Single-shot Talbot–Lau x-ray dark-field imaging of a porcine lung applying the moiré imaging approach

Abstract

Talbot-Lau x-ray imaging provides additionally to the conventional attenuation image, two further images: the differential phase-contrast image which is especially sensitive to differences in refractive properties and the dark-field image which is showing the x-ray scattering properties of the object. Thus, in the dark-field image sub-pixeled object information can be observed. As it has been shown in recent studies, this is of special interest for lung imaging. Changes in the alveoli structure, which are in the size of one detector pixel, can be seen in the dark-field images. A fast acquisition process is crucial to avoid motion artifacts due to heartbeat and breathing of the patient. Using moiré imaging the images can be acquired with a single-shot exposure. Nevertheless, the spatial resolution is reduced compared to the phase-stepping acquisition. We evaluate the results of both imaging techniques towards their feasibility in clinical routine. Furthermore, we analyse the influence of artificial linear object movement on the image quality, in order to simulate the heartbeat of a patient.

Exploration of different x-ray Talbot–Lau setups for dark-field lung imaging examined in a porcine lung

“…Furthermore, in a living body moving artifacts induced by heart beating or breathing during the phase-stepping procedure could be problematic. Here, single-shot moiré imaging, which enables a faster acquisition, already showed promising results for lung imaging (Seifert et al 2018).…”

Towards high-sensitivity and low-dose medical imaging with laser x-ray sources

“…A typical number of steps is 5-10. It is also possible to obtain absorption, refraction, and scatter images from a single moiré fringe image of the object ( [12], and Fig. 9].…”

“…A single-image or single-shot alternative to phase-stepping nevertheless exists, moiré fringe imaging. This consists in introducing high frequency moiré fringes in the interferometric image (e.g., by rotating one of the gratings), and using special algorithms to retrieve the refraction, absorption, and 'dark-field' images [12].…”

A phase-sampling method for an X-ray Talbot-Lau scanner with continuous grating movement

“…This grating-based technique provides two further images in addition to the usual attenuation image, namely the differential phase-contrast and the dark-field image. For over a decade, many fields of possible applications in medical imaging [15][16][17][18][19][20][21][22], non-destructive testing and food control [23][24][25][26] have been investigated.…”