Full body tomography for human health - PHACT

Abstract:

State of the art X-ray computer tomography uses the absorption contrast to make a 3D image of a sample . This method is relatively insensitive for only small differences in the absorption coefficient. A novel approach uses the phase shift of x-rays traveling through a sample to calculate a corresponding image. Within the PHACT project a consortium of two research institutes and two industrial partner aim to bring this novel technology to the level, where it can be integrated into todays CT-scanners. This would allow for medical images with higher contrast especially in case of soft tissue. The phase shift is detected by an x-ray talbot interferometer comprising two different types of optical gratings. Especially the so called absorption grating requires high aspect ratio gold microstructures with dimensions in the micron range and heights of more than 100 µm, which is far above the limits of todays fabrication technologies. Further improvement in the LIGA process together with an optimization of the grating geometry offers the potential to achieve this challenging goal. Thus, the PHACT project makes X-ray phase contrast imaging possible in a conventional CT-scanner even at energies used for full body tomography; it paves the way for better examination of human tissue and will contribute to better and more precise health care.