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Contrast Biases The Autocorrelation Phase Shift Estimation In Doppler Tissue Imaging

Ressner, Marcus; Jansson, Tomas LU ; Cedefamn, Jonny; Ask, Per and Janerot-Sjoberg, Birgitta (2009) In Ultrasound in Medicine and Biology 35(3). p.447-457
Abstract
Quantitative assessment of regional myocardial function at rest and during stress with Doppler tissue imaging (DTI) plays an important role in daily routine echocardiography. However, reliable visual analysis is largely dependent on image quality and adequate border delineation, which still remains a challenge in a significant number of patients. In this respect, an ultrasound contrast agent (UCA) is often used to improve visualization in patients with suboptimal image quality. The knowledge of how DTI measurements will be affected by UCA present in the tissue is therefore of significant importance for an accurate interpretation of local myocardial motion. The aim of this paper was to investigate how signal contribution from UCA and... (More)
Quantitative assessment of regional myocardial function at rest and during stress with Doppler tissue imaging (DTI) plays an important role in daily routine echocardiography. However, reliable visual analysis is largely dependent on image quality and adequate border delineation, which still remains a challenge in a significant number of patients. In this respect, an ultrasound contrast agent (UCA) is often used to improve visualization in patients with suboptimal image quality. The knowledge of how DTI measurements will be affected by UCA present in the tissue is therefore of significant importance for an accurate interpretation of local myocardial motion. The aim of this paper was to investigate how signal contribution from UCA and nonlinear wave propagation influence the performance of the autocorrelation phase shift estimator used for DTI applications. Our results are based on model experiments with a clinical 2-D grayscale scanner and computational simulations or the DTI velocity estimator for synthetically-derived pulses, simulated bubble echoes and experimentally-sampled RF data of transmitted pulses and backscattered contrast echoes. The results show that destruction of UCA present in the tissue will give rise to an apparent bidirectional velocity bias of individual velocity estimates, but that spatial averaging of individual velocity measurements within a region-of-interest will result in a negative bias (away from the transducer) of the estimated mean or mean peak velocity. The UCA destruction will also have a significant impact on the measured integrated mean velocity over time, i.e., displacement. To achieve improved visualization with UCA during DTI-examinations, we either recommend that it is performed at low acoustic powers, mechanical index <= 0.3, thereby minimizing the effects from bubble rupture, or that each Doppler pulse package is preceded by a destruction burst similar to "Flash imaging" to clear the target area of contrast microbubbles. (E-mail: marcus.ressner@imt.liu.se) (C) 2009 World Federation for Ultrasound in Medicine & Biology. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Contrast, Ultrasound, Tissue Doppler, Microbubbles, Velocity estimation
in
Ultrasound in Medicine and Biology
volume
35
issue
3
pages
447 - 457
publisher
Elsevier
external identifiers
  • wos:000263811200013
  • scopus:60249093213
ISSN
0301-5629
DOI
10.1016/j.ultrasmedbio.2008.09.012
language
English
LU publication?
yes
id
f1d446f4-77a9-4e25-b938-8b13a3ed7f79 (old id 1370836)
date added to LUP
2009-05-08 13:15:24
date last changed
2017-01-01 04:24:10
@article{f1d446f4-77a9-4e25-b938-8b13a3ed7f79,
  abstract     = {Quantitative assessment of regional myocardial function at rest and during stress with Doppler tissue imaging (DTI) plays an important role in daily routine echocardiography. However, reliable visual analysis is largely dependent on image quality and adequate border delineation, which still remains a challenge in a significant number of patients. In this respect, an ultrasound contrast agent (UCA) is often used to improve visualization in patients with suboptimal image quality. The knowledge of how DTI measurements will be affected by UCA present in the tissue is therefore of significant importance for an accurate interpretation of local myocardial motion. The aim of this paper was to investigate how signal contribution from UCA and nonlinear wave propagation influence the performance of the autocorrelation phase shift estimator used for DTI applications. Our results are based on model experiments with a clinical 2-D grayscale scanner and computational simulations or the DTI velocity estimator for synthetically-derived pulses, simulated bubble echoes and experimentally-sampled RF data of transmitted pulses and backscattered contrast echoes. The results show that destruction of UCA present in the tissue will give rise to an apparent bidirectional velocity bias of individual velocity estimates, but that spatial averaging of individual velocity measurements within a region-of-interest will result in a negative bias (away from the transducer) of the estimated mean or mean peak velocity. The UCA destruction will also have a significant impact on the measured integrated mean velocity over time, i.e., displacement. To achieve improved visualization with UCA during DTI-examinations, we either recommend that it is performed at low acoustic powers, mechanical index &lt;= 0.3, thereby minimizing the effects from bubble rupture, or that each Doppler pulse package is preceded by a destruction burst similar to "Flash imaging" to clear the target area of contrast microbubbles. (E-mail: marcus.ressner@imt.liu.se) (C) 2009 World Federation for Ultrasound in Medicine &amp; Biology.},
  author       = {Ressner, Marcus and Jansson, Tomas and Cedefamn, Jonny and Ask, Per and Janerot-Sjoberg, Birgitta},
  issn         = {0301-5629},
  keyword      = {Contrast,Ultrasound,Tissue Doppler,Microbubbles,Velocity estimation},
  language     = {eng},
  number       = {3},
  pages        = {447--457},
  publisher    = {Elsevier},
  series       = {Ultrasound in Medicine and Biology},
  title        = {Contrast Biases The Autocorrelation Phase Shift Estimation In Doppler Tissue Imaging},
  url          = {http://dx.doi.org/10.1016/j.ultrasmedbio.2008.09.012},
  volume       = {35},
  year         = {2009},
}