This three-dimensional CT scan has unraveled a number of mysteries surrounding a two-millennia-old mummy—although not the mummy itself. Back in 1989 Sarah Wisseman, an archaeologist at the University of Illinois at Urbana–Champaign, took the mummy to the university's veterinary school for x-rays and the hospital for CT scans. From these initial scans she was able to determine that inside the tightly wrapped cloth was a child from the Fayum region of Egypt around A.D. 100. She also saw that the mummy still had many of its organs inside, including the brain, heart and intestines, and that the child's skull was fractured.

But Wisseman had several unanswered questions about the child, and since the original scans in 1989 the resolution of medical imaging technology has vastly improved. "Everything is spectacularly clearer," she says. Based on dental growth revealed in the new scans, she determined that the child was probably about eight and a half years old. From bone growth patterns, she concludes that the child probably went through a period of malnutrition. The organs appeared much clearer, and the skull fracture she initially detected was far more severe than she originally thought. Using this new data, Wisseman's team has been able to create a three-dimensional reconstruction of the face and body using software employed by the National Center for Missing and Exploited Children and a supercomputer on campus.

Still, there are some things you just can't find out without a full autopsy. Wisseman still doesn't know whether this mummy is a boy or girl, for example. To find out, she would need DNA, which she would most likely find in a tooth. But getting that tooth would involve drilling into the side of the mummy's head. "Mummies are a precious resource," Wisseman says. "We don't have that many left and nobody wants to sacrifice them."

--Rose Eveleth