LED-Based Photoacoustic Imaging: From Bench to Bedside

Foreword
Contents
About the Editor
Fundamentals and Theory
Fundamentals of Photoacoustic Imaging: A Theoretical Tutorial
	1 Introduction
	2 Theory of Photoacoustic Wave Generation and Propagation
		2.1 Generation of Photoacoustic Wave (Initial PA-Pressure)
		2.2 Propagation of Photoacoustic Wave
	3 Conclusion
	References
High-Power Light Emitting Diodes; An Alternative Excitation Source for Photoacoustic Tomography
	1 Introduction
	2 Photoacoustic Tomography
	3 High-Power LEDs
		3.1 Characteristics of High-Power LEDs
	4 Major Areas of Development in LED-Based Photoacoustic Imaging
		4.1 Single Point Measurements
		4.2 Photoacoustic Tomography
		4.3 Photoacoustic Spectroscopy
		4.4 Novel Excitation Schemes
	5 Summary and Outlook
	References
Image Enhancement and Reconstruction Techniques
Deformation-Compensated Averaging for Deep-Tissue LED and Laser Diode-Based Photoacoustic Imaging Integrated with Handheld Echo Ultrasound
	1 Introduction
	2 DCA Prerequisites
		2.1 US Image Quality
		2.2 Motion Tracking Algorithm
	3 Combined Handheld PA and US System
		3.1 Acquisition System
		3.2 Image Reconstruction
		3.3 DCA Details
		3.4 Image Display
	4 Results
		4.1 Illustration of Processing Steps
		4.2 Further Results
	5 Discussion and Conclusion
	References
Ultrasound Receive-Side Strategies for Image Quality Enhancement in Low-Energy Illumination Based Photoacoustic Imaging
	1 Introduction
	2 Review of Image Enhancement Strategies for PAT Systems
		2.1 LED-PAUS Imaging System
		2.2 Effect of Hardware-Based Improvisations Implemented on Ultrasound Transducer for PAT Application
	3 Sub-pitch Translation for Improving PAT Image Quality
		3.1 Theory and Methodology
		3.2 Results and Discussion
	4 Removal of EMI in Low SNR PAT Images
		4.1 Methodology
		4.2 Results
	5 Conclusion
	References
Vascular Complexity Evaluation Using a Skeletonization Approach and 3D LED-Based Photoacoustic Images
	1 Introduction
	2 Blood Vessel Extraction Techniques
		2.1 Pattern Recognition Techniques
		2.2 Model-Based Techniques
		2.3 Vessel Tracking Techniques
		2.4 Machine Learning
	3 Vessel Architecture Quantification
		3.1 Morphological Parameters
		3.2 Tortuosity Parameters
	4 Phantom Design
		4.1 Model Design
		4.2 Phantoms Realization
		4.3 Acquisition Setup
		4.4 Device Settings
	5 Image Processing and Results
		5.1 Segmentation and Skeletonization
		5.2 Parameter Calculation and Validation
	6 Feasibility Study Results
	7 Conclusion
	References
Multiscale Signal Processing Methods for Improving Image Reconstruction and Visual Quality in LED-Based Photoacoustic Systems
	1 Introduction
	2 Block Diagram of Imaging and Signal Acquisition
	3 Signal Domain Processing of PA Acquisitions
	4 Image Processing Applications
		4.1 Pre-processing and Noise Removal
		4.2 Segmentation of Objects in PA Images
	5 Reconstructed PA Image Quality Improvement Using a Multimodal Framework
	6 Summary
	References
Data Structure Assisted Accelerated Reconstruction Strategy for Handheld Photoacoustic Imaging
	1 Introduction
	2 Analytic Equation Based Algorithms
		2.1 Filtered BackProjection Based PACT Imaging
		2.2 Time Reversal Based PACT Imaging
		2.3 F-K Migration Based PACT Imaging
	3 Model Based Iterative Image Reconstruction Algorithms
		3.1 Symmetry Conjugate Gradient Search (CGS) and Least Square Conjugate Gradient Search (LSCGS) Based Reconstruction
		3.2 Pseudo-dynamical Systems Approach for PACT Imaging
	4 Numerical Phantom Experiment
	5 Discussion and Conclusions
	References
Democratizing LED-Based Photoacoustic Imaging with Adaptive Beamforming and Deep Convolutional Neural Network
	1 Introduction
	2 Image Reconstruction from Post-beamformed RF Data
		2.1 Problem Statement
		2.2 Technical Approach
		2.3 Simulation Evaluation
		2.4 Experimental Demonstration
		2.5 Discussion
	3 SNR Enhancement with Convolutional Neural Network
		3.1 Problem Statement
		3.2 Deep Convolutional Neural Network
		3.3 Experimental Demonstration
		3.4 Discussion
	4 Conclusions and Future Directions
	References
Deep Learning for Image Processing and Reconstruction to Enhance LED-Based Photoacoustic Imaging
	1 Introduction
		1.1 Photoacoustic Imaging
		1.2 Photoacoustic Image Acquisition and Reconstruction
		1.3 Types of Artifact
		1.4 LED Based Photoacoustic Imaging
	2 Machine Learning and Artificial Intelligence
		2.1 Neural Networks
		2.2 Convolution Neural Network
		2.3 Learning by Neural Networks
		2.4 Backpropagation
		2.5 Improving the Networks Performance
		2.6 Evaluation Indices
		2.7 Training Data
		2.8 Neural Networks for Medical Imaging
	3 Monte Carlo Simulation
	4 Applications of Deep Learning in Photoacoustic Imaging
		4.1 Deep Learning for LED Based Photoacoustic Imaging
	5 Limitations of Deep Learning
	6 Future Directions for Deep Learning
	7 Conclusion
	References
Preclinical Applications, Clinical Translation, Trends and Challenges
Light Emitting Diodes Based Photoacoustic and Ultrasound Tomography: Imaging Aspects and Applications
	1 Introduction
	2 Tomographic Imaging Using Linear Array
	3 Imaging Aspects Using a Linear Array
		3.1 Transducer Characterization
		3.2 Optimal Number of Angular Views
		3.3 Tomographic Image Reconstruction
		3.4 Resolution Improvement
	4 LED-Based Illumination for Tomography
		4.1 Imaging Experiments
		4.2 Tomographic Imaging Using Top Illumination
		4.3 Finger Joint Imaging Using Side-Illumination
		4.4 Tomographic Imaging Speed
	5 Future Perspectives
	6 Conclusion
	References
Functional and Molecular Photoacoustic Computed Tomography Using Light Emitting Diodes
	1 Introduction
	2 LED-Based PAUS Imaging
		2.1 Commercial LED-PAUS Imaging System
		2.2 Capability of LED-PAUS System to Image Exogenous Contrast Agents
		2.3 Capability of LED PAUS System to Image Labeled Cells in Vivo
		2.4 LED-PAUS System for Monitoring Angiogenesis in Fibrin Scaffolds
		2.5 High Speed Photoacoustic Imaging Using LED-PAUS System
		2.6 Human Placental Vasculature Imaging Using LED-PAUS System
		2.7 In Vivo Real-Time Oxygen Saturation Imaging Using LED-PAUS System
		2.8 In Vivo Imaging of Human Lymphatic System Using LED-PAUS System
		2.9 Multispectral Photoacoustic Characterization Using LED-PAUS System
	3 LED-Based PACT System
		3.1 Design of LED-Based PACT System
		3.2 LED-PACT Data Acquisition and Image Formation
		3.3 Simulation and Experimental Studies
	4 Conclusion
	References
LED-Based Functional Photoacoustics—Portable and Affordable Solution for Preclinical Cancer Imaging
	1 Introduction
	2 LED Based Photoacoustic Imaging
		2.1 PAI to Monitor the Tumor Microenvironment
		2.2 Oxygen Enhanced PAI
		2.3 PAI to Predict the Tumor Response to Treatment
		2.4 Contrast Enhancement in PAI Using Nanoparticles
	3 Future Directions
	4 Conclusion
	References
LED-Based Photoacoustic Imaging for Guiding Peripheral Minimally Invasive Procedures
	1 Introduction
		1.1 Photoacoustic Imaging of Peripheral Vasculature
		1.2 Applications to Minimally Invasive Procedures
	2 LED-Based Photoacoustic Imaging of Vasculature
	3 LED-Based Imaging of Invasive Medical Devices
	4 Prospects for LED-Based Photoacoustic Imaging of Peripheral Nerves
	5 Challenges for Clinical Translation
	6 Conclusion
	References
Application of LED-Based Photoacoustic Imaging in Diagnosis of Human Inflammatory Arthritis
	1 Introduction
	2 LED-Based PA Imaging of Subsurface Microvasculature In Vivo: A Feasibility Study
		2.1 Imaging Microvasculature in 2D and 3D
		2.2 Arterial Pulsation and Blood Reperfusion
		2.3 Blood Oxygen Saturation
		2.4 Imaging of Peripheral Vasculature and Response to Cold Exposure
	3 LED-Based PA Imaging of Inflammatory Arthritis: A Clinical Study
		3.1 Introduction of Inflammatory Arthritis
		3.2 LED-Based PA Imaging in Three Groups of Joints: Clinically Active Arthritis, Subclinically Active Arthritis and Healthy Joints
		3.3 Statistic Results Based on Imaging
	4 Future Perspective
	5 Conclusion
	References
Diagnosis and Treatment Monitoring of Port-Wine Stain Using LED-Based Photoacoustics: Theoretical Aspects and First In-Human Clinical Pilot Study
	1 Introduction
	2 Theory
		2.1 Temperature Field
		2.2 Displacement Field in Media and Photoacoustic Signal in Liquid
		2.3 Photoacoustic Signal of PWS
	3 Clinical Pilot Study
		3.1 Material & Methods
		3.2 Results and Discussion
	4 Summary and Outlook
	5 Conclusions
	References
Clinical Translation of Photoacoustic Imaging—Opportunities and Challenges from an Industry Perspective
	1 Introduction
	2 Commercially Available Photoacoustic Imaging Systems
	3 Photoacoustic Imaging Technology: Market Trend
	4 Key Components in a Photoacoustic Imaging System
		4.1 Optical Source for Tissue Illumination
		4.2 Ultrasound Detection
		4.3 Data Acquisition System
	5 Clinical Translation of Photoacoustic Imaging: Steps, Opportunities and Challenges
		5.1 Validation Using Preclinical Models
		5.2 Clinical Studies
		5.3 Standardization of the Technology
	6 Conclusions
	References