Imaging Technology Sheds New Light on Ancient Mysteries: What Killed the Iceman

Judith Greif, RN, MS, APNC

^*Family Nurse Practitioner, East Brunswick, New Jersey.
Address correspondence to: Judith Greif, RN, MS, APNC, Family Nurse Practitioner, 50 Central Avenue, East Brunswick, NJ 08816. E-mail: grifcommedical@aol.com.

The Story of "Ötzi" the Iceman
In 1991, while climbing in the Tyrolean Alps (a region encompassing portions of Italy and Austria), 2 German hikers happened upon an amazingly well-preserved body (Figure 1). Initially thought to be a contemporary corpse, it was soon discovered, much to the astonishment and excitement of scientists, anthropologists, and archeologists, that this was the mummified remains of a man believed to be approximately 5300 years old. Named "Ötzi" after the Ötztal Alps where his body was found, this "Iceman" is the oldest intact human specimen. The man was so well preserved through the centuries by the ice and fortuitous climate conditions present at elevations of 11 000 feet above sea level that portions of his clothing, belongings, skin, fingernails, musculature, and internal organs were still intact.¹ It is hypothesized that, at some point, Ötzi's body was immersed in water for a long period of time before being freeze-dried. As a result, the fat layer turned to adipocere or "grave wax"—a substance almost immune to decay.²

Through the years, scientists have been able to solve several riddles about the enigmatic Iceman. They have determined where he traveled from and at what time of the year he set out on his journey, based on pollen residue still lurking inside his body. They also have been able to reconstruct his typical diet (bran-like foods and meat, such as wild goat) and his last meal of venison. Based on an examination of the body and the possessions found nearby, the Iceman was an "elderly" 46-year-old man of some means. His clothing consisted of 3 layers; he had sturdy shoes with bearskin soles and was well-equipped with a precious copper ax, flint-tipped dagger, and fire starting kit. Furthermore, an X-ray examination of his bone structure revealed that although he was accustomed to walking, his hands did not reveal evidence of manual labor.^1,3 The biggest mystery—that of how and why he died—has been the subject of numerous investigations and theories over the past 17 years, ranging from his having gotten lost and dying of exposure to having been the victim of a ritualistic sacrifice. Now, through advances in imaging technology, it is possible, with almost complete certainty and in great detail, to pinpoint his cause of death: murder. From scientific detective work, it seems he was fleeing for his life, seeking refuge in the wilderness of the Alps, and that he had left hastily with an arsenal of only a half-finished bow and similarly half-finished arrows before meeting his fate.¹

Using Imaging to Examine Mummified Remains
The use of imaging to scan mummified remains has a long and interesting history. People have been fascinated by mummies for hundreds of years—particularly those from ancient Egypt. In that time and place, as a means of preserving the physical body of the deceased so that the "ba" or soul could be reunited with it after death, a complex embalming process was practiced as early as 3100 BC (the late 4th millennium BC).⁴ This involved removing the internal organs and "curing" the body with a combination of dehydrating salts known as natron, then wrapping it in linen. Prior to the late 19th century, mummies would have had to undergo invasive and damaging unwrapping and anatomic dissection in order to unlock the mysteries of ancient times, including how people lived and died.⁴ Then, in 1895, Wilhelm Konrad Röntgen discovered X rays, and only 2 years later, in 1897, it was reported that an X ray had been taken of a Mochica mummy excavated in Peru.⁵ The value of obtaining radiographs of ancient artifacts, including mummies, to allow investigation of such hidden treasures without damage became almost immediately apparent.

Simple radiography, of course, has limitations in that it mainly provides information related to bone structures. Today, other imaging modalities are being used to investigate ancient remains. These include digital radiography, magnetic resonance imaging, and computed tomography (CT); the latter has proven to be the most useful for archaeologic purposes.

In 1979, the first CT scan was performed on an Egyptian mummy.^6,7 Since then, the contrast and spatial resolution of this technique has been noted to be far superior to plain X rays in allowing examination of soft tissues and internal organs. For example, in 2002, Dr Heidi Hoffman et al at Emory University in Atlanta, Georgia, performed axial thin-collimation state-of-the-art CT combined with sagittal and coronal reformatting, 3-dimensional reconstruction, and virtual "fly-through" techniques to study 9 Egyptian mummies. CT provided novel and important paleopathologic and historical information about these mummies, including not only detailed data about the mummification process itself, but also the physical appearance of these specimens. Hoffman's team also was able to evaluate the mummies' internal organs similarly to how virtual colonoscopy is conducted in the medical arena to assess intestinal anatomy.⁴

Ötzi's Postmortem
In August of 2005, Dr Frank Rühli from the Institute of Anatomy at the University of Zurich in Switzerland, Dr Eduard Egarter Vigl from the South Tyrol Museum of Archaeology in Bolzano, Italy, and Dr Patrizia Pernter and Dr Paul Gostner from the Department of Radiology at General Hospital Bolzano undertook a radiologic investigation of the Iceman.^1,8 The team used advanced imaging techniques to conduct a multislice CT scan of the Iceman (Figure 2). They determined that a stone arrowhead penetrating his torso from behind had fatally damaged the left dorsal subclavian artery. The scan revealed damage to the vessel wall—13 mm in length—as well as a 3 mm-long pseudoaneurysm. These findings are typical of a laceration to the subclavian artery, which was also accompanied by CT evidence of a large hematoma in the surrounding soft tissue (Figure 3).⁹ Such a laceration, and the presence of a hematoma, is fairly conclusive evidence that Ötzi bled to death, suffering hemorrhagic shock and cardiac arrest.⁹

However, in a new twist to the story, it is believed that the Iceman also suffered a severe head trauma, which may have contributed to his death. Although it is still unclear whether the head trauma or arrow wound was the first to be inflicted, a reexamination of the images revealed cracks in the skull in addition to brain alterations that are more consistent with an injury than with changes that might have occurred after death, as was previously hypothesized. However, it is still believed that it was hemorrhage, and not head trauma, that killed the Iceman.³ It may be that Ötzi was struck by the arrow, then either was struck again on the head or hit his head during a fall. It is believed that his attacker then retrieved the shaft of the arrow, leaving only the arrowhead in situ.

We may never know why the perpetrator of the crime took the arrow shaft, but left behind Ötzi's valuable possessions.³ However, thanks to ever-evolving and improving imaging modalities, we do know a great deal about Ötzi and about many other ancient mummies, including in many instances, details of their socioeconomic status, activities of daily living, diet, disease states, and circumstances of their death.

References
1. Hall S. Iceman mystery. Available at: http://ngm.nationalgeographic.com/2007/07/iceman/hall-text. Accessed May 27, 2008.

2. Larson M. Iceman—did you know? Available at: http://ngm.nationalgeographic.com/2007/07/iceman/did-you-know-learn. Accessed April 27, 2008.

3. Roach J. Head trauma contributed to Iceman's demise. Available at: http://ngm.nationalgeographic.com/news/pf/17902849.html. Accessed April 27, 2008.

4. Hoffman H, Torres WE, Dernst RD. Paleoradiology: advanced CT in the evaluation of nine Egyptian mummies. Radiographics. 2002;22:377-385.

5. Fiori MG, Nunzi MG. The earliest documented applications of x-rays to examination of mummified remains and archeological materials. J R Soc Med. 1995;88:67-69.

6. Chhem RK. Paleoradiology: imaging disease in mummies and ancient skeletons. Skeletal Radiol. 2006;35:803-804.

7. Harwood-Nash DC. Computed tomography of ancient Egyptian mummies. J Comput Assist Tomogr. 1979;3:768-773.

8. Mystery of 5,000 year old glacier mummy solved. Available at: http://www.sciencedaily.com/releases/2007/06/070606113424.htm. Accessed May 10, 2008.

9. Pernter P, Gostner P, Vigl EE, Rühli FJ. Radiologic proof for the Iceman's cause of death (ca.5'300 BP). J Archaeol Sciences. 2007;34:1784-1786.