CHICAGO -- When Egyptian scientists performed the first CT scan of the mummy of Tutankhamun, they turned up a key clue: Bone fragments from the pharaoh's first vertebra, near the skull, were not coated with embalming fluid.
Instead, the fragments were clean at the breaks, meaning that the damage had to have occurred after the pharaoh's remains were prepared for burial. The evidence seems to rule out a blow to the base of the skull as the cause of Tut's death, a theory in play ever since X-rays of the boy king were taken in 1968.
The bones probably broke when Englishman Howard Carter and his team handled the mummy after they found it in 1922, said Dr. Ashraf Selim, who reported the first detailed findings from the scans yesterday at the Radiological Society of North America's annual meeting in Chicago.
Selim, a radiologist at Kasr Eleini Teaching Hospital at Cairo University, led a team of scientists who used a CT scanner to obtain more than 1,900 digital images of the 3,300-year-old mummy.
Preliminary results were announced last year by Zahi Hawass, Egypt's top archaeologist, who said they indicated that Tut did not die from a blow to the head. Yesterday, Selim reported to fellow scientists on how those conclusions were reached.
The CT scans carried out by his team could pick out the residue of the resin used to preserve bodies in ancient Egypt, enabling scientists to deduce when damage to the bones had occurred.
A second clue was found by examining a fracture in Tut's left thigh bone. There was a thin coating of embalming resin around the break, indicating that Tut had broken his leg just before he died and that his death might have resulted from an infection or other complications, Selim said.
"When they embalmed the body and poured liquid resin, it went through a wound to coat the edges of the fracture," Selim said.
Tut ascended to the throne at age 8 and was about 19 when he died.
Field Museum archaeologist James Phillips, curator of the Tutankhamun exhibit on display at the museum, said films from the CT scan are included in the show. Though the images clearly show a leg fracture, the cause of death is still unknown, he said.
"Yes, he broke his leg, and, yes, 1337 B.C. medicine wasn't as great as it is today, and perhaps an infection occurred which caused death," Phillips said.
"But there are other explanations. He might have died of natural causes - even a heart attack, stroke or other type of disease, which was endemic in Egypt. It's still up in the air."
Embalmers took great care in preserving Tut's body, including using two kinds of resin, Selim said. After they put an iron rod into a nasal passage to break the thin shell of bone at the roof of the nose, they extracted the brain in pieces through the opening and poured liquid resin through the nose.
"This liquid resin would go into the skull, fill it and then it would shortly solidify," Selim said. "Assume that there are bone fragments inside the skull. The resin will coat all around the loose fragments and then it solidifies.
"What we found is that these two pieces of bone were lying loosely within the skull, not in the resin at all. This means that they got inside there after the resin was put in, after the embalming."
Selim said pieces of the vertebra probably were broken off when Carter and his team tried to pry a golden mask from the mummy using iron tools. Resin also glued the mummy to the sarcophagus, and their rough handling to dislodge it resulted in numerous broken bones in the chest and neck, he said. None of these breaks showed any resin residue, unlike the fractured leg, he added.
The CT study also suggested that the 5-foot-11-inch pharaoh was in good health before he died, Selim said.
"We could not find any disease that might have affected the bones apart from the fracture," he said. "We did not find any signs of infection in the teeth or the sinuses."
Based on the success of Tut's CT scans, Selim and his team are seeking permission from the Egyptian government to perform similar scans on all of ancient Egypt's royal mummies.
Ronald Kotulak writes for the Chicago Tribune.