Optical Coherence Tomography in Developmental Biology Studies

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Optical Coherence Tomography in Developmental
Biology Studies
Jacquelyn Martin, Wei Luo, Amy Oldenburg, Ph.D,
Daniel Marks, Ph.D. Stephen A. Boppart, M.D.,
Ph.D. Beckman Institute for Advanced Science and
Technology Department of Electrical and Computer
Engineering College of Medicine University of
Illinois at Urbana-Champaign ECE 298/299
Presentation December 4, 2003
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Outline

• Developmental Biology, Motivation
• Optical Coherence Tomography
• Experimental Methods
• Results
• Structural imaging (mouse)
• Functional imaging (chick)
• Future Work and Conclusions

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Motivation for Current Work

• Completion of the human genome project has
  ignited a desire improve our understanding of
  biological development and disease states.
• Traditionally, histology is used in a
  developmental biology study
• Not possible to image live embryos
• Purely structural information

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Motivation for Current Work

• The methodology to perform small animal
• imaging is still experimental, and significant
• limitations remain in acquisition speed,
• resolution, instrument complexity, and cost.
• confocal microscopy, video light microscopy, high
  resolution MRI, and ultrasound have been utilized

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Optical Coherence Tomography (OCT)

• Low coherence light source
• Detects backscattered light caused at tissue
  boundaries in biological subjects

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OCT Characteristics

• High Resolution
• Axial Resolution 2-5 µm
• Transverse Resolution 10 µm
• Short Imaging Depth
• attain imaging depths of about 2-3 mm by using a
  system detection sensitivity of 100-110 dB

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Previous Work

• In vivo Cardiac function in Xenopus Laevis1
• Correlation to histology of OCT chicken
  embryo2, Xenopus laevis, Rana pipiens, and
  Brachydanio rerio3
• Optical Projection Tomography used in 3-D
  microscopy studies and gene expression studies4

1 S.A. Boppart, G.J. Tearney, B.E. Bouma, et
al., Proc. Natl. Acad. Sci., vol. 94, pp.
4256-4261, April 1997. 2 T.M. Yelbuz, M.A.
Choma, L.Thrane, M.L. Kirby, J.A. Izatt,
Circulation, vol. 106, pp. 2771-2774. 3 S.A.
Boppart, M.E. Brezinski, B.E. Bouma, G.J.
Tearney, J.G. Fujimoto, Developmental Biology,
vol. 177, pp. 54-63, July 1996. 4 J. Sharpe, U.
Ahlgren, P. Perry, B. Hill, A. Ross, J.
Hecksher-Sorenson, R. Baldock, D. Davidson,
Science, vol. 296, pp. 541-545, April 2002.
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OCT Imaging Modes
A-mode scan a single axial scan B-mode scan a
series of A-mode scans that are constructed into
a two-dimensional image
M-mode scan a continuous series of A-mode scans
at the same location that provides information on
tissue movement within a subject
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Experimental Set-up
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Methods Mouse Embryo
http//www.cuttingedgeherp.com/picturesofratsmice/

• Female mouse impregnated using a paired breeding
  method.
• After 10-14 days of development, female mouse is
  euthanized
• Embryos exposed and imaged using OCT

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Results Matching OCT Images to AtlasMouse
Central Nervous System
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Results Matching OCT Images to HistologyCentral
Nervous System
OCT image (above) of a mouse embryos
head matched to histology (left) of the
sample.
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Results Matching to Atlas and HistologyMouse
Optical Cavity
ey - eye, nc nasal cavity
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Results Matching to Atlas and HistologyMouse
Abdominal Region
st stomach, sp splenic primordium, ov-left
ovary pole
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Animated Mouse Embryo DataLeft Side of Head
____
250 µm
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Methods Chicken Embryo

• Fertile chicken eggs obtained from scientific
  supply company
• Incubated at 100 F for 3-5 days
• Eggs carefully opened by cutting off the wider
  end of the egg and puncturing outer embryonic sac
• Embryo imaged in egg

http//www.ext.vt.edu/resources/4h/virtualfarm/pou
ltry/poultry_incubation.html
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Results Functional ImagingB-mode scans
OCT Images of the hearts of chicken embryos after
94 (left), and 77.5 hours (right) of
development.
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Results Functional ImagingM-mode scans
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Results Functional Imaging
OCT cardiogram demonstrating measurement of
cardiac parameters EDD end diastolic
dimension, FT fill time, ET ejection
time S.A. Boppart, M.E. Brezinski, J.G.
Fujimoto, Developmental Biology Protocols, Vol.
I, R.S. Tuan and C.W. Lo, Eds. Totowa, NJ
Humana Press Inc., pp. 217-233.
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Future Directions

• Functional Imaging of mouse embryo
• Similar to functional imaging of the mouse as
  demonstrated in the chicken
• Use of Doppler OCT in a living mouse embryo to
  demonstrate blood flow in the beating heart

Izatt Group, Duke University
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Future Directions

• Non-invasive imaging
• Use of needle probe to image mouse embryo within
  an anesthetized pregnant female
• Implementation of a 1300 nm source to improve
  depth of penetration

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Summary and Conclusions

• OCT is a useful tool for imaging embryos in
  developmental biology
• We have shown that both functional and structural
  information can be obtained using OCT
• OCT can potentially become an integral instrument
  in developmental biology studies because it may
  be able to image embryo subjects minimally
  invasively

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Acknowledgements
Beckman Institute Biophotonics Imaging
Laboratory Prof. Stephen A. Boppart
Graduate Students Jeremy Bredfeldt John
Fahrner Tin Man Lee Jose Mayen Jay Pasquesi Tyler
Ralston Chenyang Xu Adam Zysk
Undergraduates Anupama Bowonder Jillian
Gunther Annie Ko Jacquelyn Martin
Post-Doctoral Fellows Dr. Claudio Vinegoni Dr.
Amy Oldenburg Dr. Wei Tan Dr. Chuanwu Xi
Research Specialist Wei Luo Dr. Daniel Marks Ron
Stack
http//nb.beckman.uiuc.edu/biophotonics
The National Science Foundation, The Whitaker
Foundation NASA, NIH (NCI, NIBIB), UIUC Critical
Research Initiative