Noninvasive 1 H and 23 Na nuclear magnetic resonance imaging of ancient Egyptian human mummified tissue Kerstin Mqnnemann a , Thomas Bfni b , Giovanni Colacicco c , Bernhard Blqmich a, 4 , Frank Rqhli b,c a Institute for Technical and Macromolecular Chemistry, RWTH Aachen University, D-52074 Aachen, Germany b Swiss Mummy Project, Orthopedic University Clinic Balgrist and Institute for the History of Medicine, University of Zurich, 8008 Zurich, Switzerland c Institute of Anatomy, University of Zurich, 8057 Zurich, Switzerland Received 2 November 2006; revised 12 March 2007; accepted 13 March 2007 Abstract Historic mummies are a unique example of the human desire for immortality. Therefore, it is not surprising that modern diagnostic imaging has been widely applied to study them. Yet, magnetic resonance imaging (MRI) of such old remains has never been successfully achieved in a noninvasive way without rehydration. Furthermore, the impact of artificial mummification as done in ancient Egypt by natron (a blend of NaCl, Na 2 CO 3 , NaHCO 3 and NaP 2 SO 4 ) on human tissue with a particular focus on the sodium spatial distribution has never been addressed. Here, we show for the very first time completely noninvasive 1 H and 23 Na imaging of an ancient Egyptian mummified finger by nuclear magnetic resonance (NMR). Protons could be visualized by NMR only in the tissue close to surface and sodium primarily in the bone, while computer tomography images both, soft tissue and bone but does not distinguish between different chemical elements. The selective enrichment of sodium in the bone may by due to postmortem incorporation of 23 Na into the tissue by natron-based mummification because our reference measurement of a historical finger not subjected to artificial mummification showed no sodium signal at all. Our results demonstrate not only the general feasibility of nonclinical MRI to visualize historic dry human tissues but also shows the specific 1 H and 23 Na spatial distributions in such mummy tissue, which is particularly interesting for archeology and may open up a new application for MRI. D 2007 Elsevier Inc. All rights reserved. Keywords: 1 H NMR imaging; 23 Na NMR imaging; Mummy; Computer tomography 1. Introduction Ancient mummies are well-perceived objects of scientific research, and diagnostic imaging of such remains has a long tradition [1–3]. Among the various modalities, computed tomography (CT) has been established as the most useful noninvasive method since the late 1970s [4]. Contrary to that, nuclear magnetic resonance (NMR) showed no results in mummy imaging studies [5–12]. Successful visualization of mummified tissue by 1 H-NMR was reported hitherto only after invasive rehydration by acetone to increase NMR relaxation times [10] on modern mummified dogs up to 6 months postmortem [13] or by one of us in a preliminary study of the naturally mummified Neolithic iceman O ¨ tzi of South Tyrol. Unlike the classic artificial mummies from Ancient Egypt, such rare historic glacier mummies contain large amount of epi- and intracorporal hydrogen, freely movable particularly during thawing. To accomplish NMR- based images is therefore not surprising in such naturally wet mummies. Additionally, invasive 1 H- and 13 C-NMR spec- troscopy has been used, e.g., to analyze the molecular composition of nodular crystalline radiopacities of ambigu- ous intra vitam or post mortem nature, as found in the intervertebral spaces of Ancient Egyptian mummies [14–16]. This confirmed, on molecular level, the apparent absorption of artificial mummification-related substances deep into a human corpse, as shown macroscopically and radiologically as well [6,17,18]. Artificial mummification was achieved in Ancient Egypt mainly by dehydrating the corpse in natron [19,20], a blend of, e.g., NaCl and Na 2 CO 3 d 10 H 2 O [21]. Therefore, one expects 23 Na as the main component of natron to be found abundantly in such artificially mummified tissues. The aim of the study hereby was to show, for the very first time, the feasibility of NMR for noninvasive spatial imaging of 1 H and 23 Na in artificially mummified ancient human tissue 0730-725X/$ – see front matter D 2007 Elsevier Inc. All rights reserved. doi:10.1016/j.mri.2007.03.023 4 Corresponding author. Tel.: +49 241 8026420; fax: +49 241 8022185. E-mail address: bluemich@mc.rwth-aachen.de (B. Blqmich). Magnetic Resonance Imaging 25 (2007) 1341 – 1345