Letter from the Guest Editor

Article Outline

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Computed tomography (CT) is one of the landmark advances in medical technology, and has provided radiologists with a useful imaging tool capable of an accurate clinical diagnosis. The improvements in the CT technology in recent years, particularly the rapid scanning made possible by innovations in detector technology, has led to a tremendous increase in the use of CT in medicine. Improved scan times and better resolution indicate a greatly enhanced use in both emergent and non-emergent settings. Apart from increased use for established indications, such as in a trauma patient, evaluation of a patient with acute abdomen, and oncological work up, additional indications have expanded its use in clinical medicine. In patients being evaluated for possible pulmonary embolism, CT has almost completely replaced the VQ scan in most institutions. Use of CT as a screening modality in an asymptomatic patient to aid in the early detection of lung cancer, colon cancer, and coronary artery disease has led to another spurt in its use in recent years. There have been significant concerns raised, and rightly so, because of the increased exposure of the population as a whole to ionizing radiation resulting from this increased use. While this has to be a major concern for the entire population, it is particularly critical in the pediatric population, in utero exposure of the fetus as well as exposure of the breast in younger women undergoing chest CT. There is a clear reason to critically and carefully evaluate the true medical benefits of imaging with ionizing radiation of which CT, by far, delivers the greatest radiation dose. Keeping these factors in mind, we have compiled a series of excellent review articles that discuss the use of CT in various clinical scenarios in the context of radiation risks and methods of dose optimization. The authors emphasize the need for being cognizant of the radiation risk so as to make use of the modality judiciously and only when appropriate. Many of our clinical colleagues may not be aware of the long-term risks of low doses of ionizing radiation and need to be educated on the risks associated with this imaging modality. Caution is needed especially in the case of patients frequently exposed, the very young, exposure in utero, and in the exposure of the breast tissue in a young woman.

This issue starts off with a review of the indications for use of abdominal CT in pregnancy and the risks involved in the exposure of the developing fetus to ionizing radiation. It is followed by an original article on a maternity hospital experience with the most common use of abdominal CT in the evaluation of pregnant women, namely in patients with clinically suspected appendicitis. In the next article Dr. Birnbaum provides an interesting outline of a radiation safety program in a community hospital setting, describing a practical patient-based approach. In this review, the technical strategies of dose reduction and educational strategies for personnel involved with CT imaging, as well as methods of dealing with the frequently exposed patient, are presented.

There has been a significant increase in use of chest CT, consequent to its value in assessment for pulmonary emboli, as well as screening for lung cancer and coronary arterial disease. Drs. Javitt and Huppmann discuss the merits of CT use for these indications in the context of alternate methods and outline the radiation risks of breast and lung cancer, the former a source of concern especially in young women.

The accuracy of CT in assessment of a patient with abdominal complaints has contributed to a marked increase in the use of abdominal CT both in emergency rooms as well as in a non-urgent setting. Drs. Tsapaki, Saini, and Rehani discuss the radiation dosimetry in abdominal CT applications. Dose optimization methods are detailed for patients undergoing abdominal CT. PET-CT has made significant strides in the evaluation of the oncological patient. A comprehensive review is provided by Drs. Devine and Mawlawi on the radiation risks involved in PET-CT. They focus on the increased availability and use of a combined PET-CET scanner in recent years, emphasizing the need to be aware of the risk of being exposed to 2 sources of radiation resulting from a single study. The authors discuss in great detail the radiation safety issues of the patient as well as the personnel involved in the combined PET-CT imaging evaluation. Dr. Romano offers her perspective on the utilization patterns of CT since the advent of MDCT by outlining the reasons and indications that have led to an explosion in the use of CT in medicine.

Overuse of CT in medical imaging has rightly caused increasing concern, and thus numerous national and international organizations have teamed up in an effort to highlight the dangers of increased exposure to ionizing radiation resulting from diagnostic radiological procedures. In the concluding article, Dr. Goske discusses the Image Gently campaign, the justification for this type of campaign, the creation of an alliance of over 37 medical organizations and agencies, and the methods used to promote this campaign. The article discusses the strategies used by the 4 founding organizations that have pioneered this movement.

This issue provides an in-depth review of the use of CT in medical imaging, highlighting utilization patterns, radiation risks, and methods of dose optimization. The authors are recognized experts in their subspecialties and have presented excellent reviews. I would like to extend my sincere appreciation to the authors for their contribution to this issue of the journal. I am confident that the information provided will be of immense benefit not only to radiologists, but also clinicians who so frequently use this modality to aid in the clinical management of patients.