基于激光散斑成像的小鼠脑出血后大脑皮层血流时空变化的研究
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摘要
脑出血(ICH)在中风中占有15%以上的比例,且有极高的死亡率。在对其诊断及恢复的研究中,大脑皮层血流(CBF)的短期以及长期变化是一个重要的参数。本文运用激光散斑成像对脑出血小鼠的脑皮层血流进行长期观测,对其血流恢复的时空特性加以探讨。
14只雄性C57/BL6小鼠被随机分为出血组和生理盐水组,经戊巴比妥钠麻醉后分别将30μl新鲜自体血或生理盐水通过微量注射泵注入小鼠右侧尾状核制备脑出血模型。利用激光散斑成像对各组动物模型血肿周围脑皮层血流变化进行观察,记录时间点为脑出血前,脑出血后2小时内(每10分钟记录一次)、脑出血后1天、2天和3天。
在运用时域激光散斑对比度分析(tLASCA)对小鼠脑皮层不同区域以及主要的血管进行速度变化的分析后,发现小鼠脑出血后血流速度降至最低并在随后2小时内逐渐回升,出血点附近区域的血流速度回升明显小于其他区域。脑中风小鼠右侧大脑皮层的血流速度在手术后即时下降的幅度大于左侧,3天内右脑皮层血流速度的变化过程为先下降后回升再下降再回升。
实验表明注入自体血或者生理盐水,小鼠大脑损伤侧和对侧的脑皮层血流均显著降低,该现象表明了质量效应起初在小鼠颅内造成的水肿是影响血流的主导因素。通过统计差异分析以及对小鼠生命体征的观察发现,自体血对小鼠大脑的影响和危害集中在注射处,这种血肿现象将持续较长的一段时间并造成继发性损伤;而生理盐水对小鼠大脑的影响更加遍及整个脑皮层,在起初的几天会造成大脑两侧严重的水肿现象,但从第3天开始已表现出明显的恢复趋势。部分小鼠在脑出血中风后表现出的明显的血管形态变化预示着其大脑侧肢循环血管开放。小鼠大脑中血肿造成的占位效应以及严重的水肿导致血肿周区脑组织灌注不足,颅内压增高,引发血管扩张的代偿现象。
我们利用激光散斑成像技术实现了小鼠脑出血后脑皮层血流变化的长期监测,对于研究脑出血中风具有重要意义。激光散斑成像技术稳定可靠,拥有高时空分辨率,可以准确直观的反映脑出血周围脑组织异常的血液动力学变化以及血管形态变化,是活体研究脑出血周围脑组织损伤较为理想的实验方法。不过,对于大脑皮层血流在出血型中风发生后生理机制的变化还有待未来进一步的探索和发展。
Hemorrhagic stroke accounts for 15% of all stroke hospitalizations, and there is a very high mortality. In the study of its diagnosis and recovery, short-term and long-term changes of cerebral blood flow (CBF) are essential parameters. We employ laser speckle imaging technology to observe both short-term and long-term cerebral blood flow changes in mice with hemorrhagic stroke, to investigate its spatiotemporal characteristics of CBF change during the recovery.
To prepare for the model of intracerebral hemorrhage (ICH), 14 male C57/BL6 mice were randomly divided into ICH and Saline groups. After been anesthetized by sodium pentobarbital, 30 ? l fresh autologous blood and saline were injected into rightside caudate nucleus of mice brain respectively by micro-injection pump. Laser speckle imaging were used to observe cerebral blood flow changes around hematoma of each group, CBF images were recorded before the surgery, within 2 hours after the surgery (every 10 minutes), day 1, day 2 and day 3 after the stroke.
Through analysis of the laser speckle images of different regions in the mouse brain cortex and major vessels by temporal laser speckle image contrast analysis (tLASCA), we found blood flow velocity after intracerebral hemorrhage in mice reduced to the minimum and then gradually recovered within 2 hours, while areas near the hemorrhagic site recovered significantly slower than other regions. Regarding ICH mice, CBF of right hemisphere decreased more than the left counterpart immediately after the surgery. Within 3 days, CBF of right hemisphere declined at first, then increased, then declined and rebounded at last.
Experiments demonstrated that whether injecting blood or saline, the cerebral blood flow in ipsilateral and contralateral both significantly reduced which suggested the mass effect was the dominant factor in the early stage of stroke recovery. According to the statistical analysis of data as well as vital signs in mice, we found that lesion due to autologous blood was mainly around the injection site, and hematoma phenomenon would last for a long period of time, also causing secondary injury. While in saline group, lesion extended through mouse cerebrum, causing severe brain edema on both hemisphere in the first few days, but the mice showed a clear trend of stroke recovery since the third day after the surgery. In the mean time, some mice showed obvious morphological changes of the blood vessels after hemorrhagic stroke indicated a collateral circulation. Both brain edema and hematoma caused hypoperfusion are around the hematoma, which increased intracerebral pressure and then caused blood vessels dilation compensatory phenomenon.
In conclusion, we successfully used laser speckle imaging technology to achieve both short-term andlong-term monitoring of cerebral blood flow changes in mice with hemorrhagic stroke, which is important in the study of hemorrhagic stroke. Laser speckle imaging of mouse cerebral blood flow rate is reliable with high spatiotemporal resolution, which is able to accurately reflect the abnormal cerebral hemodynamic changes of areas around the hemorrhagic site, and also the vascular morphological changes. tLASCA was demonstrated to be effective in studying brain injury of hemorrhagic stroke in vivo. However, the physiological mechanisms of cerebral blood flow changes after hemorrhagic stroke are to be further explored and developed.
14只雄性C57/BL6小鼠被随机分为出血组和生理盐水组,经戊巴比妥钠麻醉后分别将30μl新鲜自体血或生理盐水通过微量注射泵注入小鼠右侧尾状核制备脑出血模型。利用激光散斑成像对各组动物模型血肿周围脑皮层血流变化进行观察,记录时间点为脑出血前,脑出血后2小时内(每10分钟记录一次)、脑出血后1天、2天和3天。
在运用时域激光散斑对比度分析(tLASCA)对小鼠脑皮层不同区域以及主要的血管进行速度变化的分析后,发现小鼠脑出血后血流速度降至最低并在随后2小时内逐渐回升,出血点附近区域的血流速度回升明显小于其他区域。脑中风小鼠右侧大脑皮层的血流速度在手术后即时下降的幅度大于左侧,3天内右脑皮层血流速度的变化过程为先下降后回升再下降再回升。
实验表明注入自体血或者生理盐水,小鼠大脑损伤侧和对侧的脑皮层血流均显著降低,该现象表明了质量效应起初在小鼠颅内造成的水肿是影响血流的主导因素。通过统计差异分析以及对小鼠生命体征的观察发现,自体血对小鼠大脑的影响和危害集中在注射处,这种血肿现象将持续较长的一段时间并造成继发性损伤;而生理盐水对小鼠大脑的影响更加遍及整个脑皮层,在起初的几天会造成大脑两侧严重的水肿现象,但从第3天开始已表现出明显的恢复趋势。部分小鼠在脑出血中风后表现出的明显的血管形态变化预示着其大脑侧肢循环血管开放。小鼠大脑中血肿造成的占位效应以及严重的水肿导致血肿周区脑组织灌注不足,颅内压增高,引发血管扩张的代偿现象。
我们利用激光散斑成像技术实现了小鼠脑出血后脑皮层血流变化的长期监测,对于研究脑出血中风具有重要意义。激光散斑成像技术稳定可靠,拥有高时空分辨率,可以准确直观的反映脑出血周围脑组织异常的血液动力学变化以及血管形态变化,是活体研究脑出血周围脑组织损伤较为理想的实验方法。不过,对于大脑皮层血流在出血型中风发生后生理机制的变化还有待未来进一步的探索和发展。
Hemorrhagic stroke accounts for 15% of all stroke hospitalizations, and there is a very high mortality. In the study of its diagnosis and recovery, short-term and long-term changes of cerebral blood flow (CBF) are essential parameters. We employ laser speckle imaging technology to observe both short-term and long-term cerebral blood flow changes in mice with hemorrhagic stroke, to investigate its spatiotemporal characteristics of CBF change during the recovery.
To prepare for the model of intracerebral hemorrhage (ICH), 14 male C57/BL6 mice were randomly divided into ICH and Saline groups. After been anesthetized by sodium pentobarbital, 30 ? l fresh autologous blood and saline were injected into rightside caudate nucleus of mice brain respectively by micro-injection pump. Laser speckle imaging were used to observe cerebral blood flow changes around hematoma of each group, CBF images were recorded before the surgery, within 2 hours after the surgery (every 10 minutes), day 1, day 2 and day 3 after the stroke.
Through analysis of the laser speckle images of different regions in the mouse brain cortex and major vessels by temporal laser speckle image contrast analysis (tLASCA), we found blood flow velocity after intracerebral hemorrhage in mice reduced to the minimum and then gradually recovered within 2 hours, while areas near the hemorrhagic site recovered significantly slower than other regions. Regarding ICH mice, CBF of right hemisphere decreased more than the left counterpart immediately after the surgery. Within 3 days, CBF of right hemisphere declined at first, then increased, then declined and rebounded at last.
Experiments demonstrated that whether injecting blood or saline, the cerebral blood flow in ipsilateral and contralateral both significantly reduced which suggested the mass effect was the dominant factor in the early stage of stroke recovery. According to the statistical analysis of data as well as vital signs in mice, we found that lesion due to autologous blood was mainly around the injection site, and hematoma phenomenon would last for a long period of time, also causing secondary injury. While in saline group, lesion extended through mouse cerebrum, causing severe brain edema on both hemisphere in the first few days, but the mice showed a clear trend of stroke recovery since the third day after the surgery. In the mean time, some mice showed obvious morphological changes of the blood vessels after hemorrhagic stroke indicated a collateral circulation. Both brain edema and hematoma caused hypoperfusion are around the hematoma, which increased intracerebral pressure and then caused blood vessels dilation compensatory phenomenon.
In conclusion, we successfully used laser speckle imaging technology to achieve both short-term andlong-term monitoring of cerebral blood flow changes in mice with hemorrhagic stroke, which is important in the study of hemorrhagic stroke. Laser speckle imaging of mouse cerebral blood flow rate is reliable with high spatiotemporal resolution, which is able to accurately reflect the abnormal cerebral hemodynamic changes of areas around the hemorrhagic site, and also the vascular morphological changes. tLASCA was demonstrated to be effective in studying brain injury of hemorrhagic stroke in vivo. However, the physiological mechanisms of cerebral blood flow changes after hemorrhagic stroke are to be further explored and developed.
引文
1. Rynkowski, M.A., et al., A mouse model of intracerebral hemorrhage using autologous blood infusion. Nat Protoc, 2008. 3(1): p. 122-8.
2. Copenhaver, B.R., et al., Racial differences in microbleed prevalence in primary intracerebral hemorrhage. Neurology, 2008. 71(15): p. 1176-82.
3. Crystal L. MacLellan, L.M.D.M.S.F. and C. Frederick, The Influence of Hypothermia on Outcome After Intracerebral Hemorrhage in Rats. Stroke, 2006. 37: p. 1266-1270.
4. Elliott J, S.M., The acute management of intracerebral hemorrhage: a clinical review. Anesth Analg., 2010. 110(5): p. 1419.
5. Ariesen Mj, A.A.W.H.B.v.d.R.G.J., Applicability and relevance of models that predict short term outcome after intracerebral hamorrhage. Journal of neurology, neurosurgery, and psychiatry, 2005. 76(6): p. 839-844.
6. Alvarez-Sabin J, D.P.A.S.M.C.A.A.J.R.M.S.E.Q.M.M.J.M.J., Temporal profile of matrix metalloproteinases and their inhibitors after spontaneous intracerebral hemorrhage: relationship to clinical and radiological outcome. Stroke, 2004. 35(6): p. 1316-1322.
7.周剑,高培毅,李小光,实验性大鼠脑血肿周围脑组织血流变化的CT灌注成像研究.中华放射学杂志, 2005. 39(5): p. 538.
8. Briers, J.D., Holographic, speckle and moire techniques in optical metrology. Quantum Electronics, 1993. 17: p. 167-233.
9. Fercher, A.F. and J.D. Briers, Flow visualization by means of single-exposure speckle photography. Optics Communications, 1981. 37: p. 326-330.
10. Laser speckle and related phenomena. Edited by j. C. Dainty. Appl Opt, 1984. 23(16): p. 2661.
11. Goldfischer, L.I., Autocorrelation Function and Power Spectral Density of Laser-Produced Speckle Patterns. J. Opt. Soc. Am., 1965. 55(3): p. 247-252.
12. J. David Briers, G.R. and H. Xiao Wei, Capillary Blood Flow Monitoring Using Laser Speckle Contrast Analysis (LASCA). J. Biomed. Opt., 1999. 4: p. 164.
13. Ayata, C., et al., Laser speckle flowmetry for the study of cerebrovascular physiology in normal and ischemic mouse cortex. J Cereb Blood Flow Metab, 2004. 24(7): p. 744-55.
14. Briers, J.D. and S. Webster, Laser Speckle Contrast Analysis (LASCA): A Nonscanning, Full-Field Technique for Monitoring Capillary Blood Flow. Journal of Biomedical Optics, 1996. 1: p. 174.
15. Ruth, B., Measuring the steady-state value and the dynamics of the skin blood flow using the non-contact laser speckle method. Med Eng Phys, 1994. 16: p. 105-11.
16. Yamamoto, Y., et al., Laserflowgraphy: a new visual blood flow meter utilizing a dynamic laser speckle effect. Plast Reconstr Surg, 1993. 91(5): p. 884-94.
17. McGuire, P.G. and T.R. Howdieshell, The importance of engraftment in flap revascularization: confirmation by laser speckle perfusion imaging. J Surg Res, 2010. 164(1): p. e201-12.
18. Y. Tamaki, M.A.E.K.S.E. and H. Fujii, Noncontact, two-dimensional measurement of retinalmicrocirculation using laser speckle phenomenon. Investigative Ophthalmology & Visual Science, 1994. 35: p. 3825-3834.
19. K. Yaoeda, M.S.S.F.H.F.T.N. and H. Abe, Measurement of microcirculation in the optic nerve head by laser speckle flowgraphy and scanning laser Doppler flowmetry. Am J Ophthalmol, 2000. 129: p. 734-9.
20. H. Cheng, Q.L.Q.L.Q.L.H.G. and S. Zeng, Laser speckle imaging of blood flow in microcirculation. Phys Med Biol, 2004. 49: p. 1347-57.
21. W. Lau, S.T. and N.V. Thakor, Spatiotemporal characteristics of low-frequency functional activation measured by laser speckle imaging. Neural Systems and Rehabilitation Engineering, IEEE Transactions on, 2005. 13: p. 179-185.
22. D. Zhu, W.L.Y.W.H.C. and Q. Luo, Monitoring thermal-induced changes in tumor blood flow and microvessels with laser speckle contrast imaging. Applied Optics, 2007. 46: p. 1911-1917.
23. H. Cheng, Q.L.S.Z.S.C.J.C. and H. Gong, Modified laser speckle imaging method with improved spatial resolution. J Biomed Opt, 2003. 8: p. 559-64.
24. Briers, J.D. and S. Webster, Laser speckle contrast analysis (LASCA): a nonscanning, full-field technique for monitoring capillary blood flow. Journal of Biomedical Optics, 1996. 1: p. 174-179.
25. J. D. Briers, G.R. and X.W. He, Capillary blood flow monitoring using laser speckle contrast analysis (LASCA). Journal of Biomedical Optics, 1999. 4: p. 164-175.
26. H. Cheng, Q.L.S.Z.S.C.J.C. and H. Gong, Modified laser speckle imaging method with improved spatial resolution. Journal of Biomedical Optics, 2003. 8: p. 559-564.
27. Rigden, J.D. and E.I. Gordon, The granularity of scattered optical maser light. Proc. IRE, 1962. 50: p. 2367-2368.
28. Goodman, J.W., Some fundamental properties of speckle. J. Opt. Soc. Am, 1976. 66: p. 1145-1150.
29. Briers, J.D., Laser Doppler, speckle and related techniques for blood perfusion mapping and imaging. Physiol. Meas, 2001. 22.
30. Rigden, J.D. and E.I. Gordon, The granularity of scattered optical maser light: SPIE-THE INTERNATIONAL SOCIETY FOR OPTICAL ENGINEERING. 1997.
31. Oliver, B.M., Sparkling spots and random diffraction. Proceedings of the IEEE, 1963. 51: p. 220-221.
32. Goodman, J.W., Some fundamental properties of speckle. Journal of optical society of American, 1976. 66: p. 1145-1150.
33. Goodman, J.W., Statistical properties of laser sparkle patterns. Technical Report SEL-63-140 (TR2303-1), Stanford Electronics Laboratories, 1963.
34. Goldfischer, L.I., Autocorrelation function and power spectral density of laser -produced speckle patterns. Journal of optical society of American, 1965. 55: p. 247-253.
35. McKechnie, T.S., Speckle reduction. Laser Speckle and Related Phenomena, 1984: p. 123-170.
36. Briers, J.D., Time-varying laser speckle for measuring motion and flow. Proceedings of SPIE, 2003. 4242: p. 25.
37. Lowenthal, S. and H. Arsenault, Image formation for coherent diffuse objects: statistical properties. Journal of the Optical Society of America, 1970. 60: p. 1478.
38. Goodman, J.W., Some effects of target-induced scintillation on optical radar performance. Proceedings of the IEEE, 1965. 53: p. 1688-1700.
39. Bonner, R. and R. Nossal, Model for laser Doppler measurements of blood flow in tissue. Appl. Opt, 1981. 20: p. 2097-2107.
40. Briers, J.D. and A.F. Fercher, Retinal blood-flow visualization by means of laser speckle photography. Invest Ophthalmol Vis Sci, 1982. 22: p. 255-9.
41. Ohtsubo, J. and T. Asakura, Velocity measurement of a diffuse object by using time-varying speckles. Optical and Quantum Electronics, 1976. 8: p. 523-529.
42. P. Miao, M.L.H.F.A.B.Y.Q. and S. Tong, Imaging the Cerebral Blood Flow with Enhanced Laser Speckle Contrast Analysis (eLASCA) by Monotonic Point Transformation. IEEE Trans. Biomed. Eng., 2009. 56(4): p. 1127-1133.
43. Rosenberg, G.A., et al., Collagenase-induced intracerebral hemorrhage in rats. Stroke, 1990. 21(5): p. 801-7.
44. K. S. Hendrich, P.M.K.J.A.M.J.K.S.K.D.S.D.S.W.D.W.M. and C. Ho, Cerebral perfusion during anesthesia with fentanyl, isoflurane, or pentobarbital in normal rats studied by arterial spin-labeled MRI. Magnetic Resonance in Medicine, 2001. 46: p. 202-206.
45. H. C. Wartenberg, J.P.W. and B.W. Urban, Pharmacological modification of sodium channels from the human heart atrium in planar lipid bilayers: electrophysiological characterization of responses to batrachotoxin and pentobarbital. European Journal of Anaesthesiology, 2005. 20: p. 354-362.
46. Wong, K.C., Physiology and pharmacology of hypothermia. West J Med, 1983. 138: p. 227-32.
2. Copenhaver, B.R., et al., Racial differences in microbleed prevalence in primary intracerebral hemorrhage. Neurology, 2008. 71(15): p. 1176-82.
3. Crystal L. MacLellan, L.M.D.M.S.F. and C. Frederick, The Influence of Hypothermia on Outcome After Intracerebral Hemorrhage in Rats. Stroke, 2006. 37: p. 1266-1270.
4. Elliott J, S.M., The acute management of intracerebral hemorrhage: a clinical review. Anesth Analg., 2010. 110(5): p. 1419.
5. Ariesen Mj, A.A.W.H.B.v.d.R.G.J., Applicability and relevance of models that predict short term outcome after intracerebral hamorrhage. Journal of neurology, neurosurgery, and psychiatry, 2005. 76(6): p. 839-844.
6. Alvarez-Sabin J, D.P.A.S.M.C.A.A.J.R.M.S.E.Q.M.M.J.M.J., Temporal profile of matrix metalloproteinases and their inhibitors after spontaneous intracerebral hemorrhage: relationship to clinical and radiological outcome. Stroke, 2004. 35(6): p. 1316-1322.
7.周剑,高培毅,李小光,实验性大鼠脑血肿周围脑组织血流变化的CT灌注成像研究.中华放射学杂志, 2005. 39(5): p. 538.
8. Briers, J.D., Holographic, speckle and moire techniques in optical metrology. Quantum Electronics, 1993. 17: p. 167-233.
9. Fercher, A.F. and J.D. Briers, Flow visualization by means of single-exposure speckle photography. Optics Communications, 1981. 37: p. 326-330.
10. Laser speckle and related phenomena. Edited by j. C. Dainty. Appl Opt, 1984. 23(16): p. 2661.
11. Goldfischer, L.I., Autocorrelation Function and Power Spectral Density of Laser-Produced Speckle Patterns. J. Opt. Soc. Am., 1965. 55(3): p. 247-252.
12. J. David Briers, G.R. and H. Xiao Wei, Capillary Blood Flow Monitoring Using Laser Speckle Contrast Analysis (LASCA). J. Biomed. Opt., 1999. 4: p. 164.
13. Ayata, C., et al., Laser speckle flowmetry for the study of cerebrovascular physiology in normal and ischemic mouse cortex. J Cereb Blood Flow Metab, 2004. 24(7): p. 744-55.
14. Briers, J.D. and S. Webster, Laser Speckle Contrast Analysis (LASCA): A Nonscanning, Full-Field Technique for Monitoring Capillary Blood Flow. Journal of Biomedical Optics, 1996. 1: p. 174.
15. Ruth, B., Measuring the steady-state value and the dynamics of the skin blood flow using the non-contact laser speckle method. Med Eng Phys, 1994. 16: p. 105-11.
16. Yamamoto, Y., et al., Laserflowgraphy: a new visual blood flow meter utilizing a dynamic laser speckle effect. Plast Reconstr Surg, 1993. 91(5): p. 884-94.
17. McGuire, P.G. and T.R. Howdieshell, The importance of engraftment in flap revascularization: confirmation by laser speckle perfusion imaging. J Surg Res, 2010. 164(1): p. e201-12.
18. Y. Tamaki, M.A.E.K.S.E. and H. Fujii, Noncontact, two-dimensional measurement of retinalmicrocirculation using laser speckle phenomenon. Investigative Ophthalmology & Visual Science, 1994. 35: p. 3825-3834.
19. K. Yaoeda, M.S.S.F.H.F.T.N. and H. Abe, Measurement of microcirculation in the optic nerve head by laser speckle flowgraphy and scanning laser Doppler flowmetry. Am J Ophthalmol, 2000. 129: p. 734-9.
20. H. Cheng, Q.L.Q.L.Q.L.H.G. and S. Zeng, Laser speckle imaging of blood flow in microcirculation. Phys Med Biol, 2004. 49: p. 1347-57.
21. W. Lau, S.T. and N.V. Thakor, Spatiotemporal characteristics of low-frequency functional activation measured by laser speckle imaging. Neural Systems and Rehabilitation Engineering, IEEE Transactions on, 2005. 13: p. 179-185.
22. D. Zhu, W.L.Y.W.H.C. and Q. Luo, Monitoring thermal-induced changes in tumor blood flow and microvessels with laser speckle contrast imaging. Applied Optics, 2007. 46: p. 1911-1917.
23. H. Cheng, Q.L.S.Z.S.C.J.C. and H. Gong, Modified laser speckle imaging method with improved spatial resolution. J Biomed Opt, 2003. 8: p. 559-64.
24. Briers, J.D. and S. Webster, Laser speckle contrast analysis (LASCA): a nonscanning, full-field technique for monitoring capillary blood flow. Journal of Biomedical Optics, 1996. 1: p. 174-179.
25. J. D. Briers, G.R. and X.W. He, Capillary blood flow monitoring using laser speckle contrast analysis (LASCA). Journal of Biomedical Optics, 1999. 4: p. 164-175.
26. H. Cheng, Q.L.S.Z.S.C.J.C. and H. Gong, Modified laser speckle imaging method with improved spatial resolution. Journal of Biomedical Optics, 2003. 8: p. 559-564.
27. Rigden, J.D. and E.I. Gordon, The granularity of scattered optical maser light. Proc. IRE, 1962. 50: p. 2367-2368.
28. Goodman, J.W., Some fundamental properties of speckle. J. Opt. Soc. Am, 1976. 66: p. 1145-1150.
29. Briers, J.D., Laser Doppler, speckle and related techniques for blood perfusion mapping and imaging. Physiol. Meas, 2001. 22.
30. Rigden, J.D. and E.I. Gordon, The granularity of scattered optical maser light: SPIE-THE INTERNATIONAL SOCIETY FOR OPTICAL ENGINEERING. 1997.
31. Oliver, B.M., Sparkling spots and random diffraction. Proceedings of the IEEE, 1963. 51: p. 220-221.
32. Goodman, J.W., Some fundamental properties of speckle. Journal of optical society of American, 1976. 66: p. 1145-1150.
33. Goodman, J.W., Statistical properties of laser sparkle patterns. Technical Report SEL-63-140 (TR2303-1), Stanford Electronics Laboratories, 1963.
34. Goldfischer, L.I., Autocorrelation function and power spectral density of laser -produced speckle patterns. Journal of optical society of American, 1965. 55: p. 247-253.
35. McKechnie, T.S., Speckle reduction. Laser Speckle and Related Phenomena, 1984: p. 123-170.
36. Briers, J.D., Time-varying laser speckle for measuring motion and flow. Proceedings of SPIE, 2003. 4242: p. 25.
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