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Development of an Anthropomorphic Phantom Coronary Artery Network for CT Imaging

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Development of an Anthropomorphic Phantom Coronary Artery Network for CT Imaging Development of an Anthropomorphic Phantom Coronary Artery Network for CT Imaging by Karolina Stepniak A thesis submitted in conformity with the requirements for the degree of Master of Applied Science Department of Mechanical and Industrial Engineering University of Toronto © Copyright by Karolina Stepniak 2019 Development of an Anthropomorphic Phantom Coronary Artery Network for CT Imaging Karolina Stepniak Master of Applied Science Department of Mechanical and Industrial Engineering University of Toronto 2019 Abstract In this work, the design of anthropomorphic phantom coronary arteries for optimization of Computed Tomography Coronary Angiography (CTCA) is presented. First, a phantom vascular wall model for minimization of motion artifacts is manufactured. The mechanical properties of porcine coronary arteries and four soft rubber materials were tested and compared to each other, and the wall attenuation of tubular contrast-filled samples was characterized and compared to literature values as well. A coronary artery model was manufactured by segmenting the main coronary arteries from CT images, 3D printing a mold, and coating it in the rubber material with the most appropriate mechanical and CT attenuation properties. In the second part, the feasibility of 3D printing a phantom directly using four flexible commercially available materials is investigated. The CT attenuation properties match ranges for lipid-rich and fibrous plaque; thus the phantom can be used for optimization of non-calcified plaque imaging. ii Acknowledgments I would like to thank my supervisors, Prof. Hani Naguib and Dr. Narinder Paul for providing me with the opportunity to work on this interesting project and for your commitment in teaching me how to become a better researcher throughout; the completion of this thesis would not have been possible without your expertise. Thank you also to Ali Ursani of the Medical Imaging department at Toronto General Hospital, who always made time in his schedule to help me with my imaging experiments and provided insightful answers to my endless questions. Thank you to my predecessor in medical imaging research, Sherif Ramadan, who did a fantastic job in introducing me to the project and provided me with invaluable resources to ensure that I hit the ground running at the start of my studies. Thank you to my fellow SAPL lab members for helping me use laboratory equipment and for providing me with your thoughtful feedback; I truly appreciate your eagerness and genuine interest in helping me succeed. Thank you to all the bright undergraduate students I had the pleasure of working with, including Capstone group members Sarah, Matthew, Gina, and Jonathan, as well as my summer research students Amanda and Rana for all the hours of hard work you dedicated to running tests and analyzing data. I would also like to thank Nikola, whose unshaken belief in me is always startling and inspiring. I truly would not have done this without your moral support and our countless pen and paper and whiteboard discussions; thank you for holding my hand through it all. Thank you also to best friend Michelle for the constant reminder that I am a strong independent woman. Finally, I would like to thank and dedicate this work to my mom, dad, and sista Nicole. Thank you for your endless love and support, no matter the weather; you are awesome. iii Table of Contents Table of Contents Acknowledgments .......................................................................................................................... iii Table of Contents ........................................................................................................................... iv List of Tables ................................................................................................................................ vii List of Figures .............................................................................................................................. viii Chapter 1 ......................................................................................................................................... 1 1 Introduction ................................................................................................................................ 1 1.1 Preamble ............................................................................................................................. 1 1.2 Anatomy of the Coronary Arteries ..................................................................................... 1 1.3 Coronary Artery Disease ..................................................................................................... 2 1.4 Diagnostic Tools and Procedure ......................................................................................... 3 1.5 Principles of Computed Tomography ................................................................................. 4 1.6 Computed Tomography Coronary Angiography ................................................................ 7 1.7 CTCA Optimization ............................................................................................................ 9 1.8 Imaging Phantoms ............................................................................................................ 11 1.9 Vascular Phantoms ............................................................................................................ 13 1.10 3D Printing Technology .................................................................................................... 14 1.11 3D Printing for Phantom Manufacturing .......................................................................... 15 1.12 3D Printed Vasculature ..................................................................................................... 16 1.13 Mechanical Properties of Coronary Arteries .................................................................... 18 1.13.1 Static Properties .................................................................................................... 18 1.13.2 Dynamic Properties ............................................................................................... 19 1.14 Motivation ......................................................................................................................... 20 iv 1.15 Thesis Objectives .............................................................................................................. 22 1.16 Thesis Organization .......................................................................................................... 22 References ..................................................................................................................................... 24 Chapter 2 Development of a Phantom Network for Optimization of Coronary Artery Disease Imaging using Computed Tomography ................................................................................... 28 2 Summary .................................................................................................................................. 28 2.1 Introduction ....................................................................................................................... 29 2.2 Methods ............................................................................................................................. 30 2.2.1 Mechanical Behavior of Coronary Arteries .......................................................... 30 2.2.2 Mechanical Behavior of Tissue-Mimicking Materials ......................................... 34 2.2.3 CT Attenuation Properties of Tissue-Mimicking Materials ................................. 35 2.2.4 Phantom Manufacturing and Validation ............................................................... 36 2.3 Results ............................................................................................................................... 37 2.3.1 Mechanical Testing of Coronary Arteries ............................................................. 37 2.3.2 Mechanical Testing of Tissue-Mimicking Materials ............................................ 42 2.3.3 CT Attenuation Properties of Tissue-Mimicking Materials ................................. 44 2.3.4 Phantom Manufacturing and Validation ............................................................... 46 2.4 Discussion ......................................................................................................................... 48 2.5 Conclusion ........................................................................................................................ 51 References ..................................................................................................................................... 53 Chapter 3 Novel 3D Printing Technology for CT Phantom Coronary Arteries with High Geometrical Accuracy .............................................................................................................. 56 3 Summary .................................................................................................................................. 56 3.1 Introduction ....................................................................................................................... 56 3.2 Materials and Methods ...................................................................................................... 58 3.2.1 Mechanical Properties of 3D Printing Materials .................................................. 59 3.2.2 CT Attenuation Properties
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