1. Optical Coherence Tomography To Evaluate Changes In Vasculature Of The Murine Fetal Brain In Utero Due To Prenatal Alcohol Exposure
Raksha Raghunathan1, Chen Wu1, Manmohan Singh1, Chih-Hao Liu1, Rajesh C. Miranda2, and Kirill V. Larin1,*
1Department of Biomedical Engineering, University of Houston
2Department of Neuroscience and Experimental Therapeutics, TAMHSC College of Medicine
*Contact author: University of Houston, 2026 SERC, Houston, TX
Ph:No:

2. Fetal Alcohol Syndrome Disorder
Fetal Alcohol Syndrome (FAS):
First described in 1973 [1].
Was defined as a pattern of birth defects associated with prenatal alcohol exposure.
However due to the broad spectrum of developmental and behavioral effects, fetal alcohol syndrome disorder (FASD) was a general term coined for any adverse effect caused with prenatal alcohol exposure [2].
FASD includes:
FAS
Partial FAS
Alcohol- related birth defects (ARBD)
Alcohol related neurodevelopmental disorder (ARND)
Neurobehavioral disorder associated with prenatal alcohol exposure (ND-PAE).
However, the term FASD is not used for clinical diagnosis.
1. Jones, K. and D. Smith, Recognition of the Fetal Alcohol Syndrome in Early Infancy. The Lancet, (7836): p
2. Williams, J.F. and V.C. Smith, Fetal Alcohol Spectrum Disorders. Pediatrics, (5): p. e1395.

3. Common Facial Defects Associated With FASD
3. Smith, S.M., Alcohol-Induced Cell Death in the Embryo. Alcohol Health Res World, (4): p

4. Effects Of Ethanol On Fetal Neurogenesis
Second trimester is a critical period for fetal neurogenesis and brain angiogenesis.
Ethanol is known to directly affect several aspects of neural development including:
Biology of stem cells [4]
Neuronal migration [5]
Also known to cause behavioral deficits.
Vasculature development in the brain during this stage is of great importance. [6]
How does maternal ethanol consumption affect this vasculature development?
4. C. Camarillo, and R. C. Miranda, "Ethanol exposure during neurogenesis induces persistent effects on neural maturation: evidence from an ex vivo model of fetal cerebral cortical neuroepithelial progenitor maturation," Gene Expr 14(3), (2008).
5. B. M. Altura et al., "Ethanol promotes rapid depletion of intracellular free Mg in cerebral vascular smooth muscle cells: Possible relation to alcohol-induced behavioral and stroke-like effects," Alcohol 10(6), (1993).
6. M. G. Norman, and J. R. O'Kusky, "The growth and development of microvasculature in human cerebral cortex," J Neuropathol Exp Neurol 45(3), (1986).

5. Previously Used Imaging Modalities For Brain Imaging To Study FASD
Histology:
Traditional method
Time consuming
Cannot be performed in vivo
Micro-Magnetic resonance imaging (MRI) [7]:
requires external contrast agent (may harm the embryos)
Long acquisition times
Micro-Computed tomography (CT) [8]:
Uses ionizing radiation (may harm the embryos)
Ultrasound(US) [9]:
Low spatial resolution.
7. V. W. Swayze et al., "Magnetic Resonance Imaging of Brain Anomalies in Fetal Alcohol Syndrome," Pediatrics 99(2), 232 (1997).
8. Belma, D., et al. (2007). "Digimouse: a 3D whole body mouse atlas from CT and cryosection data." Physics in Medicine and Biology 52(3): 577.
9. Sudheendran, N., S. Bake, R.C. Miranda, and K.V. Larin, Comparative Assessments of the Effects of Alcohol Exposure on Fetal Brain Development Using Optical Coherence Tomography and Ultrasound Imaging. J Biomed Opt, (2): p

6. Optical Coherence Tomography
Well established optical imaging modality based on low coherence interferometry [10].
Optical analog of ultrasound.
Capable of label-free, noninvasive, depth-resolved imaging of tissue with micrometer-scale spatial resolution.
Widely used in many applications today including:
Ophthamology [11]
Dermatology [12]
Cardiology [13]
Cancer imaging [14]
Embryology [15]
10. Huang, D., et al. (1991). "Optical coherence tomography." Science 254(5035):
11. Drexler, W., et al. (2003). "Enhanced visualization of macular pathology with the use of ultrahigh-resolution optical coherence tomography." Arch Ophthalmol 121(5):
12. Sattler, E., et al. (2013). "Optical coherence tomography in dermatology." J Biomed Opt 18(6):
13. Jang, I. K., et al. (2005). "In vivo characterization of coronary atherosclerotic plaque by use of optical coherence tomography." Circulation 111(12):
14. Vakoc, B. J., et al. (2012). "Cancer imaging by optical coherence tomography: preclinical progress and clinical potential." Nat Rev Cancer 12(5):
15. Raghunathan, R., et al. (2016). "Optical coherence tomography for embryonic imaging: a review." Journal of Biomedical Optics 21(5):

7. Why Use Optical Coherence Tomography In Embryology?
Ability to provide cross sectional images
Noninvasive nature
Live imaging of embryos possible
High spatial and temporal resolution
Rapid acquisition speeds
Resolution comparison of an a)OCT image b)Ultrasound image
[9]
[16]
16. Wang, S., D.S. Lakomy, M.D. Garcia, A.L. Lopez, 3rd, K.V. Larin, and I.V. Larina, Four-Dimensional Live Imaging of Hemodynamics in Mammalian Embryonic Heart with Doppler Optical Coherence Tomography. J Biophotonics, 2016.

8. Overview of The Study
Acute vasculature changes in the embryonic brain after maternal alcohol exposure.
In utero imaging using OCT.
Speckle variance OCT (SVOCT) [17, 18] was used to image the vasculature changes.
Pregnant mice at E 14.5 were used.
SVOCT measurements were taken before and upto 45 minutes after the gavage.
Intervals of 5 minutes.
Gavage: 95% ethanol at a volume of 3g/ kg.
Preliminary results have been shown.
17. Mariampillai, A., et al. (2008). "Speckle variance detection of microvasculature using swept-source optical coherence tomography." Opt Lett 33(13):
18. Sudheendran, N., et al. (2011). "Speckle variance OCT imaging of the vasculature in live mammalian embryos." Laser Physics Letters 8(3):

9. OCT System Setup Home built OCT system: A-line rate: 30kHz
Central wavelength:: ~1310 nm
Bandwidth: 150 nm
Output power: ~39 mW
Axial resolution: ~11 um in air
600 A-lines per B-scan
500 B-scans per volume

10. % Decrease in Vessel Diameter 45 mins. After Ethanol
Results
Pre-ethanol
45 minutes post- ethanol
0.5 mm
Artifacts caused due to bulk motion correction B
vessels on the uterus A
Mouse 1
Mouse 2
% Decrease in Vessel Diameter 45 mins. After Ethanol A B

11. Summary and Discussion
OCT was used to evaluate the effects of maternal ethanol consumption on the fetal brain.
SVOCT measurements were taken before and after maternal ethanol consumption.
Pregnant mice at gestational stage 14.5 dpc were used.
Preliminary results show a significant decrease in the vessel diameter of the fetal brain 45 minutes after maternal alcohol consumption.
This suggests that ethanol might act as a vasoconstrictor on the fetal brain.
Future work:
Quantification of other parameters such as vessel area density, and vessel length fraction.
Doppler OCT to verify flow speeds before and after maternal alcohol consumption.

12. Thank you, questions?!