Phase Contrast Imaging with X-ray tube

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1 Phase Contrast Imaging with X-ray tube Institute for Roentgen Optics /IRO/, Moscow Vladimir Shovkun and Muradin Kumakhov Proc. SPIE v.5943, 2005 Institute for Roentgen Optics. Vladimir Ya. Shovkun. 1

2 Phase-contrast (PC) imaging δ~ ρ λ 2, ρ -density [g cm -3 ], λ -wavelength [Å] Cph ~ ρ, ρ -density variations Λ~ λ Ro/S Spatial coherence length Λ 2.8 μm (R 0 =0.4m, S =0.01mm and λ =0.71Å) Institute for Roentgen Optics. Vladimir Ya. Shovkun. chovkoun@mail.ru 2

3 Practical Application of PC-imaging Radiographic image of fish air bubbles X-ray tube /IRO-product/ Mo-target U=30kV I=0.9mA R 0 =20cm R 1 =39 cm X-ray film: AA-400 Exposure: 300sec Institute for Roentgen Optics. Vladimir Ya. Shovkun. chovkoun@mail.ru 3

4 Practical Application of PC-imaging Radiographic image of a small fish (5 cm in length). Institute for Roentgen Optics. Vladimir Ya. Shovkun. chovkoun@mail.ru 4

Practical Application of PC-imaging The fish ribs with 0.1 0.2 mm in thickness have the edge enhancement visibility. Ribs=Model of micro calcifications.

5 Practical Application of PC-imaging The fish ribs with mm in thickness have the edge enhancement visibility. Ribs=Model of micro calcifications. X-ray tube /IRO/ Mo-target: U=30 kv i=0.3 ma R 0 =30 cm R 1 =90 cm X-ray film: SR-45 EXPOSE: 13minutes Institute for Roentgen Optics. Vladimir Ya. Shovkun. chovkoun@mail.ru 5

6 Practical Application of PC-imaging Image of joint weld for AL-Li alloys. Cracks and Inclusions. SCALE 1 millimeter Boundaries of slag inclusions in Al-Li matrix (thick 6mm) are clearly seen in radiograph. X-ray tube /IRO product/ was operated at: U=37kV (Mo-anode) and I=0.6mA. Ro=30cm. R 1 =60cm. SR-45 X-ray film. Exposition=1hour. Institute for Roentgen Optics. Vladimir Ya. Shovkun. chovkoun@mail.ru 6

Cellular metal: hollow sapphire spheres Intensity, ADU. 3,6k 3,2k 2,8k 2,4k 2,0k 0 75 150 225 300 Distance, Arb.Units. Three sapphire balls: Al 2 O 3. The CCD-camera.

7 Cellular metal: hollow sapphire spheres Intensity, ADU. 3,6k 3,2k 2,8k 2,4k 2,0k Distance, Arb.Units. Three sapphire balls: Al 2 O 3. The CCD-camera. Edge-enhancement visibility of balls boundaries. Diameter of balls 0.1mm. U=38kV (Mo-anode), I=1.2mA, R 0 =17cm, R 1 =74 cm, exposition: 11sec. There is an enhancement of the X-ray flux in the center of the upper ball (i.e. X-ray lens). Institute for Roentgen Optics. Vladimir Ya. Shovkun. chovkoun@mail.ru 7

8 Practical Applications /summary/: Histological investigation of thin specimen: thick 1cm and more. Core needle biopsy specimen radiography: thick 1mm and more. Detection of microcalcifications (ρ=3 [g cm -3 ]and ρ =2 [g cm -3 ] in breast tissue ) as a early stage of cancer. Control of cracks and inclusions in light materials (Be, Li, Al, Si and so on). Perspective of full field PC-mammography development : -field of view 18x24 cm -an average thick of breast 4.2cm -max. thick of breast 10 cm -exposition < 6 sec (to avoid motion artefact ) -entrance dose < 0.01 Gy (1R) Institute for Roentgen Optics. Vladimir Ya. Shovkun. chovkoun@mail.ru 8

9 Phase contrast imaging (PCI) Monochromator Image plane, X-ray films 1991 Somenkov V.A Ingal V.N. Disadvantage: Low efficiency of scheme ~ X-Ray Tube Object Crystalanalyzer IN LINE HOLOGRAPHY : 1995 Snegirev A Wilkins S.W. Mammography application: 1999 Kotre C.J Ohara H Wu X Donnelly E.F. Disadvantages: 1. Impractically large distances R 0 and R 1 ; Low flux. 2. Low brilliance of X-ray tube used. Institute for Roentgen Optics. Vladimir Ya. Shovkun. chovkoun@mail.ru 9

10 Characteristic features of PC-mammography experiments; cnv=conventional P, kw X-ray tube S, mm R, m Resolution micron Testobject C ph % 0.94mm Kotre C.J. cnv Mo. 28kV 0.7x Perspex. +Phantom 6cm Donnelly E.F. 40kV mm Lucite. 10 W. 0.12mm Wu X kV Plastic. +BR12 2cm. Plastic Ohara H. cnv W Diam. 8mm 15 50kV Institute for Roentgen Optics. Vladimir Ya. Shovkun. chovkoun@mail.ru 10

11 Measurements of the PC- signal Mammography: Experiment and Theory RADIOGRAPHIC IMAGE OF FIBERS WITH DIAMETERS: 0.14mm and 0.045mm Institute for Roentgen Optics. Vladimir Ya. Shovkun. 11

12 Systematic evaluation of PC-signal EXPERIMENT THEORY Optical density, OD. 0,60 C 0,58 ph 0,56 C abs Intensity, arb. unit. 1,08 1,05 1,02 0,99 energy= kev source size=0.03 mm resolution=0.03 mm R 0 =30cm, R 1 =60cm 0,54 0,0 0,4 0,8 1,2 1,6 Image plane, mm. 0,96-0,4-0,2 0,0 0,2 0,4 Image plane, mm. Experimental Results for fiber 0.14 mm without phantom: Cph = 2.9 ± 0.4% Cabs = 2.2± 0.4% with phantom : Cph = 2.5 ± 1.2% Cabs = 1.6± 1.2% Theory: Cph = 4.4% Cabs = 0.9% Institute for Roentgen Optics. Vladimir Ya. Shovkun. chovkoun@mail.ru 12

13 Theoretical estimation of the phase-contrast signal: C PH for different values of source size, detector resolution and incoming x-ray spectra. In calculations of PC- signal (C + ph ) we assumed: - X-ray tube with Mo-anode (U=30 kv); -the source-object distance R 0 = 6 cm; -the object-detector distance R 1 = 53 cm; - diameter of PMMA-fiber = 0.045mm. # Input data for calculations Results Energy range, kev Source size, microns Detector resolution, microns Phase-contrast signal, C + ph % Infinite Infinite , Institute for Roentgen Optics. Vladimir Ya. Shovkun. chovkoun@mail.ru 13

5cm R 0 =20cm R 1 =16cm Exposition:~2 sec Exposure load: ~4 ma*sec B) Future work:

14 Development of X-ray tubes in IRO A) Presented work: Power=70W Focal spot size < 50micron Resolving Power [pairs line/mm] Breast phantom CIRS 11 Thickness= 4.5cm R 0 =20cm R 1 =16cm Exposition:~2 sec Exposure load: ~4 ma*sec B) Future work: Power=200W and focal spot size=30micron Institute for Roentgen Optics. Vladimir Ya. Shovkun. chovkoun@mail.ru 14

15 Comparison of a conventional mammography unit with the developed phase-contrast radiographic apparatus. 1. Field of view 2. Power load 3. Detection of microcalcification Conventional mammography unit 24 x 18 cm 5 2kW mm practical threshold Phase contrast mammography Large field/small field 15 x 10cm/ø 3-5 cm 0.5kW? /0.1 kw 0.1mm? / mm design study/ under study 4. Contrast. Theory 5. Exposure load* ) 6. R o R 1 4% for 0.1mm microcalcification 25 ma sec 56cm 1cm 4% for 0.1mm microcalcification 4mA sec 20cm 16cm * ) Data for the breast phantom CIRS 11 with thick 4.5cm Institute for Roentgen Optics. Vladimir Ya. Shovkun. chovkoun@mail.ru 15

16 The Apparatus The apparatus consists of a micro focus X-ray tube (left), the water phantom with fibers and the X-ay film detector. Institute for Roentgen Optics. Vladimir Ya. Shovkun. chovkoun@mail.ru 16

17 Conclusions Theoretical approach was developed and experimentally proven. Phase contrast images of thin PMMA fibers can be obtained under short the sourceobject distance (6cm) and object-detector distance (30cm) in the presence of additional scattering (water phantom). It is shown that the detection threshold is 0.045mm for the density difference of 1g/cm 3. Further development of high brilliance X- ray tubes is important for phase contrast radiography and other applications. Institute for Roentgen Optics. Vladimir Ya. Shovkun. 17

Phase Imaging Using Focused Polycapillary Optics

Phase Imaging Using Focused Polycapillary Optics Sajid Bashir, Sajjad Tahir, Jonathan C. Petruccelli, C.A. MacDonald Dept. of Physics, University at Albany, Albany, New York Abstract Contrast in conventional