title: Regional myocardial long-axis strain and strain rate measured by different tissue Doppler and speckle tracking echocardiography methods: a comparison with tagged magnetic resonance imaging.
abstract: OBJECTIVE
  Compare four different echocardiographic methods, based on tissue Doppler imaging (TDI) and speckle tracking (ST) separately or combined, for long-axis strain and strain rate (SR) measurements, using magnetic resonance imaging (MRI) tagging as a reference.
  
  
  RESULTS
  In 21 subjects (10 with myocardial infarction) peak systolic strain and systolic and early diastolic SR were measured by four different echo methods: (i) two-dimensional (2D) strain (B-mode); (ii) ST (custom software) of segment end-points (B-mode); (iii) similar to (ii), but combining ST with tissue Doppler tracking; (iv) strain from tissue Doppler velocity gradients (VG). Agreement with MRI tagging was better for strain than for SR. Ninety-five per cent limits of agreement were wider for the TDI-VG method, and 2D strain showed negative bias compared with MRI tagging and the other echo methods. Reproducibility was better for 2D strain than for MRI tagging and the other echo methods.
  
  
  CONCLUSIONS
  ST alone or combined with TDI seems to be suitable for automated measurements of regional myocardial deformation. The study gives important information on the strengths and weaknesses of the different methods, which is important for further development to increase accuracy and applicability.
authors.affiliation: Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, MTFS, N-7489 Trondheim, Norway. brage.h.amundsen@ntnu.no
authors.forename: Brage H
authors.initials: BH
authors.lastname: Amundsen
authors.forename: Jonas
authors.initials: J
authors.lastname: Crosby
authors.forename: Per Arvid
authors.initials: PA
authors.lastname: Steen
authors.forename: Hans
authors.initials: H
authors.lastname: Torp
authors.forename: Stig A
authors.initials: SA
authors.lastname: Slørdahl
authors.forename: Asbjørn
authors.initials: A
authors.lastname: Støylen
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D016022:Case-Control Studies; D015150:Echocardiography, Doppler / Q000295:instrumentation / Q000379:methods*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000473:pathology*