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
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:
https://lup.lub.lu.se/record/1217986
- author
- Gran, Fredrik
; Jensen, Jörgen A.
and Jakobsson, Andreas
LU
- publishing date
- 2004
- 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
- host publication
- 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
- conference dates
- 2004-02-14 - 2004-02-19
- 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
- 2016-04-01 11:51:04
- date last changed
- 2024-01-07 22:54:18
@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}},
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}},
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}},
doi = {{10.1117/12.535222}},
volume = {{5373}},
year = {{2004}},
}