You Got a Brain Scan at the Hospital. Someday a Computer May Use It to Identify You.

In a letter published in the New England Journal of Medicine, researchers at the Mayo Clinic showed that the required steps are not complex. But privacy experts questioned whether the process could be replicated on a much larger scale with today's technology. The subjects were 84 healthy participants in a long-term study of about 2,000 residents of Olmsted County, Minn. Participants get brain scans to look for signs of Alzheimer's disease, as well as cognitive, blood and genetic tests. Over the years, the study has accumulated over 6,000 M.R.I. scans. After the participants agreed to the experiment, a team led by Christopher Schwarz, a computer scientist at the Mayo Clinic, photographed their faces and, separately, used a computer program to reconstruct faces from the M.R.I.'s.