DIGITAL RADIOGRAHY IN PRACTICE 1ST EDITION LATEST 2023

DIGITAL RADIOGRAHY IN PRACTICE 1ST EDITION LATEST 2023 CONTENTS Page Preface vii Chapter 1. NATURE OF THE DIGITAL RADIOGRAPH 3 Development of Digital Radiography 3 Nature of the Digital Image 4 ...

DIGITAL RADIOGRAHY IN PRACTICE 1ST EDITION LATEST 2023 CONTENTS Page Preface vii Chapter 1. NATURE OF THE DIGITAL RADIOGRAPH 3 Development of Digital Radiography 3 Nature of the Digital Image 4 Digitizing the Analog Image 6 Bit Depth, Dynamic Range, and Gray Scale 7 What is a Pixel? 9 Voxels, Dexels, and Pixels 10 Chapter Review Questions 11 2. CREATING THE LATENT IMAGE 12 Overview of Variables 12 Creating Subject Contrast 13 Role of Radiographic Technique in the Digital Age 17 Subject Contrast and Sharpness 17 Variables Affecting the Quality of the Final Displayed Radiographic Image 18 Chapter Review Questions 18 3. QUALITIES OF THE DIGITAL RADIOGRAPH 20 Qualities of the Final Displayed Digital Image 20 Qualities of the Latent Image Captured at the Image Receptor 26 Resolution at the Microscopic Level 27 Exposure Trace Diagrams 28 Conclusion 30 Chapter Review Questions 30 xi 4. RADIOGRAPHIC TECHNIQUE FOR DIGITAL IMAGING 32 Understanding X-Ray Beam Penetration 33 Sensitivity of Digital Units to Subject Contrast 34 Subject Contrast and Exposure Latitude 34 Use of Grids 36 Sufficient Input Gray Scale 39 Minimizing Patient Exposure with the 15 Percent Rule 39 Benefits of High kVp Radiography 41 Chapter Review Questions 45 5. PREPROCESSING AND HISTOGRAM ANALYSIS 47 The Generic Steps of Digital Image Processing 48 Preprocessing 50 Histogram Analysis 54 Chapter Review Questions 61 6. RESCALING (PROCESSING) THE DIGITAL RADIOGRAPH 63 “Normalizing” the Image 65 Q Values and the Permanent LUT 66 Chapter Review Questions 70 7. DEFAULT POSTPROCESSING I: GRADATION PROCESSING 71 Digital Processing Domains 71 Gradation Processing 75 Data Clipping 80 Dynamic Range Compression 81 Chapter Review Questions 84 8. DEFAULT POSTPROCESSING II: DETAIL PROCESSING 86 Understanding the Frequency Domain 87 Frequency Detail Processing 90 Spatial Detail Processing (kernels) 94 Preparation for Display 96 Chapter Review Questions 97 9. MANIPULATING THE DIGITAL IMAGE: OPERATOR ADJUSTMENTS 98 Processing Algorithms 98 Windowing 99 Postprocessing Features 102 Chapter Review Questions 111 Contents xiii 10. MONITORING AND CONTROLLING EXPOSURE 113 Speed Class 113 A Brief History of Exposure Indicators 114 The Deviation Index: Acceptable Parameters for Exposure 114 Limitations of the DI 118 A Note on “Controlling” Factors 118 Chapter Review Questions 119 11. DIGITAL IMAGE ACQUISITION 121 Direct-Conversion DR Detectors 123 Indirect-Conversion DR Detectors 124 Computed Radiography (CR) 125 Background and Scatter Radiation 129 Sharpness of Digital Systems 129 Efficiency of Image Receptors 135 Digital Sampling and Aliasing 136 Other Digital Artifacts 138 Chapter Review Questions 139 12. DISPLAYING THE DIGITAL IMAGE 141 The Liquid Crystal Display (LCD) Monitor 143 LCD Image Quality 149 Nature of Display Pixels 153 Chapter Review Questions 154 13. ARCHIVING PATIENT IMAGES AND INFORMATION 156 Picture Archiving and Communication Systems (PACS) 156 Medical Imaging Informatics 161 Chapter Review Questions 163 14. DIGITAL FLUOROSCOPY 165 Image Recording from an Image Intensifier Tube 166 Dynamic Flat-Panel Detectors 168 Reducing Patient Dose 169 Chapter Review Questions 171 15. QUALITY CONTROL FOR DIGITAL EQUIPMENT 172 Monitoring of Digital X-Ray Units 172 Monitoring of Electronic Image Display Systems 173 Chapter Review Questions 177