Dynamic imaging of cerebral blood flow using laser speckle
Dynamic imaging of cerebral blood flow using laser speckle
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DOI：
10.1097/00004647-200103000-00002
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发表时间：
2001-03-01
影响因子：
6.3
通讯作者：
Boas, DA
中科院分区：
文献类型：
--
作者：
Dunn, AK;Bolay, T;Boas, DA
本文介绍了一种动态、高分辨率的脑血流（CBF）成像方法。通过用激光照射大脑皮层并对产生的散斑图案进行成像，可获得具有数十微米空间分辨率和毫秒级时间分辨率的相对脑血流图像。通过与传统的激光多普勒测量直接比较，验证了散斑技术所测量的局部脑血流变化。利用这种方法，在获取电生理记录的同时，还获得了局灶性脑缺血和皮质扩散性抑制期间相对脑血流变化的动态图像。大脑中动脉（MCA）闭塞后，散斑技术在6×4毫米的皮层区域上产生了包含缺血核心、半暗带、低灌注区和正常灌注组织的剩余脑血流梯度的高分辨率图像。连续的散斑图像显示剩余脑血流进一步减少，表明缺血区域边界清晰地扩大。皮质扩散性抑制期间的动态脑血流图像显示，有一个2到3毫米的区域脑血流增加（160%到250%），其传播速度为2到3毫米/分钟。这种技术易于实施，可用于在脑病理生理学研究中高分辨率地监测脑血流变化的时空演变。
A method for dynamic, high-resolution cerebral blood flow (CBF) imaging is presented in this article. By illuminating the cortex with laser light and imaging the resulting speckle pattern, relative CBF images with tens of microns spatial and millisecond temporal resolution are obtained. The regional CBF changes measured with the speckle technique are validated through direct comparison with conventional laser-Doppler measurements. Using this method, dynamic images of the relative CBF changes during focal cerebral ischemia and cortical spreading depression were obtained along with electrophysiologic recordings. Upon middle cerebral artery (MCA) occlusion, the speckle technique yielded high-resolution images of the residual CBF gradient encompassing the ischemic core, penumbra, oligemic, and normally perfused tissues over a 6 x 4 mm cortical area. Successive speckle images demonstrated a further decrease in residual CBF indicating an expansion of the ischemic zone with finely delineated borders. Dynamic CBF images during cortical spreading depression revealed a 2 to 3 mm area of increased CBF (160% to 250%) that propagated with a velocity of 2 to 3 mm/min. This technique is easy to implement and can be used to monitor the spatial and temporal evolution of CBF changes with high resolution in studies of cerebral pathophysiology.