Research Terms
These materials, made with nano fluids or metal-filled putties, for instance, minimize scatter that arises most strongly during an X-ray or computed tomography (CT) scan of an object, where the object interfaces with the surrounding air. In dentistry, for instance, scatter occurs from existing fillings and crowns, which can distort X-ray images used in diagnosis. The automotive and aviation industries also use X-ray and CT frequently because imaging can help manufacturers inspect and analyze complex manufactured parts and systems without destroying them. Estimates value the global market for industrial X-ray inspection systems to grow to about $350 million by 2022. While available imaging techniques are useful, scattering artifacts can obscure images, causing misinterpretation. Since X-ray attenuation of a spectrum of X-ray energies is a combination of energy, absorption, Rayleigh scatter, and Compton scatter, tailoring a surface-conforming material will greatly increase edge definition. Some imaging instrument manufacturers provide hardware and software solutions to resolve this issue, but they are often expensive and imperfect.
Researchers at the University of Florida have developed scatter mitigation methods using a variety of materials that improve the fidelity of X-ray images by reducing scattering at either the interior surface of an object, or the exterior surface, as long as there is an open path to the exterior of the sample. These materials mitigate scattering by preferentially absorbing scattered photons, which provides a simple and cost-effective strategy for improving clarity of X-rayed and CT scanned objects.
Application
Materials to reduce scattering artifacts in X-ray and CT scan images
Advantages
In X-ray and CT imaging, the most noticeable scatter artifacts appear at the boundary between the surface of an object and the surrounding air or between high attenuation areas within a scan, such as between two fillings in a 3D scan of a mouth, for example. A major factor in these artifacts is Compton scattering, which includes energy partly absorbed and partly re-emitted as an X-ray. These emit in all directions from a scatter event. If emitted towards the interior, they should eventually completely absorb, but if emitted towards air, they will likely reach the detector. A material tailored to absorb these scattered X-rays placed either within the sample or around it can greatly enhance edge definition, as long as there is minimal change in scan time or noise.
