Anders Persson, director of the Center for Medical Image Science and Visualization at Linköping University, Sweden, received the Lennart Nillson Award for scientific photography this year, for his groundbreaking work on improving CT scans.
His sharp, 3D images provide new perspectives on human and animal bodies, and are even used by police to perform virtual autopsies and look inside a corpse without leaving a trace.
CT scans build up an image from a series of many "slices" taken through a body by an X-ray machine, as it sweeps along its length. Software stitches the slices together again afterwards, to create a 3D representation of the body. The highest resolution scans of a person can be built up from 25,000 separate slices.
Colours are added by instructing the software to make parts with a certain density a certain colour
This scan of a patient with scoliosis, an unnatural curvature of the spine, shows how CT scans can make parts of the body transparent. Instead of colouring in certain structures, the software simply makes them transparent.
It was taken using a dual energy CT scanner, which has two X-ray units rather than the usual one. By creating slices using two different X-ray energies at once it can gather much more information. "You can actually see the ch emistry of the body," says Lennart Nillson, the photographer who the awards commemorate.
Being able to determine the actual elements at a particular point in the body makes it easier to separate tissues with similar density that would confuse a normal scan.
A live chimpanzee from Kålmården zoo near Norrköping, Sweden.
"We have taken scans of many different animals now," Persson told New Scientist. "Until now almost no images like this have ever been made of these species."
Performing a CT scan of a chimp is not easy, he adds, and requires the very latest scanners. This is because chimps have dense bodies, with strong compact bones, a lot of muscle and little fat.
Blood vessels in the head of a dead horse. This image was taken while testing a new contrast agent, intended to be injected into the veins of human bodies before a virtual autopsy.
The veins stand out sharply from their surroundings. The scan also demonstrates a processing step able to remove bones from the final image
very high-resolution scan of a dead boar; each voxel in the image is just 0.15mm across. "Note how you can see the pulp in individual teeth," says Persson. "Only with the latest dual-energy scanner is it possible to see that detail inside the very dense teeth of animals like boar and horses."
Scans of horses' teeth have shown how the soft pulp can extend closer to the surface of their teeth than suspected before, he told New Scientist, leading some vets involved with the centre to conclude that rasps should no long er be used so routinely to file down horses' teeth.
Various images created from a single scan of a living lioness.
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