Simultaneous scattering-absorption dual-modal cell imaging in a single shot by a transmission-mode photoacoustic microscope

Abstract

A microscopy scheme is proposed to simultaneously achieve optical scattering-absorption dual-contrast imaging of a transparent or semi-transparent specimen. This scheme is based on a transmission-mode photoacoustic microscope. We find that two peaks exist in the detected photoacoustic signal. One peak is caused by the optical absorption of the specimen, and the other is related to both the optical scattering and absorption of the specimen. Therefore, both the absorption and scattering information can be simultaneously extracted by analyzing the same photoacoustic signal excited by a single-shot laser pulse. After the microscope is validated by imaging a binary mixture consisting of particles with different optical properties, it successfully acquires dual images of red blood cells with different contrasts. Quantitative analysis reveals that the optical absorption and scattering properties of the specimen can be derived from the two images. The proposed dual-modal imaging method would be useful in revealing the structural and functional properties of tissues at the cell level or the clinical assessment of pathological sections.

High-Sensitivity Optical-Resolution Photoacoustic Microscopy with an Optical-Acoustic Combiner Based on an Off-Axis Parabolic Acoustic Mirror

“…Moreover, it is unique among optical microscopy technologies for its label-free detection of optical absorption with a relative sensitivity of 100% [14]. Hence, OR-PAM has shown great potentials in various biomedical applications, such as brain imaging [2,5,15,16], breast cancer imaging [3], animal embryo imaging [4,17], cell imaging [18][19][20], and microcirculation imaging [6,[21][22][23][24][25][26][27][28][29][30].…”

Optical and ultrasonic dual-sensitive sensor and its application in photoacoustic microscopy

“…7) Researchers have proposed an optical scattering-absorption dual-mode imaging system to study the structural and functional properties of tissues at the cell level. [8][9][10] Usually, multi-modality imaging relies on several kinds of detectors to pick up different signals. Photodetectors, including photodiodes, phototransistors, etc., are used to detect light.…”

“…We have reported the detailed description of the dual-mode imaging system previously. 8) When the laser irradiates the sample, a part of the laser energy is absorbed and converted into ultrasound. Then the remaining photons pass through the sample and reach the dual-sensitive sensor.…”

Tunable spatiotemporal resolution photoacoustic microscopy by combining quasi-periodic scanning and register-fusion algorithm

“…PAM achieves a rich optical contrast with 100% sensitivity; moreover, it exhibits good biological safety owing to its nonionizing radiation, and can sensitively reveal structural and functional information of biological tissues. PAM has great application potential in biomedicine fields, including organology, 2) histology, [3][4][5] cytology, [6][7][8] vascular biology, [9][10][11][12][13][14][15] oncology, [6][7][8][9][10][11][12][13][14][15][16][17][18] neuroscience, 19,20) ophthalmology, 21,22) stomatology, 23,24) and dermatology. 25) PAM imaging usually relies on a point-by-point scanning scheme.…”

“…The spatial resolution and temporal resolution of a PAM are both highly related to the design of the scanning path. Theoretically, the spatial resolution in the lateral direction of a PAM depends on the size of the optical focus (opticalresolution PAM) [8][9][10]13,14,18,24,28) or the acoustic focus (acoustic-resolution PAM). 2,3,13,17,20,25) However, if the scanning step size is larger than the laser spot or acoustic focus, the practical spatial resolution of the image depends on the scanning line spacing.…”