Dinosaur bone CT scan and 3D printing

September 3, 2016 By ag

A radiology team in Berlin have successfully CT scanned and 3D printed a replica of an ancient dinosaur bone stored at the Museum für Natuurkunde (Museum of Natural History), Berlin, Germany, having been encased and preserved in plaster.

Between 1909 and 1913, two German palaeontologists, commissioned by the museum, led an excavation that yielded approximately 235 tons of fossil bones in the region of today’s Tanzania. Other fossil remains from Germany were also discovered and stored over the forthcoming years.

It was common practise, for dinosaur bones to be wrapped and protected in plaster of Paris for transportation due to the fragile and brittle nature of these precious objects.

Further exploratory excavation, even by experts, can be problematic as the removal of the plaster jacket may destroy the underlying fossil in question.

CT scans are an ideal form of assessment as they are commonly used to help separate plaster from bone in human bodies that have suffered fractures.

The German radiology team successfully scanned an ancient bone wrapped in plaster – without any disruption to the internal integrity of the fossil. The scan with 3D reconstructions, demonstrated the bone to be a vertebral body (back bone segment) from a Plateosaurus dorsal vertebra. Numerous fracture lines were also demonstrated within the preserved bone. The bone measured 21.11cm in length, 17.78cm in width and 8.74cm in height. (The average adult vertebral body may measure approximately 4-5cm in width).

The team then successfully reconstructed the images in CAD software for 3D printing producing a fantastic replica of the object that could be further analysed, safely held and placed on display.

The research paper has been successfully published in the journal, Radiology:

http://pubs.rsna.org/doi/abs/10.1148/radiol.13130666

dinosaur bone ct scan

By Ryan Somma – Plateosaurus trossingensisUploaded by FunkMonk, CC BY-SA 2.0, https://commons.wikimedia.org/w/index.php?curid=8164313

Antique xray – 2D images with some limitations

September 3, 2016 By ag

Traditionally, museums have assessed antiquities and museum pieces with conventional xrays. This produces a 2D image of the object only (like a medical xray of a bone), which may be adequate in some circumstances but clearly fails to capture the 3D nature and layer-by-layer internal structure of an object. Therefore an antique xray may be an inadequate or suboptimal form of imaging an object.

As a consequence of 2D imaging, certain important areas of the object may be masked and remain hidden.

This problem is generally alleviated by CT scans as multiple xrays are taken around an object producing a 3D image.

How do CT scans work?

antique xray

A 2D antique xray through the mechanism, trigger and barrel of an 18th century musket. The 2D xray image has certain limitations including detail regarding the grain and integrity of the wood, for example. This is better achieved with CT scans which have higher contrast resolution.

(Image attributed to Lighthouse Archaeological Maritime Program)

CT scan investigation of fakes, forgeries and copies of antiquities

August 20, 2016 By ag

The high resolution, high contrast nature of CT imaging is ideal for the assessment of the internal structure of artefacts. Where conventional x-rays can only produce a 2D image, the sequential ‘slices’ through an item with CT, produce an internal 3D reconstruction.

CT is extremely useful for identifying the inner density of materials which can help to reveal the extent of restoration of artefacts.

Unexpected differing densities of materials, internal rods and glue lines together with expert knowledge of the piece in question can all be used to suggest a forgery or fake.

Sometimes real materials from the period in question are placed on the surface of an item, to fool experts and laboratory tests such as thermoluminescence (TL) – with more modern materials used internally which are hidden to the naked eye. These internal differing densities can be detected on a CT scan helping identify forgeries or fakes.

The high resolution nature of CT can help identify tiny cracks, repair lines and inner wear.

What is Thermoluminescence (TL)?

July 15, 2016 By ag

After a piece of pottery has been fired in a kiln, over time, it begins to absorb natural radiation from the outside world. The absorption of radiation causes the ancient pottery to glow with a blue light when it is heated and this is termed the thermoluminescence (TL) of the pottery.

The older the pottery, the more thermoluminescence the item has.

It is therefore possible to date items of pottery using this method with a TL reader.

The technique can also help detect restoration material and if multiple samples are taken date clay/terracotta from different sections of the piece.

x-rays, which are produced from CT scanners, can theoretically affect the results of TL testing so it is probably best to TL test your piece prior to scanning.

We do not perform these tests ourselves at antiquectscan.co.uk but can work with with TL testing centres on your behalf to assist in dating your pieces.

3D Printing

July 15, 2016 By ag

CT scans can be used for 3D printing

CT scans can be converted to specialised CAD images to allow for 3D printing of your scanned object. In many circumstances, the entire object may be printed as a replica. Sometimes, only a section of an object is required for printing to assist with future repair.

There are a variety of materials (usually plastics but sometimes metals) in which objects can be 3D printed. The printed model can be a true representation of the dimensions and shape of the object, or can be scaled up or down as desired.

The printed colour range is usually limited – and if a colour replica is required, specialist painting on top of the printed plastic may be required, like when painting a plastic model.

There are a large variety of 3D printers and materials to print with and we would be happy to advise you with the best approach for your objects.

3D printing is providing novel ways of assessing ancient relics. The research team at the University of Connecticut utilised the technology to print 3D working parts of ancient 19th century musical instruments. The 3D printed models could be used to listen to the way in which ancient musical instruments were meant to sound, without damaging the original priceless artefacts.

Painted 3D models have also been used by museums for their displays and exhibitions – such as in Egyptian mummies displays.

As an example, the team at The Field Museum, Chicago IL, USA, have utilised CT scan imaging and 3D printing to assist with the re-restoration of an ancient skull.

Siemens Somatom FORCE dual energy CT Scanner

June 20, 2016 By ag

The Siemens Somatom Force CT scanner, takes CT imaging to the next level.

I have been working with the Siemens Force for a while now and I can say it truly is a spectacular CT scanner. We use it for all our CT imaging at antiquectscan.co.uk

It has a very wide bore at 78cm, meaning that larger items are more likely to fit into the scanner (other scanners tend to have a bore diameter of around 70cm).

The Force also is one of the highest resolution CT scanners on the market – meaning that some of the best quality images of antiques and artwork can be obtained. We often scan at 0.6mm slice thickness.

The power that the scanner can generate is phenomenal. This increased power allows for a greater penetration of objects by x-rays. This can be important when dealing with very dense materials such as metals.

The scanner also has a dual-energy capability meaning that the materials within objects can be assessed in a novel manner.

Designed for healthcare – it is proving to be an excellent scanner for antiques and artwork!

We perform all our UK CT scans at a location approximately 30 minutes from Central London by car.