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![Page 1: LMN](https://reader036.fdocuments.net/reader036/viewer/2022081604/56813328550346895d9a1551/html5/thumbnails/1.jpg)
C. David, IEEE Conference, Rome, 21.10.2004
LMNLMN
SLSSLS
Phase Contrast X-Ray Radiography and Tomography Based on a Grating Interferometer
C. David, T. Weitkamp, A. DiazLaboratory for Micro- and Nanotechnology (LMN), Paul Scherrer Institut, Switzerland
F. Pfeiffer, M. Stampanoni, J.F. van der Veen Swiss Light Source (SLS), Paul Scherrer Institut, Switzerland
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C. David, IEEE Conference, Rome, 21.10.2004
X-rays for medical imaging
• Minimizing the radiation dose is an important issue – especially in mammography
• low absorption contrast => large dose required to obtain sufficiently good S/N
• low applied photon energy (Mo anodes) • screening submits a large number of healthy patients to radiation dose
![Page 3: LMN](https://reader036.fdocuments.net/reader036/viewer/2022081604/56813328550346895d9a1551/html5/thumbnails/3.jpg)
C. David, IEEE Conference, Rome, 21.10.2004
Improving contrast
Source Sample Detector
![Page 4: LMN](https://reader036.fdocuments.net/reader036/viewer/2022081604/56813328550346895d9a1551/html5/thumbnails/4.jpg)
C. David, IEEE Conference, Rome, 21.10.2004
Improving contrast
Source Sample Detector
efficiency, size, resolution
![Page 5: LMN](https://reader036.fdocuments.net/reader036/viewer/2022081604/56813328550346895d9a1551/html5/thumbnails/5.jpg)
C. David, IEEE Conference, Rome, 21.10.2004
Improving contrast
Source Sample Detector
spectrum, power, coherence
efficiency, size, resolution
![Page 6: LMN](https://reader036.fdocuments.net/reader036/viewer/2022081604/56813328550346895d9a1551/html5/thumbnails/6.jpg)
C. David, IEEE Conference, Rome, 21.10.2004
Improving contrast
Source Sample Detector
spectrum, power, coherence
efficiency, size, resolution
contrast mechanism
![Page 7: LMN](https://reader036.fdocuments.net/reader036/viewer/2022081604/56813328550346895d9a1551/html5/thumbnails/7.jpg)
C. David, IEEE Conference, Rome, 21.10.2004
Phase contrast vs. amplitude contrast
n = 1 – + i
x-rays
![Page 8: LMN](https://reader036.fdocuments.net/reader036/viewer/2022081604/56813328550346895d9a1551/html5/thumbnails/8.jpg)
C. David, IEEE Conference, Rome, 21.10.2004
Phase contrast vs. amplitude contrast
n = 1 – + i
x-rays
![Page 9: LMN](https://reader036.fdocuments.net/reader036/viewer/2022081604/56813328550346895d9a1551/html5/thumbnails/9.jpg)
C. David, IEEE Conference, Rome, 21.10.2004
Phase contrast vs. amplitude contrast
n = 1 – + i
x-rays
![Page 10: LMN](https://reader036.fdocuments.net/reader036/viewer/2022081604/56813328550346895d9a1551/html5/thumbnails/10.jpg)
C. David, IEEE Conference, Rome, 21.10.2004
Phase contrast vs. amplitude contrast
Example:• 20 keV• Organic sample (polymer, biological, medical…) .• 50 m thickness
n = 1 – + i
x-rays
![Page 11: LMN](https://reader036.fdocuments.net/reader036/viewer/2022081604/56813328550346895d9a1551/html5/thumbnails/11.jpg)
C. David, IEEE Conference, Rome, 21.10.2004
Phase contrast vs. amplitude contrast
Example:• 20 keV• Organic sample (polymer, biological, medical…) .• 50 m thickness only 0.2 % absorption, but - phase shift
n = 1 – + i
x-rays
![Page 12: LMN](https://reader036.fdocuments.net/reader036/viewer/2022081604/56813328550346895d9a1551/html5/thumbnails/12.jpg)
C. David, IEEE Conference, Rome, 21.10.2004
Phase contrast vs. amplitude contrast
Example:• 20 keV• Organic sample (polymer, biological, medical…) .• 50 m thickness only 0.2 % absorption, but - phase shift
n = 1 – + i
x-rays
+
![Page 13: LMN](https://reader036.fdocuments.net/reader036/viewer/2022081604/56813328550346895d9a1551/html5/thumbnails/13.jpg)
C. David, IEEE Conference, Rome, 21.10.2004
Phase contrast vs. amplitude contrast
Example:• 20 keV• Organic sample (polymer, biological, medical…) .• 50 m thickness only 0.2 % absorption, but - phase shift much higher contrast less dose required
n = 1 – + i
x-rays
+
![Page 14: LMN](https://reader036.fdocuments.net/reader036/viewer/2022081604/56813328550346895d9a1551/html5/thumbnails/14.jpg)
C. David, IEEE Conference, Rome, 21.10.2004
Hard x-ray interferometry
Bonse-Hart Interferometer (since 1965)
detector
Object
![Page 15: LMN](https://reader036.fdocuments.net/reader036/viewer/2022081604/56813328550346895d9a1551/html5/thumbnails/15.jpg)
C. David, IEEE Conference, Rome, 21.10.2004
Hard x-ray interferometry
Bonse-Hart Interferometer (since 1965)
detector
• Object beam and reference beam are generated by Bragg reflections on thin Si crystals
• The interference of both beams gives a phase image
Object
![Page 16: LMN](https://reader036.fdocuments.net/reader036/viewer/2022081604/56813328550346895d9a1551/html5/thumbnails/16.jpg)
C. David, IEEE Conference, Rome, 21.10.2004
Hard x-ray interferometry
Bonse-Hart Interferometer (since 1965)
detector
• optical path length difference needs to be stable to a fraction of a wavelengths
picometer stability required
cannot be scaled up
• Object beam and reference beam are generated by Bragg reflections on thin Si crystals
• The interference of both beams gives a phase image
Object
![Page 17: LMN](https://reader036.fdocuments.net/reader036/viewer/2022081604/56813328550346895d9a1551/html5/thumbnails/17.jpg)
C. David, IEEE Conference, Rome, 21.10.2004
Propagation methods – edge contrast
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C. David, IEEE Conference, Rome, 21.10.2004
• phase shift greatly enhances contrast of edges
• can be used to retrieve phase information
• requires high degree of transverse coherence (i.e. small source size)
• cannot be scaled up to large fields of view (required detector resolution)
Propagation methods – edge contrast
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C. David, IEEE Conference, Rome, 21.10.2004
50 nm
Grating x-ray interferometry
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C. David, IEEE Conference, Rome, 21.10.2004
beam-splitter phase grating
s
Grating x-ray interferometry
![Page 21: LMN](https://reader036.fdocuments.net/reader036/viewer/2022081604/56813328550346895d9a1551/html5/thumbnails/21.jpg)
C. David, IEEE Conference, Rome, 21.10.2004
beam-splitter phase grating
s
Grating x-ray interferometry
![Page 22: LMN](https://reader036.fdocuments.net/reader036/viewer/2022081604/56813328550346895d9a1551/html5/thumbnails/22.jpg)
C. David, IEEE Conference, Rome, 21.10.2004
beam-splitter phase grating
interference pattern
s
Grating x-ray interferometry
![Page 23: LMN](https://reader036.fdocuments.net/reader036/viewer/2022081604/56813328550346895d9a1551/html5/thumbnails/23.jpg)
C. David, IEEE Conference, Rome, 21.10.2004
beam-splitter phase grating
analyzer amplitude grating
interference pattern
camera
Grating x-ray interferometry
![Page 24: LMN](https://reader036.fdocuments.net/reader036/viewer/2022081604/56813328550346895d9a1551/html5/thumbnails/24.jpg)
C. David, IEEE Conference, Rome, 21.10.2004
beam-splitter phase grating
interference pattern
analyzer amplitude grating
Moiré fringes
camera
Grating x-ray interferometry
![Page 25: LMN](https://reader036.fdocuments.net/reader036/viewer/2022081604/56813328550346895d9a1551/html5/thumbnails/25.jpg)
C. David, IEEE Conference, Rome, 21.10.2004
beam-splitter phase grating
analyzer amplitude grating
interference pattern
camera
Grating x-ray interferometry
![Page 26: LMN](https://reader036.fdocuments.net/reader036/viewer/2022081604/56813328550346895d9a1551/html5/thumbnails/26.jpg)
C. David, IEEE Conference, Rome, 21.10.2004
beam-splitter phase grating
analyzer amplitude grating
interference pattern
camera
Grating x-ray interferometry
![Page 27: LMN](https://reader036.fdocuments.net/reader036/viewer/2022081604/56813328550346895d9a1551/html5/thumbnails/27.jpg)
C. David, IEEE Conference, Rome, 21.10.2004
beam-splitter phase grating
analyzer amplitude grating
interference pattern
camera
Grating x-ray interferometry
![Page 28: LMN](https://reader036.fdocuments.net/reader036/viewer/2022081604/56813328550346895d9a1551/html5/thumbnails/28.jpg)
C. David, IEEE Conference, Rome, 21.10.2004
beam-splitter phase grating
analyzer amplitude grating
interference pattern
camera
Grating x-ray interferometry
![Page 29: LMN](https://reader036.fdocuments.net/reader036/viewer/2022081604/56813328550346895d9a1551/html5/thumbnails/29.jpg)
C. David, IEEE Conference, Rome, 21.10.2004
beam-splitter phase grating
analyzer amplitude grating
interference pattern
camera
Grating x-ray interferometry
![Page 30: LMN](https://reader036.fdocuments.net/reader036/viewer/2022081604/56813328550346895d9a1551/html5/thumbnails/30.jpg)
C. David, IEEE Conference, Rome, 21.10.2004
beam-splitter phase grating
analyzer amplitude grating
interference pattern
camera
Grating x-ray interferometry
![Page 31: LMN](https://reader036.fdocuments.net/reader036/viewer/2022081604/56813328550346895d9a1551/html5/thumbnails/31.jpg)
C. David, IEEE Conference, Rome, 21.10.2004
beam-splitter phase grating
analyzer amplitude grating
interference pattern
camera
Grating x-ray interferometry
![Page 32: LMN](https://reader036.fdocuments.net/reader036/viewer/2022081604/56813328550346895d9a1551/html5/thumbnails/32.jpg)
C. David, IEEE Conference, Rome, 21.10.2004
beam-splitter phase grating
analyzer amplitude grating
interference pattern
camera
Grating x-ray interferometry
![Page 33: LMN](https://reader036.fdocuments.net/reader036/viewer/2022081604/56813328550346895d9a1551/html5/thumbnails/33.jpg)
C. David, IEEE Conference, Rome, 21.10.2004
beam-splitter phase grating
analyzer amplitude grating
interference pattern
camera
Grating x-ray interferometry
![Page 34: LMN](https://reader036.fdocuments.net/reader036/viewer/2022081604/56813328550346895d9a1551/html5/thumbnails/34.jpg)
C. David, IEEE Conference, Rome, 21.10.2004
beam-splitter phase grating
analyzer amplitude grating
interference pattern
camera
Grating x-ray interferometry
![Page 35: LMN](https://reader036.fdocuments.net/reader036/viewer/2022081604/56813328550346895d9a1551/html5/thumbnails/35.jpg)
C. David, IEEE Conference, Rome, 21.10.2004
beam-splitter phase grating
analyzer amplitude grating
interference pattern
camera
Grating x-ray interferometry
![Page 36: LMN](https://reader036.fdocuments.net/reader036/viewer/2022081604/56813328550346895d9a1551/html5/thumbnails/36.jpg)
C. David, IEEE Conference, Rome, 21.10.2004
beam-splitter phase grating
analyzer amplitude grating
interference pattern
camera
Grating x-ray interferometry
![Page 37: LMN](https://reader036.fdocuments.net/reader036/viewer/2022081604/56813328550346895d9a1551/html5/thumbnails/37.jpg)
C. David, IEEE Conference, Rome, 21.10.2004
beam-splitter phase grating
analyzer amplitude grating
interference pattern
phase object
camera
Grating x-ray interferometry
![Page 38: LMN](https://reader036.fdocuments.net/reader036/viewer/2022081604/56813328550346895d9a1551/html5/thumbnails/38.jpg)
C. David, IEEE Conference, Rome, 21.10.2004
beam-splitter phase grating
analyzer amplitude grating
interference pattern
phase object
camera
Grating x-ray interferometry
![Page 39: LMN](https://reader036.fdocuments.net/reader036/viewer/2022081604/56813328550346895d9a1551/html5/thumbnails/39.jpg)
C. David, IEEE Conference, Rome, 21.10.2004
beam-splitter phase grating
analyzer amplitude grating
interference pattern
phase object
camera
Grating x-ray interferometry
![Page 40: LMN](https://reader036.fdocuments.net/reader036/viewer/2022081604/56813328550346895d9a1551/html5/thumbnails/40.jpg)
C. David, IEEE Conference, Rome, 21.10.2004
beam-splitter phase grating
analyzer amplitude gratingphase object
interference pattern
camera
Grating x-ray interferometry
![Page 41: LMN](https://reader036.fdocuments.net/reader036/viewer/2022081604/56813328550346895d9a1551/html5/thumbnails/41.jpg)
C. David, IEEE Conference, Rome, 21.10.2004
beam-splitter phase grating
analyzer amplitude grating
interference pattern
phase object
camera
Grating x-ray interferometry
![Page 42: LMN](https://reader036.fdocuments.net/reader036/viewer/2022081604/56813328550346895d9a1551/html5/thumbnails/42.jpg)
C. David, IEEE Conference, Rome, 21.10.2004
Differential phase contrast imaging!
camera
beam-splitter phase grating
analyzer amplitude grating
interference pattern
phase object
Grating x-ray interferometry
![Page 43: LMN](https://reader036.fdocuments.net/reader036/viewer/2022081604/56813328550346895d9a1551/html5/thumbnails/43.jpg)
C. David, IEEE Conference, Rome, 21.10.2004
4 µm4 µm 4 µm
Phase grating (silicon, p = 4 µm)
•Si-110 wet-etched•Depth of structures chosen so that
phase shift is π no zeroth order
The gratings
![Page 44: LMN](https://reader036.fdocuments.net/reader036/viewer/2022081604/56813328550346895d9a1551/html5/thumbnails/44.jpg)
C. David, IEEE Conference, Rome, 21.10.2004
4 µm4 µm 4 µm
Absorption grating (Au in silicon, q = 2 µm)
•Au in gaps of Si grating•Grown electrochemically•Period is half that of the phase grating
The gratings
Phase grating (silicon, p = 4 µm)
4 µm4 µm
•Si-110 wet-etched•Depth of structures chosen so that
phase shift is π no zeroth order
![Page 45: LMN](https://reader036.fdocuments.net/reader036/viewer/2022081604/56813328550346895d9a1551/html5/thumbnails/45.jpg)
C. David, IEEE Conference, Rome, 21.10.2004
polystyrene spheres Ø 100 and 200 µm
Photon energy: 12.4 keVp = 4 µm q = 2 µm
BM 5, ESRF, Dec. 2002
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C. David, IEEE Conference, Rome, 21.10.2004
Absorption contrast andedge contrast
Interferometric phase contrast
![Page 47: LMN](https://reader036.fdocuments.net/reader036/viewer/2022081604/56813328550346895d9a1551/html5/thumbnails/47.jpg)
C. David, IEEE Conference, Rome, 21.10.2004
Absorption contrast andedge contrast
Interferometric phase contrast
Differential phase contrast
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C. David, IEEE Conference, Rome, 21.10.2004
Absorption contrast andedge contrast
Can be integrated to yield projected phase shift of sample
Suited for tomographic reconstruction
Interferometric phase contrast
Differential phase contrast Phase contrast
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C. David, IEEE Conference, Rome, 21.10.2004
Edge contrast vs. Interferometric contrast
Non-interferometric
Absorption andEdge contrast
Tomogram
Projection0.5mm
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C. David, IEEE Conference, Rome, 21.10.2004
Interferometric phase contrastNon-interferometric
Phase gradientAbsorption andEdge contrast Phase
Tomogram
Projection Projection
Tomogram
Projection
ID19, ESRF, June 200414.4 keV
0.5mm
Edge contrast vs. Interferometric contrast
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C. David, IEEE Conference, Rome, 21.10.2004
0.5mm
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C. David, IEEE Conference, Rome, 21.10.20041mm
0.5 mm
![Page 53: LMN](https://reader036.fdocuments.net/reader036/viewer/2022081604/56813328550346895d9a1551/html5/thumbnails/53.jpg)
C. David, IEEE Conference, Rome, 21.10.20041mm
0.5 mm
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C. David, IEEE Conference, Rome, 21.10.2004
Polychromatic radiation
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C. David, IEEE Conference, Rome, 21.10.2004
camera
beam-splitter phase grating
analyzer amplitude grating
interference pattern
phase object
λ1
Polychromatic radiation
![Page 56: LMN](https://reader036.fdocuments.net/reader036/viewer/2022081604/56813328550346895d9a1551/html5/thumbnails/56.jpg)
C. David, IEEE Conference, Rome, 21.10.2004
camera
beam-splitter phase grating
analyzer amplitude grating
interference pattern
phase object
λ1
λ2
Polychromatic radiation
![Page 57: LMN](https://reader036.fdocuments.net/reader036/viewer/2022081604/56813328550346895d9a1551/html5/thumbnails/57.jpg)
C. David, IEEE Conference, Rome, 21.10.2004
camera
beam-splitter phase grating
analyzer amplitude grating
interference pattern
phase object
λ1
λ2
Polychromatic radiation
![Page 58: LMN](https://reader036.fdocuments.net/reader036/viewer/2022081604/56813328550346895d9a1551/html5/thumbnails/58.jpg)
C. David, IEEE Conference, Rome, 21.10.2004
camera
beam-splitter phase grating
analyzer amplitude grating
interference pattern
phase object
λ1
λ2
Polychromatic radiation
![Page 59: LMN](https://reader036.fdocuments.net/reader036/viewer/2022081604/56813328550346895d9a1551/html5/thumbnails/59.jpg)
C. David, IEEE Conference, Rome, 21.10.2004
Pink-beam phase tomography
• SLS wiggler• No monochromator• Zr absorption filter 100 µm• Camera scintillator YAG:
Y absorption edge at 17.0 keVacts as high-pass filter
• Mean energy E = 17.5 keVBandwidth ΔE ≈ 1 keV
Beam conditioning:
![Page 60: LMN](https://reader036.fdocuments.net/reader036/viewer/2022081604/56813328550346895d9a1551/html5/thumbnails/60.jpg)
C. David, IEEE Conference, Rome, 21.10.2004
Pink-beam phase tomography
Three fibers• Polyamide Ø 225 µm• Boron Ø 200 µm, core: W Ø 10 µm• PBT Ø 190 µm
• SLS wiggler• No monochromator• Zr absorption filter 100 µm• Camera scintillator YAG:
Y absorption edge at 17.0 keVacts as high-pass filter
• Mean energy E = 17.5 keVBandwidth ΔE ≈ 1 keV
Beam conditioning:
Sample:
![Page 61: LMN](https://reader036.fdocuments.net/reader036/viewer/2022081604/56813328550346895d9a1551/html5/thumbnails/61.jpg)
C. David, IEEE Conference, Rome, 21.10.2004
Pink-beam phase tomography
Three fibers• Polyamide Ø 225 µm• Boron Ø 200 µm, core: W Ø 10 µm• PBT Ø 190 µm
Sample:
Edge contrast
![Page 62: LMN](https://reader036.fdocuments.net/reader036/viewer/2022081604/56813328550346895d9a1551/html5/thumbnails/62.jpg)
C. David, IEEE Conference, Rome, 21.10.2004
Pink-beam phase tomography
Three fibers• Polyamide Ø 225 µm• Boron Ø 200 µm, core: W Ø 10 µm• PBT Ø 190 µm
Sample:
Differential phase contrast
Edge contrast
![Page 63: LMN](https://reader036.fdocuments.net/reader036/viewer/2022081604/56813328550346895d9a1551/html5/thumbnails/63.jpg)
C. David, IEEE Conference, Rome, 21.10.2004
Pink-beam phase tomography
Three fibers• Polyamide Ø 225 µm• Boron Ø 200 µm, core: W Ø 10 µm• PBT Ø 190 µm
Sample:
Differential phase contrast Phase contrast
Edge contrast
![Page 64: LMN](https://reader036.fdocuments.net/reader036/viewer/2022081604/56813328550346895d9a1551/html5/thumbnails/64.jpg)
C. David, IEEE Conference, Rome, 21.10.2004
Pink-beam phase tomography
Three fibers• Polyamide Ø 225 µm• Boron Ø 200 µm, core: W Ø 10 µm• PBT Ø 190 µm
Sample:
Differential phase contrast Phase contrast
Edge contrast Edge contrasttomogram
Phase contrasttomogram
![Page 65: LMN](https://reader036.fdocuments.net/reader036/viewer/2022081604/56813328550346895d9a1551/html5/thumbnails/65.jpg)
C. David, IEEE Conference, Rome, 21.10.2004
Pink-beam phase tomography
![Page 66: LMN](https://reader036.fdocuments.net/reader036/viewer/2022081604/56813328550346895d9a1551/html5/thumbnails/66.jpg)
C. David, IEEE Conference, Rome, 21.10.2004
Required transverse coherence
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C. David, IEEE Conference, Rome, 21.10.2004
s camera
d
Required transverse coherence
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C. David, IEEE Conference, Rome, 21.10.2004
s camera
dIn our experiments:
E = 17.5 keV, => = 0.07nm
d = 28mm, => s = 1m
Required transverse coherence
![Page 69: LMN](https://reader036.fdocuments.net/reader036/viewer/2022081604/56813328550346895d9a1551/html5/thumbnails/69.jpg)
C. David, IEEE Conference, Rome, 21.10.2004
s camera
dIn our experiments:
E = 17.5 keV, => = 0.07nm
d = 28mm, => s = 1m
Transverse coherence length c:
c = * p/s
p: source distance, e.g. 2m s: source size, e.g. 100m
Required transverse coherence
![Page 70: LMN](https://reader036.fdocuments.net/reader036/viewer/2022081604/56813328550346895d9a1551/html5/thumbnails/70.jpg)
C. David, IEEE Conference, Rome, 21.10.2004
s camera
dIn our experiments:
E = 17.5 keV, => = 0.07nm
d = 28mm, => s = 1m
Transverse coherence length c:
c = * p/s = 1.4m
p: source distance, e.g. 2m s: source size, e.g. 100m
Required transverse coherence
![Page 71: LMN](https://reader036.fdocuments.net/reader036/viewer/2022081604/56813328550346895d9a1551/html5/thumbnails/71.jpg)
C. David, IEEE Conference, Rome, 21.10.2004
Summary
![Page 72: LMN](https://reader036.fdocuments.net/reader036/viewer/2022081604/56813328550346895d9a1551/html5/thumbnails/72.jpg)
C. David, IEEE Conference, Rome, 21.10.2004
Summary
• There is a large potential to reduce the x-ray dose in medical imaging by exploiting the phase shifting property of matter rather than the absorption
![Page 73: LMN](https://reader036.fdocuments.net/reader036/viewer/2022081604/56813328550346895d9a1551/html5/thumbnails/73.jpg)
C. David, IEEE Conference, Rome, 21.10.2004
Summary
• There is a large potential to reduce the x-ray dose in medical imaging by exploiting the phase shifting property of matter rather than the absorption
• Grating interferometry offers advantages compared to other phase imaging methods :
![Page 74: LMN](https://reader036.fdocuments.net/reader036/viewer/2022081604/56813328550346895d9a1551/html5/thumbnails/74.jpg)
C. David, IEEE Conference, Rome, 21.10.2004
Summary
• There is a large potential to reduce the x-ray dose in medical imaging by exploiting the phase shifting property of matter rather than the absorption
• Grating interferometry offers advantages compared to other phase imaging methods :
• Robustness • Quantitative method • Works fine at energies suitable for mammography • Requires no temporal and little spatial coherence • Has potential to be scaled up to large fields of view
![Page 75: LMN](https://reader036.fdocuments.net/reader036/viewer/2022081604/56813328550346895d9a1551/html5/thumbnails/75.jpg)
C. David, IEEE Conference, Rome, 21.10.2004
AcknowledgmentsAcknowledgments
At ESRF:
P. CloetensJ. Hoszowska E. Ziegler
and many others ...
Funding: Swiss National Science Foundation European Community
Many thanks to:
At PSIE. DeckardtF. GlausB. HaasY. HemmerlingL. HeydermanM. Lange J. Lehmann D. Meister T. Neiger B. Nöhammer T. Rohbeck
![Page 76: LMN](https://reader036.fdocuments.net/reader036/viewer/2022081604/56813328550346895d9a1551/html5/thumbnails/76.jpg)
C. David, IEEE Conference, Rome, 21.10.2004
AcknowledgmentsAcknowledgments
At ESRF:
P. CloetensJ. Hoszowska E. Ziegler
and many others ...
Funding: Swiss National Science Foundation European Community
Many thanks to:
At PSIE. DeckardtF. GlausB. HaasY. HemmerlingL. HeydermanM. Lange J. Lehmann D. Meister T. Neiger B. Nöhammer T. Rohbeck
Postdoc Position available