Aortic valve calcification, which can be an early sign of heart disease, occurs when calcium deposits form on the aortic valve in the heart causing the soft tissue to harden. This striking image from the Wellcome Images Awards 2014 offers a microscopic view of clumps of calcium salts building up on the heart valve. A description on the winners' photo gallery offers more detail about how it was created:
This image was produced using a type of scanning electron microscopy called density-dependent colour scanning electron microscopy. In this method, images are taken of a sample using two different detectors, one which records topographical information about the surface of the sample and one which records information about its density. A different colour is assigned to each and the images are then superimposed to produce a composite image like the one you see here. In this particular image, the orange colour identifies denser material (calcified material composed of calcium phosphate), while structures that appear in green are less dense (corresponding to the organic component of the tissue).
Previously: Big hand, beautiful biofilms, Image of the Week: One of 2013′s “coolest” microscopic images, Image of the Week: Microscopic view of lung surfactant and Touring the microscopic worlds of the human body
Photo by Sergio Bertazzo, Wellcome Images