 20.3% for circumferential strain17, 18, 29, 30 was reported. Reproducibility with DENSE is higher than with Tagging 30.…”

Cardiovascular Magnetic Resonance Myocardial Feature Tracking

“…28,29 Reference values for LV circumferential, radial and longitudinal strain have been published recently. 30,31 Assessment of ventricular deformation at rest and with inotropic stimulation using dobutamine has provided clinically relevant data in health 18,20 and disease states. 23, 24 Schneeweis et al 23 demonstrated the ability to use circumferential short-axis strain to identify inducible ischemia during intermediate and high-dose dobutamine stimulation.…”

“…The technique can be applied for the quantification of right and left ventricular (LV) systolic and diastolic function using strain 10,18 and SR 19 imaging as well as myocardial torsion and diastolic recoil quantification. 20,21 The study of atrial physiology using strain and SR imaging has recently been explored.…”

Cardiovascular magnetic resonance imaging of isolated perfused pig hearts in a 3T clinical MR scanner

“…Late gadolinium-enhanced cardiovascular magnetic resonance (LGE-CMR) was performed in identical slice orientations using conventional methods with a repetition time of 4.9 ms, echo time of 2.4 ms, flip angle of 15°, and spatial resolution at 1.7×1.7×8 mm 3 . Post-processing of perfusion images was performed with dedicated software (Circle Cardiovascular imaging Suite 12, Release 3.4.0 (84) Calgary, Alberta, Canada) and a dedicated feature tracking prototype software (Diogenes MRi, Tomtec, Germany) [14].…”