Soft-Tissue Imaging in a Human Mummy: Propagation-based Phase-Contrast CT

Purpose To evaluate phase-contrast CT as a noninvasive alternative to histology in the study of ancient soft tissue. Materials and Methods The imaging was performed between May 8 and June 13, 2017. A mummified human hand from ancient Egypt was imaged in a laboratory phase-contrast CT arrangement with propagation-based imaging. The experimental arrangement for propagation-based imaging included a microfocus x-ray source, a rotation stage for the sample, and an x-ray detector. The mummified hand was imaged in two different modes. First, a CT scan of the whole hand was performed in an overview arrangement. Then, a detailed scan of the tip of the middle finger was performed. With imaging distances tailored for a large magnification and to maximize the phase-contrast signal, the estimated resolution in the final images was 6-9 µm. Results The overview CT allowed identification of the tendons of the hand, as well as identification of arteries and nerves in the dehydrated soft tissue. In the detailed phase-contrast setting, virtual histology of the soft tissues of the fingertip could be performed. Blood vessels in the nail bed and the microanatomy of the bone marrow and hypodermis were imaged, and the layers of the skin could be distinguished. Round structures in the adipose tissue were identified as the remains of adipocytes. Conclusion Laboratory phase-contrast CT enables imaging of the anatomy and microanatomy of mummified soft tissue with sub-10-µm resolution and may serve as a complement or alternative to the classic invasive histologic methods used in soft-tissue paleopathology. © RSNA, 2018 Online supplemental material is available for this article.