Modern imaging techniques correct older findings that claim ancient Egyptian royals suffered from a kind of arthritis called ankylosing spondylitis.

Some scientific debates may never be settled — even if the evidence is millennia old.

A new study refutes previous claims that ancient Egyptian royals were afflicted with a kind of spinal joint inflammation called ankylosing spondylitis. Instead, it turns out that these mummified kings and queens may have suffered from a different malady called diffuse idiopathic skeletal hyperostosis (DISH).

Researchers from the Kasr Al Ainy Faculty of Medicine of Cairo University in Egypt published their findings this week in Arthritis & Rheumatology. Using an updated imaging technique — computed tomography (CT) scans — on 13 mummified subjects, researchers found that previous work with X-ray scans on some of the same mummies may have yielded an incorrect diagnosis.

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“Previous studies which diagnosed spine diseases in the royal ancient Egyptian mummies used only X-rays. The diagnosis was limited by several factors, such as the presence of dense embalming materials obscuring the spine,” said study co-author Dr. Sahar Saleem, a professor of radiology at Cairo University.

CT scans offer several significant advantages over X-rays, including two- and three-dimensional imaging of bones and soft tissues.

“CT clearly refuted the diagnosis of ankylosing spondylitis disease that was for decades claimed to affect these royal ancient mummies,” Saleem told Healthline. Researchers discovered that four mummies instead had DISH, another degenerative disease.

The cause of DISH is unknown, but it is often associated with metabolic conditions that affect modern populations, such as type 2 diabetes and obesity. DISH is generally linked to a higher standard of living, better nutrition than the general population, and a longer life, Saleem says, which could partly explain why Egyptian royals had a high rate of the disease. In the study, four out of 13 mummies, or nearly 31 percent, showed signs of DISH.

“The high occurrence … could be possibly related to their standard of living and dietary habits,” Saleem said. “Excavations at the Giza worker’s village have uncovered evidence of massive slaughter of beef that indicated that meat was eaten every day in ancient Egypt.”

More than a correction, these findings offer a cautionary tale for future studies involving ancient remains.

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“The investigator should be knowledgeable about the mummification procedure and aware of the findings that likely resulted from the mummification process,” Saleem said.

When you’re dealing with ancient remains that have undergone different preservation processes, reading tissues for clues to the deceased’s life can get complicated.

Dry, dense, desiccated mummified tissues and ligaments should not be mistaken for calcifications caused by disease, for example, Saleem said. The mummification process can also leave dense particles around the spine that shouldn’t be mistaken for abnormal bone formations.

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“Accordingly, more strict criteria for diagnosis of the disease should be adopted when investigating ancient mummified remains,” Saleem said. Now may be the time for a handbook on decoding mummified remains.

Because of the discrepancies between past and current findings, future studies are needed to compare CT scans of royal mummies to those of non-royal ancient Egyptians, Saleem said.

The more data gathered on ancient remains, the clearer the picture of the lives and deaths of these long-deceased Egyptians.