Title

A Unified Framework for Vascular Imaging Enhancement in Ultrasound and Photoacoustics

DGIST Authors

Guezzi Nizar ; Jaesok Yu ; Hoejoon Kim

Advisor

유재석

Co-Advisor(s)

Hoejoon Kim

Issued Date

2026

Awarded Date

2026-02-01

Type

Thesis

Description

Signal Processing, Image Processing, Image reconstruction

Table Of Contents

LIST OF CONTENTS
ABSTRACT i
LIST OF CONTENTS iv
LIST OF TABLES viii
LIST OF FIGURES viii
1. Introduction 1
1.1 Background and Motivation 1
1.2 Challenges in Vascular Imaging 3
1.2.1 Hardware Complexity and Safety in 3D Ultrasound 3
1.2.2 Clutter and Beamforming Limitations in Doppler Ultrasound 4
1.2.3 Noise and Energy Constraints in Photoacoustic Microscopy 5
1.2.4 General Trade-offs in Vascular Imaging 6
1.3 State of the Art 7
1.3.1 Three-Dimensional Ultrasound with Row-Column Arrays 7
1.3.2 Advanced Beamformers in Ultrafast Doppler Imaging 8
1.3.3 Post-Processing in Photoacoustic Microscopy 9
1.3.4 Summary of the State of the Art 10
1.4 Vascular Enhancement Across the Imaging Chain 11
1.4.1 Transmit Optimization 11
1.4.2 Reconstruction 11
1.4.3 Post-Processing 12
1.5 Contributions of This Thesis 13
1.5.1 Transmit-Level Enhancement in 3D Ultrasound with RCA Arrays 13

1.5.2 Reconstruction-Level Enhancement with Dual-Stage Coherence Beamforming 14
1.5.3 Post-Processing Enhancement in Photoacoustic Microscopy 15
1.5.4 Summary of Contributions. 15
1.6 Thesis Outline 16
2. Transmit Level Vascular Enhancement in 3D Ultrasound with Row-Column Arrays 19
2.1 Introduction 20
2.2 Methods 24
2.2.1 Transmission scheme 24
2.2.2 Coded excitation and pulse decoding 25
2.2.3 Optimization of transmission parameters 28
2.2.4 Data acquisition 29
2.2.5 Image reconstruction scheme 30
2.3 Results 32
2.3.1 Image spatial resolution evaluation 32
2.3.2 Optimized transmission parameters 33
2.3.3 Axial resolution and sidelobe level 35
2.3.5 Increased penetration depth 36
2.3.6 In vivo results 38
2.4 Discussion 40
2.5 Conclusion 43
2.6 Acknowledgement 43
3. Reconstruction-Level Vascular Enhancement with Dual-Stage Coherence Beamforming 44
3.1 Introduction 45
3.2 Methods 47

3.2.1 DAS and CF beamformers 47
3.2.2 Dual stage coherence beamformer 49
3.2.2 Simulation and experimental setup 51
3.2.3 Signal processing pipeline 52
3.3 Results 53
3.3.1 Point spread function (PSF) analysis 53
3.3.2 Three target scenario 54
3.3.3 Noise floor estimation in multi-target scenarios 55
3.3.4 In-vivo rat brain data (single frame analysis) 56
3.3.5 In-vivo rat brain data (power doppler imaging) 58
3.3.6 In-vivo rat brain data (directional power doppler ) 59
3.4 Discussion 61
3.5 Conclusion 63
3.6 Acknowledgement 63
4. Post-Processing Level Vascular Enhancement in Photoacoustic Microscopy 64
4.1 Introduction 64
4.2 Methods 66
4.2.1 Optical-resolution photoacoustic microscopy 66
4.2.2 Animal preparation 68
4.2.3 Image pre-processing 68
4.2.4 Image post-processing 69
4.3 Results and discussion 73
4.3.1 Phantom experiment results 73
4.3.2 In vivo experiment results 75

4.4 Conclusion 81
4.5 Acknowledgment 81
5. A Unified Framework for Vascular Imaging Enhancement: An Ultrasound Case Study 82
5.1 Introduction 82
5.2 Methods 83
5.3 Results 84
5.4 Discussion and Conclusion 87
6. Conclusion and Perspectives 89
6.1 Conclusion 89
6.2 Perspectives 93
Acknowledgments 95
List of achievements 96
Journal publications (first authored papers) 96
Conferences 97
References 98
초음파 및 광음향 영상에서 혈관 영상 향상을 위한 통합 프레임워크 116
요 약 문 116

URI

https://scholar.dgist.ac.kr/handle/20.500.11750/59604
http://dgist.dcollection.net/common/orgView/200000943273

DOI

10.22677/THESIS.200000943273

Degree

Doctor

Department

Department of Robotics and Mechatronics Engineering

Publisher

DGIST

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