Applications of justification and optimization in medical imaging: examples of clinical guidance for computed tomography use in emergency medicine.

Availability, reliability, and technical improvements have led to continued expansion of computed tomography (CT) imaging. During a CT scan, there is substantially more exposure to ionizing radiation than with conventional radiography. This has led to questions and critical conclusions about whether the continuous growth of CT scans should be subjected to review and potentially restraints or, at a minimum, closer investigation.

Communication of benefits and risks of medical radiation: a historical perspective.

X-rays were discovered by Wilhelm Röntgen in 1895. Within one year, benefits of x-rays, such as visualization of fractures, and detriments, such as x-ray dermatitis, were recognized. Nobel Laureates Pierre and Marie Sklodowska Curie discovered the radioactive element radium in 1898, and a year later the application of radiation to cure cancer was reported.

Controversies in mammography.

Concerns about screening mammography include questions of efficacy, high recall rates, false positives, and age at which to institute annual screening. Annual screening mammography can decrease breast cancer mortality by 45% in women over fifty and 23% in women between forty and fifty years of age. Patient recall rates and accuracy of interpretation vary among radiologists.

Current issues in hormone replacement therapy.

Initially used to treat the vasomotor and vaginal symptoms of menopause, hormone replacement therapy (HRT) appeared to have many unexpected beneficial effects in early observational trials. It was hailed as a deterrent of atherosclerosis, osteoporosis, cognitive impairment, and Alzheimer disease. While its salutary effects on bone mass were substantiated, randomized clinical trials noted an increased risk of breast cancer, coronary artery disease, and thromboembolism, and raised doubts about the efficacy of HRT in improving quality of life.

Radiological terrorism.

A radiological terrorist attack on the United States is a possibility. This could involve the dispersal of radioactive material by an attack on a nuclear facility, deployment of a radiation dispersal device, or, less likely, detonation of a nuclear weapon. To decrease our vulnerability to this type of threat, the medical community should have a basic understanding of radiation hazards and their medical management, and it should be prepared to interact with appropriate federal agencies to facilitate the employment of emergency response plans.