Computed Radiography Reveals the Secrets of Ancient Artifacts

Digital medical imaging and information technology are playing major roles in helping a museum in the United States to discover and analyze secrets concealed within its world-renowned collections.

Carestream Health, Inc. (Rochester, NY, USA) has donated a computed radiography (CR) system that enables the Field Museum (Chicago, IL, USA)--for the first time--to capture, archive, and share digital X-ray images from more than one million priceless specimens and artifacts in its anthropology collection. The Field Museum is also using a picture archiving and communications system (PACS) from Carestream Health for the management, viewing, and storage of the growing collection of digital images managed by the museum's staff.

"The availability of this advanced X-ray system will have tremendous benefits not only for research, but also for management of our collections,” said Robert D. Martin, the A. Watson Armour III curator of biologic anthropology at The Field Museum. "Noninvasive visualization of specimens and artifacts can yield valuable new scientific information, and it can also provide crucial indications for proper conservation of specimens in our care.”

Images of an ancient Egyptian mummy demonstrate how digital images are superior to film images. Recently captured digital images have shown a previously unknown erosion of the parietal lobes in the mummy's skull. This could indicate the presence of anemia, parasites, or malnourishment shortly before death. Similarly, curators will be looking for signs of spinal cord deterioration in other specimens, which could be a sign of tuberculosis.

"The nice part about this new digital equipment is that it is very fast and the images are so sharp,” remarked J.P. Brown, a conservator of anthropology, The Field Museum. "This system allows us to do in a day what it used to take a week to accomplish.”

The CR system has already led to new discoveries, according to Mr. Brown. A digital image of the pelvis of the same Egyptian mummy revealed that the person was most likely a woman between 30 and 40 years old. Moreover, an image of a Peruvian "false head” (cabeza falsa) revealed the surprising presence of shells inside the artifact. Anthropology collections manager Chris Philip identified shells inside the stuffing of the mask. The clarity of the image allowed invertebrates collections manager Jochen Gerber to specify two complete shells as Mesodesma donacium, an edible marine clam inhabiting the waters off the west coast of South America. This may help to answer the tantalizing question of why this "false head” was packed with shells. The shells appear to be a deliberate addition to the filling of the mask, possibly a food offering, but their meaning is unclear since no other specimens with added shells are known.

In another example, an image of the head of a statue of a king from a Sassanian palace in Iraq revealed metal pieces that had been added to the statue as part of a restoration that was probably performed in the late 1940s. Before capturing this image, Field Museum conservators had planned to treat the statue with water to soak out salts that had accumulated in it over the years while it was buried in the ground. If they had done so, the metal pieces would have rusted and the pressure from the rust would have caused the piece to break apart. Now--fortified with new information--the conservators are developing a method to stabilize the artifact that does not involve immersing it in water.

Carestream Health's CR system is suited for use with organic objects such as mummies, leather goods, and baskets, and can generate excellent images of denser museum pieces such as ceramics, stucco, and beads. The company's digital workstation--also on site--allows the museum to have one centralized image review platform with a powerful database that provides quick and easy access to studies and images.


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Carestream Health
The Field Museum