Optical coherence tomography-guided dynamic focusing for combined optical and mechanical scanning multimodal photoacoustic microscopy.

Shuliang Jiao,Arash Dadkhah

doi:10.1117/1.jbo.24.12.121906

Abstract

.To achieve fast imaging and large field of view (FOV), we improved our multimodal imaging system, which integrated optical resolution photoacoustic microscopy, optical coherence tomography (OCT), and confocal fluorescence microscopy in one platform, by combining optical scanning with mechanical scanning. To ensure good focusing of the objective lens over all the imaged area, we employed OCT-guided dynamic focusing. Different from our previous point-by-point dynamic focusing, we employed an area-by-area focusing adjustment strategy, in which each fast optical scanning area has a fixed focusing depth. We have demonstrated the performance of the system by imaging biological samples ex vivo (plant leaf) and in vivo (mouse ear). The system has achieved uniform resolution in an FOV of with an imaging time of about 5 min.

Highlights

Photoacoustic microscopy (PAM) is an emerging biomedical optical imaging technology, which is capable of imaging the optical absorption contrast of biological tissues
PAM-based multimodal imaging has been achieved by combining PAM with other microscopic imaging modalities such as optical coherence tomography (OCT), optical Doppler tomography, confocal fluorescence microscopy (CFM), multiphoton microscopy, or second-harmonic generation microscopy.[1,2,3,4,5,6,7]
Field of view (FOV) and imaging speed are the two important parameters affecting the application of PAM-based multimodal imaging systems

Summary

Introduction

Photoacoustic microscopy (PAM) is an emerging biomedical optical imaging technology, which is capable of imaging the optical absorption contrast of biological tissues. PAM-based multimodal imaging technologies combine different imaging modalities to reveal complementary information of biological tissues for potential applications in both research and clinical diagnosis. Field of view (FOV) and imaging speed are the two important parameters affecting the application of PAM-based multimodal imaging systems. Using optical scanning and an unfocused ultrasonic transducer, optical-scanning PAM can achieve real-time imaging with an imaging speed depending on the pulse repetition rate (PRR) of the excitation laser. In such a configuration, the FOV is limited by the field of sensitivity of the fixed unfocused ultrasonic transducer. One method to achieve faster imaging speed and large FOV is to combine optical scanning with mechanical scanning.[13]

Methods

Results

Conclusion