Using CT scans can provide a lot of added value for researchers. For example, they can examine the annual rings of a wooden sculpture, without having to damage the sculpture to do so. However, existing equipment suitable for this purpose are not easily accessible and are also very pricey. A new method offers a solution and allows existing X-ray equipment to be used for CT scanning.
The method was developed by an international team of researchers led by the Centre for Mathematics & Computer Science (CWI). The team presents its results in the scientific journal Nature Communications. Using X-ray equipment to examine art is not new. For instance, research departments of larger museums often have an X-ray machine. This allows them to analyse objects.
Digitally section 3D image
The procedure is similar to taking an X-ray of a broken bone. Here, the bone is visible in the photo because it has a higher density than the surrounding muscles and tissues. As a result, the bone blocks more radiation. Taking multiple photos allows a bone fracture to be viewed from multiple angles.
An X-ray thus differs from a CT scan, although the underlying technology is similar. In a CT scan, doctors take hundreds of X-ray images from a wide range of angles. Combining these using algorithms creates a 3D image, which you can digitally 'slice through'. This allows you to look inside an object, viewing it layer by layer.
Also interesting for examining art
A CT scan can also be interesting for examining art. For instance, the technique can be used to examine the inside of an art object in detail. This is done without damaging the object so that it can be exhibited after analysis.
The technique can provide interesting insights in the art sector. For instance, as mentioned earlier, by looking at the annual rings of a wooden sculpture. Or by looking for clues to the techniques or methods the artist used.
Complex
A CT scanner and an X-ray machine basically consist of the same components: an X-ray source, a turntable and a detector. However, a CT scan requires the positions of these components to be imaged very precisely during the scan.
Researchers at CWI are simplifying this process with a new method. This method makes it possible to calculate the required position using only a number of metal balls. The researchers pierce the balls into a block of foam, then scan them along with the object. They then calculate the required positions based on the location of the balls on the X-ray image, and use them to make a CT scan.
Various parties involved
Several parties are involved in the research. From the Netherlands, besides CWI, these include the Leiden Institute of Advanced Computer Science and the Rijksmuseum in Amsterdam. The British Museum in British London and J. Paul Getty Museum in US Los Angeles are also involved.
Author: Wouter Hoeffnagel
Image: Roman Paroubek via Pixabay (pictured: a traditional CT scanner in a hospital)
