We have recently presented a new algorithm for high-speed parallel processing of ultrasound pulse-echo data for real-time three-dimensional (3-D) imaging. The approach utilizes a discretized linear model of the echo data received from the region of interest (ROI) using a conventional beam former. The transmitter array elements are fed with binary codes designed to produce distinct impulse responses from different directions in ROI. Image reconstruction in ROI is achieved with a regularized pseudoinverse operator derived from the linear receive signal model. The reconstruction operator can be implemented using a transversal filter bank with every filter in the bank designed to extract echoes from a specific direction in the ROI. The number of filters in the bank determines the number of image lines acquired simultaneously. In this paper, we present images of a cyst phantom reconstructed based on our formulation. A number of issues of practical significance in image reconstruction are addressed. Specifically, an augmented model is introduced to account for imperfect blocking of echoes from outside the ROI. We have also introduced a column-weighting algorithm for minimizing the number of filter coefficients. In addition, a detailed illustration of a full image reconstruction using subimage acquisition and compounding is given. Experimental results have shown that the new approach is valid for phased-array pulseecho imaging of speckle-generating phantoms typically used in characterizing medical imaging systems. Such coded-excitationbased image reconstruction from speckle-generating phantoms, to the best of our knowledge, have not been reported previously.
Bibliographical noteFunding Information:
Manuscript received September 16, 1996; revised June 30, 1998. This work was supported by the National Science Foundation (NSF) under Grant ECS-9358301 and by the National Institutes of Health (NIH) under Grant HL57167. The Associate Editor responsible for coordinating the review of this paper and recommending its publication was C. Meyer. Asterisk indicates corresponding author. J. Shen is with Lucent Technologies, Inc., Whippany, NJ 07981 USA. *E. S. Ebbini is with the Department of Electrical and Computer Engineering, University of Minnesota, 4-174 EE/CSci Building, 200 Union Street S.E., Minneapolis, MN 55455 USA (e-mail: firstname.lastname@example.org). Publisher Item Identifier S 0278-0062(98)09676-1.
- Acoustic arrays
- Biomedical imaging
- Image reconstruction
- Parallel processing