title: Feature tracking measurement of dyssynchrony from cardiovascular magnetic resonance cine acquisitions: comparison with echocardiographic speckle tracking.
abstract: BACKGROUND
  Analysis of left ventricular (LV) mechanical dyssynchrony may provide incremental prognostic information regarding cardiac resynchronization therapy (CRT) response in addition to QRS width alone. Our objective was to quantify LV dyssynchrony using feature tracking post processing of routine cardiovascular magnetic resonance (CMR) cine acquisitions (FT-CMR) in comparison to speckle tracking echocardiography.
  
  
  METHODS
  We studied 72 consecutive patients who had both steady-state free precession CMR and echocardiography. Mid-LV short axis CMR cines were analyzed using FT-CMR software and compared with echocardiographic speckle tracking radial dyssynchrony (time difference between the anteroseptal and posterior wall peak strain).
  
  
  RESULTS
  Radial dyssynchrony analysis was possible by FT-CMR in all patients, and in 67 (93%) by echocardiography. Dyssynchrony by FT-CMR and speckle tracking showed limits of agreement of strain delays of ± 84 ms. These were large (up to 100% or more) relative to the small mean delays measured in more synchronous patients, but acceptable (mainly <25%) in those with mean delays of >200 ms. Radial dyssynchrony was significantly greater in wide QRS patients than narrow QRS patients by both FT-CMR (radial strain delay 230 ± 94 vs. 77 ± 92* ms) and speckle tracking (radial strain delay 242 ± 101 vs. 75 ± 88* ms, all *p < 0.001).
  
  
  CONCLUSIONS
  FT-CMR delivered measurements of radial dyssynchrony from CMR cine acquisitions which, at least for the patients with more marked dyssynchrony, showed reasonable agreement with those from speckle tracking echocardiography. The clinical usefulness of the method, for example in predicting prognosis in CRT patients, remains to be investigated.
authors.forename: Toshinari
authors.initials: T
authors.lastname: Onishi
authors.forename: Samir K
authors.initials: SK
authors.lastname: Saha
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Ludwig
authors.forename: Tetsuari
authors.initials: T
authors.lastname: Onishi
authors.forename: Josef J
authors.initials: JJ
authors.lastname: Marek
authors.forename: João L
authors.initials: JL
authors.lastname: Cavalcante
authors.forename: Erik B
authors.initials: EB
authors.lastname: Schelbert
authors.forename: David
authors.initials: D
authors.lastname: Schwartzman
authors.affiliation: The University of Pittsburgh, 200 Lothrop Street, Pittsburgh, PA, USA. gorcsanj@upmc.edu.
authors.forename: John
authors.initials: J
authors.lastname: Gorcsan
mesh_terms: D000328:Adult; D000368:Aged; D000465:Algorithms; D057205:Automation, Laboratory; D001696:Biomechanical Phenomena; D004452:Echocardiography; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D019028:Magnetic Resonance Imaging, Cine; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012984:Software; D013314:Stress, Mechanical; D013997:Time Factors; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000503:physiopathology; D016277:Ventricular Function, Left