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Noninvasive laser-induced photoacoustic tomography for structural and functional in vivo imaging of the brain


Imaging techniques based on optical contrast analysis can be used to visualize dynamic and functional properties of the nervous system via optical signals resulting from changes in blood volume, oxygen consumption and cellular swelling associated with brain physiology and pathology. Here we report in vivo noninvasive transdermal and transcranial imaging of the structure and function of rat brains by means of laser-induced photoacoustic tomography (PAT). The advantage of PAT over pure optical imaging is that it retains intrinsic optical contrast characteristics while taking advantage of the diffraction-limited high spatial resolution of ultrasound. We accurately mapped rat brain structures, with and without lesions, and functional cerebral hemodynamic changes in cortical blood vessels around the whisker-barrel cortex in response to whisker stimulation. We also imaged hyperoxia- and hypoxia-induced cerebral hemodynamic changes. This neuroimaging modality holds promise for applications in neurophysiology, neuropathology and neurotherapy.

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Figure 1
Figure 2: PAT imaging of the rat brain in vivo.
Figure 3: PAT imaging of the rat brain lesion in situ.
Figure 4: Functional imaging of cerebral hemodynamic changes in response to whisker stimulation.


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This research was supported in part by the US Department of Defense, National Institutes of Health, National Science Foundation, and Texas Advanced Research Program.

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Correspondence to Lihong V Wang.

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Wang, X., Pang, Y., Ku, G. et al. Noninvasive laser-induced photoacoustic tomography for structural and functional in vivo imaging of the brain. Nat Biotechnol 21, 803–806 (2003).

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