title: Automated analysis of strain rate and strain: feasibility and clinical implications.
abstract: BACKGROUND
  This study evaluated 3 new automated methods, based on a combination of speckle tracking and tissue Doppler, for the analysis of strain rate (SR) and strain. Feasibility and values for peak systolic strain rate (SR s ) and end-systolic strain (S es ) were assessed.
  
  
  METHODS
  Thirty patients with myocardial infarction and 30 normal subjects were examined. Customized software with automatic definition of segments was used for automated measurements. SR s and SR es were measured over each segment simultaneously and identified automatically. The study compared tissue Doppler-based SR and strain measurements without (method 1) and with segment tracking (method 2) to speckle tracking-based measurements (method 3). For tracking, speckle tracking and tissue Doppler were used in combination. Standard manual analysis was used as a reference.
  
  
  RESULTS
  The automated analysis (16 segments, 3 apical views) required 2 minutes; manual analysis took 11 minutes. Accuracy was compared in 56 segments (28 mid-infarcted and 28 normal) from 28 patients and was 93.9% for method 1, 93.8% for method 2, 95.8% for method 3, and 96.2% for the manual method. In the normal group, mean SR s (0.27 s -1 ) was less with method 3 than with the other methods ( P < .001).
  
  
  CONCLUSIONS
  Our findings indicate that automated analysis of SR and strain, with some manual adjustment, is feasible and quicker than manual analysis. Diagnostic accuracy was similar with all methods. SR s was lower in the speckle tracking-based method than in the Doppler-based methods.
authors.affiliation: Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Tronsheim, Norway. charlotte.b.ingul@ntnu.no
authors.forename: Charlotte Bjork
authors.initials: CB
authors.lastname: Ingul
authors.forename: Hans
authors.initials: H
authors.lastname: Torp
authors.forename: Svein Arne
authors.initials: SA
authors.lastname: Aase
authors.forename: Sigrid
authors.initials: S
authors.lastname: Berg
authors.forename: Asbjorn
authors.initials: A
authors.lastname: Stoylen
authors.forename: Stig A
authors.initials: SA
authors.lastname: Slordahl
mesh_terms: D015150:Echocardiography, Doppler; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D009203:Myocardial Infarction / Q000000981:diagnostic imaging*; D012372:ROC Curve; D012680:Sensitivity and Specificity