Non-invasive spatial tissue discrimination in ancient mummies and bones in situ by portable nuclear magnetic resonance

Historic mummies and skeletons have been investigated extensively by modern diagnostic imaging using computed tomography. But magnetic resonance imaging (MRI) has never been applied successfully to mummies in a non-invasive way without tissue rehydration. The aim of this study is to show the feasibility and diagnostic impact of mobile MR technology to historic human tissues. The natural glacier mummy Iceman, a mummified recent human cadaver, historic mummified body parts, historic bones, and living volunteers have been analysed by non-invasive, single sided NMR with the NMR-MOUSE^®. We acquired high-resolution depth profiles and T₂ relaxation curves of the head region of the Iceman mummy in situ in the storage room at the Museum and of the cadaver in the hospital. A spatial differentiation of surface ice layer, cutis, and skull bone up to a depth of 5 mm was possible. In ancient Egyptian mummified specimens, the thickness of a fingernail and a differentiation of a single bandage layer versus the skin underneath were possible. A comparison of depth profiles through different foreheads of mummies, skulls, and living people gives strong evidence, that single-sided NMR with the NMR-MOUSE is a non-invasive technique to determine bone density. Our results demonstrate for the first time the feasibility of non-clinical MRI to visualize historic human tissues in a non-invasive approach.