Software-Based Implementation of Ultrasonic Array Imaging
Date Issued
2010
Date
2010
Author(s)
Li, Yen-Feng
Abstract
In this research, we investigate software-based ultrasonic array imaging. The advantages of a software-based architecture include lower hardware complexity, development time and cost. size. Compared to CPU-based systems, with which performance is often limited by its inadequate parallelism, the GPU-based architecture has the potential of increasing computation speed significantly. In this research, CUDA GPU-based parallel programming is used. The imaging tasks under investigation include phased array imaging, color Doppler, and synthetic transmit aperture (STA) imaging.
The software is implemented with NVIDIA GeForce GTX 260 and Intel core i7 920 CPU. Frame rate of this system is 42 fps with a 128 elements array transducer, 2048 samples per firing and 189 beams per image. Frame rate of STA imaging is 40 fps with 16 firings per image. Color Doppler imaging is tested with similar B-mode data, and flow data consisted of 1024 samples per firing, 90 beams and an ensemble of 8 firings per beam. The frame rate is 14 fps with single beam, and it is 20 fps with dual beams.
The large data transfer requirement of software-based system may be a bottleneck to achieve real time imaging. In this research, we also investigated channel data compression methods to overcome the limitation. In channel data compression, when the average error is under 4dB, the maximum acceptable compression ratio is 10 with JPEG and 20 with JPEG2000.
In order to realize real time STA flow estimation, accuracy of STA color Doppler is investigated by simulations. Field II is used to compare accuracy of various flow estimations. The frame rate of STA color Doppler is equal to PRF, and the error is about 1% lower than plane wave and conventional method with half autocorrelation samples. However, the accuracy of STA color Doppler is lower than the other methods when SNR is 20dB or lower. Also, the maximum detectable velocity with STA color Doppler is half of that with conventional method.
Subjects
ultrasonic array imaging
software parallel programming
synthetic transmit aperture imaging
synthetic transmit aperture flow estimation
ultrasonic signal compression
Type
thesis
File(s)![Thumbnail Image]()
Loading...
Name
ntu-99-R97945002-1.pdf
Size
23.32 KB
Format
Adobe PDF
Checksum
(MD5):4682eacb40bd9cd3e56ea8e147854f21