Mobile CT Nondestructively Reveals
New Insights into Egyptian Mummies 

Chicago’s Field Museum of Natural History took on a sizeable research project. "Inside Ancient Egypt” is one of the most popular exhibits at the museum. It includes a three-story replica of a type of tomb called a mastaba and the replica’s burial chambers contain twenty-three human mummies plus more than thirty animal mummies.  

Field Museum staff members, Erin Murphy, Nicole Schmidt, and Sam Frank, brave the elements to shuttle a mummy from a back entrance into an MXR mobile imaging unit.  

Secrets Unwrapped with Mobile CT Scanning Technology

Over four days, The Field Museum scanned twenty-six individuals in the mobile CT scanner rental unit, capturing enough data to keep its researchers busy for years. There were surprises along the way, not the least of which was one coffin always thought to be empty, but actually has human remains. 

The museum’s team set out with the intentions of researching: 

• The overall condition of each mummy inside of their coffins. 
• The variation in the mummification process throughout time.

• How compressed their individual spines are, which in turn clues researchers in to: 

• How old they were at the time of their death 
  • What their lifestyle was like? For example, were they working-class individuals who performed manual labor, or were they instead upper-class individuals who lived more comfortably?
  • Details about each deceased person as an individual and insights into their societal role. 

•  What their community deemed significant enough to carry into their everlasting lives beyond. 

• Pathologies within parts of the body and other medical conditions.  

• Stature measurements, which include soft tissues that are not achievable through X-ray. 

Lady Chennet-aa in her visibly seamless sarcophagus awaiting to be run through the CT scanner. 

Mysteries of Lady Chenet-aa Resolved

One of the museum's most remarkable mummies in their collection is Lady Chenet-aa. She lived during the Third Intermediate Period of Egypt, during the 22nd Dynasty, which makes her remains over 3,000 years old and yet, in extraordinary condition. 

For years, Chenet-aa and her funerary box constructed from cartonnage have puzzled researchers. Cartonnage was used both as a decorative and structural material, with the top gesso layer creating a smooth paintable surface. In her case, it was used for both, with her elaborate sarcophagus leaving no surface area untouched. 

A Peek into Lady Chenet-aa's Life 

The CT scans showed evidence that Lady Chenet-aa was an upper-middle-class woman in her late 30s or early 40s. Surprisingly she had glass eyes placed in her sockets, presumably to ensure they followed to the afterlife. Dietary wear and tear on her teeth suggests that the food she ate contained stray grains of sand, which were both tough on the enamel and caused tooth loss. 

A Sarcophagus Puzzle Assembled 

While pharaohs were afforded extravagant top-tier burials, Lady Chenet-aa's burial can be classified below that, yet still on a more exclusive scale. The cartonnage-based inner coffin's structure with a lack of a visible seam and only a small opening at the feet had left staff baffled as to the entry point for Lady Chenet-aa’s body, which created a ship in a bottle type of mystery. A series of CT scans, however, solved this mystery. 

The CT scans showed a fine slit down the back of the inner coffin, which clearly was the seam. The scans also revealed rope bindings around her legs, suggesting she was tied upright to a post, then the cartonnage structure was gently worked onto her mummified remains. The inner underside of the cartonnage exhibited a lacing technique, showing the inner coffin was first stitched closed once positioned over her remains, then plastered over on the outer exterior. 

Previous research on damaged cartonnage coffins has revealed this slitting technique, but because only fragments had been inspected, this may be one of the first times that this technique has been well documented via CT imaging techniques. 

The Field Museum’s curator, J.P. Brown, and teammate Mackenzie Fairchild prepare the CT Scanner
for one of the mummies from their “Inside Ancient Egypt” collection. 

Sensational Ethical Dilemmas & The Rise of Medical Imaging 

Decades ago, unwrapping mummies was commonplace. During much of the 18th and 19th century, fascination with Egypt, the afterlife, and everything involving mummies became so obsessively popular, that it was even given a name: Egyptomania. During the Victorian era, people even had mummy unwrapping parties.  

Despite this falling out of favor, mummies continued to be unwrapped for research purposes until after 1896 when X-ray machines became available. The X-ray made it possible for researchers to look inside without disturbing a mummy’s wrappings.  

Today, the use of CT imaging technology has become the gold standard for mummy research. One Field Museum researcher explained that unwrapping is disrespectful to the individual and “once you have unpeeled something, then you're never going to be able to see the way it was originally.”  However, a CT scan gives researchers a view of all the soft tissue not visible in an X-ray, which is usually well preserved by the mummification process.  

Additionally, computed tomography can provide the method of mummification, but this does not pop out through projection X-radiography.

Researcher Tom Murphy quickly reviews and discuss the last scan, noting immediate observations. 

Rectifying a Destructive History

Tomb robbing plagued ancient Egypt, particularly during the First and Second Intermediate Periods. Typically, only the richest 10% of people during this time were mummified and usually amulets along with other valuables were buried with them, making them prime targets for theft.  

Precautionary measures like curses and hidden tombs were implemented throughout time, but they often proved to not be entirely effective due to tomb sealers being able to exploit their knowledge. Robbers, frequently those tasked with sealing the tombs, would unfortunately desecrate the bodies, focusing on the torso area to pilfer treasures. 

This historic destruction has created a practice of interventive conservation, where Egyptian mummies are rewrapped in linen to hold their remains together. The Field Museum has done this type of protective rewrapping at least once in the past for an individual who became disarticulated, likely as a result sliding around in his coffin during transportation. This latest round of mobile CT imaging revealed that, once again, another individual may require interventive conservation. 

Ongoing Digital Imaging Research

These CT scans have already provided a wealth of knowledge into those individuals who were placed through the scanning process, but the comprehensive study of these individuals has just begun. Lady Chenet-aa is just one example of the mountain of knowledge being gained into these individuals through this research project. Scientists expect the study of these twenty-six individuals’ scans to continue over the next year as they digitally peel back the layers through to uncover new insights that may have remained unknown without modern CT scanning technology. 

Have you been to the Field Museum yet? Make a stop on your next visit to Chicago, IL!