A Study on the Optimal Transmit-Receive Conditions for Ultrasound Localization Microscopy
- 주제어 (키워드) Ultrasound Localization Microscopy , Spatial Sampling , Point Spread Function , Beam pattern
- 발행기관 서강대학교 일반대학원
- 지도교수 유양모
- 발행년도 2025
- 학위수여년월 2025. 2
- 학위명 석사
- 학과 및 전공 일반대학원 전자공학과
- 실제 URI http://www.dcollection.net/handler/sogang/000000079680
- UCI I804:11029-000000079680
- 본문언어 영어
- 저작권 서강대학교 논문은 저작권 보호를 받습니다.
초록 (요약문)
Ultrasound localization microscopy (ULM) is an imaging technique that can achieve more than ten times the resolution compared to conventional ultrasound imaging (B-mode, Doppler) while maintaining a similar penetration depth. ULM leverages these properties to visualize microvessels deep within the body without biopsy and is expected to enable the quantification of microcirculation. However, if the spatial sampling rate of the B-mode cine used in ULM is insufficient, artifacts that degrade the results may occur during the motion correction and localization process. This issue can be resolved by adjusting the spatial sampling rate, but in ULM, which has high computational demands, narrowing the beamforming grid leads to a significant time burden. Moreover, using an arbitrary beamforming grid size that does not correspond to the pitch size of the transducer can cause image distortion. Therefore, in this paper, we present optimal transmission and reception conditions for a fixed beamforming grid based on an analysis of the beampattern and PSF aliasing in ultrafast imaging. To verify the proposed method, simulations and experiments using the Verasonics Vantage 128 system were conducted. B-mode imaging and frequency spectrum analysis were performed on point targets located at various depths. From these, we confirmed that the PSF generated under the proposed optimal conditions for sub-pixel translation of the point source achieves maximum resolution without aliasing. Additionally, when localizing a point source moving diagonally, it was observed that gridding artifacts were well suppressed under the optimal conditions, and motion correction artifacts were reduced in a multipurpose phantom. Finally, improvements in the final ULM images were confirmed using a custom-made flow phantom.
more목차
Ⅰ. Introduction 1
Ⅱ. Methods 8
A. PSF aliasing pattern analysis 8
B. Beampattern of plane wave synthetic aperture (PWSA) 14
C. Transmit/Receive Condition Optimization 20
Ⅲ. Results 22
A. PSF sub-pixel translation study 24
B. Localization Study 28
C. Motion Correction Study 30
D. Flow phantom ULM Study 32
Ⅳ. Discussion 35
V. Conclusion 37
References 38
