Abstract
ed H D Nagel et al COCIR, European Coordination Committee of the Radiological and Electromedical Industries (2000) 85pp, 25 euros
This short book was first published in German in 1999. This translation, by one of the contributors (Nagel) and arguably the UK's foremost CT dosimetry expert (Paul Shrimpton), has ensured that the second edition is accurate both in idiom and sense. Although produced in booklet-type binding, the layout is, nevertheless, accessible and the mathematics, diagrams and graphs are clearly set out.
The material is organized into six chapters. The introduction contains an historical perspective on CT usage within Europe, but with a particular focus on Germany. This does not detract from its usefulness; indeed it is interesting as many readers will be well aware of the equivalent UK data published from time to time by the NRPB. Chapter two deals with the fundamentals of CT dosimetry, with particular attention upon the various guises of the CTDI (computed tomography dose index). This is a welcome discourse on a subject which often results in confusion. Newer concepts such as the dose length product are introduced and followed through to the definitions of organ and effective dose using the ICRP60 organ factors.
Chapter three introduces organ and effective doses, both in terms of practical means of calculation and a review of the literature. Paediatric dose is briefly addressed. Chapter four looks at the theoretical factors which influence dose. It includes a discussion of third versus fourth generation, detector type, spiral and multiple-slice scanners and CT fluoroscopy. It also addresses the related aspect of image quality. The image quality theme is carried into the next chapter which is dedicated to a review of low dose CT in clinical practice. This is a chapter which should have wider appeal to the whole radiological community. Finally there is a chapter on practical measurement procedures with many worked examples. Additionally, there is a very informative appendix on current scanner specifications from seven manufacturers, and a glossary of terms.
This is a highly informative book that draws together in one volume the diverse and patchy information on CT dosimetry. It is accurate, up-to-date and accessible. To benefit fully the reader needs to possess some background knowledge of CT technology and methods. My only two minor complaints were that I did not agree with the view that scattered doses in CT fluoroscopy are comparable to conventional fluoroscopy (CT fluoro is substantially higher), and that the referencing system used is rather idiosyncratic. Other than that, this is a super little book. Every medical imaging physicist and engineer should possess a copy. Additionally, parts of it will be useful to the wider radiological community.