CAT Scans Reveal Secrets

Smithsonian Institution scientists are finding surprises every day as they use the latest in modern technology to study the inner secrets of the distant past.

Turning a CAT scan machine on one of the world's largest collection of artifacts, researchers at the National Museum of Natural History have discovered how dinosaur bones were repaired a century ago, learned the sex and age of a mummy from Mexico and even may have uncovered a bit of ancient mortuary fraud.

And they did it all without opening, unwrapping or damaging the specimens.

Donated to the museum by Siemens Medical Systems Inc., the complex Computed Tomography machine can scan artifacts to produce images of their inner workings in hundreds of thin slices. Computers allow the scientists to twist and turn the images to study them from any angle.

"I'm surprised every day," said researcher Bruno Frohlich. "The beautiful thing is we have this big collection. I could spend my next ten lifetimes doing research."

Next to Frohlich, on the bed of the CAT scan machine, are the remains of a person who died in Chihuahua, Mexico, late in the 19th century. The cloth-wrapped body, mummified in dry desert air, eventually found its way into the Natural History Museum's anthropology collection.

An X-ray exam taken previously led researchers to think it was the body of a pregnant woman because it showed a collection of small bones in the pelvic area.

Now Frohlich proudly displays the CAT scan images of what turns out to be an older male. The small bones in the pelvic area are his hands, folded into his lap. The pelvis shows the narrow profile of a man, the wear on his teeth indicate a person age 50 or older.

A mummy of a baboon from an ancient Egyptian tomb proved to be empty and Frohlich suspects fraud.

The family would have arranged to have their dead relative mummified, but would most likely have purchased burial goods from people who mummified animals for others, he said. In this case, the baboon mummy they obtained was only a decorated shell.

On the other hand, a cat mummy, also from ancient Egypt, does contain a mummified cat.

A drawer just outside the workroom contains the bones of Carl A. Weiss, killer of Louisiana Sen. Huey Long.

The bones in use inside the workroom are much older -- the 18-inch long head of a 255 million-year-old dinosaur, with dozens of sharp teeth lining its jaw.

Speaking of dinosaurs, Frolich and co-worker David Hunt used the machine to study the bones of the museum's Triceratops and discovered, to their surprise, that curators in the 19th century put the bones together by running metal rods and wires through them.

Frohlich tries not to be judgmental.

"That was the best they could do," he said. "Today we do the best we can do, and in a century people will probably look back and say, 'Were they crazy?'"

Before the museum received the machin three years ago it took some artifacts to George Washington University for scanning. But many items scientists wanted to look into were too fragile to make even that three-mile trip.

The machine also has been used to look at minerals, fossilized plants, pottery, stone and wood tools, insects and even rare book bindings.