Patient self-referral for radiologic screening tests: clinical and ethical concerns.

Retail marketing of radiologic screening tests is increasingly common in the United States. Without a physician referral, patients can now directly purchase screening computed tomography (CT) or ultrasound scans. In this article, we consider the clinical and ethical ramifications of widespread screening of low-risk populations with 4 commonly marketed tests: whole-body CT, CT-based heart scans, heel ultrasound for osteoporosis, and carotid duplex sonography for carotid stenosis. All the tests are too inaccurate for screening in low-risk populations, and none has been proven to lead to early, beneficial intervention. Screening could be harmful if false-positive tests lead to extensive or invasive diagnostic evaluation. Finally, widespread testing could increase health care costs with little public health benefit. Patients should probably avoid radiologic screening tests until the tests have been appropriately evaluated in controlled studies and recommended by unbiased national panels, such as the United States Preventive Services Task Force. Primary care physicians and their professional societies should emphasize the uncertain benefits and potential hazards of indiscriminate imaging among healthy, asymptomatic consumers.