Modified laser speckle imaging method with improved spatial resolution.

A two-dimensional map of blood flow is crucial for physiological studies. We present a modified laser speckle imaging method (LSI) that is based on the temporal statistics of a time-integrated speckle. A model experiment was performed for the validation of this technique. The spatial and temporal resolutions of this method were studied in theory and compared with current laser speckle contrast analysis (LASCA); the comparison indicates that the spatial resolution of the modified LSI is five times higher than that of current LASCA. Cerebral blood flow under different temperatures was investigated by our modified LSI. Compared with the results obtained by LASCA, the blood flow map obtained by the modified LSI possessed higher spatial resolution and provided additional information about changes in blood perfusion in small blood vessels. These results suggest that this is a suitable method for imaging the full field of blood flow without scanning and provides much higher spatial resolution than that of current LASCA and other laser Doppler perfusion imaging methods.

[1]  R. Nossal,et al.  Model for laser Doppler measurements of blood flow in tissue. , 1981, Applied optics.

[2]  Shaoqun Zeng,et al.  Optical dynamic imaging of the regional blood flow in the rat mesentery under the effect of noradrenalin , 2003 .

[3]  John A. Detre,et al.  Laser Doppler Imaging of Activation-Flow Coupling in the Rat Somatosensory Cortex , 1999, NeuroImage.

[4]  G. Nilsson,et al.  Evaluation of enhanced high-resolution laser Doppler imaging in an in vitro tube model with the aim of assessing blood flow in separate microvessels. , 1998, Microvascular research.

[5]  P O Byrne,et al.  A laser Doppler scanner for imaging blood flow in skin. , 1991, Journal of biomedical engineering.

[6]  D. Kleinfeld,et al.  Fluctuations and stimulus-induced changes in blood flow observed in individual capillaries in layers 2 through 4 of rat neocortex. , 1998, Proceedings of the National Academy of Sciences of the United States of America.

[7]  Hitoshi Fujii,et al.  Real-time visualization of retinal microcirculation by laser flowgraphy , 1995 .

[8]  Wiendelt Steenbergen,et al.  Laser Doppler perfusion imaging with a complimentary metal oxide semiconductor image sensor. , 2002, Optics letters.

[9]  Andrew K. Dunn,et al.  Intrinsic brain activity triggers trigeminal meningeal afferents in a migraine model , 2002, Nature Medicine.

[10]  M. Moskowitz,et al.  Dynamic Imaging of Cerebral Blood Flow Using Laser Speckle , 2001, Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism.

[11]  Toshimitsu Asakura,et al.  Velocity measurement of a diffuse object by using time-varying speckles , 1976 .

[12]  Cheng Hai-ying.  Optical Monitoring of the Dynamic Change of Blood Perfusion , 2003 .

[13]  J D Briers,et al.  Laser speckle contrast analysis (LASCA): a nonscanning, full-field technique for monitoring capillary blood flow. , 1996, Journal of biomedical optics.

[14]  J. David Briers,et al.  Laser Doppler and time-varying speckle: a reconciliation , 1996 .