Many will undergo a CT scan at some point in their lifetime — being slid in and out of a tunnel as a large machine rotates around. X-ray computed tomography, better known by its acronym CT, is a widely used method of obtaining cross-sectional images of objects.
Now a research team at Tohoku University has developed a new method using intense synchrotron radiation that produces higher quality images within milliseconds.
High-speed, high-resolution X-ray CT is currently possible using intense synchrotron radiation. However, this requires samples to be rotated at high speed to obtain images from many directions. This would make CT scans more akin to a rollercoaster ride. Extreme rotation also makes controlling the temperature or atmosphere of the sample impossible.
The research team solved this conundrum by creating an optical system that splits single synchrotron X-ray beams into many. These beams then shine onto the sample from different directions at the same time; thus, negating the need to rotate the sample.
This “multi-beam” method is no easy task, however, since the direction of X-rays cannot be easily changed. Unlike visible light, X-rays interact with matter weakly, making it difficult to utilize mirrors and prisms to change the path of the beams.
To overcome this, the research team used micro-fabrication techniques to create uniquely shaped crystals. These crystals were then bent in the shape of a hyperbola. By combining three rows of crystals, the multi-beam optics were able to cover an angle of ±70°.
Carrying out their experiments at the SPring-8 synchrotron radiation facility, the research team took advantage of a cuttingedge compressed-sensing algorithm that needs only a few dozen projection images for image reconstruction.
According to the researchers, the invention makes 3-D observations of living beings and liquid samples within milliseconds possible. Its possible applications are widespread, from fundamental material science to life sciences to industry.