For more details see:

1
For more details see
K. Ren, G. Abdoulaev, G. Bal, A.H. Hielscher,
"Frequency-domain optical tomography based on the
equation of radiative transfer, accepted for
publication in SIAM Journal of Scientific
Computing 28(4), pp. 1463-1489 (2006). G.
Abdoulaev, K. Ren, A.H. Hielscher, "Optical
tomography as a constrained optimization
problem, Inverse Problems 21, pp. 15071530
(2005). G. Abdoulaev and A.H. Hielscher,
"Three-dimensional optical tomography with the
equation of radiative transfer," J. of Electronic
Imaging 12(4), pp. 594-60 (2003). A.H. Hielscher,
A.D. Klose, U. Netz, J. Beuthan, "Optical
tomography using the time-independent equation of
radiative transfer. Part 1 Forward model,"
Journal of Quantitative Spectroscopy and
Radiative Transfer, Vol 72/5, pp. 691-713,
2002. A.D. Klose, A.H. Hielscher, "Optical
tomography using the time-independent equation of
radiative transfer. Part 2 Inverse model,"
Journal of Quantitative Spectroscopy and
Radiative Transfer, Vol 72/5, pp. 715-732,
2002. A.D. Klose and A.H. Hielscher, "Iterative
reconstruction scheme for optical tomo-graphy
based on the equation of radiative transfer,"
Medical Physics, vol. 26, no. 8, pp. 1698-1707,
1999. A.H. Hielscher, A.D. Klose, K.M. Hanson,
"Gradient-based iterative image recon-struction
scheme for time-resolved optical tomography,"
IEEE Transactions on Medical Imaging 18, pp.
262-271, 1999.
www.optical-tomography.net
2
Measurement Geometry
Source Detectors
NIRx
?1 760 nm and l2 830nm
3
Time Series Valsalva Maneuver
Source 13?????? 760 nm
1.2
1.1
1
0.9
Signal au
0.8
0.7
0.6
0.5
400
200
300
500
600
0
100
Time
sec
4
Time Series Valsalva Maneuver
Source 13?????? 830 nm
1.2
1.1
1
0.9
Signal au
0.8
0.7
0.6
0.5
80
40
60
100
120
0
20
sec
Time
5
DDeoxy Three Views
front
side
mM
aerial
6
D?Oxyhemoglobin Three Views
front
side
mM
aerial
7
Blood Volume Three Views
front
side
D?HbHbO2)
Blood Volume
mM
aerial
8
Overview

• Topography (NIR - Spectroscopy)
• Tomography
• validation in small animals
• Instrumentation
• Challenges

12
9
Probe Geometry
Forehead shaven

Animals head fixed in place using stereotaxic
Optical probe with fixed geometry positioned in
line with lambda (l) suture line, optodes begin 2
mm anterior to l.
10
Probe Location
Dorsal view
posterior
l
b
animals left
animals right
anterior
11
Carotid Occlusion
12
Carotid Occlusion
46.
left occlusion
right occlusion
35.
24.
Hb mM
13.
2.0
-3.0
HbO2 mM
12.
0.4
THb mM
-10.
-20.
Lt.
Lt.
-34.
-40.
13
Movie
D Hb, HbO2, THb (source 1, detector 12)
14
Forepaw Stimulation
15
Right Forepaw Stimulation
lt.
rt.
50
-27.0
D mM
?xyhemoglobin
16
Reconstruction
Blood Volume
Cut 3
Cut 7
Cut 10
lt.
rt.
0.004
-0.003
0
DTHb mM
17
Visual Stimulation in Humans
10 sec visual stimulus followed by 35 sec of
darkness. Multichannel CW NIRS system consisting
of 24 radio-frequency-encoded light-emitting LEDs
at 760 and 850 nm, and 28 avalanche photodiode
detectors.
J. P. Culver, B. L. Schlaggar, H. Dehghani, and
B. W. Zeff, Diffuse optical tomography for
mapping human brain function, Proc. IEEE LSSA
Workshop, pp. 122123 2006 .
18
Overview

• Topography (NIR - Spectroscopy)
• Tomography
• Instrumentation
• Challenges

15
19
Optical Imaging Modalities
1 M
1 image /min
TIME DOMAIN
FREQUENCYDOMAIN
data acquisition rate
information content
complexity/price of system
STEADY-STATE DOMAIN
10 images /sec
100k
20
Frequency vs Steady-State Domain
steady-state domain reconstruction (w 0)
frequency domain reconstruction (w 600 MHz)
target
absorption coefficient ma
scattering coefficient ms