E-book: Ultrasound in Medicine

Contributing Authors xvii Glossary xix Introduction xxv Francis A Duck Acknowledgements xxx References xxx PART 1 THE PHYSICS OF MEDICAL ULTRASOUND 1(88) Ultrasonic Fields: Structure and Prediction 3(20) Victor F Humphrey Francis A Duck Circular plane sources 4(6) Pressure variation on the axis 6(3) Pressure variation off the axis 9(1) Pulsed fields 10(3) Focused fields 13(2) Source amplitude weighting 15(2) Rectangular sources 17(3) Conclusion 20(3) References 21(2) Nonlinear Effects in Ultrasound Propagation 23(16) Andrew C Baker Nonlinear propagation in medical ultrasound 24(3) Consequences of nonlinear propagation 27(12) Experimental measurements 27(4) Theoretical predictions 31(3) Clinical systems 34(2) References 36(3) Radiation Pressure and Acoustic Streaming 39(18) Francis A Duck Radiation pressure 39(1) Langevin radiation pressure, PLan 40(3) Radiation stress tensor 43(1) The excess pressure 43(1) Rayleigh radiation pressure, PRay 44(2) Acoustic streaming 46(6) Methods of measuring acoustic streaming 50(2) Observations in vivo of radiation pressure effects 52(1) Streaming 52(1) Observed biological effects apparently related to radiation pressure 52(1) Discussion 53(4) References 54(3) Ultrasonic Properties of Tissues 57(32) Jeffrey C Bamber Basic concepts 57(7) Attenuation, absorption, scattering and reflection 57(4) Speed of sound 61(1) Nonlinearity 61(1) Transducer diffraction field 61(1) Pulse-echo imaging, speckle and echo texture 62(2) Receiver phase sensitivity 64(1) Measurement methods 64(9) Measurement of the absorption coefficient 64(1) Measurement of the attenuation coefficient 65(3) Measurement of sound speed 68(2) Measurement of scattering 70(2) Measurement of nonlinearity 72(1) Ultrasonic properties of tissues 73(16) Absorption and attenuation 73(3) Sound speed 76(2) Scattering 78(5) Nonlinearity 83(1) References 83(6) PART 2 TECHNOLOGY AND MEASUREMENT IN DIAGNOSTIC IMAGING 89(60) Transducer Arrays for Medical Ultrasound Imaging 91(22) Thomas L Szabo Piezoelectric transducer elements 91(11) A basic transducer model 91(2) Transducer elements as acoustic resonators 93(2) Transducer array structures 95(1) Transducer models 96(3) Transducer design 99(3) Imaging 102(1) Beam-forming 103(5) Other imaging modes 108(1) Conclusion 109(4) References 109(4) Current Doppler Technology and Techniques 113(16) Peter N T Wells The Doppler effect 113(1) The origin of the Doppler signal 114(2) The narrow frequency band technique 116(4) The continuous wave Doppler technique 116(2) The pulsed Doppler technique 118(2) Frequency spectrum analysis 120(1) Duplex scanning 120(1) Colour flow imaging 121(5) Basic principles 121(2) Autocorrelation detection 123(1) Other Doppler frequency estimators 123(1) Time-domain processing 124(1) Colour coding schemes 125(1) Three-dimensional display 126(1) Contrast agents and second harmonic imaging 126(3) References 127(2) The Purpose and Techniques of Acoustic Output Measurement 129(20) T A Whittingham Why measure acoustic outputs? 129(1) Ultrasound damage mechanisms and their biological significance 129(4) Heating 130(1) Cavitation 131(2) Trends in acoustic outputs 133(1) Regulations and standards 134(3) FDA 510(k) regulations 135(1) AIUM/NEMA Output Display Standard 135(1) IEC 61157 136(1) Is there a need for independent measurements? 137(1) Which output parameters should be measured? 137(1) The Newcastle portable system for acoustic output measurements at hospital sites 138(4) The hydrophone and pre-amplifier 138(2) Variable attenuator, power amplifier and power meter 140(1) Oscilloscope 141(1) Oscilloscope camera, PC and digitisation tablet 141(1) The measurement tank 141(1) The hydrophone positioning system 142(1) The probe mounting system 142(1) Calibration and accuracy 142(1) The NPL ultrasound beam calibrator 142(1) Measurement of acoustic power 143(2) Finding worst case values 145(1) Worst case Ispta of stationary beams, e.g. pulsed Doppler mode 145(1) Worst case Ispta for scanned beam modes, e.g B-mode 146(1) Conclusions 146(3) References 147(2) PART 3 ULTRASOUND HYPERTHERMIA AND SURGERY 149(48) Ultrasound Hyperthermia and the Prediction of Heating 151(26) Jeffrey W Hand Ultrasound hyperthermia 151(14) Introduction 151(1) Ultrasound intensity, attenuation and absorption 152(2) Transducers for hyperthermia 154(9) High-intensity short-duration hyperthermia 163(2) Prediction of heating 165(6) Thermal conduction 165(1) Pennes bioheat transfer equation 166(2) Other approaches to thermal modelling 168(3) Summary 171(6) Acknowledgments 172(1) References 172(5) Focused Ultrasound Surgery 177(12) Gail R ter Haar Mechanisms of lesion production 178(1) Thermal effects 178(1) Cavitation 179(1) Lesion shape and position 179(1) Sources of ultrasound 179(3) Imaging of focused ultrasound surgery treatments 182(1) Ultrasound techniques 182(1) Magnetic resonance imaging 182(1) Clinical applications 182(2) Neurology 182(1) Ophthalmology 183(1) Urology 183(1) Oncology 184(1) Other applications 184(1) Conclusion 184(5) References 184(5) Acoustic Wave Lithoripsy 189(8) Michael Halliwell Percutaneous continuous-wave systems 189(1) Extracorporeally induced lithotripsy 190(7) Types of pressure wave transducer 190(1) Positioning systems 191(1) Field measurement 192(4) References 196(1) PART 4 ULTRASOUND AND BUBBLES 197(64) An Introduction to Acoustic Cavitation 199(26) Timothy G Leighton The acoustic properties of the bubble 199(7) Stiffness and inertia 199(1) Resonance 200(1) Inertial cavitation 201(5) Types of cavitation 206(4) The implications of the occurrence of one type of cavitation for the occurrence of another 210(7) Alteration of the bubble size by rectified diffusion 210(2) Alteration of the acoustic pressure field at the bubble by radiation forces 212(2) Nucleation 214(1) Population effects 214(3) The implications of the occurrence of one type of cavitation for causing change to the medium 217(2) Conclusion 219(6) References 219(6) Echo-Enhancing (Ultrasound Contrast) Agents 225(16) David O Cosgrove Non-bubble approaches 225(1) Microbubble agents 226(10) History 226(3) Safety of contrast agents 229(1) Basic principles 230(1) Clinical applications 230(3) Quantification and functional studies 233(1) New uses: agents and techniques 234(2) Conclusion 236(5) References 236(5) Sonochemistry and Drug Delivery 241(20) Gareth J Price Cavitation and its effects 243(2) What can ultrasound do for chemists? 245(7) Bio-effects and drug delivery 252(9) References 256(5) PART 5 RESEARCH TOPICS IN MEDICAL ULTRASOUND 261(46) Imaging Elastic Properties of Tissue 263(16) James F Greenleaf Richard L Ehman Mostafa Fatemi Raja Muthupillai Introduction 263(1) Exogenous transverse waves: imaging with MRE 263(1) Stimulated acoustic emission: imaging with USAE 264(1) Magnetic resonance elastography (MRE) 264(6) Theory 264(1) Methods 265(1) MRE results 266(4) Ultrasound stimulated acoustic emission (USAE) 270(5) Theory of USAE 270(2) USAE results 272(3) Conclusions 275(4) MRE 275(1) USAE 276(1) Acknowledgments 276(1) References 276(3) The Signal-to-Noise Relationship for Investigative Ultrasound 279(8) Christopher R Hill References 286(1) Challenges in the Ultrasonic Measurement of Bone 287(20) John G Truscott Roland Strelitzki Bone 288(1) Ultrasonic measurements suitable for bone 289(6) Speed of sound (SOS) 291(1) Attenuation 292(3) Problems 295(1) Effect of structure on broadband ultrasonic attenuation 295(2) Problems in the measurement of speed of sound 297(6) Time domain (zero-crossing point measurement) 297(3) Frequency domain measurements 300(3) Discussion 303(4) Acknowledgment 305(1) References 305(2) Index 307

Francis A. Duck, Andrew C. Baker, Hazel C. Starritt