Examination of Egyptian mummified animal
CT scanning is a great technique for non-destructively examining the interior of museum objects in three dimensions. A regular x-radiograph provides a picture of the interior of an object projected onto a flat plane (the film, phosphor plate, or digital detector). These projection x-radiographs can be difficult to interpret, particularly when the object is made of many pieces with similar x-ray attenutation and when features in the object overlap. Computed tomography (CT) scanning is a related technique which takes many x-radiographs of an object from all sides and then mathematically predicts the volume which would have caused this series of projections to appear. The result is usually delivered as a series of images of evenly spaced 'slices' through the object. The stack of slices can be rendered in three dimensions and areas with similar x-ray attenuation can be false-colored for further study. The images below illustrate the technical examination of an Late Period Egyptian mummified animal.
After CT scanning, the slices from the CT scan have been rendered as a volume. You can see that the wrappings are rendered reasonably faithfully.
|We can use software to remove the wrappings from the volume and look at what is underneath. Here you can see what remains of the animal that was mummified.|
|By selectively making some areas more transparent, we can see additional features. There is a metal hook (rendered green) which was left in the animal's hind-quarters. There is also a piece of cane (rendered orange) thrust through two of the cervical vertebrae and into the foramen magnum of the skull, presumably to ensure that the head was kept in the required position.|
|A maximum intensity projection taken from the CT scan allows us to see detail in the skull. The images of the skull allowed the animal to be identified as an early adult of the North-African sub-group of Gazella dorcas.|