Preface of the Medical Imaging Consultant               Back

       The basic purpose and design of the Medical Imaging Consultant remains unchanged. It is intended as a guide to assist health care professionals in selecting the medical imaging procedure that will provide the greatest clinical value at the lowest possible risk.
       This edition includes contributions from numerous individuals and a variety of medical specialties. Many but not all of those contributing to this addition are listed in this book. We wish to acknowledge our appreciation for the contributions of all who participated in creating the improvements in this edition.
      Arranged by symptoms and/or suspected clinical diagnoses, the Medical Imaging Consultant presents the most useful exams listed in the order of clinical benefit. Selecting the single most appropriate study will typically eliminate the need for duplicative imaging. Now the ordering physician can weigh the risk, the reward, and the cost in order to to make the best selection for his or her patient. Although there will be times that a more expensive exam is recommended, it is believed that ordering the right test at the right time can eliminate the scheduling of several other exams which contribute little to the patient workup, yet increase cost and radiation exposure.
       In a great majority of cases, the better decision will be to do no test until other actions have been considered. With this information, the ordering physician is better prepared to explain to the concerned patient that the test being ordered is safe and appropriate.
       For the patient who expects or even demands a study that is not necessary, the ordering physician has this documentation to back up the appropriate conservative approach. The Medical Imaging Consultant helps the ordering physician explain his or her testing procedures on the basis of nationally reviewed guidelines and standards.
       Diagnostic x-rays have been available to assist in the care of patients for the last century. Shortly after the discovery of the x-ray by Conrad Roentgen, concern for over exposure to radiation became a routine part of clinical care. For the most part, this concern was for healthcare workers who were exposed to very high doses. Commonly these individuals would demonstrate changes such as dermatitis, erythema, and skin cancer after repeatedly placing their hands in the primary x-ray beam.
       During most of the last century there has been a steady increase in the concern regarding ionizing radiation exposure, and a gradual decrease the amount of exposure considered "allowable."
       Today, for radiation workers in the United States, and for radiation workers and patients in most other modern healthcare systems, the amount of ionizing radiation that an individual is exposed to is to be kept "As Low as Reasonably Achievable." This principle of ALARA (As Low as Reasonably Achievable), is broadly accepted as the "best practice" when the use of ionizing radiation is considered.
       Although all forms of ionizing radiation carry significant risks, most recently there has been increased concern regarding the use of computed tomography (CT). CT has been widely used as a clinical diagnostic tool for the better part of the last quarter century. More recently, helical and multislice CT have enabled evaluation of large segments of the body in only a few seconds. This has allowed the possibility of performing CT scans in pediatric or uncooperative patients without the need for sedation or restraint.
       It has also enabled CT to proliferate into the open market place in an unprecedented manner. Broad advertising and the placement of CT scanners in shopping malls are now commonplace. It is imperative that physicians be aware of the risks that exist in both the imaging studies they order or perform as well as those that their patients may obtain through self-referral.
       The risks from CT and other procedures that require ionizing radiation can be, and often are, significant. Recent publications have highlighted the fact that for children under the age of 15, the risk of fatal cancer from a single CT scan may approach one in 1,200 and for adults one in 2000.
       Although calculations such as these are open to interpretation and in some cases skepticism, the fact that there is a direct relationship between ionizing radiation and conditions such as cancer and genetic mutations appears to be relatively irrefutable in the medical literature.
       This lead to the National Toxicology Program listing ionizing radiation as a carcinogen in January of 2005. (X-Radiation and Gamma Radiation - Known to be Human Carcinogens" Report on Carcinogens, Eleventh Edition, National Toxicology Program, released January 28, 2005).
       It is incumbent upon the physician who either orders and/or performs medical imaging procedures to be knowledgeable about the potential risks and benefits of each study. It is the purpose of this manual to ensure that all healthcare providers understand the relative risks, both biological and economic, of each of the medical imaging procedures included.
       In the pediatric section, we have made the assumption that all uses of MRI include the use of sedation; thus the risk of 1 is shown even for MRI without contrast. It is anticipated that this information will be used to insure that the highest possible benefit is obtained at the lowest possible risk to the patient.
       There is no publication that can cover every contingency encountered in the daily practice of medicine. This guide is intended as an aid to the care of the patient, but can in no manner substitute for the clinical judgment of the treating physician. It is also impossible to ensure that by the time of publication the contents remain entirely consistent with current best practices. Therefore, when in doubt, it is suggested that the referring clinician seek specialty consultation when ordering imaging procedures.
       The authors have done their best to provide an error free and timely work. As with the first edition of the Medical Imaging Consultant, we would very much appreciate receiving feedback and suggestions regarding the usefulness of this text, as well as requests for additions or changes. Please visit or contact us at our web site where you will find updates, corrections, and the latest in imaging topics. 		A guide to assist health care professionals in selecting the medical imaging procedure that will provide the greatest clinical value at the lowest possible risk.

The risks from CT and other procedures that require ionizing radiation can be, and often are, significant. Recent publications have highlighted the fact that for children under the age of 15, the risk of fatal cancer from a single CT scan may approach one in 1,200 and for adults one in 2000.