Grid-enhanced X-ray coded aperture microscopy with polycapillary optics

Abstract

Polycapillary devices focus X-rays by means of multiple reflections of X-rays in arrays of bent glass capillaries. The size of the focal spot (typically 10–100 μm) limits the resolution of scanning, absorption and phase-contrast X-ray imaging using these devices. At the expense of a moderate resolution, polycapillary elements provide high intensity and are frequently used for X-ray micro-imaging with both synchrotrons and X-ray tubes. Recent studies have shown that the internal microstructure of such an optics can be used as a coded aperture that encodes high-resolution information about objects located inside the focal spot. However, further improvements to this variant of X-ray microscopy will require the challenging fabrication of tailored devices with a well-defined capillary microstructure. Here, we show that submicron coded aperture microscopy can be realized using a periodic grid that is placed at the output surface of a polycapillary optics. Grid-enhanced X-ray coded aperture microscopy with polycapillary optics does not rely on the specific microstructure of the optics but rather takes advantage only of its focusing properties. Hence, submicron X-ray imaging can be realized with standard polycapillary devices and existing set-ups for micro X-ray fluorescence spectroscopy.

Whole Transcriptome Analysis of Notochord-Derived Cells during Embryonic Formation of the Nucleus Pulposus

“…In the adult disc, Col1 is predominantly confined to the outer annulus fibrosus 1 except during aging and degeneration when the NP becomes more fibrous 63 . Consistent with our results, however, Col1 mRNA and protein have been demonstrated previously in the developing notochord and NP in humans and mice 12 , 54 , 57 , 65 . We also found significantly elevated Col6 mRNA expression at P0 (Table 4 , Fig.…”

3356097.pdf

“…For X-ray detection, we used two X-ray cameras. The first was an 80 mm × 80 mm Gadox scintillator, which was lens-coupled to a 4M pixel sCMOS camera (Photonic Science) [5]. The spatial resolution was limited to approximately 150 µm in the image centre.…”

Plenoptic x-ray microscopy

“…However, depth resolution was achieved by scanning the sample in both the lateral and axial directions and the main objective of single exposure 3D imaging has not been realized. Moreover, coded aperture approach has strong disadvantages, and the weak signalto-noise ratio made the imaging of weak features via phasecontrast impractical 28 . More recently, it was demonstrated that individual capillaries 29 (or even defects 30 ) inside a polycapillary optics can be used to generate an array of secondary quasi-point x-ray sources and to obtain replicated projections of planar objects that are placed at the focal plane in the socalled multipoint projection geometry.…”