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Single-image phase retrieval using an edge illumination X-ray phase-contrast imaging setup.

Diemoz PC, Vittoria FA, Hagen CK, Endrizzi M, Coan P, Brun E, Wagner UH, Rau C, Robinson IK, Bravin A, Olivo A - J Synchrotron Radiat (2015)

Bottom Line: Furthermore, the fact that phase information is directly extracted, instead of its derivative, can enable a simpler image interpretation and be beneficial for subsequent processing such as segmentation.Quantitative accuracy in the case of homogeneous objects as well as enhanced image quality for the imaging of complex biological samples are demonstrated through experiments at two synchrotron radiation facilities.The large range of applicability, the robustness against noise and the need for only one input image suggest a high potential for investigations in various research subjects.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Medical Physics and Biomedical Engineering, University College London, London WC1 E6BT, UK.

ABSTRACT
A method is proposed which enables the retrieval of the thickness or of the projected electron density of a sample from a single input image acquired with an edge illumination phase-contrast imaging setup. The method assumes the case of a quasi-homogeneous sample, i.e. a sample with a constant ratio between the real and imaginary parts of its complex refractive index. Compared with current methods based on combining two edge illumination images acquired in different configurations of the setup, this new approach presents advantages in terms of simplicity of acquisition procedure and shorter data collection time, which are very important especially for applications such as computed tomography and dynamical imaging. Furthermore, the fact that phase information is directly extracted, instead of its derivative, can enable a simpler image interpretation and be beneficial for subsequent processing such as segmentation. The method is first theoretically derived and its conditions of applicability defined. Quantitative accuracy in the case of homogeneous objects as well as enhanced image quality for the imaging of complex biological samples are demonstrated through experiments at two synchrotron radiation facilities. The large range of applicability, the robustness against noise and the need for only one input image suggest a high potential for investigations in various research subjects.

No MeSH data available.


(a) Retrieved phase map of the flower sample, obtained after adding 30% Poisson noise to the image in Fig. 3(a). (b) Difference between phase maps in Figs. 3(b) and 4(a) (note the different color scale used).
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fig4: (a) Retrieved phase map of the flower sample, obtained after adding 30% Poisson noise to the image in Fig. 3(a). (b) Difference between phase maps in Figs. 3(b) and 4(a) (note the different color scale used).

Mentions: Finally, a test of the method’s robustness with respect to noise was carried out. Poisson noise corresponding to statistics of only 10 photons per pixel (standard deviation ∼30%) was added numerically to the image of the petal before the retrieval. Despite the very high noise in the input image, the retrieved map of still maintains its ability to correctly visualize most of the sample structures, as seen in Fig. 4 ▸(a). The difference between the retrieved maps obtained with low (Fig. 3 ▸b) and high (Fig. 4 ▸a) levels of noise is presented in Fig. 4 ▸(b) (note that a different color scale has been used since the values are small).


Single-image phase retrieval using an edge illumination X-ray phase-contrast imaging setup.

Diemoz PC, Vittoria FA, Hagen CK, Endrizzi M, Coan P, Brun E, Wagner UH, Rau C, Robinson IK, Bravin A, Olivo A - J Synchrotron Radiat (2015)

(a) Retrieved phase map of the flower sample, obtained after adding 30% Poisson noise to the image in Fig. 3(a). (b) Difference between phase maps in Figs. 3(b) and 4(a) (note the different color scale used).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4489537&req=5

fig4: (a) Retrieved phase map of the flower sample, obtained after adding 30% Poisson noise to the image in Fig. 3(a). (b) Difference between phase maps in Figs. 3(b) and 4(a) (note the different color scale used).
Mentions: Finally, a test of the method’s robustness with respect to noise was carried out. Poisson noise corresponding to statistics of only 10 photons per pixel (standard deviation ∼30%) was added numerically to the image of the petal before the retrieval. Despite the very high noise in the input image, the retrieved map of still maintains its ability to correctly visualize most of the sample structures, as seen in Fig. 4 ▸(a). The difference between the retrieved maps obtained with low (Fig. 3 ▸b) and high (Fig. 4 ▸a) levels of noise is presented in Fig. 4 ▸(b) (note that a different color scale has been used since the values are small).

Bottom Line: Furthermore, the fact that phase information is directly extracted, instead of its derivative, can enable a simpler image interpretation and be beneficial for subsequent processing such as segmentation.Quantitative accuracy in the case of homogeneous objects as well as enhanced image quality for the imaging of complex biological samples are demonstrated through experiments at two synchrotron radiation facilities.The large range of applicability, the robustness against noise and the need for only one input image suggest a high potential for investigations in various research subjects.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Medical Physics and Biomedical Engineering, University College London, London WC1 E6BT, UK.

ABSTRACT
A method is proposed which enables the retrieval of the thickness or of the projected electron density of a sample from a single input image acquired with an edge illumination phase-contrast imaging setup. The method assumes the case of a quasi-homogeneous sample, i.e. a sample with a constant ratio between the real and imaginary parts of its complex refractive index. Compared with current methods based on combining two edge illumination images acquired in different configurations of the setup, this new approach presents advantages in terms of simplicity of acquisition procedure and shorter data collection time, which are very important especially for applications such as computed tomography and dynamical imaging. Furthermore, the fact that phase information is directly extracted, instead of its derivative, can enable a simpler image interpretation and be beneficial for subsequent processing such as segmentation. The method is first theoretically derived and its conditions of applicability defined. Quantitative accuracy in the case of homogeneous objects as well as enhanced image quality for the imaging of complex biological samples are demonstrated through experiments at two synchrotron radiation facilities. The large range of applicability, the robustness against noise and the need for only one input image suggest a high potential for investigations in various research subjects.

No MeSH data available.