Rad Tech's Guide to Computed Tomography

An up-to-date guide to CT that offers a comprehensive discussion of the technology and science of computed tomography and instructions for applying that knowledge to real-world practice Rad Tech’s Guide to Computed Tomography: Physics and Instrumentation is a comprehensive and accessible approach to learning the physics and instrumentation of CT. The text offers an intuitively organized treatment of the history of CT development, data acquisition, image reconstruction, and the relationship between image quality and radiation dose. Using clear language, hands-on examples and useful diagrams, the book is written to demystify complex topics like Hounsfield units, attenuation coefficients, and interpolation algorithms, without compromising technical accuracy. This is an educational resource that shows readers how to perform imaging that generates diagnostically useful results that keep patients safe. Readers will find: An up-to-date exploration of the use of artificial intelligence in medical imaging Concise explorations of the physics of state-of-the-art CT scanners, relevant to the day-to-day work of practicing RTs Practical discussions of relevant, selected topics, including multi-slice CT, the basics of image postprocessing, and quality control fundamentals Guidance on how to ensure consistent diagnostic performance without compromising patient safety Complete treatments of data acquisition, including slice-by-slice and volume data acquisition Perfect for students preparing to take professional certification examinations in CT, Rad Tech’s Guide to Computed Tomography will also benefit practicing technologists interested in advancing their understanding, refining their technique, and expanding their professional skillset.

Foreword viii Preface xi Acknowledgments xiv 1 The Invention of the CT Scanner and the Nobel Prize 1 Computed Tomography: A Definition 2 Three Major Stages of CT Imaging 4 Invention of the CT Scanner: The Nobel Prize for Pioneers Godfrey Hounsfield and Alan Cormack 8 Evolution of CT Scanners Leading to Present- Day Multi- Slice CT Imaging 10 References 14 2 Essential Physics of CT 17 Introduction 17 Radiation Attenuation: Essential Physics Related to CT Imaging 18 Attenuation and Hounsfield Units 22 The CT Gray- Scale Image 24 References 25 3 Data Acquisition: Principles and Technology 27 What Is Data Acquisition? 28 Types of Data Acquisition 28 Major Technical Data Acquisition Components 31 Detectors: Types, Principles, and Technology 35 References 41 4 Image Reconstruction Principles 43 Image Reconstruction: A Definition 45 Image Reconstruction Algorithms 45 Artificial Intelligence and Its Subsets: Definitions 52 References 59 5 Multi- Slice CT: Principles and Instrumentation 62 What Is Multi- Slice CT (MSCT)? 63 MSCT System Components 65 Selectable Scan Parameters 71 Advantages of MSCT 73 References 74 6 Image Postprocessing 76 Scope of Image Processing 77 Windowing: Effect on Image Contrast and Image Brightness 79 Multiplanar Image Reformatting 82 Advanced Image Postprocessing Techniques 84 References 88 7 Image Quality 90 What Is Image Quality in Computed Tomography? 90 Spatial Resolution 91 Low- Contrast Resolution 93 Noise 95 Artifacts in a Nutshell 98 References 99 8 CT Radiation Dose Considerations 101 CT Dose Trends 101 The Basics of CT Dosimetry 102 Factors Affecting the Dose in CT 105 Dose Optimization 107 References 109 9 CT Quality Control for Technologists/ Radiographers 114 Quality Assurance/Quality Control: Definitions 115 Essential Steps in QC 116 Tolerance Limits/Acceptance Criteria 117 Equipment for QC Testing 118 Routine QC Tests for the CT Technologist 121 References 124 Index 125