Study of Phase-Dispersive X-Ray Imaging Tomomi Ohgaki and Ichita Endo (Hiroshima Univ.)
Plane wave passing through the object X-Ray Imaging Equipments Absorption Contrast Method ( Usual ) Phase Contrast Method For Medical application Early diagnoses of breast cancer Imaging for living soft tissues Study of Phase-Dispersive X-Ray Imaging
Cross Section of X-Ray Absorption and Phase Shift Phase Contrast Phase shift of light elements 1000 times higher than absorption Radiation dose by phase contrast imaging can be reduced. Phase Shift Atomic Number Cross Section (cm 2 ) X-ray Energy 8.3 keV 13.5keV 24.8keV 62.0keV Absorption
Setup for X-Ray Phase-Dispersive Measurements X-Ray Tube Characteristic X-Ray 60 ~ 70 keV Target W,Re,Au Monochrometor Silicon single crystal Asymmetric Bragg Diffraction Crystal Analyzer Silicon single crystal Higher order diffraction Maximum contrast by rotating Crystal analyzer X-Ray Detectors Imaging plate several 10 m Emulsion several m X-Ray CCD several 10 m Transmission, Reflection X-Ray measurements
Reflection and Transmission Intensities W K -Line (59.3keV) Crystal analyzer Si(422) thickness 560 m Rotating crystal analyzer rotation angle No object case
Transmission Intensity W K -Line (59.3keV) Crystal analyzer Si(422) thickness 560 m Object (Prism, base 2mm, base angle 45degree) d dx
W K -Line (59.3keV) Crystal analyzer Si(422) thickness 560 m Object (Prism, base 2mm, base angle 45degree) Reflection Intensity
Reflection and Transmission Intensities W K -Line (59.3keV) Crystal analyzer Si(422) thickness 560 m Object (Prism, base 2mm, base angle 45degree) x rad ( =-0.70)
Arteries of mouse (V.N.Ingal et al.,1998 ) Veins of leaf (S.Wilkins et al., 1998) Samples of Phase Contrast Method
Medical application, Electronics, Aerospace, Food industries Medical diagnoses … breast cancer, malignant tumors Search for impurity objects in Foods Study of Biology Search of oil …fluid mechanics Investigation of object of art or craft object Investigation of new materials like ceramics or fiber Approach to Venture Business
Simulation by Dynamical Diffraction Theory Crystal surface Disagreement between analytical formulas and experimental results where d /dx is large changeable. X -Ray Solve Takagi-Taupin equations using Simulation. Reflection X-Ray Transmission X-Ray
Simulation code CPRI X-ray tube or SOR light : Target size, current, voltage Slit : Transfer matrix Monochromator : Asymmetric Bragg diffraction Object : Linear absorption coefficient, refractive index Crystal analyzer : Takagi-Taupin eqs. Detector : Detection area, Detection efficiency Purpose : Calculate Phase Radiological Imaging
Intensity of one photon incidence Crystal surface Si Crystal Crystal surface Incident X-Ray
Intensities by Simulation
Prototype experiments
Prototype Products
X-Ray Tube 22.5mA 55kV Target Mo
Imaging plate
Imaging Plate Reader Rigaku R-AXIS-D53
Prototype experiments Asymmetric Bragg Diffraction Ge crystal (115) b= Laue case Ge crystal(220) thickness200 m Mo K 1 -line w= keV Polypropylene =0.95g/cm 3
Rocking curve from crystal analyzer Laue case =295 rad =329 rad Ge (220) =27.4 rad x =820 rad y =13mrad
Transmission Image of Polypropylene =+160 rad =-160 rad 0 rad
Rocking curve from crystal analyzer Bragg case =235 rad Si (220) =10.9 rad
Reflection Image of Polypropylene 0 rad
We have done the prototype experiments for PDI. We have made the simulation code for PDI. Now Hiroshima group will study PDI with Betatron. 「位相コントラスト X 線撮像装置」大垣智巳、遠藤一太、特願 (July 11, 2001) "Simulation code for phase radiological imaging using dynamical theory” T.Ohgaki and I.Endo Summary
REFER Hiroshima Univ. got RF cavity Beam life time is 4min.