Preface xv

Introduction xix

About the Companion Website xxxi

1 Image and Imaging System Characteristics 1

1.1 General Image and Imaging System Characteristics 1

1.2 Concept of Spatial Frequency 2

1.3 Spatial Resolution 3

1.3.1 Imaging System Point Spread Function 4

1.3.2 Imaging System Resolving Power 5

1.3.3 Imaging System Modulation Transfer Function 6

1.4 Signal-to-Noise Ratio 7

1.5 Contrast-to-Noise Ratio 9

1.6 Signal Digitization: Dynamic Range and Resolution 9

1.7 Post-acquisition Image Filtering 11

1.8 Assessing the Clinical Impact of Improvements in System Performance 12

1.8.1 The Receiver Operating Characteristic Curve 13

1.A.1 Fourier Transforms 14

1.A.2 Fourier Transforms of Time Domain and Spatial Frequency Domain Signals 15

1.A.3 Useful Properties of the Fourier Transform 16

Exercises 17

References 19

Further Reading 20

2 X-ray Imaging and Computed Tomography 23

2.1 General Principles of Imaging with X-rays 23

2.2 X-ray Production 25

2.2.1 The X-ray Tube 25

2.2.2 The X-ray Energy Spectrum 29

2.3 Interactions of X-rays with Tissue 32

2.3.1 Compton Scattering 33

2.3.2 The Photoelectric Effect 34

2.4 Linear and Mass Attenuation Coefficients of X-rays in Tissue 36

2.5 Instrumentation for Planar X-ray Imaging 38

2.5.1 Collimator 38

2.5.2 Anti-scatter Grid 38

2.6 Digital X-ray Detectors 40

2.7 X-ray Image Characteristics 42

2.7.1 Signal-to-Noise 42

2.7.2 Spatial Resolution 44

2.7.3 Contrast-to-Noise 45

2.8 X-ray Contrast Agents 46

2.8.1 Contrast Agents for the Gastrointestinal Tract 46

2.8.2 Iodine-Based Contrast Agents 46

2.9 X-ray Imaging Methods 47

2.9.1 X-ray Fluoroscopy 48

2.9.2 Digital Subtraction Angiography 48

2.10 Clinical Applications of X-ray Imaging 49

2.10.1 Digital Mammography 49

2.10.2 Abdominal X-ray Scans 50

2.11 Computed Tomography 51

2.12 CT Scanner Instrumentation 53

2.12.1 Beam Filtration 55

2.12.2 Detectors for Computed Tomography 56

2.13 Image Processing for Computed Tomography 57

2.13.1 Filtered Backprojection (FBP) Techniques 57

2.13.2 Fan-Beam and Spiral Reconstructions 61

2.14 Iterative Algorithms 63

2.15 Radiation Dose 65

2.16 Spectral/Dual Energy CT 66

2.17 Photon-Counting CT 69

2.18 Cone Beam, Mobile, and Portable CT Units 71

2.19 Clinical Applications of Computed Tomography 72

2.19.1 Head and Neurovascular Scans 72

2.19.2 Pulmonary Disease 73

2.19.3 Abdominal Imaging 73

2.19.4 Cardiovascular Imaging 74

Exercises 75

References 81

Further Reading 82

3 Nuclear Medicine 85

3.1 General Principles of Nuclear Medicine 85

3.2 Radioactivity and Radiotracer Half-life 87

3.3 Common Radiotracers Used for SPECT 89

3.4 The Technetium Generator 90

3.5 The Distribution of Technetium-Based Radiotracers within the Body 92

3.6 Instrumentation for SPECT and SPECT/CT 94

3.6.1 Collimators 94

3.6.2 Scintillation Crystal and Photomultiplier Tube-Based Detectors 98

3.6.3 The Anger Position Network and Pulse Height Analyzer 100

3.6.4 Solid-State Detectors and Specialized Cardiac Scanners 102

3.7 Image Recons