Modern Diagnostic X-Ray Sources: Technology, Manufacturing, Reliability

Description

Now fully updated, the second edition of Modern Diagnostic X-Ray Sources: Technology, Manufacturing, Reliability gives an up-to-date summary of X-ray source technology and design for applications in modern diagnostic medical imaging. It lays a sound groundwork for education and advanced training in the physics of X-ray production, X-ray interactions with matter, and imaging modalities and assesses their prospects. The book begins with a comprehensive and easy-to-read historical overview of X-ray tube and generator development, including key achievements leading up to the current technological and economic state of the field. The book covers the physics of X-ray generation, including the process of constructing X-ray source devices. The stand-alone chapters can be read in order or in selections. They take you inside diagnostic X-ray tubes, illustrating their design, functions, metrics for validation, and interfaces. The detailed descriptions enable objective comparison and benchmarking. This detailed presentation of X-ray tube creation and functions enables you to understand how to optimize tube efficiency, particularly with consideration for economics and environmental care. It also simplifies faultfinding. Along with covering the past and current state of the field, the book assesses the future regarding developing new X-ray sources that can enhance performance and yield greater benefits to the scientific community and to the public. After heading international R&D, marketing and advanced development for X-ray sources with Philips, and working in the X-ray industry for more than four decades, Rolf Behling retired in 2020 and is now the owner of the consulting firm XtraininX, Germany. He holds numerous patents and is continuously publishing, consulting and training. Cover Half Title Title Page Copyright Page Table of Contents Preface Preface to the Second Edition Acknowledgments Author Symbols 1 Historical introduction and survey 1.1 The discovery—November 1895 1.2 The prehistory of X-rays 1.2.1 Cathode rays: first generation of X-rays—1857 1.2.2 Spooky rays 1.3 Early clinical use and industrialization from 1896 1.3.1 First sustained clinical installation 1.4 Beginning industrial production 1.4.1 Major pitfalls 1.4.2 Exploding span of ideas 1.4.3 Generator development 1.4.4 Clinical exploration 1.4.4.1 Three-dimensional imaging 1.4.4.2 Beam quality—low-energy X-rays 1.5 Victims and safety 1.6 High vacuum vs. semi-vacuum 1.7 Goetze’s line focus 1.8 Rotating targets 1.9 Stationary anode tubes 1.10 Metal center section and metal-ceramic tubes—1980 1.11 Philips liquid metal bearings—1989 1.12 Varian’s finned anode and electron trapping—1998 1.13 Electron beam computed tomography—mid-1980 1.14 Rotating frame tubes—2003 1.15 GE’s largest rotating anode—2005 1.16 CT requirements on the move 1.17 The highest power density CT tube platform—2007 1.18 Production 1.19 Epilog 1.20 Problems References 2 Physics of generation of bremsstrahlung 2.1 Acceleration of electrons 2.2 Efficiency of energy conversion 2.3 The X-ray continuum spectrum 2.4 Characteristic radiation 2.5 Characteristic radiation and discontinuous attenuation 2.6 Theory of the angular distribution of the continuum radiation 2.7 Angular distribution of characteristic radiation 2.8 Polarization 2.9 Theory of electron scatter in the anode 2.10 Electron backscatter 2.11 The Thomson–Whiddington law in more detail 2.12 Measured and simulated isotropic X-ray intensity distribution 2.13 The heel effect 2.14 Problems References 3 The interaction of X-ray with matter 3.1 Basics of the attenuation of X-rays 3.2 X-ray refraction and X-ray lenses 3.3 Thomson scattering 3.4 Rayleigh scattering 3.5 Compton scattering 3.6 Photoelectric absorption 3.7 Problems References 4 More background on medical imaging 4.1 Non-X-ray methods 4.2 X-ray imaging 4.2.1 Attenuation imaging 4.2.2 Linear systems theory 4.2.3 Modulation transfer function 4.2.4 Stating the MTF 4.3 Spectral imaging 4.4 Phase-contrast imaging 4.5 Fluorescence imaging 4.6 Polarized X-rays 4.7 Problems References 5 Imaging modalities and challenges 5.1 Computed tomography 5.1.1 History of CT 5.1.1.1 The beginning 5.1.1.2 Modern systems 5.1.2 Theoretical basis of CT 5.1.2.1 Image reconstruction 5.1.3 Multidetector CT 5.1.4 Cone-beam CT 5.1.5 Spiral CT 5.1.6 Spectral CT 5.1.6.1 Physical background 5.1.6.2 Spectral CT concepts in comparison 5.1.6.3 Spectral material decomposition 5.1.6.4 Source-based spectral CT 5.1.6.5 Detection-based spectral CT 5.1.7 Components of CT systems 5.1.7.1 The rotating gantry 5.1.7.2 Operating parameters for CT 5.1.7.3 Changing requirements for CT sources 5.1.7.4 X-ray source features for CT 5.1.7.5 CT collimators and beam shapers 5.1.7.6 Generators 5.1.7.7 X-ray detectors 5.1.8 Clinical outcome 5.1.9 Alternative concepts 5.1.9.1 Fourth-generation CT 5.1.9.2 Electron beam CT 5.1.9.3 Switching source stationary CT 5.1.9.4 Tomosynthesis versus computed tomography 5.1.9.5 Future development of CT 5.2 Cardiac and vascular imaging 5.3 Radiographic systems 5.4 Radiography/fluoroscopy (R/F) systems 5.5 Mammography systems 5.6 Surgical C-arm systems with monoblocks 5.7 Problems References 6 Diagnostic X-ray sources from the inside 6.1 Working principle and types of medical X-ray tubes 6.1.1 Stationary anode tubes 6.1.2 Miniature tubes 6.1.3 Rotating anode tubes 6.1.4 Rotating frame tubes 6.2 Tube components in detail 6.2.1 The cathode 6.2.1.1 Energy required for electron production—work function 6.2.1.2 Mechanisms of electron emission 6.2.1.3 Robustness of the tungsten emitter 6.2.1.4 Cathode characteristics—the emission chart 6.2.1.5 Filament heating 6.2.1.6 Electron beam focusing and metric for the focal spot size 6.2.1.7 Off-focal radiation 6.2.1.8 Special cathode features 6.2.1.9 Grid switching for fluoroscopy application 6.2.1.10 Advanced electron optics in medical X-ray tubes 6.2.1.11 Alternatives to tungsten emitters 6.2.1.12 Charge balance inside the X-ray tube 6.2.2 The anode 6.2.2.1 Stationary anode targets 6.2.2.2 Rotating anode targets 6.2.2.3 Thermal balance 6.2.2.4 Cooling channels 6.2.2.5 Temperatures in CT application 6.2.2.6 Temperatures in interventional and general radiography application 6.2.2.7 Metric of anode heat storage capacity abandoned—IEC standard 6.2.2.8 Stating thermal X-ray tube performance 6.2.3 Rotor systems, drives, and vacuum bearings 6.2.3.1 Rotor drive 6.2.3.2 Rotor dynamics, moment of inertia, and start-up time 6.2.3.3 Vibration and noise 6.2.3.4 Gyroscopic momentum 6.2.3.5 Ball bearing systems 6.2.3.6 Spiral groove or liquid metal bearings 6.2.3.7 Magnetic bearings 6.3 The tube frame 6.4 Maintaining vacuum 6.5 Vacuum discharges and high-voltage stability 6.6 Problems References 7 Housings, system interfacing, and auxiliary equipment 7.1 X-ray source assembly 7.2 Radiation shield 7.3 Beam quality 7.4 Beam limitation 7.5 Protection against implosion and explosion 7.6 Cooling 7.6.1 Air convection and limits 7.6.2 Enforced cooling 7.7 Problems References 8 The source of power 8.1 Basic functionality of the X-ray generator 8.2 High voltage chain 8.3 Sensing tube voltage and current 8.4 Energy quantization 8.5 Voltage ripple 8.6 Dual-energy (dual-X-ray color) imaging 8.7 Filament heating and emission control 8.8 Grid and electrostatic deflection supply 8.9 Multiple tubes 8.10 Other auxiliary supplies 8.11 Tube temperature supervision 8.12 Dose control 8.13 Matching generator and tube 8.14 Monoblocks 8.15 Problems References 9 Manufacturing, service, and tube replacement 9.1 Introduction 9.2 Manufacturing of X-ray tubes 9.2.1 Cleanliness 9.2.2 Basic logistics 9.2.3 Production lines 9.2.4 Final testing 9.3 Process-oriented versus assembly-oriented production 9.4 Production yield 9.5 Installation and service 9.5.1 Reconditioning 9.5.2 Warm-up 9.6 Tube replacement and recycling 9.6.1 Average tube lifetime 9.6.2 Warranty and costs of ownership 9.7 Recycling 9.8 Problems Reference 10 X-ray source development for medical imaging 10.1 Application trends for the development of medical X-ray sources 10.1.1 Trends for computed tomography 10.1.2 Trends for interventional X-ray and general radiography 10.2 Developments that have not (yet?) made it to the marketplace 10.2.1 High-throughput rotating frame tube 10.2.2 Fourth-generation CT torus 10.2.3 Stationary CT tube with carbon nanotube field emission cathodes 10.2.4 Other dedicated sources for three-dimension-like imaging 10.2.5 Sources for inverse geometries 10.3 Candidates for next-generation bremsstrahlung sources 10.3.1 Enhanced brilliance: Liquid metal anodes 10.3.2 Alternative high-voltage generation 10.3.3 Microfabricated dielectric laser electron accelerator 10.4 Dream and reality: Deficits of bremsstrahlung sources 10.5 Non-bremsstrahlung sources of X-rays for imaging 10.5.1 Synchrotron radiation 10.5.2 Free electron lasers 10.5.3 Laser-wakefield X-ray sources 10.5.4 Other selected physical processes of X-ray generation 10.6 Industrial development of novel X-ray sources 10.6.1 Evolution or game changers? 10.6.2 Development process 10.6.3 Value engineering 10.7 Problems References Index