Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Super-resolution microscopy wikipedia , lookup
Hyperspectral imaging wikipedia , lookup
Breathalyzer wikipedia , lookup
Imagery analysis wikipedia , lookup
Optical tweezers wikipedia , lookup
Harold Hopkins (physicist) wikipedia , lookup
Chemical imaging wikipedia , lookup
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 77204. Email: [email protected] Ph:No: 832-842-8834 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, 1973. 302(7836): p. 999-1001. 2. Williams, J.F. and V.C. Smith, Fetal Alcohol Spectrum Disorders. Pediatrics, 2015. 136(5): p. e1395. Common Facial Defects Associated With FASD 3. Smith, S.M., Alcohol-Induced Cell Death in the Embryo. Alcohol Health Res World, 1997. 21(4): p. 287-97. 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), 159-171 (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), 563-566 (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), 222-232 (1986). 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, 2013. 18(2): p. 20506. 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): 1178-1181 11. Drexler, W., et al. (2003). "Enhanced visualization of macular pathology with the use of ultrahigh-resolution optical coherence tomography." Arch Ophthalmol 121(5): 695-706. 12. Sattler, E., et al. (2013). "Optical coherence tomography in dermatology." J Biomed Opt 18(6): 061224. 13. Jang, I. K., et al. (2005). "In vivo characterization of coronary atherosclerotic plaque by use of optical coherence tomography." Circulation 111(12): 1551-1555. 14. Vakoc, B. J., et al. (2012). "Cancer imaging by optical coherence tomography: preclinical progress and clinical potential." Nat Rev Cancer 12(5): 363-368. 15. Raghunathan, R., et al. (2016). "Optical coherence tomography for embryonic imaging: a review." Journal of Biomedical Optics 21(5): 050902-050902. 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 [9] Resolution comparison of an a)OCT image b)Ultrasound image 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. [16] 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): 1530-1532. 18. Sudheendran, N., et al. (2011). "Speckle variance OCT imaging of the vasculature in live mammalian embryos." Laser Physics Letters 8(3): 247-252. 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 Results Pre-ethanol A 45 minutes post- ethanol vessels on the uterus A B B Mouse 1 A B 0.5 mm A Mouse 2 % Decrease in Vessel Diameter 45 mins. After Ethanol Artifacts caused due to bulk motion correction 0.5 mm B A vessels on the uterus 0.5 mm 0.5 mm 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. Thank you, questions?!