Quantitative amplitude and phase contrast imaging in a scanning transmission X-ray microscope

Hornberger, Benjamin; Feser, Michael; Jacobsen, Chris

doi:10.1016/j.ultramic.2006.12.006

Cited by 63 publications

(37 citation statements)

References 30 publications

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“…As a first online analysis step, conventional differential phase contrast and dark-field images were generated by using the same procedure as in conventional scanning transmission x-ray microscopy (5). Images corresponding to a subset of 35 × 35 scan points out of the short-exposure dataset are shown in Fig.…”

Section: Resultsmentioning

confidence: 99%

Quantitative biological imaging by ptychographic x-ray diffraction microscopy

Giewekemeyer

Thibault²,

Kalbfleisch³

et al. 2009

Proc. Natl. Acad. Sci. U.S.A.

249

206

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Recent advances in coherent x-ray diffractive imaging have paved the way to reliable and quantitative imaging of noncompact specimens at the nanometer scale. Introduced a year ago, an advanced implementation of ptychographic coherent diffractive imaging has removed much of the previous limitations regarding sample preparation and illumination conditions. Here, we apply this recent approach toward structure determination at the nanoscale to biological microscopy. We show that the projected electron density of unstained and unsliced freeze-dried cells of the bacterium Deinococcus radiodurans can be derived from the reconstructed phase in a straightforward and reproducible way, with quantified and small errors. Thus, the approach may contribute in the future to the understanding of the highly disputed nucleoid structure of bacterial cells. In the present study, the estimated resolution for the cells was 85 nm (half-period length), whereas 50-nm resolution was demonstrated for lithographic test structures. With respect to the diameter of the pinhole used to illuminate the samples, a superresolution of about 15 was achieved for the cells and 30 for the test structures, respectively. These values should be assessed in view of the low dose applied on the order of ≃1.3 · 10 5 Gy, and were shown to scale with photon fluence.bacterial nucleoid | cellular imaging | coherent x-ray diffractive imaging | x-ray microscopy

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Section: Resultsmentioning

confidence: 99%

Quantitative biological imaging by ptychographic x-ray diffraction microscopy

Giewekemeyer

Thibault²,

Kalbfleisch³

et al. 2009

Proc. Natl. Acad. Sci. U.S.A.

249

206

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“…Two different methods for reconstructing quantitative values of the phase for scanning x-ray microprobe have been reported recently [5,6]. Although the detector configurations used for these demonstrations were identical, the analytical approaches are completely different.…”

Section: Differential Phase Contrast Imaging In the Stxmmentioning

confidence: 99%

“…Although the detector configurations used for these demonstrations were identical, the analytical approaches are completely different. The method of Hornberger [5] determines the CTF appropriate to the detector elements, and inverts this CTF to determine the phase advance and absorption of the specimen. This method is most general, and can be applied to any configuration of detector.…”

Section: Differential Phase Contrast Imaging In the Stxmmentioning

confidence: 99%

Quantitative scanning differential phase contrast microscopy

Jonge

Hornberger

Holzner

et al. 2009

J. Phys.: Conf. Ser.

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Abstract. Differential phase contrast can be realised in the scanning transmission x-ray microscope by use of a detector with an appropriate configuration of detector elements. Use of such a configured detector significantly improves the ability to image specimens with low absorption contrast. A natural application is found in scanning fluorescence x-ray microprobe studies of biological specimens. We discuss the technique and several applications. IntroductionThe scanning fluorescence x-ray microprobe can be used to map elemental distributions, to obtain spatially-resolved chemical information by means of XANES measurements, and to obtain longerrange bonding and co-ordination information from XAFS measurements. The spatial resolution of such measurements ranges from several micrometres down to around 50 nm using present synchrotron facilities. Virtually any format of specimen can be measured, with limitations coming mainly from mechanical constraints and the desire to avoid imaging artifacts. Studies have been performed on geological, environmental, and soil specimens and a wide range of biological specimens, including cells, plants, and whole organisms. While the microprobe can be used to investigate distributions on one side of a bulk specimen, the high penetration of hard x-rays recommends the application to a particular class of specimens with low absorption. In this regime the incident probe beam maintains its intensity as it traverses the specimen. Quantitative studies are possible when fluorescence x-rays escape with only minimal absorption [1]. While such studies can be performed on thin sections of specimens with high linear attenuation coefficient, a popular alternate regime is the measurement of thick specimens with low linear attenuation. This regime is particularly applicable to the imaging of trace metals in a biological context, and is ideally suited to measure almost any specimen coming from the biological community.The high penetration of x-rays is required to produce high-fidelity and quantitative fluorescence maps; however, the same condition leads to transmission images having extremely low contrast. The framework of a cell or organism is largely composed of lipid, protein, and water. These components absorb high-energy x-rays only weakly, and so studies involving biological specimens are usually blind to the biological ultrastructure in which the trace metals are situated. Detailed ultrastructural knowledge can help an investigator identify various organelles within the organism and thereby contextualise the elemental maps. While it has long been known that phase offers stronger contrast at high x-ray energies, phase contrast methods have only recently been developed for the STXM.

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“…Moreover, synchrotron radiation can be tuned at the desired wavelength, and because of its high intensity, it is also able to detect very low amount of contaminants. Different techniques can be applied using X-rays from synchrotron sources: dual-energy (i.e., imaging of samples at X-ray energy above and below the edge of the heavy elements under study) radiography and tomography (Kaiser et al, 2005(Kaiser et al, , 2007Reale et al, 2008), projection microscopy with zone plate lenses (Yada 2009;Awaji et al, 2001), diffraction microscopy (Shapiro et al, 2005), X-ray scanning transmission microscopy (Hornberger et al, 2007), as well as X-ray microfluorescence.…”

Section: Introductionmentioning

confidence: 99%

Detection of lead in Zea mays by dual‐energy X‐ray microtomography at the SYRMEP beamline of the ELETTRA synchrotron and by atomic absorption spectroscopy

Reale

Kaiser

Pace

et al. 2009

Microscopy Res & Technique

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This study is related to the application of the X-ray dual-energy microradiography technique together with the atomic absorption spectroscopy (AAS) for the detection of lead on Zea mays stem, ear, root, and leaf samples. To highlight the places with lead intake, the planar radiographs taken with monochromatic X-ray radiation in absorption regime with photon energy below and above the absorption edge of a given chemical element, respectively, are analyzed and processed. To recognize the biological structures involved in the intake, the dual-energy images with the lead signal have been compared with the optical images of the same Z. mays stem. The ear, stem, root, and leaf samples have also been analyzed with the AAS technique to measure the exact amount of the hyperaccumulated lead. The AAS measurement revealed that the highest intake occurred in the roots while the lowest in the maize ears and in the leaf. It seems there is a particular mechanism that protects the seeds and the leaves in the intake process.

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Quantitative amplitude and phase contrast imaging in a scanning transmission X-ray microscope

Cited by 63 publications

References 30 publications

Quantitative biological imaging by ptychographic x-ray diffraction microscopy

Quantitative biological imaging by ptychographic x-ray diffraction microscopy

Quantitative scanning differential phase contrast microscopy

Detection of lead in Zea mays by dual‐energy X‐ray microtomography at the SYRMEP beamline of the ELETTRA synchrotron and by atomic absorption spectroscopy

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