Improving ultrafast ultrasound imaging in both image quality and processing speed

Kou, Zhengchang

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https://hdl.handle.net/2142/121931 Copy

Description

Title

Improving ultrafast ultrasound imaging in both image quality and processing speed

Author(s)

Kou, Zhengchang

Issue Date

2023-08-18

Director of Research (if dissertation) or Advisor (if thesis)

Oelze, Michael L

Doctoral Committee Chair(s)

Oelze, Michael L

Committee Member(s)

• Song, Pengfei
• Gruev, Viktor
• Kripfgans, Oliver

Department of Study

Electrical & Computer Eng

Discipline

Electrical & Computer Engr

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

Ph.D.

Degree Level

Dissertation

Keyword(s)

• Ultrasound
• Medical Imaging
• FPGA
• Ultrafast Ultrasound

Abstract

Ultrafast power Doppler imaging has been explored as a powerful tool to image microvasculature because it can significantly boost the signal to noise ratio compared to that of traditional power Doppler imaging. However, most of these methods are computationally expensive and cannot be implemented in a real-time fashion. As an alternative, null subtraction imaging (NSI)-based ultrafast power Doppler has been proposed to provide high spatial resolution and good image quality without significantly increasing the computational cost. NSI-based power Doppler with the presence of contrast agents was able to provide high quality images with the ability to resolve two vessels that were 50 μm apart with low computational overhead. Aside from improving spatial resolution, NSI can also reduce grating lobes, which occurs when the wavelength is larger than the pitch of the imaging array. According to this feature, NSI was combined with pulse inversion (PI) harmonic imaging to improve the image quality of contrast free ultrafast power Doppler imaging. With NSI-based PI UPD imaging, a spatial resolution of 29 µm has been achieved with a short acquisition length of 162 ms. Ultrafast ultrasound imaging could generate digital channel data at a data rate far beyond the data transfer capabilities of current ultrasound research platforms. The processing speed of current CPU- or GPU-based beamformers cannot keep pace with the data generation speed. To amend this bridge between the data generation and processing, a novel design of field programmable gate array (FPGA) based beamformer has been proposed. In this study, a combination of a novel beamforming architecture based on delay reuse and the highly parallel feature of FPGA enabled an ultrafast ultrasound beamformer with up to 4.8 GSPS processing speed in terms of input sample rate or 29,000 frames per second in terms of frame rate. The power consumption of the proposed beamformer was only a little over 12 Watts. With such processing speed, continuous real time ultrafast ultrasound imaging is possible.

Graduation Semester

2023-12

Type of Resource

Thesis

Copyright and License Information

Copyright 2023 Zhengchang Kou

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