July 1, 2007 Medical physicists used computed tomography to compose a picture of the body within an ancient mummy. The scan provided more detail in both bone and tissue than a conventional x-ray. The three dimensional image can offer much more information to determine the age and cause of death of the person inside a mummy.
It's a high-tech medical tool doctors use to find tumors, or to map out surgery. A computed tomography scan -- or a CT scan -- gives doctors a precise look at what's going on inside, without surgery. But the technology is also allowing radiologists to unveil some amazing secrets from the past.
Science knew little about the story behind a two thousand year old mummy -- until now. "We had a number of questions because a doctor had x-rayed it in 1986 and had thought he was a bit older than he has actually proven to be," says Sandra Olsen, Ph.D. and Anthropologist at the Carnegie Museum of Natural History.
Archaeologists unearthed the three-foot tall Egyptian child mummy in 1912, but could offer very few other facts about the boy's past. Two decades ago, researchers thought the child might have had an enlarged head -- and possibly died from a genetic disease -- but removing any wrapping to investigate would damage the priceless artifact.
"What's so exciting about CT scanning -- the reason why we turned to that medical technique -- is that it is non-invasive and non-destructive," Olsen explains.
The CT scan takes hundreds of images and uses a computer to join them together in three dimensional views. Bone and tissue are seen with more clarity than a traditional x-ray. Anthropologists were able to better determine the age of the mummy after they found a missing tooth at the base of the child's skull. Had it fallen out naturally, this child would have been closer to eight when he died.
"In the end we found out he was only about three years old and his head is probably normal in relationship to his body," Olsen says.
Researchers are hoping to have an artist build a cast of his face, like investigators do in forensics, to see what the mummy looked like as a living little boy.
"The tools that we have at our disposal are fortunately ideally suited to uncovering mysteries that are in archeology-in addition to anybody with an ailment who comes our way," says Jeffrey Towers, MD, Chief of Muscular-Skeletal Radiation at the University of Pittsburgh.
BACKGROUND: The Carnegie Museum of Natural History has collaborated with the University of Pittsburgh Medical Center to scan the mummy of a small child now on display at the museum. Child mummies are rare, and this one is smaller than normal, with an oversized head and a slight curvature of the spine. The researchers hope to determine what disorder the child may have suffered from in life to cause those features.
MUMMIFY ME: To mummify the deceased in Egypt, first, the brain was scrambled with hot, sharp hooks to liquefy the gray matter, then yanked out through the nostrils; the Egyptians didn't consider the brain to be an important asset for the afterlife, unlike the rest of the vital organs, which were carefully removed and stored in jars. The head was stuffed with sawdust and various resins, and the body covered in natron, a salt common to the region. This dried out the body and prevented decomposition. The corpse was then wrapped in strips of white linen treated with resins from fir and pine trees, beeswax, myrrh, palm wine, cassia, camphor oil, and other naturally microbe-resistant ingredients. The mummy was then wrapped in a sheet of canvas in a coffin, surrounded by various sacred charms and amulets.
ABOUT CAT SCANS: Any X-ray imaging machining shoots a beam of x-rays onto the body. As they pass through the body, different tissues absorb different amounts of the radiation. Bones absorb a lot of the energy and appear white on the x-ray image. Soft tissues, such as skin, fat and muscle, absorb less ad appear in various shades of gray. The lungs, filled with air, absorb almost no energy and appear dark. A CAT scan is just like a standard x-ray, except it uses an x-ray generating device that moves around the entire body to generate cross-sectioned images that are fed into a computer to produce a full 3D image. CAT scan images reveal far more detail of things like internal organs, adrenal glands and blood vessels, than conventional x-ray machines reveal.
WHO KILLED KING TUT? In 2005, scientists subjected the mummified corpse of Tutankhamen to a 15-minute CT scan, producing 1700 images. Earlier x-rays seemed to indicate the presence of bone fragments, suggestive of a blow to the head, leading to speculation that Tut had been murdered. There also was a dense spot at the lower back of the skull, which researchers interpreted as evidence of a subdural hematoma, also consistent with a blow to the head. The 2005 CT scans put the speculation to rest, finding no evidence of foul play. Rather, it seems Tut died of a broken leg that turned gangrenous, killing him within days, possibly even hours.
Further information: http://archive.ncsa.uiuc.edu/Cyberia/videoTestbed/Projects/Mummy/mummyhome.html