Biomedical ultrasonics

Italian Physical Society in prompting these summer courses in the delightful surroundings of Villa Monastero at Varenna on Lake Como. The 1974 Seminar was the second devoted to physical acoustics and the organizer on both occasions has been Prof D. Sette of the University of Rome. In the present instance he had gathered an imposing school of lecturers whose topics covered a wide canvas of physical acoustics, commencing with an introductory lecture entitled ‘Historical development of physical acoustics and future perspectives’, by the world-renowned acoustical figure of Prof Bruce Lindsay. It would not be possible to describe here, in detail, the various excellent articles in the volume of proceedings, which vary in length from five to over sixty pages. Among the more familiar topics are ‘production and detection of H.F. waves’ (Dransfeld); ‘propagation of finite amplitude waves in fluids (Berktay) and solids’ (Stephens); ‘sound propagation in superfluid helium’ (Rudnick) and ‘surface acoustic wave devices’ (Atzeni and Masotti). Two very comprehensive and fundamental contributions are those by Mason on ‘acoustical properties of solids’ and by de Klerk on ‘a physical approach to elastic surface waves’, while Carome gives a short but most interesting description of superconducting transducers for use in the 50 to 1000 GHz range. On the usually less-emphasized topics in general acoustical literature are the articles, by Montrose on ‘correlation functions and light scattering in molecular acoustics’ and by Candau and Martinoty (in French) on ‘absorption of ultrasonic waves in liquid crystals’. Another article in French by Joffin and Levelt introduces what to the average reader is a more recent concept of physical acoustics, phonon echoes, where echoes have the same significance as in spin systems. The seminar proceedings of over 500 pages closes with a short but most up-to-date contribution by Wang of the Jet Propulsion Laboratory, California, on the application of acoustic radiation pressure to the manipulation and control of weightless liquid systems, an essential requirement in space technology. The book is well presented and the illustrations, mostly line diagrams, are very clear. Each contribution is complete in itself and has its own bibliography at the end of the article. Workers in acoustics and in overlapping disciplines will find this volume a very desirable addition to their bookshelves. R. W. 6.

Stephens

Biomedical P. N. T.

ultrasonics

Welts

Academic

Press

(1977)

635pp

f24.00,

$46.90

To attempt to write a monograph on the subject of the principles and applications of ultrasonics in medicine and biology with the vigorous growth in the subject is a

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brave act in which Dr Wells has succeeded admirably. In the preface to this tome the author expresses the hope that it will contribute to the development of the subject by serving as the primary source of reference for everyone interested in the basic principles and applications of ultrasonic energy in medicine and biology’. There can be little doubt that the book will indeed fulfil this function and has few serious competitors at the present time. The range of material covered by the book is vast. The opening chapter deals with wave fundamentals as the essential foundation of succeeding chapters. Although it is familiar material to many physicists the relevance and limitations of the idealized concepts presented are not very clearly defined. The following 19 page chapter entitled ‘radiation’ contains much vital material but has a similar air of uncertain importance. However this feeling quickly disappears in the practicalities of the chapter on the generation and detection of ultrasound, which includes transducer design and instruction. This is followed by two short, crisp chapters on the acoustical properties of tissues and their measurement (velocity, absorption, attenuation and scattering). The major section of the book is the practical and detailed chapter on pulse-echo imaging which covers 210 pages with 123 sub-sections. It is an extremely comprehensive chapter including basic principles, electronic circuitry, display methods, aids for training operators and clinical applications. This is followed by chapters on Doppler methods, and ‘other diagnostic methods’; the latter covering the more sophisticated approaches that are still at the research stage. The text of the book concludes with 50 pages reviewing the biological effects of ultrasound and a final chapter on functional modifications that may be of clinical value. Dr Well’s style is characteristically lucid. At times one feels a desire to challenge the valued judgements that result from a relatively superficial treatment of many areas that is inevitable in a monograph covering such a wide area of work. Thre is no doubt that in spite of the price the book is an essential desk companion for anyone with a serious interest in biomedical ultrasound. The major criticism that could be levelled against it is that it tends to be descriptive rather than critical. However, this approach has permitted the inclusion of some two and a half thousand references (at just under lp each!) which are collected in chapter and section headings and are complemented by an author index indicating the pages on which reference to the author occurs, and the conventional subject index. With so much indexed detail, the standard of the proofreading is high, although some errors have slipped through-the present author, for example, is discovered by the historical review in the third appendix to have been working for his PhD while at Primary School!

R. C.

Chivers

ULTRASONICS.

JULY 1979