缺血性中風在工業國家是高盛行率且存活者的醫療照護耗費不貲，建立一套有效的診斷工具對於中風患者而言是有幫助的，為了研究這項疾病在人體上的影響，通常會建立動物模型做深入的探討及觀察中風在一段時間內的變化，中風動物模式方面，我們選擇其中一種常見的缺血性中風大鼠模型--中大腦動脈阻塞缺血性中風，並採用波長為690 nm與830 nm的非侵入式近紅外光光譜儀量測大鼠腦部的光學訊號。組織中衰減的光學訊號主要來自於吸收和散射，將吸收係數帶入修正後的比爾-朗伯定律，便可以換算出含氧血紅素與去氧血紅素的濃度，而常用來描述組織中散射性質的是等效散射係數，與組織結構的性質有關。本研究目的是為了分析缺血性中風大鼠的血氧濃度相關參數、吸收係數和等效散射係數在一段期間的變化情形，並加入控制組加以比較。我們將47隻大鼠隨機分配成控制組和中風組，量測的時間為中風前到中風後第三天，在第三天量測結束後犧牲大鼠並做組織化學染色以定量缺損體積。實驗結束後，由組織染色結果近一步將中風大鼠分成兩類，分別為缺損區域只包含非皮質區的中風組及缺損區域包含皮質和非皮質區的中風組。針對缺損區域包含皮質區的中風組，中風後第三天的總血氧濃度及兩波長下的等效散射係數，顯著地高於其他兩組 (p〈0.001).。更進一步的探討發現，兩波長下的等效散射係數和缺損體積有顯著的相關性，然而，若是不考慮缺損在側邊皮質區的大鼠，則兩者並沒有顯著的相關性，可以由此推論等效散射係數與皮質缺損的區域可能是相關的，但與缺損體積則沒有相關性。在本研究中，我們推論等效散射係數的增加可能與皮質區的缺損有關。這些結果在缺血性中風的診斷上是相當有潛力的，也可做為治療後後續追蹤觀察的依據。

Ischemic stroke is a high prevailing disease and the aftercare of survivors is costly in industrialized countries. Developing an effective diagnostic tool is beneficial to patients of ischemic stroke. In order to study the disease in human beings, animal model is commonly used for aggressive approach and time-course observation. Among various models, middle cerebral artery occlusion (MCAO) model, was chosen to induce ischemic stroke. In this study, noninvasive near infrared spectroscopy (NIRS) with the wavelength in 690 and 830nm was applied to measure optical signals of brain in rats. The attenuated optical signals in tissue are mainly caused by absorption and scattering of brain tissue to obtain the changes in concentrations of oxy-hemoglobin and deoxy-hemoglobin from absorption coefficient based on Beer Lambert’s law. In tissue, reduced scattering coefficient (µs’) is often used to describe scattering properties, and is basically associated with tissue structure. The aim of this study is to analyze the time-course changes of hemodynamic responses, absorption coefficient and reduced scattering coefficient in cerebral ischemic rats and sham control group. Forty-seven rats were randomly assigned into sham control and MCAO groups to observe optical properties from pre-MCAO to the 3rd day after stroke. On the 3rd day, the rats were sacrificed for 2,3,5-triphenyltetrazolium chloride (TTC) stain to quantify the infarct volume. From the TTC staining, MCAO rats were further divided into two groups based on the infarction area of subcortical-only as well as both cortical and subcortical infarction. For the MCAO group of cortical and subcortical infarction, concentration of total hemoglobin (tHb), µs’ (830 nm) and µs’ (690 nm) on POD 3 are significantly higher compared with other two groups (p〈0.001). Furthermore, The Pearson’s correlation analysis showed significant correlation between infarct volume and µs’ (830 nm) on POD 3 (p〈0.001), µs’ (690 nm) on POD 3 (p〈0.05). However, no significant correlation was found without considering the rats of lateral cortical infarction. This suggests that µs’ may be related to the cortical infarct region, but may not infarct volume. Our study showed that the enhancement of µs’ might be due to cortical infarction and have potential in diagnosis and longitudinal monitoring of ischemic stroke progression after treatment.

摘要...I
Abstract...II
Keywords: near infrared spectroscopy, ischemic stroke, histochemical stain...III
誌謝...IV
Contents...VI
List of Tables...VIII
List of Figures...IX
Chapter 1 Introduction...1
1.1 Introduction to ischemic stroke...1
1.2 The animal models of ischemic stroke...1
1.3 Brain scanning techniques...2
1.4 Near infrared spectroscopy...3
1.4.1 NIRS measurement system...4
1.4.2 Quantitative determination of optical signals...5
1.5 Ischemic stroke and NIRS techniques...7
1.6 Motivations and the aims of this study...9
Chapter 2 Materials and Methods...10
2.1 Animal preparation and grouping...10
2.2 Animal model of ischemic stroke...10
2.3 NIRS system...11
2.4 Neurological scores...12
2.5 Quantitation of infarct area...12
2.6 Experimental design...13
2.7 Statistical analysis...14
Chapter 3 Results...16
3.1 Classification of two MCAO groups...16
3.2 Neurological scores of two MCAO groups...17
3.3 Comparison of NIRS signals in both hemispheres ...17
3.4 Comparison of NIRS signals among three groups ...25
3.5 Distribution of µs’ with infarct region...28
3.6 Correlation between NIRS signals and infarct volume ...30
Chapter 4 Discussion and Conclusion...32
4.1 The experimental design and initial results in three groups...32
4.2 Comparison of optical properties in this study and previous studies...33
4.3 Conclusion...35
References...36

Abookasis D, Lay C C, Mathews M S, Linskey M E, Frostig R D, ＆ Tromberg B J. (2009). Imaging cortical absorption, scattering, and hemodynamic response during ischemic stroke using spatially modulated near-infrared illumination. J Biomed Opt, 14(2), 024033.
Beauvoit B, Evans S M, Jenkins T W, Miller E E, ＆ Chance B. (1995). Correlation between the light scattering and the mitochondrial content of normal tissues and transplantable rodent tumors. Anal Biochem, 226(1), 167-174.
Bederson J B, Pitts L H, Tsuji M, Nishimura M, Davis R, ＆ Bartkowski H. (1986). Rat middle cerebral artery occlusion: evaluation of the model and development of a neurologic examination. Stroke, 17(3), 472-476.
Belayev L, Alonso O F, Busto R, Zhao W, ＆ Ginsberg M D. (1996). Middle cerebral artery occlusion in the rat by intraluminal suture. Neurological and pathological evaluation of an improved model. Stroke, 27(9), 1616-1622; discussion 1623.
Beuthan J, Minet O, Helfmann J, Herrig M, ＆ Muller G. (1996). The spatial variation of the refractive index in biological cells. Phys Med Biol, 41(3), 369-382.
Calderon-Arnulphi M, Alaraj A, Amin-Hanjani S, Mantulin W W, Polzonetti C M, Gratton E, ＆ Charbel F T. (2007). Detection of cerebral ischemia in neurovascular surgery using quantitative frequency-domain near-infrared spectroscopy. J Neurosurg, 106(2), 283-290.
Cerussi A E, Berger A J, Bevilacqua F, Shah N, Jakubowski D, Butler J, Holcombe R F, ＆ Tromberg B J. (2001). Sources of absorption and scattering contrast for near-infrared optical mammography. Acad Radiol, 8(3), 211-218.
Chýlek P. (1977). Light scattering by small particles in an absorbing medium. JOSA, 67(4), 561-563.
Chen H, Lin Z, Wu H, Wang L, Wu T, ＆ Tan C. (2014). Diagnosis of colorectal cancer by near-infrared optical fiber spectroscopy and random forest. Spectrochim Acta A Mol Biomol Spectrosc, 135c, 185-191.
Chen W, Lu G, ＆ Lichty W. (2002). Localizing the focus of ischemic stroke with near infrared spectroscopy. Chin Med J (Engl), 115(1), 84-88.
Culver J P, Durduran T, Furuya D, Cheung C, Greenberg J H, ＆ Yodh A G. (2003). Diffuse optical tomography of cerebral blood flow, oxygenation, and metabolism in rat during focal ischemia. J Cereb Blood Flow Metab, 23(8), 911-924.
Dai L, Qian Z, Li K, Yang T, ＆ Wang H. (2008). In vivo detection of reduced scattering coefficient of C6 glioma in rat brain tissue by near-infrared spectroscopy. J Biomed Opt, 13(4), 044003.
Delpy D T, Cope M, Van Der Zee P, Arridge S, Wray S, ＆ Wyatt J. (1988). Estimation of optical pathlength through tissue from direct time of flight measurement. Phys Med Biol, 33(12), 1433-1442.
Demet G, Talip A, Nevzat U, Serhat O, ＆ Gazi O. (2000). The evaluation of cerebral oxygenation by oximetry in patients with ischaemic stroke. J Postgrad Med, 46(2), 70-74.
Fantini S, Franceschini M A, Fishkin J B, Barbieri B, ＆ Gratton E. (1994). Quantitative determination of the absorption spectra of chromophores in strongly scattering media: a light-emitting-diode based technique. Appl Opt, 33(22), 5204-5213.
Ferrari M, ＆ Quaresima V. (2012). A brief review on the history of human functional near-infrared spectroscopy (fNIRS) development and fields of application. Neuroimage, 63(2), 921-935.
Fisher M. (2003). Recommendations for advancing development of acute stroke therapies: Stroke Therapy Academic Industry Roundtable 3. Stroke, 34(6), 1539-1546.
Frackowiak R S, Lenzi G L, Jones T, ＆ Heather J D. (1980). Quantitative measurement of regional cerebral blood flow and oxygen metabolism in man using 15O and positron emission tomography: theory, procedure, and normal values. J Comput Assist Tomogr, 4(6), 727-736.
Hillman E M. (2007). Optical brain imaging in vivo: techniques and applications from animal to man. J Biomed Opt, 12(5), 051402.
Hornung R, Spichtig S, Banos A, Stahel M, Zimmermann R, ＆ Wolf M. (2011). Frequency-domain near-infrared spectroscopy of the uterine cervix during regular pregnancies. Lasers Med Sci, 26(2), 205-212.
Huber E, ＆ Frost M. (1998). Light scattering by small particles. Aqua, 47, 87-94.
Hunter A J, Green A R, ＆ Cross A J. (1995). Animal models of acute ischaemic stroke: can they predict clinically successful neuroprotective drugs? Trends Pharmacol Sci, 16(4), 123-128.
Ilkka Nissila, Tommi Noponen, Jenni Heino T K, ＆ Katila A T. (2005). Diffuse optical imaging (Vol. 4).
Ishimaru A. (1978). Wave propagation and scattering in random media. Volume I-Single scattering and transport theory. Research supported by the US Air Force, NSF, and NIH. New York, Academic Press, Inc., 1978. 267 p., 1.
Johns M, Giller C, ＆ Liu H. (1998). Computational and in vivo investigation of optical reflectance from human brain to assist neurosurgery. J Biomed Opt, 3(4), 437-445.
Koizumi J Y Y, Nakazawa T, Ooneda G. (1986). Experimental studies of ischemic brain edema, I: a new experimental model of cerebral embolism in rats in which recirculation can be introduced in the ischemic area. Jpn J stroke, 8(1), 1-8.
Liu F, Schafer D P, ＆ Mccullough L D. (2009). TTC, fluoro-Jade B and NeuN staining confirm evolving phases of infarction induced by middle cerebral artery occlusion. J Neurosci Methods, 179(1), 1-8.
Minagawa-Kawai Y, Mori K, Hebden J C, ＆ Dupoux E. (2008). Optical imaging of infants' neurocognitive development: recent advances and perspectives. Dev Neurobiol, 68(6), 712-728.
Nishimura E, Stautzenberger J P, Robinson W, Downs T H, ＆ Downs J H, 3rd. (2007). A new approach to functional near-infrared technology. IEEE Eng Med Biol Mag, 26(4), 25-29.
Regan H K, Detwiler T J, Huang J C, Lynch J J, ＆ Regan C P. (2007). An improved automated method to quantitate infarct volume in triphenyltetrazolium stained rat brain sections. J Pharmacol Toxicol Methods, 56(3), 339-343.
Sacco R, Wolf P, ＆ Gorelick P. (1999). Risk factors and their management for stroke prevention: outlook for 1999 and beyond. Neurology, 53(7 Suppl 4), S15-24.
Selb J, Ogden T M, Dubb J, Fang Q, ＆ Boas D A. (2014). Comparison of a layered slab and an atlas head model for Monte Carlo fitting of time-domain near-infrared spectroscopy data of the adult head. J Biomed Opt, 19(1), 16010.
Sicard K M, ＆ Fisher M. (2009). Animal models of focal brain ischemia. Exp Transl Stroke Med, 1, 7.
Talukdar T, Moore J H, ＆ Diamond S G. (2013). Continuous correction of differential path length factor in near-infrared spectroscopy. J Biomed Opt, 18(5), 56001.
Tamura A, Graham D I, Mcculloch J, ＆ Teasdale G M. (1981). Focal cerebral ischaemia in the rat: 1. Description of technique and early neuropathological consequences following middle cerebral artery occlusion. J Cereb Blood Flow Metab, 1(1), 53-60.
Tonnesen J, Pryds A, Larsen E H, Paulson O B, Hauerberg J, ＆ Knudsen G M. (2005). Laser Doppler flowmetry is valid for measurement of cerebral blood flow autoregulation lower limit in rats. Exp Physiol, 90(3), 349-355.
Wang X, Pogue B W, Kogel C, Wells W A, Poplack S P, Jiang S, Song X, ＆ Paulsen K D. (2005). Approximation of Mie scattering parameters in near-infrared tomography of normal breast tissue in vivo. J Biomed Opt, 10(5), 051704-051704-051708.
Wolf T, Lindauer U, Reuter U, Back T, Villringer A, Einhaupl K, ＆ Dirnagl U. (1997). Noninvasive near infrared spectroscopy monitoring of regional cerebral blood oxygenation changes during peri-infarct depolarizations in focal cerebral ischemia in the rat. J Cereb Blood Flow Metab, 17(9), 950-954.
Xie J, Qian Z, Yang T, Li W, ＆ Hu G. (2010). Minimally invasive assessment of the effect of mannitol and hypertonic saline therapy on traumatic brain edema using measurements of reduced scattering coefficient (μs′). Appl Opt, 49(28), 5407-5414.
Xiong Y, Zhu W Z, Zhang Q, ＆ Wang W. (2014). Observation of post-MCAO cortical inflammatory edema in rats by 7.0 Tesla MRI. J Huazhong Univ Sci Technolog Med Sci, 34(1), 120-124.
Zhang Y-M, Xu H, Sun H, Chen S-H, ＆ Wang F-M. (2014). Electroacupuncture Treatment Improves Neurological Function Associated with Regulation of Tight Junction Proteins in Rats with Cerebral Ischemia Reperfusion Injury. J Evid Based Complementary Altern Med, 2014, 10.
Zhang Y, Sun J W, ＆ Rolfe P. (2012). RLS adaptive filtering for physiological interference reduction in NIRS brain activity measurement: a Monte Carlo study. Physiol Meas, 33(6), 925-942.
Zhao J, Ding H S, Hou X L, Zhou C L, ＆ Chance B. (2005). In vivo determination of the optical properties of infant brain using frequency-domain near-infrared spectroscopy. J Biomed Opt, 10(2), 024028.