Nuclear Instrumentation Laboratory
Federal University of Rio de Janeiro -BRAZIL
X-ray Fluorescence and X-ray Transmission X-ray Fluorescence and X-ray Transmission Microtomography Imaging SystemMicrotomography Imaging System
G. R. Pereira(1)*, H.S. Rocha(1), M. J. Anjos (2), P. Faria(3), C. A. Pérez (4) and R. T. Lopes (1).
(1) Nuclear Instrumentation Laboratory – COPPE / UFRJ, BrazilP.O. Box 68509, 21945-970, Fax: +55 (021) 25628444, [email protected]
(2) Physics Institute - UERJ, Brazil(3) Brazilian National Cancer Institute – LNLS, Brazil
(4) Brazilian Synchrotron Light Source, Brazil
OBJECTIVE
The main of this work is to determine the elemental and absorption distribution map in tissue samples.
Nuclear Instrumentation Laboratory
Federal University of Rio de Janeiro -BRAZIL
INTRODUCTION
Nuclear Instrumentation Laboratory
Federal University of Rio de Janeiro -BRAZIL
•New techniques have been developed using excellent properties of synchrotron radiation such as high photon flux, the broad energy spectrum and the natural collimation.
•In many studies, it is necessary to analyze biological tissues with small details that have close attenuation coefficients where transmission tomography is not adjusted.
•Some properties also depend on the individual distribution of elements inside of the sample.
Nuclear Instrumentation Laboratory
Federal University of Rio de Janeiro -BRAZIL
INTRODUCTION
• In order to get the distribution of an element in particular, fluorescence properties and the tomographic techniques can simultaneously be used.
• A technique for fluorescence tomography was attempted for the first time in 1989 by Cesareo and Mascarenhas.
• Since then, several papers have been presented in this area.
INTRODUCTION
Nuclear Instrumentation Laboratory
Federal University of Rio de Janeiro -BRAZIL
• One complication of fluorescence tomography is the reconstruction calculations that are more complex than transmission tomography’s algorithm. Hogan et al (1990) proposed adapting one of the algorithms used in X-ray transmission tomography.
• The simplest algorithm is based on the classical back projection algorithm used in transmission tomography. A algorithm more accurate applies corrections for absorption before and after the fluorescence point.
INTRODUCTION
Nuclear Instrumentation Laboratory
Federal University of Rio de Janeiro -BRAZIL
• The choice for breast tissue samples was accomplished with the
world tendency to find diagnostic techniques for cancer and other
diseases.
• The fluorescence mapping of iron, copper and zinc is very
important in diagnostics.
• The biochemistry of these elements suggests that these metals may
play an important role in carcinogenesis. However, the evidence
linking iron, copper and zinc to cancer is far from conclusive.
Using X-ray fluorescence tomography it can be obtained the
elemental map of this metals without sample preparation.
For a particular element i and an atomic level , the fluorescence radiation hitting the energy dispersive detector can be obtained through integration over y’
f x y eB
y
x y dy
( , ' , ' ) ;( ', ') '
'
g x y d e
F
x y
Det
D
l dl
( , ' , ' ) ;( )
( ', ')
14
'.')','( dyNdyyxp elem
Nuclear Instrumentation Laboratory
Federal University of Rio de Janeiro -BRAZIL
)',',()','()',',(')',( 0 yxgyxpyxfdyIxI i
Translation
Beam
x
y’ y
x’
X-Ray
Beam
Fluorescen
ce
Detecto
r
D
x’ = x cos + y sin
y ’ = - x sin + y cos
Rotation
Transmission Detector
THEORY
THEORY
Nuclear Instrumentation Laboratory
Federal University of Rio de Janeiro -BRAZIL
If the solid angle defined by the detector surface is almost constant
and the attenuation is small (μB ≈ μF ≈ 0) then
cte)',',(,1)',',( gyxgyxf
-
elem
-
(x',y')dy'N'p(x',y')dyg,x')I(
In this case, the concentration of the element is proportional to the experimental projections and the usual algorithms of transmission tomography can be used for fluorescence tomography.
Nuclear Instrumentation Laboratory
Federal University of Rio de Janeiro -BRAZIL
EXPERIMENT
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RECONSTRUCTION
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EXPERIMENT
XRF
• Operation Nominal Energy: 1.37GeV• Injection Energy: 500MeV• Electron Beam Current (maximum):
250 mA• Beam Life Time: 15 h
EXPERIMENT
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Federal University of Rio de Janeiro -BRAZIL
White beam (4-23) keV
Multilayer Monochromator
Ionization Chamber
Two Sets of Slits (200μm x 200μm) and Transmission Detector
Fluorescence Detector
SampleTransmission
Detector
Fluorescence Detector
Tomography images of paper filter (right: x-ray fluorescence and left: Transmission)
RESULTS
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Tomographic images of polyethylene samples filled with a standard solutions of Cu (200 ppm) (right: x-ray fluorescence and left: Transmission).
RESULTS
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Tomography images of lung sample (top: transmission and bottom: fluorescence) (a)Fe (b) Cu, (c)Zn.
RESULTS
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Federal University of Rio de Janeiro -BRAZIL
(a) (b) (c)
X-Ray Fluorescence Tomography images of lung sample.
RESULTS
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Federal University of Rio de Janeiro -BRAZIL
Tomography images of coronary vein sample (top: transmission and bottom: fluorescence) (a)Fe (b) Cu (c) Zn.
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Federal University of Rio de Janeiro -BRAZIL
RESULTS
(a) (b) (c)
Tomography images of heart sample (top: transmission and bottom: fluorescence) (a)Fe, (b) Cu, (c) Zn.
RESULTS
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(a) (b) (c)
Normal lobular breast parenchymaCystAdipose tissue
RESULTS
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Micro cystSample of breast cancer
RESULTS
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Sample of breast cancer after chemotherapy reduction.
RESULTS
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RESULTS
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Tomography images of healthy breast tissue sample (top: transmission and bottom: fluorescence) (a)Fe, (b) Cu, (c) Zn.
(a) (b) (c)
RESULTS
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Tomography images of malignant breast tumor sample (top: transmission and bottom: fluorescence) (a)Fe (b) Cu, (c) Zn.
(a) (b) (c)
RESULTS
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Federal University of Rio de Janeiro -BRAZIL
Tomography images of benign breast tumor sample (top: transmission and bottom: fluorescence) (a)Fe (b) Cu, (c) Zn.
(a) (b) (c)
RESULTS
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Federal University of Rio de Janeiro -BRAZIL
Normalized Fe fluorescence counting in 30º and 31º projection
1020 1035 1050 1065 10800.000
0.001
0.002
0.003
0.004
0.005
0.006
0.007
Sum Ray of the 30O and 31O projection
NO
RM
AL
IZE
D F
e F
LU
OR
ES
CE
NC
E benign tumor malignant tumor normal tissue
Iron
RESULTS
Nuclear Instrumentation Laboratory
Federal University of Rio de Janeiro -BRAZIL
Normalized Cu fluorescence counting in 30º and 31º projection
1020 1035 1050 1065 1080
0.0000
0.0001
0.0002
0.0003
0.0004
0.0005
Sum ray of the 30Oand 31o projection
NO
RM
AL
IZE
D C
u F
LU
OR
ES
CE
NC
E benign tumor tmalignant tumornormal tissue
Copper
RESULTS
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Federal University of Rio de Janeiro -BRAZIL
Normalized Zn fluorescence counting in 30º and 31º projection
1020 1035 1050 1065 1080-0.0002
0.0000
0.0002
0.0004
0.0006
0.0008
0.0010
0.0012
0.0014N
OR
MA
LIZ
ED
Zn
FL
UO
RE
SC
EN
CE
Sum ray of the 30Oand 31Oprojection
benign tumormalignant tumornormal tissue
Zinc
CONCLUSION
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Federal University of Rio de Janeiro -BRAZIL
We have shown that was possible to visualize the distribution of high atomic number elements on both, artificial and tissues samples. It was possible to compare the quantity of Zn, Cu and Fe for the breast tissue sample and was verified that these elements have a higher concentration on malignant tumor than normal tissue.
CONCLUSION
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Federal University of Rio de Janeiro -BRAZIL
It will be necessary to measure more samples and quantify the difference in concentration in one sample and between normal and abnormal tissues to use the X-ray fluorescence microtomography as an analytic tool to analyze biological tissues.
CONCLUSION
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Federal University of Rio de Janeiro -BRAZIL
The better definition of the interfaces in X-ray fluorescence images was striking and the spatial resolution of the system can be optimized as a function of the application. The experimental set up at XRF-LNLS has shown to be very promising and this effort at implementing X-ray fluorescence microtomography wasjustified by the high quality of the images obtained.
ACKNOWLEDGEMENTS
This work was partially supported by the National Center for Science and Technology Development (CNPq), Rio de Janeiro State Research Foundation (FAPERJ) and Brazilian Synchrotron Light Laboratory (LNLS).
Nuclear Instrumentation Laboratory
Federal University of Rio de Janeiro -BRAZIL
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