CT technique expands possibilities of imaging ancient remains

September 25, 2018

OAK BROOK, Ill. - Researchers in Sweden using computed tomography (CT) have successfully imaged the soft tissue of an ancient Egyptian mummy's hand down to a microscopic level, according to a study published in the journal Radiology.

Non-destructive imaging of human and animal mummies with X-rays and CT has been a boon to the fields of archaeology and paleopathology, or the study of ancient diseases. Imaging studies have contributed to a better knowledge of life and death in ancient times and have the potential to improve our understanding of modern diseases.

Both X-ray and conventional CT take advantage of the fact that materials absorb different amounts of X-rays. This phenomenon, known as absorption contrast, creates different degrees of contrast within an image.

"For studying bone and other hard, dense materials, absorption contrast works well, but for soft tissues the absorption contrast is too low to provide detailed information," said Jenny Romell, M.Sc., from KTH Royal Institute of Technology/Albanova University Center in Stockholm, Sweden. "This is why we instead propose propagation-based phase-contrast imaging."

Propagation-based imaging enhances the contrast of X-ray images by detecting both the absorption and phase shift that occurs as X-rays pass through a sample. The phase effect with X-rays is similar to how a ray of light changes direction as it passes through a lens. Capturing both absorption and phase shift provides higher contrast for soft tissues.

"There is a risk of missing traces of diseases only preserved within the soft tissue if only absorption-contrast imaging is used," Romell said. "With phase-contrast imaging, however, the soft tissue structures can be imaged down to cellular resolution, which opens up the opportunity for detailed analysis of the soft tissues."

Romell and colleagues evaluated phase-contrast CT by imaging a mummified human right hand from ancient Egypt. The hand, today in the collection of the Museum of Mediterranean and Near Eastern Antiquities, was brought to Sweden at the end of the 19th century, along with other mummified body parts and a fragment of mummy cartonnage (papier-mâché case). The cartonnage belonged to an Egyptian man and has been dated to around 400 BCE (before common era). They scanned the entire hand and then performed a detailed scan of the tip of the middle finger.

The estimated resolution of the final images was between 6 to 9 micrometers, or slightly more than the width of a human red blood cell. Researchers were able to see the remains of adipose cells, blood vessels and nerves; they were even able to detect blood vessels in the nail bed and distinguish the different layers of the skin.

"With phase-contrast CT, ancient soft tissues can be imaged in a way that we have never seen before," Romell said.

The findings point the way to a role for phase-contrast CT as an adjunct or alternative to invasive methods used in soft-tissue paleopathology that require extraction and chemical processing of the tissue. Due to their potentially destructive nature, these methods are undesirable or unacceptable for the analysis of many old and fragile specimens.

"Just as conventional CT has become a standard procedure in the investigation of mummies and other ancient remains, we see phase-contrast CT as a natural complement to the existing methods," Romell said. "We hope that phase-contrast CT will find its way to the medical researchers and archaeologists who have long struggled to retrieve information from soft tissues, and that a widespread use of the phase-contrast method will lead to new discoveries in the field of paleopathology."
-end-
"Soft-Tissue Imaging in a Human Mummy: Propagation-based Phase-contrast CT." Collaborating with Romell were William Vågberg, M.Sc., Mikael Romell, M.D., Sofia Häggman, Ph.D., Salima Ikram, Ph.D., and Hans M. Hertz, Ph.D.

Radiology is edited by David A. Bluemke, M.D., Ph.D., University of Wisconsin School of Medicine and Public Health, Madison, Wis., and owned and published by the Radiological Society of North America, Inc.

RSNA is an association of over 54,200 radiologists, radiation oncologists, medical physicists and related scientists promoting excellence in patient care and health care delivery through education, research and technologic innovation. The Society is based in Oak Brook, Ill. (RSNA.org)

For patient-friendly information on CT, visit RadiologyInfo.org.

Radiological Society of North America

Related Blood Vessels Articles from Brightsurf:

Biofriendly protocells pump up blood vessels
In a new study published today in Nature Chemistry, Professor Stephen Mann and Dr Mei Li from Bristol's School of Chemistry, together with Associate Professor Jianbo Liu and colleagues at Hunan University and Central South University in China, prepared synthetic protocells coated in red blood cell fragments for use as nitric oxide generating bio-bots within blood vessels.

Specific and rapid expansion of blood vessels
Upon a heart infarct or stroke, rapid restoration of blood flow, and oxygen delivery to the hypo perfused regions is of eminent importance to prevent further damage to heart or brain.

Flexible and biodegradable electronic blood vessels
Researchers in China and Switzerland have developed electronic blood vessels that can be actively tuned to address subtle changes in the body after implantation.

Lumpy proteins stiffen blood vessels of the brain
Deposits of a protein called ''Medin'', which manifest in virtually all older adults, reduce the elasticity of blood vessels during aging and hence may be a risk factor for vascular dementia.

Cancer cells take over blood vessels to spread
In laboratory studies, Johns Hopkins Kimmel Cancer Center and Johns Hopkins University researchers observed a key step in how cancer cells may spread from a primary tumor to a distant site within the body, a process known as metastasis.

Novel function of platelets in tumor blood vessels found
Scientists at Uppsala University have discovered a hitherto unknown function of blood platelets in cancer.

Blood vessels can make you fat, and yet fit
IBS scientists have reported Angiopoietin-2 (Angpt2) as a key driver that inhibits the accumulation of potbellies by enabling the proper transport of fatty acid into general circulation in blood vessels, thus preventing insulin resistance.

Brothers in arms: The brain and its blood vessels
The brain and its surrounding blood vessels exist in a close relationship.

Feeling the pressure: How blood vessels sense their environment
Researchers from the University of Tsukuba discovered that Thbs1 is a key extracellular mediator of mechanotransduction upon mechanical stress.

Human textiles to repair blood vessels
As the leading cause of mortality worldwide, cardiovascular diseases claim over 17 million lives each year, according to World Health Organization estimates.

Read More: Blood Vessels News and Blood Vessels Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.