title: Measurement of ventricular torsion by two-dimensional ultrasound speckle tracking imaging.
abstract: OBJECTIVE
  We sought to examine the accuracy/consistency of a novel ultrasound speckle tracking imaging (STI) method for left ventricular torsion (LVtor) measurement in comparison with tagged magnetic resonance imaging (MRI) (a time-domain method similar to STI) and Doppler tissue imaging (DTI) (a velocity-based approach).
  
  
  BACKGROUND
  Left ventricular torsion from helically oriented myofibers is a key parameter of cardiac performance but is difficult to measure. Ultrasound STI is potentially suitable for measurement of angular motion because of its angle-independence.
  
  
  METHODS
  We acquired basal and apical short-axis left ventricular (LV) images in 15 patients to estimate LVtor by STI and compare it with tagged MRI and DTI. Left ventricular torsion was defined as the net difference of LV rotation at the basal and apical planes. For the STI analysis, we used high-frame (104 +/- 12 frames/s) second harmonic two-dimensional images.
  
  
  RESULTS
  Data on 13 of 15 patients were usable for STI analysis, and LVtor profile estimated by STI strongly correlated with those by tagged MRI (y = 0.95x + 0.19, r = 0.93, p < 0.0001, analyzed by repeated-measures regression models). The STI torsional velocity profile also correlated well with that by the DTI method (y = 0.79x + 2.4, r = 0.76, p < 0.0001, by repeated-measures regression models) with acceptable bias.
  
  
  CONCLUSIONS
  The STI estimation of LVtor is concordant with those analyzed by tagged MRI (data derived from tissue displacement) and also showed good agreement with those by DTI (data derived from tissue velocity). Ultrasound STI is a promising new method to assess LV torsional deformation and may make the assessment more available in clinical and research cardiology.
authors.affiliation: Department of Cardiovascular Medicine, The Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, OH 44195, USA.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Notomi
authors.forename: Peter
authors.initials: P
authors.lastname: Lysyansky
authors.forename: Randolph M
authors.initials: RM
authors.lastname: Setser
authors.forename: Takahiro
authors.initials: T
authors.lastname: Shiota
authors.forename: Zoran B
authors.initials: ZB
authors.lastname: Popović
authors.forename: Maureen G
authors.initials: MG
authors.lastname: Martin-Miklovic
authors.forename: Joan A
authors.initials: JA
authors.lastname: Weaver
authors.forename: Stephanie J
authors.initials: SJ
authors.lastname: Oryszak
authors.forename: Neil L
authors.initials: NL
authors.lastname: Greenberg
authors.forename: Richard D
authors.initials: RD
authors.lastname: White
authors.forename: James D
authors.initials: JD
authors.lastname: Thomas
mesh_terms: D004452:Echocardiography / Q000379:methods*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D009200:Myocardial Contraction / Q000502:physiology; D015203:Reproducibility of Results; D014102:Torsion Abnormality / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000473:pathology / Q000503:physiopathology