Functional imaging of cerebrovascular activities in small animals using high‐resolution photoacoustic tomography

Abstract

Photoacoustic imaging (PAI) is a noninvasive, nonionizing modality based on the differences in light absorption of various biological tissues. PAI utilizes the endogenous contrast characteristics of traditional optical imaging, while benefiting from high spatial resolution of the ultrasound imaging. A PAI system was developed to reconstruct the two-dimensional cross section image and to visualize the cerebrovascular activities of mouse in vivo. The spatial resolution of the PAI system was determined to be 0.110 mm by a two-point-source phantom with the Rayleigh criterion. The potential applications of the system were clearly demonstrated by successfully mapping a traumatic lesion in the mouse brain cerebral cortex, by its ability to monitor physiological changes in the brain due to carotid ligation and drug stimulation, and two-dimensional sliced images of a traumatic mouse brain at different depths were also provided. Our experimental results indicate that PAI has the potential for studying of traumatic brain injury and physiological functions of the brain.

Indocyanine green loaded graphene oxide for high-efficient photoacoustic tumor therapy

“…4,5 When pulse laser irradiation to biological tissue, optical absorber in tissue can be produced ultrasonic signal based on photoacoustic e®ect. Photoacoustic signals from the biological tissue carry the light absorption characteristics of absorber in tissue.…”

“…1,4 In photoacoustic therapy, photoacoustic probes (or agents) are exposed to a pulsed laser, the light energy absorbed by photoacoustic probes can be converted into acoustic energy based on photoacoustic e®ect. [5][6][7][8][9][10][11][12][13][14] Then, the magnitude of photoacoustic amplitude can generate a strong shock wave, with peak pressure of 100 Mpa. 15 Such a strong shock wave can destroy the cell membrane, resulting in cell apoptosis.…”

Photoacoustic viscoelasticity imaging dedicated to mechanical characterization of biological tissues

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] It overcomes the resolution disadvantages of pure optical imaging and the contrast disadvantages of pure ultrasound imaging, bene¯ting from the capacity of high-resolution sensing optical contrast at depths beyond the optical transport mean-free-paths. [20][21][22][23][24][25][26][27][28][29][30][31][32][33] PA imaging is based on the PA e®ect.…”

Photoacoustic molecular imaging with functional nanoparticles

“…When the pulse laser irradiation (thermoacoustic imaging, especially with the pulse of radio frequency laser irradiation) in biological tissue, tissue optical absorption domain will produce ultrasonic signal; we call this by ultrasonic signal as the excitation light produced by PA signal. [6][7][8][9][10][11][12] The PA signal generated by the biological tissue carries the information of optical absorption characteristics of the tissue, and the optical absorption distribution image can be reconstructed by detecting the PA signal.…”