Looking at the mummy x-rays
From Canterbury Museums and Galleries.
The radiographs of the head. The left image shows an anterior-posterior projection, whilst the image on the right is a lateral view. The 'R' indicates that the right side is closest to the image detector. This is important, as whatever is closest to the detector is least distorted by geometric unsharpness (i.e. magnification).
I spent the morning with the filming guys to record my thoughts about the x-ray session last week and what I think can be seen from the x-rays. I was lucky to have a impromptu visit by Dr Ellie Williams from the Archaeology department at CCCU. Before settling down to film the second installment for the YouTube video we had a chat about the x-rays to discuss the main questions.
Male or female?
My opinion - definitely, definitely, definitely a female.
I've used my reference book - The Human Bone Manual by Tim White and Peter Folkens to examine the morphology of the skull. Male and female skulls are shaped differently (sexual dimorphism), although these differences are generally only seen once they have reached sexual maturity. Although I wouldn't want to make any assumptions, this person was clearly an adult due to the eruption of their teeth and proportions of their anatomy. From looking at the lateral and anterior-posterior images I can trace around the major bone landmarks and compare these to the reference book.
Sexual dimorphism of the skull, taken from The Human Bone Manual book. The appearances of the bone landmarks go from 1 (very female) to 5 (very male), with graduations between.
The annotated lateral view of the skull. Blue line = Supra-orbital ridge. Green = Mastoid process. Red = Nuchal crest. A copy of the x-ray without annotation is shown for direct comparison of position.
From examining the major bone landmarks of the lateral x-ray the appearances are remarkably female. I could have added a further line for the supra-orbital margin too, which I suspect would also show female characteristics.
The anterior-posterior view of the skull. This is almost a clinical projection, if I only had x-ray at my disposal I would have recreated the 'proper' radiographic positioning for the head. Despite this limitation, the general features are shown. Red line = Mental eminence.
The anterior-posterior view shows the mandible in its natural position (i.e. it has not been forcibly moved since death). The mental eminence has the characteristics of a female mandible, it is gracile and relatively slim. A male mandible would be more robust and large - think Judge Dredd or Bruce Forsyth (for UK readers). There are a few problems however, one of which is the inherent distortion of the anatomy due to geometric unsharpness. In essence, anatomy that is further from the detector will have a greater x-ray 'shadow', and this artificial enlargement of the anatomy creates an inaccurate depiction. Measuring the mandible in this view would not be advisable, or accurate. The problem is compounded by having the tongue sticking out (in this mummy), which would have shown the mandible in a slightly oblique view.
Despite the problems listed above, I am confident this mummy is a female.
Evidence of foreign bodies?
This question is tricky. Items that are very low density would not be easily seen on x-ray, depending on the exposure factors used. However, I am still convinced that the eyes of this mummy are not the original as eyes are mostly liquid and would therefore not survive the preservation process of dehydration. The eyes of this mummy are seen nicely on the anterior-posterior view as small, irregular bundles of medium density. A CT scan would provide greater information about their nature; density, structure.
The soft tissues preservation is remarkable, but I cannot tell if there are remnants of brain in the brain cavity or small amounts of resin. Previous published accounts of ancient Egyptian mummies have shown considerable quantities of resin inside the skull, enough to show a fluid-level. I cannot see a fluid level in this mummy although the skull thickness is rather large posteriorly.
Evidence of trauma?
We know that the right maxilla has been reattached to the skull by the conservators. From the imaging I cannot see any remnants of brain, although this would undoubtedly be very low density anyway. If the brain has been removed it could be possible to discern the entry/exit route for brain removal (by tools used by the ancient Egyptians). But if they went through the right maxilla? This is not common, but what other damage has been done to the skull that we are not fully aware of? Either way, a CT scan would be ideal for demonstrating the anatomy of the face and the presence/absence of brain matter.
Evidence of pathologies?
This is an interesting matter. My radiologist colleague, Dr Meeran Naji, commented upon the relatively good preservation of the cervical spine joints. From my own reading of mummy literature I know we must bear in mind that the individual is dehydrated and therefore the joint space is no longer comparable to modern imaging - when we are alive we have soft tissue which has a high water content! However, when looking at the quality of the bone we could not perceive extensive osteoarthritis - typically an age-related disease. In contrast the teeth are well worn down, the oblique views I created showed the molars to be almost worn down to the pulp in many teeth. This could be due to age and diet - as the high cereal content of their diet would have included particles of sand or grit which would have accelerated the damage to teeth.
There are various radiolucencies in the skull vault which may be accounted for as normal anatomy - sutures or areas of lower bone thickness (e.g. temporal bones). The frontal sinuses are clear shown. I could not see any other pathologies within the x-ray imaging.
A tricky one, and I'll admit I have not compared the imaging to text books yet. There's a wealth of information that can be extracted from the x-rays, but I haven't started doing so. We can tell that this is an adult from the eruption state of the teeth. I could make estimations for anatomy measurements and compare to the developmental state of modern populations, but this is tricky due to the inherent inaccuracies in projectional radiography (i.e. taking 'x-rays'). From the visualisation of cranial sutures I could infer that this is not a very old person, as these tend to fuse in late life. The question is, would they still be visible on x-ray anyway? Would the fusing be superficial, on the surface of the skull?
I'm thinking between 35-40 years of age. But this is subject to further investigation.
I shall investigate previous publications of ancient Egyptian mummified heads to see what they have found out - what can be seen, what can you tell from an isolated head? I would like to articulate my thoughts, alongside Dana Goodburn-Brown (conservator), for academic dissemination. In the meantime, I shall investigate having a CT done so that we can better answer the questions highlighted in the section above.
All radiographic images and annotated versions were created by the author with kind permission from Dana Goodburn-Brown and the Canterbury Museums and Galleries.