title: Evaluation of tissue Doppler-based velocity and deformation imaging: a phantom study of ultrasound systems.
abstract: OBJECTIVE
  The objective of this study was to test the accuracy and diagnostic interchangeability of tissue Doppler-based displacement, velocity, strain, and strain rate measurements in commercially used ultrasound (US) systems.
  
  
  RESULTS
  Using an in-house made phantom, four different US scanner models were evaluated. Two different scanners of the same model were tested, and one scanner acquisition was tested twice with two generations of the same workstation giving six test results in total. The scanners were in active clinical use and are subject to regular maintenance checks. There were three displacement and four velocity results that stood out from the rest and could be regarded as accurate and interchangeable. Among the deformation measurements, three acceptable strain results were found while there were no acceptable strain rate results. Furthermore, the study showed that measurements from scanners of the same model, same acquisition post-processed on different workstations and repeated measurements from the same scanner, can yield disparate results.
  
  
  CONCLUSIONS
  Measurements that are accurate and of interchangeable use can be found for displacement and velocity measurements, but are less likely to be found for strain and strain rate measurements. It is strongly recommended that the ability of each individual US scanner to measure displacement, velocity, strain, and strain rate is evaluated before it is introduced into clinical practice, and it must always be evaluated together with the workstation the scanner is intended to be used in conjunction with.
authors.affiliation: School of Technology and Health, Royal Institute of Technology (KTH), Campus Flemingsberg, Alfred Nobels Allé 10, 141 52 Huddinge, Sweden. mmar@kth.se
authors.forename: Mattias
authors.initials: M
authors.lastname: Mårtensson
authors.forename: Anna
authors.initials: A
authors.lastname: Bjällmark
authors.forename: Lars-Åke
authors.initials: LÅ
authors.lastname: Brodin
mesh_terms: D003198:Computer Simulation; D015150:Echocardiography, Doppler / Q000295:instrumentation*; D006801:Humans; D009206:Myocardium; D019047:Phantoms, Imaging; D011785:Quality Assurance, Health Care