Lena M. Öhrström

Technical note: Terahertz imaging of ancient mummies and bone

Ancient mummified soft-tissues are a unique source to study the evolution of disease. Diagnostic imaging of such historic tissues is of foremost interest in paleoanthropology or paleopathology, with conventional x-ray and computed tomography (CT) being the gold-standard. Longer wavelength radiation in the far-infrared or Terahertz region allows diagnostic close-to-surface tissue differentiation of bone morphology while being harmless to human cells. The aim of this study is to show the feasibility and the morpho-diagnostic impact of THz imaging of historic remains. Images of an artificially embalmed ancient Egyptian human mummy hand, an artificially embalmed ancient Egyptian mummified fish and a macerated human lumbar vertebra were obtained by THz-pulse imaging and compared with conventional X-ray and CT images. Although conventional x-ray imaging provides higher spatial resolution, we found that THz-imaging is well-suited for the investigation of ancient mummified soft tissue and embalming-related substances / wrappings. In particular, bone and cartilaginous structures can be well differentiated from surrounding soft-tissues and bandage-wrappings by THz imaging. Furthermore, THz-pulse imaging also measures the time-delay of the pulsed signal when passing through the sample, which provides supplementary information on the optical density of the sample that is not obtained by X-ray and CT. Terahertz radiation provides a completely non-invasive diagnostic imaging modality for historic dry specimens. We anticipate this modality also to be used for detection of hidden objects in historic samples such as funerary amulets still in situ in wrapped mummies, as well as potentially for the identification of spectral signatures from chemical substances, e.g., in embalming essences.

Scenes from the Past: MR Imaging versus CT of Ancient Peruvian and Egyptian Mummified Tissues

Ancient Egyptian and Peruvian mummies are extremely valuable historical remains, and noninvasive methods for their examination are desirable. The current standard of reference for radiologic imaging of mummies is computed tomography (CT), with tissue having a homogeneous appearance on all CT images. It was long believed that ancient mummified tissue could not be studied with magnetic resonance (MR) imaging because of the low water content in mummies. Recently, however, the usefulness of MR imaging in the evaluation of mummified tissue was demonstrated for the first time, with use of a special ultrashort echo time technique. The authors of the present study acquired and analyzed MR imaging and CT data from the left hands of two ancient Egyptian mummies and the head of a third Egyptian mummy (ca 1500-1100 bce), as well as data from an ancient Peruvian mummy (ca 1100 ce). CT was found to provide superior detail of the anatomic structures, mainly because of its higher spatial resolution. The signal intensity of mummified tissue varied greatly on MR images; thus, the quality of these images is not yet comparable to that of clinical MR images, and further research will be needed to determine the full capacity of MR imaging in this setting. Nevertheless, additional information may theoretically be obtained with MR imaging, which should be viewed as complementary to, rather than a replacement for, CT.

Terahertz imaging modalities of ancient Egyptian mummified objects and of a naturally mummified rat.

During the last few years, terahertz (THz) imaging has been used to investigate artwork and historic artifacts. The application of THz imaging to mummy investigations is very attractive since it provides spectroscopic information over a broad frequency range and its radiation has proven to be harmless to human cells. However, compared with the current standard imaging methods in mummy imaging—X‐ray and computed tomography (CT)—it remains a novel, emerging technique whose potential still needs to be fully evaluated. Here, ancient Egyptian mummified objects as well as a naturally mummified rat have been investigated by two different THz imaging systems: a broadband THz time domain imaging system and an electronic THz scanner. The obtained THz images are compared with conventional CT, X‐ray, and magnetic resonance images. While the broadband THz time domain setup permits analyses of smaller samples, the electronic THz scanner allows the recording of data of thicker and larger samples at the expense of a limited spectral bandwidth. Terahertz imaging shows clear potential for mummy investigations, although currently CT imaging offers much higher spatial resolution. Furthermore, as commercial mobile THz scanners become available, THz imaging could be applied directly in museums or at excavation sites. Anat Rec, 298:1135–1143, 2015.

Shedding New Light on the 18th Dynasty Mummies of the Royal Architect Kha and His Spouse Merit

The mummies of Kha and his wife Merit were found intact in an undisturbed tomb in western Thebes near the ancient workers’ village of Deir el-Medina. Previous MDCT (this abbreviation needs spelling out) investigations showed that the bodies of Kha and Merit did not undergo classical royal 18th Dynasty artificial mummification, which included removal of the internal organs. It was, therefore, concluded that the retention of the viscera in the body, combined with an absence of canopic jars in the burial chamber, meant the couple underwent a short and shoddy funerary procedure, despite their relative wealth at death. Nevertheless, all internal organs - brain, ocular bulbs/ocular nerves, thoracic and abdominal organs - showed a very good state of preservation, which contradicts the previous interpretation above. In order to better understand the type of mummification used to embalm these bodies, both wrapped mummies were reinvestigated using new generation X-ray imaging and chemical microanalyses Here we provide evidence that both individuals underwent a relatively high quality of mummification, fundamentally contradicting previous understanding. Elucidated “recipes”, whose components had anti-bacterial and anti-insecticidal properties, were used to treat their bodies. The time and effort undoubtedly employed to embalm both Kha and Merit and the use of imported costly resins, notably Pistacia, do not support the previously held view that the two individuals were poorly mummified. Despite a lack of evisceration, the approach clearly allowed their in situ preservation as well as affording a fairly successful mummification.

CT-Based Assessment of Relative Soft-Tissue Alteration in Different Types of Ancient Mummies

Mummification leads to alteration of soft‐tissue morphology. No research has focused specifically on differences in soft‐tissue shrinkage depending on mummification type. This study evaluated whether soft‐tissue alteration is dependent on type of mummification. A total of 17 human mummies have been investigated by computed tomography (CT). Samples included artificially embalmed ancient Egyptian mummies, naturally mummified South American corpses, ice mummies (including the Iceman, South Tyrol Museum of Archeology, Bolzano, Italy, ca. 3,300 BC), bog bodies and a desiccated mummy of possibly Asian provenance. The acquired data were compared to four contemporary bodies. The extent of soft‐tissue shrinkage was evaluated using CT data. Shrinkage was defined as soft‐tissue relative to area of bone (in number of voxels). Measurements were taken at 13 anatomically defined locations. Ice mummies show the highest degree of preservation. This finding is most likely explained due to frozen water within tissues. All other types of mummies show significantly (at P < 0.05) smaller relative area of preserved soft‐tissue. Variation between different anatomical structures (e.g., upper lip vs. mid‐femur) is significant, unlike variation within one compartment (e.g., proximal vs. distal humerus). Mummification type strongly affects the degree of soft‐tissue alteration, surprisingly mostly independent of overall historical age. These results highlight the unique morphological impact of taphonomy on soft‐tissue preservation and are of particular interest in tissue research as well as in forensics. Anat Rec, 298:1162–1174, 2015.

Comparison of ultrashort echo time sequences for MRI of an ancient mummified human hand

To compare the three different short‐echo time (TE) pulse sequences ultrashort echo time (UTE), point‐wise encoding time reduction with radial acquisition (PETRA), and single point imaging (SPI) for MRI of ancient remains.

Body Height of Mummified Pharaohs Supports Historical Suggestions of Sibling Marriages

Body height is an important factor in reconstructing health conditions and it serves as an indicator of socio-economic status. Researchers rely on ancient data to analyze evolutionary aspects of human health and its interrelation with environmental influences. This study presents body height estimates from all periods of ancient Egyptian history and compares the general population with the existing mummies of the members of royal families. A sample of 259 adult Egyptian mummies originating from various collections and published sources with body lengths (long bone measures or/and overall measurements, CT data) were analyzed, and royal mummies were scored with respect to the level of consanguinity. Male royals were taller than males in the general ancient Egyptian population, while female royals were shorter than females in the general population. The body height variation of the royals is significantly reduced when compared with a pool of non-royal mummies. This provides evidence for inbreeding resulting from consanguineous marriages. However, there appears to be no correlation between the level of inbreeding and individual body height. The random sample of general population does not show signs of inbreeding. Due to the present lack of larger, technically and ethically challenging genetic studies, the selected non-invasive approach of body height is the most reliable indicator of sibling marriages of pharaohs based on direct physical evidence.

Queen Nefertari, the Royal Spouse of Pharaoh Ramses II: A Multidisciplinary Investigation of the Mummified Remains Found in Her Tomb (QV66)

Queen Nefertari, the favourite Royal Consort of Pharaoh Ramses II (Ancient Egypt, New Kingdom, 19th Dynasty c. 1250 BC) is famous for her beautifully decorated tomb in the Valley of the Queens. Her burial was plundered in ancient times yet still many objects were found broken in the debris when the tomb was excavated. Amongst the found objects was a pair of mummified legs. They came to the Egyptian Museum in Turin and are henceforth regarded as the remains of this famous Queen, although they were never scientifically investigated. The following multidisciplinary investigation is the first ever performed on those remains. The results (radiocarbon dating, anthropology, paleopathology, genetics, chemistry and Egyptology) all strongly speak in favour of an identification of the remains as Nefertari’s, although different explanations—albeit less likely—are considered and discussed. The legs probably belong to a lady, a fully adult individual, of about 40 years of age. The materials used for embalming are consistent with Ramesside mummification traditions and indeed all objects within the tomb robustly support the burial as of Queen Nefertari.

Erratum to: Radiological findings in an ancient Iranian salt mummy (Chehrābād ca. 410–350 BC)

“Radiological findings in an ancient Iranian salt mummy” published in Skeletal Radiology June 2015 Vol 44 Issue 6 p 811–821 included a significant amount of material that had previously been published in Metalla, the Journal of the German Mining Museum, Nr.21/2014, 103–112. We take duplicate publication very seriously. This duplication was brought to our attention by one of the authors and we are convinced that it was an honest error. Since Metalla is not widely indexed, and since there is no overlap of the readership, we have obtained agreement from the editor of Metalla to permit publication of this erratum rather than retracting the article.