title: An automated in vitro model for the evaluation of ultrasound modalities measuring myocardial deformation.
abstract: BACKGROUND
  Echocardiography is the method of choice when one wishes to examine myocardial function. Qualitative assessment of the 2D grey scale images obtained is subjective, and objective methods are required. Speckle Tracking Ultrasound is an emerging technology, offering an objective mean of quantifying left ventricular wall motion. However, before a new ultrasound technology can be adopted in the clinic, accuracy and reproducibility needs to be investigated.
  
  
  OBJECTIVE
  It was hypothesized that the collection of ultrasound sample data from an in vitro model could be automated. The aim was to optimize an in vitro model to allow for efficient collection of sample data.
  
  
  METHODS
  A tissue-mimicking phantom was made from water, gelatin powder, psyllium fibers and a preservative. Sonomicrometry crystals were molded into the phantom. The solid phantom was mounted in a stable stand and cyclically compressed. Peak strain was then measured by Speckle Tracking Ultrasound and sonomicrometry.
  
  
  RESULTS
  We succeeded in automating the acquisition and analysis of sample data. Sample data was collected at a rate of 200 measurement pairs in 30 minutes. We found good agreement between Speckle Tracking Ultrasound and sonomicrometry in the in vitro model. Best agreement was 0.83 ± 0.70%. Worst agreement was -1.13 ± 6.46%.
  
  
  CONCLUSIONS
  It has been shown possible to automate a model that can be used for evaluating the in vitro accuracy and precision of ultrasound modalities measuring deformation. Sonomicrometry and Speckle Tracking Ultrasound had acceptable agreement.
authors.affiliation: Department of Anesthesia and Intensive Care, Aarhus University Hospital, Skejby, Aarhus, Denmark. albin.stigo@gmail.com
authors.forename: Albin
authors.initials: A
authors.lastname: Stigö
authors.forename: Peter
authors.initials: P
authors.lastname: Johansen
authors.forename: Morten Ø
authors.initials: MØ
authors.lastname: Jensen
authors.forename: Kim
authors.initials: K
authors.lastname: Sivesgaard
authors.forename: Hans
authors.initials: H
authors.lastname: Nygaard
authors.forename: Erik
authors.initials: E
authors.lastname: Sloth
mesh_terms: D004452:Echocardiography / Q000295:instrumentation*; D004548:Elasticity; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D009200:Myocardial Contraction / Q000502:physiology*; D009206:Myocardium; D019047:Phantoms, Imaging
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