Art, by its uniqueness and fragility, limits access, study, and conservation. Modern radiologic imaging methods have lead to many art and archaeological discoveries. Surface digitizers, combined with 3D modeling, have been used to create outer surface models of art objects. Radiography and CT have been used to examine inner contents, including mummified humans. We sought to use CT and state-of-the-art modeling techniques to 1) analyze 3D structure of a 5,300 year Egyptian mummy mask, 2) provide world-wide access to the mask, and 3) assist stabilization and restoration of the mask.
METHOD AND MATERIALS
Volumetric CT imaging was performed. Mask materials included gauze, bitumen, gold, glass, wood, and paints. 3D volume renderings, computer-aided design (CAD), and rapid-prototyping (RP) models were created from volumetric CT image sets. Multi-angle photographs were texture mapped onto the computer model creating a replica viewable from any angle. A life-size plastic RP model was manufactured to assist conservation of the mask’s damaged left parietal region. Accuracy and reliability of the model were calculated by comparing repeated measures of caliper landmark marker measurements with repeated measures from 3D methods (CT, CAD, and RP).
CT revealed repair areas not detectable by visual examination and assisted analysis of original fabrication methods. The texture mapped 3D model allowed public viewing of the mask from any angle- impossible with traditional museum displays. The life-size RP model was used to assist restoration of the damaged parietal region. 3D methods (CT, CAD, RP), compared to direct caliper measurements, underestimated landmark measurements by less than 0.5 mm. Test-retest reliability for CT and 3D methods averaged 0.5 mm.
This is the first time that CT and 3D modeling have been used for structural analysis, world-wide display, and conservation of an antiquity with an outer and inner surface. Cross-sectional imaging together with engineering and virtual reality modeling software permit analyses and true-to-life replica creations, expanding the usefulness of imaging in art.