The Physics of Radiology and Imaging

 This book explains the principles, instrumentation, function, application and limitations of all radiological techniques – radiography, fluoroscopy, mammography, computed tomography, ultrasound and magnetic resonance imaging.

Beginning with an introduction to the fundamental concepts, the following chapters provide in depth coverage of each of the techniques from the perspective of a medical physicist.

Presented in an easy to read format, this book is an invaluable reference for postgraduates students in medical physics and radiology and candidates training for FRCR exams. It includes nearly 280 images, illustrations and tables to enhance learning.

 

Key points

• Explains principles, instrumentation, function, application and limitations of all radiological techniques
• Presented from perspective of medical physicists
• Includes nearly 280 images, illustrations and tables
• Highly useful for postgraduates in medical physics and radiology, and FRCR candidates

1. Fundamental Concepts 1

Measurement and units 1

Density, mole, pressure, and gas laws 3

Mechanics 4

Temperature and heat 7

Atomic structure 10

Electromagnetic radiation 15

Radiological mathematics 19

2. Electricity, Electronics and Magnetism 24

Electric charge 24

Electrical potential 25

Conductors, insulators and semiconductors 26

Capacitance 31

Electrical current 32

Electrical power 35

Magnetism 36

Electromagnetic induction 39

Alternating current 42

3. Physics of X-rays 50

Discovery of X-rays 50

Production of X-rays 51

X-ray tube design 57

Historical X-ray tubes 64

Modern X-ray tubes 66

Filters 75

Scattered radiations 77

4. Generation and Control of X-rays 80

Transformer 80

Rectifier circuit 88

Filament circuit 91

Kilovoltage (kV) control circuit 92

Single-phase X-ray generator 94

Three-phase X-ray generator 96

High-frequency generator 98

Exposure switching and timers 100

Quality and intensity of X-rays 102

Generator rating and heat loading 105

5. Radiation Units and Interactions with Medium 107

Radiation units: Activity 107

– Exposure-roentgen 108

– Kerma 109

CONTENTSx The Physics of Radiology and Imaging

– Absorbed dose-Gray/Rad 110

– RBE, Equivalent dose and effective dose 112

Radiation interaction with matter 115

– Attenuation 115

– Coherent or Rayleigh scattering 118

– Compton scattering 119

– Photoelectric effect 120

– Pair production 122

– Relative importance of attenuation process 123

6. Radiation Detection and Measurements 130

Radiation detection 130

Types of detectors 131

Practical dosimeters 143

Area monitoring 149

Personnel monitoring systems 152

7. Screen-Film Radiography 157

Primary radiological image 158

Contrast agents, Grids 159

Cassette 163

Intensifying screen 164

Structure of X-ray film 167

Automatic film processor 178

Image Quality 180

8. Computed and Digital Radiography 187

Computed radiography 189

Charge-coupled devices 195

Digital radiography systems 196

Comparison of detector systems and image quality 200

Picture archiving and communication system 203

9. Fluoroscopy Imaging 205

Visual physiology 205

Direct vision fluoroscopy and Image intensifier fluoroscopy 206

X-ray generator 216

Digital fluoroscopy 218

Image quality 224

Patient radiation dose 225

10. Mammography 226

Breast anatomy, Mammography equipment 227

Screen-Film system 234

Magnification mammography 235

Digital mammography 236

Stereotactic biopsy system, Breast tomosynthesis 238

Radiation dose, Quality assurance 239Contents xi

11. Computed Tomography Scanner 242

Computed tomography 243

Equipment for computed tomography 249

Generation of CT scanners 253

Image reconstruction 257

Helical and multislice computed tomography 261

CT image quality, artifacts and radiation dose 267

12. Gamma Imaging 273

Radioactivity 273

Nuclear transformation 276

Production of radioisotopes 280

Radiopharmaceuticals 285

Gamma camera 288

Single photon emission computed tomography 294

Positron emission tomography 295

PET-CT scanner 301

13. Radiological Health and Safety 306

Sources of radiation 306

Biological effects of radiation 308

Principles of radiation protection 313

Planning of diagnostic X-ray installations 322

Quality assurance in diagnostic radiology 326

Atomic energy regulation board 328

14. Ultrasound Imaging 334

Basics of ultrasound 334

Ultrasound transducer 340

Image data acquisition 347

Ultrasound image display 351

Doppler ultrasound 355

Ultrasound image quality, artifacts and bioeffects 362

15. Magnetic Resonance Imaging 369

MRI: The basics 369

Relaxation times 375

MRI signal localization 380

MRI imaging sequences 384

MRI instrumentation and biosafety 394

MRI image quality and artifacts 398