10/2/2008

Basics of X
X--ray Imaging
Imaging with Synchrotron
Light
Rob Lewis
Monash University
Australia

General Radiography

Hierarchy of Biological Organisation■ 2-D image from 3-D
object (patient)■ Organismm■ Organ System m■ Organcm■ Tissuemm■ Cell10μm■ Organelle
1μm■ Macromolecules 100nm■ Molecules
0.1nm■ Map of attenuation foreach photon path
■ Essentially an imageof density, or structure

Imaging Requirements

Conventional Radiography■ High spatial resolution♦ Preferably sub cellular (μm)

■ High temporal resolution♦ Cell kinetics, Chemokinetics (ms to μs)■ Highi h anatomical
i l contrast■ Specificity for tracers110/2/2008

X-ray Spectra

Albert Einstein

Nobel prize inphysics 1921

Flux (photons/ 1keeV(bw)/mA/mm2(@1m)/sec

70000"for his services to
Theoretical Physics,
and especially for his
discovery of the lawof the photoelectriceffect"

100kVp 0mmAl
60000
50000

Soft X-rays

40000

Photoelectric EffectHard X-rays

30000

Germany and Switzerland
Kaiser-Wilhelm-Institut(now Max-Planck-Institut)
für Physik
Berlin-Dahlem, Germany
1879 - 1955

20000

Photoelectron

e-

10000
+
+ ++
+ +

0
0

20

40

60

80

100

120

K fluoresence
X-ray E~Ek-

Energy (keV)

X-ray photon λ1-

Arthur Holly Compton

Nobel prize inphysics 1927
"for his discovery of
the effect named
after him"

Compton Effect

University of Chicago
Chicago, IL, USA
1892 - 1962

X-ray photon
λ2 > λ1
+
+ ++
+ +

X-ray
photon λ1

φ
-

-

Δλ =

h
(1− cosϕ )m0cWater Attenuation Coefficients■ Photo electric falls rapidly
with increasing energy■ Compton scatteringroughly constant■ Coherent scattering falls
with
ith increasingii energy
but less rapidly thanphotoelectric (important
see later)e-Radiographic Imaging

Interaction of XX-rays & Matter
Detector

Patient
Transmitted X-rays■ Interaction with matter (human tissue)♦ Scattering (loss of energy & direction change)♦ Absorption (energy transferred to tissue)■ Scattering + absorption = attenuation

X-ray tube

IS (scattered)Absorbed X-rays

Io(incident)

It (transmitted)

SourceScattered X-rays

Detector
Object2

10/2/2008

X-ray Attenuation

X-rays and Contrasttμ(x, y)IosourceIt
detector

objectμ1

μ2■ Difference in attenuation
coefficients generates
contrast■ μ1 < μ2■ Scatter reduces contrast■ Homogeneous: It = Io exp -[μt]■ Inhomogeneous: It = Io exp -[Σμ dt]■ ln (Io/ It) = loge (Io/ It) = μt = attenuation/ray-sum

Transmitted
Intensity■ μ = linear attenuation coefficient (cm-1)

Air Gap

Scatter in Medical Imaging
Contrast & CNR

100.0%

10.0%

1.0%
Contrast

0.1%
0.001

Examination

EnergyChest

120 kVp

Abdomen

80 kVpMammography

30 kVp (Mo)

0.01

0.1

SPR

1

10

Field Size (cm) Antiscattermechanism
30 x 30
6.7 cm air gap
20 cm air gap

ScatterTotal/
Primary
2.3

ScatterCoherent /ScatterTotal
0.12

1.2

0.11

2.7

0.26

Grid

0.34

0.075

Grid

0.6

0.24

17 x 1712 cm diam

100

Air Gap

Use of Grid to Remove Scatter■ Air gap is good because
r1

■ But
♦ Increases the effect ofr2

Patient♦ No mechanics♦ No increase in dose

Grid

Detector

X-ray tube

penumbralb l blurring
bl i♦ Blurring=f r2/r1 where f is
the size of the focal spot
♦ For f = 0.5mm & r1=1m
blurring= 5×10-4 r2♦ This translates into a lateral
coherence of 0.1μm

310/2/2008

Effect of Antiscatter Grid.

Contrast

Fluoroscopic images of an anthropomorphic abdominal phantom

Bone

SurroundObject

0.5cm

0.5cm

Brain

12cm

10cm

Soft tissue

0cm

2cm

Intensity (phts/pix)

Scatter/Primary=0

155.6
155.5
155.4
155.3
155.2
155.1
155
154.9
154.8
154.7
154.6
154.5
1

4

7 10 13 16 19 22 25 28 31 34 37 40 43 46 49
Position (pix)Intensity (phts/pix)

Scatter/Primary=3

With Grid

Without Grid

155.6
155.5
155.4
155.3
155.2
155.1
155
154.9
154.8
154.7
154.6
154.5
1

4

7 10 13 16 19 22 25 28 31 34 37 40 43 46 49
Position (pix)JP Taubel, B A Schueler, TJ. Vrieze, JE. Gray Radiographics. 2001;21:507-518■ Grids reduce x-ray scatter■ Grids improve film contrast & resolution■ Grids increase patient dose

Noise

SurroundObject

Bone

0.5cm

0.5cm

Brain

12cm

10cm

Soft tissue

0cm

2cm

156

Noise=1
Intensity (phts/pix)

Use of grids

155.5

155

154.5

154
1

4

7 10 13 16 19 22 25 28 31 34 37 40 43 46 49
Position (pix)156

Intensity (phts/pix)

Noise=3

155.5

155

154.5

154
1

4

7 10 13 16 19 22 25 28 31 34 37 40 43 46 49
Position (pix)Counting Statistics■ Photons are quantised and hence subject to probabilities■ The Poisson distribution expresses the probability of anumber of events occurring in a time periodnk e−n■ If the expected number is n thenP(n, k ) =k!
■ The mean of P(n,k) is n
■ The variance of P(n,k) is n
■ The standard deviation is √n■ Fractional error = (√n)/n=1/√n■ As n increases, uncertainty and noise decrease

Photon Noise (Quantum Mottle)
2.5mGy250μGy25μGySimulated images of a 1mm thick Aluminium disc in 20cm of water recorded by aperfect detector
Illumination = Tungsten anode operated at 120kVp with 3mm Al filtration
Entrance doses as shown4

10/2/2008

Effect of Resolution

Contrast Detail Curve

120

100

1 pixe l
5 pixe l
10pixe l

60

40

Obje
ect Contrast

2 pixe l

80

Objects Visible

20

Objects Invisible

0-20
PositionObject Size

Contrast, Resolution & NoiseRadiography and Dose

■ Noise degrades image■ Transmitted X-rays deposit no dose
■ Absorbed X-rays deposit dose
■ Scattered X-rays also deposit dose.

♦ Arises from many things● No of photons, i.e. source● Scatter, age, processing■ Resolution♦ Specifies how sharp an image is♦ Specified as● As distance between features, d (mm)● As LPPM (line pairs per mm), d-1 (mm-1)● As MTF, in LPPM at given percentage MTF■ Contrast - ability to differentiate regions♦ Grey scale regions GA and GB♦ Contrast, C = 100*(GA - GB)/(GA + GB) %X-ray DoseHow Does Radiation Interact with the Body?

■ Exposure■ When ionising radiation is absorbed in the body it can create freeradicals which may alter normal cell function

♦
♦
♦
♦

Quantity of X-rays as measured by ionisation in air is exposure
Kinetic Energy Released in Matter (KERMA)
Units are C kg-1
Old unit is the Roentgen (R) (1R=2.58×10-4 C kg-1)♦♦♦■ Dose♦ Energy absorbed♦ Units are J kg-1 = Gy

● Nb. DNA repair mechanisms

Old unit is the rad. (1 rad =0.01Gy)■ Equivalent dose♦♦♦♦

E.g. DNA damage leading to genetic mutations
At high doses (> 1 sievert) this can result in massive cell death, organ damage anddeath to the individual.
At low doses (less than 50 mSv) the situation is more complex

Not all types of radiation cause the same biological damage per unit dose
Unit is the Sievert
Old unit is the rem (1 rem=0.01Sv)
Equivalent dose H(Sv)=wR(Sv)×D(Gy)For X-rays wR=1

■ A dose of one millisievert♦

Individual♦

A large population● A chance of 6 in 100,000 of contracting cancer● Compare with normal lifetime cancer incidence of 25,000 cases per 100,000● Will produce two cases of severe hereditary effects per million births● Compare with the normal incidence of severe congenital abnormalities which is 23,000
per million births

510/2/2008

Man's Exposure To Ionizing Radiation
Source Of Exposure

Exposure

Natural Radiation (Terrestrial and Airborne)

1.2 mSv per year

Dose Deposited in Soft Tissue
Mass energy absorption coefficient
Mass attenuation coefficient
Dose / photon

Natural Radiation (Cosmic radiation at sea level)

0.3 mSv per year

Total Natural Radiation

1.5 mSv per year

Seven Hour Aeroplane Flight0.05 mSv

Chest X-Ray

0.04 mSv

Nuclear Fallout (From atmospheric tests in 50's & 60's)

0.02 mSv per Year

Chernobyl (People living in Control Zones near Chernobyl)

10 mSv per year

Cosmic Radiation Exposure of Domestic Airline Pilot

2 mSv per year

Attenuation coeffficient (cm 2/g) andKERMA
A/photon

100

10

1

0.1

0.01
10

Energy (keV)100

http://www.arpansa.gov.au/is_rad.htm

3rd Generation CT Scanner

Projection and the Radon transform
Equation of this line l is:■ Multiple detectors■ Translation-rotation■ Large fan beam
■ Patient stationary foreach 2-D slice
acquisition; about 1-2
seconds per slice■ kV = 120, mA = 500■ Image thenreconstructed in about
1-2 seconds

FBP in PracticeS = x sin(θ ) − y cos(θ )yf ( x, y )xθg (θ , S ) = ∫ f ( x, y )dlg (θ , S )0l

Detector

Volume CT image
Uses 3rd or 4th generation scanner.
Continuous patient motion.

Often with multi-slice detector arrays.
Affords “true” 3-D volume images.

6

10/2/2008

Beam Harding Artefacts

Beam Harding Artefacts

Image of uniform phantom

Cone Beam Artefacts

Synchrotron Differences

Inner detector row image

Outer detector row image

Synchrotron Radiography
Scanning motion

SR Radiography
Detector

Scatteredradiation

Front slits

Rear slits

SampleDetector
S h tSynchrotron

S hSynchrotron
Monochromator7

10/2/2008

Mouse CT

Synchrotron
Advantages

Disadvantages■ Monochromatic♦ No beam hardening artefacts■ Parallel beam
♦ No cone beam artefacts♦ Reduced scatter■ High Intensity♦ High speed■ Source cannot be rotated♦ Object must be rotated which
limits speed of CT■ Beam height is limited,
especially at high energies♦ Object
Obj may hhave to bbe scannedd♦ Limits size of object and/or time
resolution

David Parsons and Karen Siu

Mouse Cochlea

Mouse Fly ThroughDavid Parsons and Karen Siu

Mouse CT

Kaye Morgan

Rabbit Pup CT

David Parsons and Karen Siu

810/2/2008

Rabbit Pup CT Still

Advantages of synchrotron micro
micro--CT
12 hrs

0.5 hrs

VIFM-427

SkyScan 1072 (Desktop) 7 μm

Spring8 (Synchrotron) 12 μm

Thanks to Rob Lewis and his team from MCSS for the help with acquiring this data.

David Cooper, UBC; David Thomas, Melbourne

The Search for Contrast

Soft Tissue Contrast
10

Water
MuscleAttenationn coefficient (cm‐1)

Lung
AdiposeBlood
Breast1

0.1
10Absorption gives us little

The Use of Contrast Agents
10000

Water ‐ Bone
Water ‐ Muscle
Water ‐ Lung
Water ‐ Adipose
Water ‐ Blood
Water ‐ Breast

40

20

0
10

100

‐20

Water

1000

Attenation cooefficient (cm‐1)

60

Attenation coefficie
ent difference (cm‐1)

100

Energy (keV)

Bone
100

MuscleLung

10Adipose
Blood

1

‐40

BreastIodine‐60

Energy (keV)

0.1

Gold
10

100
Energy (keV)910/2/2008

Dual Energy Digital Subtraction

Kidney Movie (Mouse)

High

Low

W. Thomlinson

Pulmonary Hypertension (Mouse)

James Pearson, Physiology

Tracking Cells inin-vivo■ C6 glioma cells
labeled with gold
nano-particles■ Cell implantation♦ small volume injected
over extended time
period♦ minimal mechanicalinjury fromJames Pearson, Physiology

Rat 3: 600000 cells, 14 days incubation

U. Saskatchewan, Sincrotrone Trieste , Monash University, Charles Gardiner Hosp.

U. Saskatchewan, Sincrotrone Trieste , Monash University, Charles Gardiner Hosp.

Spinal Column

U. Saskatchewan, Sincrotrone Trieste , Monash University, Charles Gardiner Hosp.

1010/2/2008

Scatter processes in biological tissue

Radiographic imaging

1

Fraction of total
scattering power as afunction of x-ray energy

X-ray

Detector (film)

generator

objectμ,ρFraction of total sca
attering power

I0

Slit system
z0

−

0.1

I (x, y) = I 0 ⋅ e

∫ρ

−z
0

z

μ ( x,y,z)⋅ ρ ( x, y,z)⋅dz( x,y,z)

= E*E

⎛ 2⋅π
⎞
−i ⋅ x⋅⎜− na ⋅r0⋅λ⋅ f1 +ω⋅t + i ⋅na ⋅r0⋅λ⋅ f2 ⎟⎠⎝ λ

E= E ⋅ e

Coherent scatter
Incoherent scatter
Photoelectric scattermeasures intensity I

0

phase

Phase shift ~ f1
scattering angle ~ ∇f1

μ

0.01
10

20

30

40

50

60

70

80 90 100

Energy (keV)

Ralf Menk, Elettra

Complex Refractive Index
Breast Tissue

Refractive index
η = 1- δ -iβ

10-6
delta
beta

10-7

Delta and beta

Refraction

Where β = absorption
δ = phase shift

10-8

Nb.
δ ~ 1000 βδ ~ E-2
β ~ E-4

10-9
10-10
10-11
10-12
10-13
15

20

25

30

40

50

60

70 80

100

150

Energy (keV)

Phase Contrast 1: ABI

Analyser Based Imaging
Sometimes called Diffraction Enhanced Imaging

11

10/2/2008

Crystal Rocking Curve
Low Angle
Side

Beamline Camera

High Angle
Side

1.00

ΔΙ/Ι~0.1

0.80

Relative Intensity I/Io

δz~0.4μrad

0.60

RL

RH

0.40

0.20

0.00
-10

-5
0
Analyzer Angle (μradians)

510Rocking CurveABI How it works

Relative Intensity I/Io

1.00

1.6
1.4
1.2
1
0.8

Refractive index for X-rays is less than 1 by about 1 part in a million

0.6

0.60

0.40

0.20

0.00
-10

Minus
0.4

0.80

-5

0

5

10

Analyzer Angle (μradians)

Plus

0.2

Energy = 25keV

00

ABI Mathematics

100

200

300

400

500

TORMam Conventional■ IL & IH = Intensities on
low and high angle sides Givenof rocking curve
IL IR⋅ ( RL + GradL⋅ Δθ Z)■ GradL & GradH =Gradients of low and high IH IR⋅ (RH + GradH⋅ Δθ Z)
angle sides of rocking⎛⎜ GradH⋅ IL − GradL⋅ IH ⎞⎟
curve

(

■ IR is intensity■ Δθz= refraction angle)⎜ GradH⋅ RL − GradL⋅ RH ⎟⎟IH⋅ RL − IL⋅ RH⎜⎟⎜ GradH⋅ IL − GradL⋅ IH ⎟⎝⎠Find IR , Δθ Z → ⎜SimulatedbreasttissueSpectrum = Mo:Mo 28kVp

12

10/2/2008

TORMAM Peak

TORMAM Refraction

Energy = 20keV

Energy = 20keV

ABI vs Slot Scanning

Human Finger

1.0

Conventional

0.9

Image
e Score0.8

Synchrotron
ABI

0.7

Peak of Analyser

Refraction

Synchrotron
Slot scanning

60%

0.6

50×

0.5

Conventional

0.4
4 5 6 7 80.1

Liver
Conventional2

3 4 5 6 7 81.0

2

3 4 5 6 7 10.0

2

Mean Glandular Dose (mGy)

Femur head core cuts

Peak of Analyser
Refraction

transmission image

apparent absorption image

refraction image

Sharmila Majumdar and Ahi Sema Issever , University of California, Luigi Rigon Univ.
Trieste13

10/2/2008

Imaging Setup

Laue analyser crystal■ Beamline 20B2, Spring-8, Japan.
■ 25 keV beam of highly coherent radiation.

θB

HUTCH 3~206 m■ 100 μm thickSi(1,-1,0) surfacecut designed for
25 keV X-ray
beam
15 cm
CCD

y
SPring-8
Bending Magnet
Source23 cm

xz

Si(111)
Monochromator

92 cm

Si(111)
Sample Analyser

Detectors

Marcus Kitchen, Monash University

Laue based ABI of Rabbit

Rocking Curves and their Ratio■ Refraction angle image

Si(111) RC 25keV
0.3

10000
9000

0.25

I D ,T = I O RD ,T (θ )7000

(Geometrical Optics Approximation)

0.2

6000

Diffracted

I D I O RD (θ ) RD (θ )==I T I O RT (θ ) RT (θ )

5000

0 15
0.15

Transmitted
Ratio

4000

Use RC ratio with linear fit between points
3000

Rockingg Curve Ratio

Intensitty (arb. units)

8000

0.1

to determine θ given the reflectivity ratio.

2000■ Apparent absorption
image

0.05

1000
0

0
-55

-50

-45

-40

-35

-30

-25

-20

-15

-10

-5

0

5

10

15

20

25

30

35

40

45

50

55

Theta (micro radian)

From Phase to Absorption■ Exp=0.3 s, Int=2 s, 20 fps

Phase Contrast 2: Interferometry■ Back to the phase, andelectron density∂∂⎡⎤
I DEI (X, Y) = I IN (X, Y)⎢R( −ξ 0 ) + R' (ξ − ξ 0 )log e I IN (X, Y)⎥
ϕ IN (X, Y) − α
∂X
∂X
⎣
⎦

⎡
⎛ ⎛ S ⎞ ⎞ ⎛ ⎛ S ⎞ ⎞ I (X, Y) ⎤⎛S⎞
ϕ IN (X, Y) = ∫ dX ⎢ − Re⎜ ⎟ + sgn⎜ Re⎜ ⎟ ⎟ ⎜ Im⎜ ⎟ ⎟ + OUT 2 ⎥
⎢
⎥
⎝T⎠
I0 T
⎝ ⎝ T ⎠⎠ ⎝ ⎝ T ⎠⎠⎣⎦2

D. Paganin, T.E. Gureyev, K.M. Pavlov, R. A. Lewis and M. Kitchen, “Phase retrieval using coherent imaging systems with linear
propagators”, Optics Communications, 234(2004) 87-105

1410/2/2008

Interferometry

An xx--ray interferometer

A. Momose et al

Interferometry

Phase Contrast 3: Propogation BI
Histopathology slice

Rabbit liver with cancer. Phase contrast at 17.7keV

Propagation Based Imaging

Phase Contrast

127cm
107cm
147cm
87cm
67cm
47cm
27cm
17cm

■ Contact:

NF =

d2
λz

♦
♦

NF >> 1
NF >> 1

Fresnel approximation

The image loses more and more resemblance with the object.

■ Far field:♦

Geometric approximation

Contrast is given by sharp changes in the refractive index, i. e. at interfaces.

■ Intermediate field: NF ~ 1♦

Geometric approximation

The intensity distribution is a pure absorption image.

■ Near field:

NF << 1

Far: Fraunhöfer approximation

The image is the Fourier transform of the object transmission function
Timm Weitkamp ESRF ID2215

10/2/2008

Using SR light characteristics■ Coherence♦ The coherence length is less than a micron on older
sources but at third generation sources gets up to
100’s of microns.
♦ This opens up potentials for several coherence
imaging techniques.

Mouse and Nebuliser

Phase contrast imaging techniques
So far:■ Interferometry – Phase directly■ Analyser based imaging – Gradient of the
phase
h
(diff
(differential
i l ∇φ)φ)■ Propagation based imaging – Laplacianof the phase (second order differential∇2φ).

Bead Tracking

David Parsons and Karen Siu

A Case Study: Lung Imaging

David Parsons and Karen Siu

Rabbit Lung

Contact

3m

16

10/2/2008

Glass Spheres BL20XU

Refractive lenses?

■ 10 mm thick lung: Alveoli ~ 60 µm ø
Pixels 6μm
EnergyR2
Spheres

Pixels 0.6μm

20 keV
1.45m
45-75μm♦ Max number of aligned spheres is ~ 150■ At 33 keV, assuming ~ 50% aligned♦ Max number of aligned spheres is ~ 75

■ Consequently fm ~ 0.7 m.
N. Yagi, K. Uesugi, SPring-8

Birth:
One of the greatest Physiological challenges

Artificial Ventilation■ During fetal life the future airways of the lungs are liquid-filled■ At birth lungs must rapidly transform from being liquid to air filled■ How this happens is poorly understood but the process♦♦

Develops late in pregnancy
Is initiated by labour■ Preterm and caesarean section infants can develop problems■ LackL k off clearancel♦♦♦Requires weeks of assisted ventilation (>$2,000/day)~30% develop chronic lung disease
Incidence is increasing■ Our ability to study the problem has been greatly inhibited by thelack of a suitable imaging modality

Surfactant

Post Mortem Artificial Ventilation17

10/2/2008

Rabbit Pup Post Mortem Pneumothorax

Phase to Projected Thickness■ Can we retrieve quantitative information fromthese images?
■ Full phase retrieval♦ If no assumptions are made 4 images required■ Single image phase retrieval assumptions♦ Plane waves♦ Single-material object embedded in a substrate of
approximately uniform thickness■ Lungs (air) in the chest (water)David Paganin, Timur E. Gureyev, Konstantin M. Pavlov, Robert A.
Lewis, Marcus Kitchen; Optics Communications 234 (2004) 87–105

Phase Retrieval: Single Image

Test Object – Perspex Step Wedge
Noise: 1 std dev = 0.5% ofmean■ Approximate ‘contact’ intensity from Beer’s Law
I (r⊥ , z = 0) = I O exp(− μT (r⊥ ))■ Approximate ‘contact’ phase byφ (r⊥ , z = 0) = −2πλδ T (r⊥ )■ Use Transport-of-Intensity Equation (TIE)∇ ⊥ ⋅ ( I (r⊥ , z )∇ ⊥φ (r⊥ , z )) = −2π ∂I (r⊥ , z )λ ∂z

1.78 mm at thickest point
0.10 mm steps■ Solve for object’s projected thickness using Fourier
Derivative Theorem
T (r⊥ ) = −{}⎛ ⎧⎪ F M 2 I ( Mr , z = R ) / I ⎫⎪ ⎞O ⎟2⊥ln⎜ F −1 ⎨μ⎬⎟2μ ⎜ ⎪⎩
MR
k
+
δ
μ
⎪⎭ ⎠
2
⊥
⎝
1

Marcus Kitchen, Monash

Paganin, D et al., Journal of Microscopy, Vol. 206 Pt 1 April 2002, pp. 33-

Phase Retrieval■■■

Phase to Projected Thickness

Step height matches measured thickness
Noise, surface defects and sharp diffraction edges produce
roughness in the projected thickness.
μ and δ must be well known.
Marcus Kitchen, Monash

Phase image R2=4.26m, E=33keV

Projected thickness■ Surface Entrance Dose
~ 8.6 mGy
■ 1% Noise■ Use μ and δ for lungtissue at 33 keV■ Projected thickness
resembles conventional
radiographMarcus Kitchen, Monash

18

10/2/2008

Phase to Projected Thickness

Phase to Projected Thickness

Phase image R2=4.26m, E=33keV

Phase image R2=4.26m, E=33keV

Projected thickness

Marcus Kitchen, Monash

Rabbit Spontaneous Breathing■ Major inspiratory
activity important
for aeration

RA Lewis et al Phys. Med. Biol. 50, 5031-5040
S. Hooper et al FASEB 21, 3330 (2007)

Rabbit Pup: No PEEP

Projected thickness

Marcus Kitchen, Monash

Non--uniform Aeration
Non
Dependent lungaerates less wellthan nondependant lung

Hooper et al FASEB 21, 3330 (2007)

Rabbit Pup: With PEEP

19

10/2/2008

Detecting lung shear stress during ventilation“Particle image Velocimetry”
Velocimetry”

A. Fouras, J. Dusting, R. Lewis, and K. Hourigan
064916 2007

Particle image velocimetry

J. Appl. Phys. 102,
A. Fouras, J. Dusting, R. Lewis, and K. Hourigan J. Appl. Phys. 102,
064916
2007

Blood Flow. No Contrast Medium

Phase Contrast Comparison

570μm

190nm
pixelsInterferometer

Analyser

Propagation

Spatial coherenceHigh

ReasonableHigh

Temporal coherence

High

High

Low

Very difficult

Difficult

Easy

Movies

Hard

Hard

Easy

Sensitivity

Outstanding

Excellent but
unidirectional

Good

Requirements

Capabilities
Large objects

A. Fouras, J. Dusting, R. Lewis, and K. Hourigan, J. Appl. Phys. 102, 064916, 2007
B. Sally Irvine et al Applied Physics Letters (accepted)

How Many Does it Take?
■

■

■
■

Monash Physics♦
Ivan Williams♦
Karen Siu♦
Marcus Kitchen♦
Konstantin Pavlov♦
Jeff Crosbie♦
Rob Lewis♦
Chris Hall♦
Sally Irvine♦
Michael Morgan
Monash Physiology♦
Stuart Hooper♦
Megan Wallace♦
Melissa Siew
Adelaide University♦
David Parsons
Spring-8, Japan♦K Uesugi♦
Naoto Yagi♦
M Suzuki

Why do Imaging on Synchrotrons?
■ The only way to get♦ Deep penetration♦ Micron spatial resolution♦ High sensitivity (soft tissue contrast), elemental
specificitypy♦ Video time resolution■ Methods developed on synchrotrons can betranslated to humans♦ We require some beamlines suitable for humanstudies20

10/2/2008

SYRMA project: patient support

SYRMA: Clinical Images

Carbonfibre
support26 cm ØTrieste Hospital (GE Senographe
2000D)

Synchrotron at 18 keV

Fulvia Arfelli, University Trieste

Fulvia Arfelli, Univ. Trieste

Phase Contrast at Monash Medical Centre

Detail

X-ray tube
Collimator
Moveable Trays
Contact

Optimal

‘Konica like’

Note: This is not a very good way to show a digital image.

Control Desk
Ivan Williams

Ivan Williams

Results

Future Prospects■ Drive is to understand dynamic processes■ Alternative imaging modalities will continue toimprove♦ MRI, PET, SPECT, optical, IR♦ Can be placed in lab■ Synchrotron must concentrate on strengths♦ Combined high spatial and temporal resolution in ‘thick’
objects♦ We must move towards multi-modality imaging
Box-and-whiskers plot of the raw data averaged for each scorer for each of the three scoring comparisons, a positive score indicates thatthe second of the two geometries involved in the comparison was scored to advantage. The horizontal line within each box denotes
median, box covers 25th percentile, whiskers denote the greater of 3.5 times 25th percentile and outer most point.
The two left-most show that two PCI geometries scored better than the Contact. The bar on the right shows that the Konica geometry
was scored better than the Optimised. The single data point at 1.4 in the Optimised vs Konica comparison is an extreme outlier morethan three standard deviations from the median.

Ivan Williams

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10/2/2008

11.7T MRI

BioSpec 117/16 USR

Turbo Spin Echo (RARE) with 68 x 68 µm2
in plane resolution, 0.5 mm slice thickness.

Methods

microPET-CT
bioluminescence

Robin Absorption and Phase

microPET

Autoradiography Optical

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