## Abstract

In a previous paper we have demonstrated that the velocity can be estimated for a plug flow using recursive ultrasound imaging [1]. The approach involved the estimation of the velocity at every emission and using the estimates for motion compensation. An error in the estimates, however, would lead to an error in the compensation further increasing the error in the estimates.

In this paper the approach is further developed such that no motion compensation is necessary. In recursive ultrasound imaging a new high resolution image is created after every emission. The velocity was estimated by cross correlating RF lines from two successive emissions n and n + 1, and then average over a number of lines. In the new approach images n and n + N, n + 1 and n + N + 1 are cross correlated, where N is the number of emissions for one image. These images experience the same phase distortion due to motion and therefore have a high correlation without motion compensation. The advantage of the approach is that a color flow map can be created for all directions in the image simultaneously at every emission, which makes it possible to average over a large number of lines. This makes stationary echo canceling easier and significantly improves the velocity estimates. The approach is verified using simulations with the program Field II and measurements on a blood-mimicking phantom. The estimates from the simulations have a bias of -3.5% and a mean standard deviation less than 2.0% for a parabolic velocity profile. The estimates from the measurements for the same setup exhibit a larger bias -11%, but the standard deviation is comparable to the simulations (sigma similar to 2.5%).

In this paper the approach is further developed such that no motion compensation is necessary. In recursive ultrasound imaging a new high resolution image is created after every emission. The velocity was estimated by cross correlating RF lines from two successive emissions n and n + 1, and then average over a number of lines. In the new approach images n and n + N, n + 1 and n + N + 1 are cross correlated, where N is the number of emissions for one image. These images experience the same phase distortion due to motion and therefore have a high correlation without motion compensation. The advantage of the approach is that a color flow map can be created for all directions in the image simultaneously at every emission, which makes it possible to average over a large number of lines. This makes stationary echo canceling easier and significantly improves the velocity estimates. The approach is verified using simulations with the program Field II and measurements on a blood-mimicking phantom. The estimates from the simulations have a bias of -3.5% and a mean standard deviation less than 2.0% for a parabolic velocity profile. The estimates from the measurements for the same setup exhibit a larger bias -11%, but the standard deviation is comparable to the simulations (sigma similar to 2.5%).

Original language | English |
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Title of host publication | 2001 IEEE Ultrasonics Symposium Proceedings |

Volume | 1-2 |

Publication date | 2001 |

Pages | 1409-1412 |

ISBN (Print) | 0-7803-7177-1 |

Publication status | Published - 2001 |

Event | 2001 IEEE Ultrasonics Symposium - Atlanta, United States Duration: 7 Oct 2001 → 10 Oct 2001 http://ieeexplore.ieee.org/xpl/mostRecentIssue.jsp?punumber=7781 |

### Conference

Conference | 2001 IEEE Ultrasonics Symposium |
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Country/Territory | United States |

City | Atlanta |

Period | 07/10/2001 → 10/10/2001 |

Internet address |

Series | I E E E International Ultrasonics Symposium. Proceedings |
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ISSN | 1051-0117 |