MRI of the Liver: A Practical Guide PDF

Preface

MRI of the liver has come of age. After a prolonged gradual period of development, MRI is now sufficiently accessible to radiologists with an interest in hepatobiliary imaging, and MRI techniques are sufficiently stable for this practical guide to be of value.We have been privileged to obtain extensive experience of liver MRI over the last 15 years, so committing to paper the knowledge, ideas, and opinions that we have accumulated during that time has been a natural consequence of our work.

This book is aimed at clinical professionals—from any discipline—who wish to develop or to supplement an interest in the clinical applications of MRI in patients with liver disease. After the first four chapters, which relate to the clinical indications, techniques, contrast agents, and anatomic aspects of liver MRI, we have taken a broadly systematic approach to the recognition and interpretation of different liver disorders.

For us it is axiomatic that by the time a patient is referred for MRI of the liver, he or she will already have undergone first line investigations which typically include sonography and liver function tests. Each of the Chapters 5–13 are based upon the outcome of preliminary liver screening results—for example, cysts and cyst-like lesions are dealt with in Chapter 5, solid focal lesions in the non-cirrhotic liver in Chapter 6 and so on.

One of our major aims in producing this book has been to offer the reader a large number of illustrative examples of different pathologies.We have deliberately included multiple examples of some pathologies in order to indicate the potential range of appearances, including atypical as well as typical cases. Essential technical aspects of image acquisition are included in each of the "clinical" chapters, but the reader is urged to refer to Chapters 2 and 3 for a more detailed discussion of the choice of acquisition sequences and the use of contrast agents. Wherever possible we have also included a discussion of the differential diagnosis of conditions that may appear similar, and illustrative examples have been provided. This has inevitably led to some overlap between the contents of different chapters, but it has also allowed us to reduce the frequency of cross-referencing between chapters.

Well over 99% of the images illustrated here are from our own department, so we have to admit that this book presents a personal and possibly idiosyncratic view of our subject. However, presenting personal experience does allow us to be more detailed and more specific in our recommendations for technique and interpretation, and we hope this aspect will improve the practical value of this guide to the less experienced reader. For the same reasons we have not provided exhaustive references to support all the points made in the text, but instead offer a limited selected bibliography.

Finally, this book is aimed at clinical professionals who share our view that the role of the investigating diagnostician is not just to interpret a set of images put in front of her or him, but to establish what is wrong with the patient. As mentioned above, when a patient presents for liver MRI the results of the first line investigations should have crystallized the clinical question, and a careful review of the history and results of initial investigations is often helpful in guiding the interpretion of the MRI findings and assessing their significance. Particularly in patients who have already undergone treatment, it is often critical to establish the details—has the patient had previous liver surgery? if so, exactly what procedure was carried out and what is the expected residual anatomy? has the patient been treated with chemotherapy? has the patient had thermal ablation of liver lesions, and if so, how long ago? The more you know when you start, the easier it is to interpret the result of further imaging.

There is a second reason for carrying out a thorough assessment of each patient before undertaking liver MRI—that is to ensure the correct technical approach.We need to establish what exactly we are trying to discover, in order to ensure the appropriate choice of contrast agents and to select the relevant acquisition sequences. In our view, liver MRI is not a "one size fits all" technique—each patient must be assessed individually. This is not to say that there is an infinite range of technical approaches—most patients can be successfully investigated by selecting from a short menu of protocols, each comprising a set of sequences with one or more contrast agents. Obtaining good results with liver MRI are only achieved with careful attention to practical details, and a thorough study of the clinical context.

This volume could not have been created without the help and support of our staff and colleagues at St. James's University Hospital. We have enjoyed enthusiastic and productive collaboration with colleagues in hepatology, liver surgery, and pathology. We have had the continuing support of an enthusiastic group of radiographers and radiographic assistants in the MR section. We are grateful to our radiologic colleagues for their co-operation and support, particularly Dr. M.B. Sheridan and Dr. H. Woodley. Our regular collaborator Dr. J. Ashley Guthrie has generously allowed us to use a large number of his cases. Dr. Daniel Wilson has given us sustained scientific support and much helpful discussion. We would like to thank Mrs. S. Callaghan for secretarial assistance and we are particularly indebted to Mrs. S. Boyes who has spent many hours retrieving images and preparing them for publication, in addition to her help with references and typing.