An Egyptian mummy that was decorated with a woman's portrait contained a surprise — the body of a child who was only 5 years old when she died.

Computed X-ray tomography (CT) scans of the mummy's teeth and femur confirmed the girl's age, though they showed no signs of trauma in her bones that could suggest the cause of her death. .

For the new analysis, researchers conducted new CT scans to visualize the mummy's structure in its entirety.

They then focused on specific regions using X-ray diffraction, in which a tightly concentrated beam of X-rays bounces off the atoms in crystalline structures; variations in the diffraction patterns reveal what type of material the object is made of.

This is the first time that X-ray diffraction has been used on an intact mummy, said lead study author Stuart Stock, a research professor of cell and developmental biology in the Feinberg School of Medicine at Northwestern University in Chicago.

"Many thousands were made, but most of the portraits have been removed from the mummies we have — maybe only 100 to 150 still have the portrait attached to the mummy," he said.

4 showed an adult woman, the small size of the mummy hinted otherwise — and the scans confirmed that the mummy was a child, still so young that none of her permanent teeth had emerged.

X-ray diffraction determined that these were modern metal wires or pins that may have been added to stabilize the artifact sometime during the last century.

One surprising find was an irregular layer of sediment in the mummy's wrappings, perhaps mud that had been used by the attending priests to secure the mummy's bandages, Stock suggested.

Another puzzling discovery was a small, elliptical object about 0.3 inches (7 mm) long, which the researchers found in the mummy's wrappings over the abdomen, dubbing the object "Inclusion F." .