AI can tell your race from X-ray image

A new study by an international team of scientists from Canada, the U.S., Australia and Taiwan reports that artificial intelligence used to read X-rays and CT scans can predict a person's race with 90 per cent accuracy — and humans can't.

The scientists, including those from Massachusetts Institute of Technology and Harvard Medical School, have no idea how the program does it.

“When my graduate students showed me some of the results that were in this paper, I actually thought it must be a mistake,” Marzyeh Ghassemi, an MIT assistant professor of electrical engineering and computer science, and co-author of the paper, published in The Lancet Digital Health, told the Boston Globe. The study began after scientists noticed that an AI program for examining chest X-rays was more likely to miss signs of illness in Black patients.

“We asked ourselves, how can that be if computers cannot tell the race of a person?” a co-author and an associate professor at Harvard Medical School Leo Anthony Celi told the Boston Globe.

Researchers taught the AI program by showing it large numbers of race-labelled images of different parts of the body, including the chest, hand and spine — with no obvious markers of race, such as skin colour or hair texture — and then sets of unlabelled images.

The program identified the race in the unmarked images with more than 90 per cent accuracy, and could differentiate Black patients from white even when images were from people of the same size, age or gender.

Ghassemi believes the answer to the mystery is related to melanin, where X-rays and CT scanners detect the higher melanin content of darker skin, and embed this information in the digital image in some way that has gone unnoticed. More research will be carried out on this — but not everyone agrees with the hypothesis.

Rather than being proof of innate differences between races, Alan Goodman, a professor of biological anthropology at Hampshire College and co-author of the book Racism Not Race, suggests AI is picking up differences resulting from geography.

Osteoarcheologists and geneticists have found no evidence of substantial racial differences in the human genome, but they do find major differences between people based on where their ancestors lived.

“Instead of using race, if they looked at somebody's geographic co-ordinates, would the machine do just as well? My sense is the (AI) machine would do just as well,” Goodman told the paper.

So, while AI might be able to determine from an X-ray whether a person's ancestors were from Scandinavia, Africa or Asia, Goodman says it's not about race. “You call this race. I call this geographical variation,” said Goodman.