Quantitative x-ray dark-field computed tomography.
The basic principles of x-ray image formation in radiology have remained essentially unchanged since Röntgen first discovered x-rays over a hundred years ago. The conventional approach relies on x-ray attenuation as the sole source of contrast and draws exclusively on ray or geometrical optics to describe and interpret image formation. Phase-contrast or coherent scatter imaging techniques, which can be understood using wave optics rather than ray optics, offer ways to augment or complement the conventional approach by incorporating the wave-optical interaction of x-rays with the specimen. With a recently developed approach based on x-ray optical gratings, advanced phase-contrast and dark-field scatter imaging modalities are now in reach for routine medical imaging and non-destructive testing applications. To quantitatively assess the new potential of particularly the grating-based dark-field imaging modality, we here introduce a mathematical formalism together with a material-dependent parameter, the so-called linear diffusion coefficient and show that this description can yield quantitative dark-field computed tomography (QDFCT) images of experimental test phantoms.
Bech
M
M
Physik-Department, Technische Universität München, 85748 Garching, Germany. martin.bech@tum.de
Bunk
O
O
Donath
T
T
Feidenhans'l
R
R
David
C
C
Pfeiffer
F
F
D003624:Darkness; D004058:Diffusion; D007091:Image Processing, Computer-Assisted; D016014:Linear Models; D019047:Phantoms, Imaging; D014057:Tomography, X-Ray Computed / Q000379:methods*