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Movement artefact suppression in blood perfusion measurements using a multifrequency technique

Jansson, Tomas LU ; Persson, Hans W LU and Linström, Kjell (2002) In Ultrasound in Medicine and Biology 28(1). p.69-79
Abstract
The standard way of suppressing movement artefacts in Doppler measurements is by means of a high-pass filter. This is because artefacts usually are of high amplitude, but have low frequencies. The immediate drawback is, then, that low-velocity blood flow is also filtered out. In this paper, a method to reduce movement artefacts in blood perfusion measurements is proposed, using simultaneous transmission and reception of multiple frequencies in a continuous-wave Doppler system. It is shown that Doppler signals originating from blood may be considered uncorrelated for a large enough frequency separation between channels, and tissue movements are more correlated. By subtracting perfusion estimates obtained by time-domain processing,... (More)
The standard way of suppressing movement artefacts in Doppler measurements is by means of a high-pass filter. This is because artefacts usually are of high amplitude, but have low frequencies. The immediate drawback is, then, that low-velocity blood flow is also filtered out. In this paper, a method to reduce movement artefacts in blood perfusion measurements is proposed, using simultaneous transmission and reception of multiple frequencies in a continuous-wave Doppler system. It is shown that Doppler signals originating from blood may be considered uncorrelated for a large enough frequency separation between channels, and tissue movements are more correlated. By subtracting perfusion estimates obtained by time-domain processing, correlated signals can be suppressed. The subtraction algorithm is shown to produce a linear perfusion estimate, but with twice the standard deviation compared to an estimate obtained by simply averaging channels. Movement artefacts in both in vitro and in vivo models are shown to be reduced by the algorithm. Imbalance between channels does, however, cause the artefacts to be only partly reduced. The problem can be alleviated by filtering the signals prior to subtraction, but this results in a nonlinear estimate, especially for large time constants in the filter. Some amount of filtering can still be desirable to suppress partly correlated artefacts, even if identical time-domain processing units are implemented, as could be done digitally. (E-mail: tomas.jansson@elmat.lth.se) (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
clutter, artefact, perfusion, compounding, frequency, speckle, Doppler ultrasound, continuous-wave Doppler
in
Ultrasound in Medicine and Biology
volume
28
issue
1
pages
69 - 79
publisher
Elsevier
external identifiers
  • pmid:11879954
  • wos:000174317900008
  • scopus:0036197267
ISSN
0301-5629
DOI
10.1016/S0301-5629(01)00476-8
language
English
LU publication?
yes
id
f6f2b005-e847-495b-8af2-196c6ec5ec82 (old id 342211)
date added to LUP
2007-10-24 13:55:39
date last changed
2017-07-30 03:35:52
@article{f6f2b005-e847-495b-8af2-196c6ec5ec82,
  abstract     = {The standard way of suppressing movement artefacts in Doppler measurements is by means of a high-pass filter. This is because artefacts usually are of high amplitude, but have low frequencies. The immediate drawback is, then, that low-velocity blood flow is also filtered out. In this paper, a method to reduce movement artefacts in blood perfusion measurements is proposed, using simultaneous transmission and reception of multiple frequencies in a continuous-wave Doppler system. It is shown that Doppler signals originating from blood may be considered uncorrelated for a large enough frequency separation between channels, and tissue movements are more correlated. By subtracting perfusion estimates obtained by time-domain processing, correlated signals can be suppressed. The subtraction algorithm is shown to produce a linear perfusion estimate, but with twice the standard deviation compared to an estimate obtained by simply averaging channels. Movement artefacts in both in vitro and in vivo models are shown to be reduced by the algorithm. Imbalance between channels does, however, cause the artefacts to be only partly reduced. The problem can be alleviated by filtering the signals prior to subtraction, but this results in a nonlinear estimate, especially for large time constants in the filter. Some amount of filtering can still be desirable to suppress partly correlated artefacts, even if identical time-domain processing units are implemented, as could be done digitally. (E-mail: tomas.jansson@elmat.lth.se)},
  author       = {Jansson, Tomas and Persson, Hans W and Linström, Kjell},
  issn         = {0301-5629},
  keyword      = {clutter,artefact,perfusion,compounding,frequency,speckle,Doppler ultrasound,continuous-wave Doppler},
  language     = {eng},
  number       = {1},
  pages        = {69--79},
  publisher    = {Elsevier},
  series       = {Ultrasound in Medicine and Biology},
  title        = {Movement artefact suppression in blood perfusion measurements using a multifrequency technique},
  url          = {http://dx.doi.org/10.1016/S0301-5629(01)00476-8},
  volume       = {28},
  year         = {2002},
}