Ultrasound in MedicineEds. F. A. Duck, A. C. Baker, H. C. Starritt. Medical Science Series,IoP Publishing, Bristol, 1998, 314 pages ISBN 0 7503 0593 2 £80.00 This book is the outcome of the Third Mayneord-Philips Summer School in Oxford in 1997. According to the preface the book aims to ‘bridge the gap between the tutorial texts widely available for the sonographer, and books of acoustics which contain few links between theoretical acoustics and the applications of medicine’. The authorship list is impressive with six of the 16 chapters from the Bath-Bristol connection, and the remainder by other UK and US experts. The book is divided into five sections. Ultrasound physics is extremely well covered in the first section of four chapters. This includes ultrasound fields, acoustic streaming and ultrasound properties of human tissues. A recently developed imaging technique relies on the presence of harmonic components in the received ultrasound signal, and the origins of these from non-linear wave propagation are well explained. The second section deals with technology and acoustic output measurement. Modern imaging performance arises from two sources, the transducer and the signal processing. Although there are many textbooks which describe technology at a basic level, suitable for the sonographer, there are very few which adequately describe instrumentation at a level suitable for the physicist or engineer. This book only goes some of the way, with chapters on transducer design and Doppler technology. It would have been very valuable to have a chapter covering signal processing in B-scanners. Part 3 covers therapeutic ultrasound: hyperthermia, focussed ultrasound surgeryand lithotripsy. Bubble physics and applications are the subject of section 4, and this includes superb chapters on acoustic cavitation by Tim Leighton and on contrast agents by David Cosgrove. The third chapter in this section is on the less familiar(to a medical ultrasound audience) subject of sonochemistry and drug delivery. This chapter explains that ultrasound induced cavitation causes a variety of chemical effects which may be usefully employed; such as in ultrasound cleaning baths, mixing and dispersion of liquids in the food industry, degradation of polymers, and drug delivery. The final section is titled ‘research topics’. From a potentially enormous number of possible topics, the editors have included chapters on imaging tissue elastic properties, measurement of bone properties, and a short but stimulating chapter by Prof. Hill on the signal-to-noise ratio for investigative ultrasound. This chapter makes the observation that medical ultrasound is ‘based almost entirely on two types of measurement that happened to be technically feasible some 30 years ago: backscatter amplitude imaging and backscatter Doppler processing. The point is made that there are a number of different measurements that could be made, and that by resistricting ourselves to just the above two, potentially useful information is being neglected. This point is reflected in abudance in the chapter by Prof. Greenleaf who describes imaging the elastic properties of tissue. He uses two continuous wave transducers whose frequencies are slightly different; this induces vibration and acoustic wave production at the intersection point of the two beams which is measured using a remote hydrophone. Images are then produced related to the amplitude of the stimulated ultrrasound, which in turn is related to the eslastic properties of the tissue. This magnificent book is recommended to all those who wish an intermediate/advanced text on the physics and technology of medical ultrasound. Due to the fact that this is not an introductory text, it is unlikely to be of interest to clinical users, suiting a more physics and engineering audience. P. R. Hoskins | ||