Close

Search

Search Menu
Photonics Media Photonics Buyers' Guide Photonics Spectra BioPhotonics EuroPhotonics Vision Spectra Photonics Showcase Photonics ProdSpec Photonics Handbook
More News

Photoacoustic Microscopy System Improves SNR, Resolution

Facebook Twitter LinkedIn Email Comments
A superresolution localization photoacoustic microscopy (PAM) technique has been developed by a team at Pohang University of Science and Technology (POSTECH). The new system can monitor the flow of red blood cells without using a contrast absorber, enabling it to image blood vessels with exceptional resolution. Spatial resolution is improved by a factor of 2.5 in vivo, the team said.

The new system uses a stable, commercially available galvanometer scanner with a custom-made scanning mirror. This novel hardware implementation enhances the temporal resolution of the microscope significantly while maintaining a high signal-to-noise ratio (SNR). The new system has a fast B-mode rate (500 Hz).

The researchers used their system to photoacoustically and noninvasively observe the microvasculatures of small animals and humans in vivo. The blood flow rate in the microvasculatures was successfully monitored and quantified in vivo. The researchers were able to obtain microvascular images in human cuticles in just 2 seconds. They visualized the flow of red blood cells in a mouse ear and quantified the flow rate. They were able to apply the localization process to in vivo PAM images without any agent.

Photoacoustic images of microvessels in the ears, eyes, and brains of mice captured by the newly developed photoacoustic microscopy. Courtesy of Chulhong Kim/POSTECH.

Photoacoustic images of microvessels in the ears, eyes, and brains of mice captured by the newly developed photoacoustic microscopy. Courtesy of Chulhong Kim/POSTECH.

Conventional PAM systems are hampered by limited temporal and/or spatial resolution. The POSTECH system, which can scan photoacoustic waves and optical beams simultaneously, shows promise as a tool for the diagnosis and treatment of stroke and cardiovascular disease. It can monitor and image the blood vessels with the flow of blood cells in real time, making it a potentially useful tool for diagnosing and treating urgent cases of vascular disease. Moreover, it allows direct monitoring of hemodynamics in the microvessels and could be applied in various fields including hemodynamic response.

(left) Photoacoustic image of microvessels in a mouse ear (Middle) Photoacoustic image obtained by applying the localization method without using a contrast absorber. It shows enhanced images of microvessels which cannot be seen with the conventional photoacoustic microscopy system. (Right) Three-dimensional image of the microvascular structure shown in the middle image. Courtesy of Chulhong Kim/POSTECH.

(Left) Photoacoustic image of microvessels in a mouse ear. (Center) Photoacoustic image obtained by applying the localization method without using a contrast absorber. It shows enhanced images of microvessels that cannot be seen with the conventional photoacoustic microscopy system. (Right) Three-dimensional image of the microvascular structure shown in the center image. Courtesy of Chulhong Kim/POSTECH.

“We successfully imaged microvessels in the ears, eyes, and brains of mice and a human fingertip with this new photoacoustic microscopy system,” professor Chulhong Kim said. “What we have developed can be a complementary tool to the conventional brain imaging system and it can also be a promising tool for future preclinical and clinical studies.”

The research was published in Light: Science & Applications (www.doi.org/10.1038/s41377-019-0220-4). 

BioPhotonics
Mar/Apr 2020
GLOSSARY
photoacoustic imaging
Abbreviated PAI. An imaging modality with a hybrid technique based on the acoustic detection of optical absorption from endogenous chromophores or exogenous contrast agents. Light is absorbed by the chromophores and converted into transient heating, and through thermoelastic expansion there is a resulting emission of ultrasonic waves. In tissue, ultrasound scatters less than light, therefore PAI generates high-resolution images in the diffusive and optical ballistic regimes compared to purely...
Research & TechnologyeducationAsia-PacificPohang University of Science & Technologyimaginglight sourcesopticsSensors & DetectorsMicroscopyPhotoacoustic Microscopyphotoacoustic imagingmirrorsBiophotonicsmedicalBioScan

Comments
back to top
Facebook Twitter Instagram LinkedIn YouTube RSS
©2020 Photonics Media, 100 West St., Pittsfield, MA, 01201 USA, [email protected]

Photonics Media, Laurin Publishing
x Subscribe to BioPhotonics magazine - FREE!
We use cookies to improve user experience and analyze our website traffic as stated in our Privacy Policy. By using this website, you agree to the use of cookies unless you have disabled them.