Full-body CT scan

Skip it. Full-body computed-tomography (CT) scans, which can cost $1,000, have been touted as a way to detect early signs of cancer and heart disease. But if you're healthy, they're of no proven benefit. The American College of Radiology warns that they can lead to costly and potentially risky follow-up exams to check out harmless abnormalities that otherwise would have gone undetected.

And then there's the risk of radiation. "The average radiation dose from medical imaging has increased more than six-fold over the last 30 years, with CT scans being the largest contributor," says Dr. David J. Brenner, director of the Center for Radiological Research at Columbia University. "We've found that full body CT scans expose patients to far more radiation than conventional plain film X-rays and consequently a higher lifetime risk of cancer deaths, about one in 1,250 for a 45-year-old adult and one in 1,700 for a 65-year-old adult," he said.

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