title: Left ventricular mechanics assessed by two-dimensional echocardiography and cardiac magnetic resonance imaging: comparison of high-resolution speckle tracking and feature tracking.
abstract: OBJECTIVE
  Assessment of left ventricular (LV) systolic function plays a central role in cardiac imaging. Calculation of ejection fraction (EF) is the current method of choice; however, its limited intermodal comparability represents a major drawback. The assessment of myocardial mechanics by strain imaging may better reflect the complex myocardial contractility. We aimed to evaluate different methods for quantification of LV strain on global and regional levels with a focus on the new non-proprietary feature tracking (FT) algorithm.
  
  
  RESULTS
  Measurements of LV deformation were performed by means of high-resolution two-dimensional (2D) speckle tracking echocardiography (STE) and compared with values obtained by 2D feature tracking echocardiography (FT-E) and feature tracking cardiac magnetic resonance imaging (FT-CMR). Assessments with echocardiography started within 30 min after CMR examination to minimize time-dependent variations in myocardial function. Forty-seven patients were included. Assessments by STE were -15.7 ± 5.0% for global longitudinal strain (GLS), -14.6 ± 4.5% for global circumferential strain (GCS), and 21.6 ± 13.3% for global radial strain (GRS), while values obtained with FT-E were -13.1 ± 4.0, -13.6 ± 4.0, 20.3 ± 9.5, and with FT-CMR -15.0 ± 4.0, -16.9 ± 5.4, and 35.0 ± 10.8, respectively. Linear regression and the Bland-Altman analysis showed the best intramodal association for STE GLS and FT-E GLS (r = 0.88, bias = -2.7%, LOA = ±4.7%). The correlation for GCS and GRS was weaker, and for regional strain was poor. In contrast to EF, GLS showed a better intermodal correlation between echocardiography and CMR (r = 0.81 by speckle tracking, r = 0.8 by FT, and r = 0.78 by EF).
  
  
  CONCLUSIONS
  In our study, measurement of global longitudinal LV strain using the new FT algorithm with CMR and echocardiography was comparable with measurements obtained by high-resolution STE. Compared with echocardiographic EF determination, FT-E GLS shows a better reproducibility and a better intermodal agreement with CMR, representing a fair non-proprietary solution for this assessment.
  
  
  BACKGROUND
  clinicaltrials.gov. Unique identifier: NCT01275963.
authors.affiliation: Department of Internal Medicine III, Cardiology, Angiology and Pneumology, University of Heidelberg, Im Neuenheimer Feld 410, Heidelberg 69120, Germany matthias.aurich@med.uni-heidelberg.de.
authors.forename: Matthias
authors.initials: M
authors.lastname: Aurich
authors.affiliation: Department of Internal Medicine III, Cardiology, Angiology and Pneumology, University of Heidelberg, Im Neuenheimer Feld 410, Heidelberg 69120, Germany.
authors.forename: Marius
authors.initials: M
authors.lastname: Keller
authors.affiliation: Department of Internal Medicine III, Cardiology, Angiology and Pneumology, University of Heidelberg, Im Neuenheimer Feld 410, Heidelberg 69120, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Greiner
authors.affiliation: Department of Internal Medicine III, Cardiology, Angiology and Pneumology, University of Heidelberg, Im Neuenheimer Feld 410, Heidelberg 69120, Germany.
authors.forename: Henning
authors.initials: H
authors.lastname: Steen
authors.affiliation: Department of Internal Medicine III, Cardiology, Angiology and Pneumology, University of Heidelberg, Im Neuenheimer Feld 410, Heidelberg 69120, Germany.
authors.forename: Fabian
authors.initials: F
authors.lastname: Aus dem Siepen
authors.affiliation: Department of Internal Medicine III, Cardiology, Angiology and Pneumology, University of Heidelberg, Im Neuenheimer Feld 410, Heidelberg 69120, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Riffel
authors.affiliation: Department of Internal Medicine III, Cardiology, Angiology and Pneumology, University of Heidelberg, Im Neuenheimer Feld 410, Heidelberg 69120, Germany.
authors.forename: Hugo A
authors.initials: HA
authors.lastname: Katus
authors.affiliation: Department of Internal Medicine III, Cardiology, Angiology and Pneumology, University of Heidelberg, Im Neuenheimer Feld 410, Heidelberg 69120, Germany.
authors.forename: Sebastian J
authors.initials: SJ
authors.lastname: Buss
authors.affiliation: Department of Internal Medicine III, Cardiology, Angiology and Pneumology, University of Heidelberg, Im Neuenheimer Feld 410, Heidelberg 69120, Germany.
authors.forename: Derliz
authors.initials: D
authors.lastname: Mereles
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D004452:Echocardiography / Q000379:methods*; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011446:Prospective Studies; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000503:physiopathology; D016277:Ventricular Function, Left / Q000502:physiology
keywords: left ventricular systolic function; strain imaging