Physics of Radiology

Author:  Anthony B. Wolbarst
ISBN:  9780944838952
Published:  1993 | 461 pp. | Hardcover



Medical Physics  |  January 1996

"The author states in the Preface that this book is written primarily for radiology residents and medical students taking courses in this subject. Anyone with experience in the teaching of mathematics or physics to medical students will recognize that most of them are rather weak in these areas. The main challenge for a physicist teaching this type of student, therefore, is to get across the concepts with limited use of mathematics. "Wolbarst meets this challenge extremely well. Physical concepts are presented clearly, with minimal use of mathematics. Even then, most of the mathematics is elementary, involving no more than proportionalities. When it is necessary to use the occasional exponential or the basic ideas about probability and statistics, these concepts are reviewed in appendices to the appropriate chapters. Such reviews are presented so clearly that they are easy to follow, even by those who may have experienced difficulties previously. "The structure of the book should also be very appealing to the resident. The first two chapters are like appetizers before the main course. The title of the first chapter is ‘Sketches of the Imaging Modalities,' and outlines the basic principles of the main procedures currently used in diagnostic imaging. The second chapter introduces radiography, outlining the four processes; (1) Generation of the x-ray beam, (2) Differential attenuation, (3) Detection of the various shades of gray on film and (4) Analysis and interpretation of the image. "It is worth noting here that the diagrams in this book are outstanding. They are so impressive in illustrating the principles of imaging that every radiology administrator should keep a copy of the book available, and persuade the hospital administrator to whom he or she reports to read these first two chapters, at least. This would provide some insight into this whole field of radiology, especially for those administrators who take over this responsibility without previous experience. Such an excellent overview of the field with fantastic illustrations is remarkable, especially when it is presented so well in less than twenty-five pages. "The main course follows this excellent appetizer with the same high quality of text and diagrams. Part 1 covers the basic physics of energy and matter in five short chapters of about thirty pages. Even in this section, the author consciously links the basic physics with some radiological applications wherever possible. This is the only chapter in the book where the title may seem to be unrelated to the final objective of understanding radiology, yet the style of presentation of this basic physics is so interesting and the examples and exercises so focused, that only a student's lack of interest or some other problem should induce boredom in studying this material. "Parts 2 and 3 deal with the production of x-rays and the interactions with matter, respectively, thus laying the foundation for understanding how x-ray images are formed and recorded on screen-film combinations (Part 4) as well as images in fluoroscopy and mammography (Part 5). The inclusion of xeroradiolgraphy seems questionable as it is seldom, if ever, used today. "Part 6 diverges from imaging, just a bit, to address the pertinent issues of radiation dose, biological effects and the principles of radiation protection. The mathematical treatment of dosimetry may be more involved than is needed by the average resident, but it is not as formidable as it may appear, only requiring a little more concentration than most of the book. This chapter includes units and instrumentation for measuring radiation. Typical radiation doses for some procedures are also included. This is very useful information for physicians ordering procedures as well as those performing them. The significance of any risks for these procedures may also be estimated from the information given about radiation risks. This subject is largely exaggerated in society, even among physicians, so it would have been an additional asset to include a table relating the estimated risks of low level radiation used in medical diagnosis to other risks encountered in normal living, such as driving automobiles and smoking. "Part 7 introduces us to digital imaging, which involves the use of computers. Hence a useful introduction into computers and how they feature in digital imaging is presented in this section. Common applications of computers in digital angiography and radiography, as well as computerized tomography, are very well presented with excellent illustrations. "The uses of radiopharmaceuticals in nuclear medicine for organ uptake studies as well as imaging, are treated in Part 8. Included in this section are studies in nuclear cardiology, single-photon emission computed tomography, and positron emission tomography. Once again, very clear diagrams illustrate the material very well and no real problems in following this section are anticipated. Parts 9 and 10 complete current, common imaging modes with magnetic resonance imaging and ultrasound which is also used for blood flow studies. "The main course is now complete, and Part 11 supplies a little dessert by addressing ‘Computer-based Image Handling Networks.' As would be expected, this field of computer applications develops so rapidly that any book which is two years old is already out of date. Among the issues addressed here are picture archiving and communications systems (PACS), as well as image management and communications systems (IMACS). These systems are available but not yet common enough to be in every modern community hospital. This should therefore still produce some exciting explanations to what is relatively new. "Since this book is written as a teaching text for residents, it is appropriate to comment on its treatment of exercises. Relatively few exercises are presented in the text, located where the principles are discussed. This location is commendable. However, the solutions are presented immediately after the respective exercises. This makes it easy for the student to read the solution before thinking about the problem. An important component of the learning process is to think through solutions to problems. Only the highly disciplined and motivated student is likely to resist reading the solution before thinking about it. The solutions should better be placed elsewhere, such as at the end of each part or after the complete text. It would also be advantageous to have available more board-type questions, selected for the material covered in each part. This would certainly be a valuable compliment, [sic] either after each part, or in a separate booklet. "In conclusion, this book is highly recommended as a text for residents in radiology. It appears that the physics necessary for board examinations in diagnostic radiology is well covered, and the principles clearly illustrated by excellent diagrams. Supplemental material would be needed for board examinations in nuclear medicine or radiotherapy. The size of the book is small (only about one inch thick) for the material covered. There are less than four hundred and fifty pages of text, and the cost is very reasonable ($60.00)* at the writing of this review. This is an excellent investment in knowledge for those to whom it is directed."

E. Theo Agard, Ph.D.
Director of Medical Physics Flower Hospital Oncology Center
Sylvania, Ohio