Medical imaging used to probe Tower of London mural

Tucked away in the Tower of London, a mysterious wall painting has been intriguing art historians. Commonly called the Byward Angel, it's one of the most well-preserved murals in the UK and the only surviving medieval interior at the castle. The style of the painting suggests it dates back to the 1390s - but nobody knows who painted it or why it's there.

Until recently, investigating the mural has been a painstaking task as it could only be analysed invasively by taking tiny samples of paint. Now, Haida Liang and her team from Nottingham Trent University have repurposed a medical imaging technique called Optical Coherence Tomography (OCT) to peer inside the paint. "It was first developed to look at 3D in vivo imaging of the eye," says Liang. "In 2004, we started using it for paintings, but it's the first time that we're using it to scan a wall painting."

Click here to read this article from New Scientist