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Code Division Multiple Element Synthetic Aperture Transmission

Gran, Fredrik; Jensen, Jörgen A. and Jakobsson, Andreas LU (2004) Medical Imaging 2004. Ultrasonic Imaging and Signal Processing In Proceedings of the SPIE - The International Society for Optical Engineering 5373(1). p.300-306
Abstract
In conventional synthetic transmit aperture imaging (STA) the image is built up from a number of low resolution images each originating from consecutive single element firings to yield a high resolution image. This lowers the frame rate and may result in motion artifacts. This paper, describes a method in which all transmitting centers can be excited at the same time and separated at the receiver to yield a full image in only one transmission. Hereby the benefits from traditional STA can be utilized and a high frame rate can be maintained, which thereby prevents motion artifacts. The different centers are excited using mutually orthogonal codes. The signal at the receiver is a linear combination of the transmitted signals convolved with... (More)
In conventional synthetic transmit aperture imaging (STA) the image is built up from a number of low resolution images each originating from consecutive single element firings to yield a high resolution image. This lowers the frame rate and may result in motion artifacts. This paper, describes a method in which all transmitting centers can be excited at the same time and separated at the receiver to yield a full image in only one transmission. Hereby the benefits from traditional STA can be utilized and a high frame rate can be maintained, which thereby prevents motion artifacts. The different centers are excited using mutually orthogonal codes. The signal at the receiver is a linear combination of the transmitted signals convolved with the corresponding pulse-echo impulse response. The pulse-echo impulse responses for the different elements are modeled as finite impulse response channels and estimated using a maximum likelihood technique. The method was verified using simulations in Field II. A 7 MHz transducer was simulated with 128 receiving elements and 64 transmitting elements divided into subapertures so that 4 virtual transmission centers were formed. The point spread function was simulated and the axial resolution was 0.23 mm (-3 dB) and 0.31 mm (-6 dB). lateral resolution 0.53 mm (-3 dB) and 0.71 mm (-6 dB) and maximum lateral sidelobe level less than 44 dB. Conventional STA is given as a reference with the same aperture setup using 4 emissions excited with a single cycle sinusoid at 7 MHz. The axial resolution is here 0.23 mm (-3 dB) and 0.31 mm (-6 dB), lateral resolution 0.53 mm (-3 dB) and 0.71 mm (-6 dB) and maximum lateral sidelobe level less than 44 dB (Less)
Please use this url to cite or link to this publication:
author
publishing date
type
Chapter in Book/Report/Conference proceeding
publication status
published
subject
keywords
biomedical ultrasonics, convolution, image resolution, maximum likelihood estimation, medical image processing, code division technique, multiple element synthetic aperture transmission, motion artifacts, pulse-echo impulse response, finite impulse response channels, point spread function, ultrasound imaging, 7 MHz, -3 dB, -6 dB
in
Proceedings of the SPIE - The International Society for Optical Engineering
volume
5373
issue
1
pages
300 - 306
publisher
SPIE
conference name
Medical Imaging 2004. Ultrasonic Imaging and Signal Processing
external identifiers
  • scopus:12144280958
ISSN
1996-756X
0277-786X
DOI
10.1117/12.535222
language
English
LU publication?
no
id
f22f6d2b-4ef7-4abe-8819-626123503e94 (old id 1217986)
date added to LUP
2008-10-06 12:52:59
date last changed
2017-11-20 15:05:58
@inproceedings{f22f6d2b-4ef7-4abe-8819-626123503e94,
  abstract     = {In conventional synthetic transmit aperture imaging (STA) the image is built up from a number of low resolution images each originating from consecutive single element firings to yield a high resolution image. This lowers the frame rate and may result in motion artifacts. This paper, describes a method in which all transmitting centers can be excited at the same time and separated at the receiver to yield a full image in only one transmission. Hereby the benefits from traditional STA can be utilized and a high frame rate can be maintained, which thereby prevents motion artifacts. The different centers are excited using mutually orthogonal codes. The signal at the receiver is a linear combination of the transmitted signals convolved with the corresponding pulse-echo impulse response. The pulse-echo impulse responses for the different elements are modeled as finite impulse response channels and estimated using a maximum likelihood technique. The method was verified using simulations in Field II. A 7 MHz transducer was simulated with 128 receiving elements and 64 transmitting elements divided into subapertures so that 4 virtual transmission centers were formed. The point spread function was simulated and the axial resolution was 0.23 mm (-3 dB) and 0.31 mm (-6 dB). lateral resolution 0.53 mm (-3 dB) and 0.71 mm (-6 dB) and maximum lateral sidelobe level less than 44 dB. Conventional STA is given as a reference with the same aperture setup using 4 emissions excited with a single cycle sinusoid at 7 MHz. The axial resolution is here 0.23 mm (-3 dB) and 0.31 mm (-6 dB), lateral resolution 0.53 mm (-3 dB) and 0.71 mm (-6 dB) and maximum lateral sidelobe level less than 44 dB},
  author       = {Gran, Fredrik and Jensen, Jörgen A. and Jakobsson, Andreas},
  booktitle    = {Proceedings of the SPIE - The International Society for Optical Engineering},
  issn         = {1996-756X},
  keyword      = {biomedical ultrasonics,convolution,image resolution,maximum likelihood estimation,medical image processing,code division technique,multiple element synthetic aperture transmission,motion artifacts,pulse-echo impulse response,finite impulse response channels,point spread function,ultrasound imaging,7 MHz,-3 dB,-6 dB},
  language     = {eng},
  number       = {1},
  pages        = {300--306},
  publisher    = {SPIE},
  title        = {Code Division Multiple Element Synthetic Aperture Transmission},
  url          = {http://dx.doi.org/10.1117/12.535222},
  volume       = {5373},
  year         = {2004},
}