Integrated multimodal photoacoustic microscopy with OCT- guided dynamic focusing

Abstract

Combining different contrast mechanisms to achieve simultaneous multimodal imaging is always desirable but is challenging due to the various optical and hardware requirements for different imaging systems. We developed a multimodal microscopic optical imaging system with the capability of providing comprehensive structural, functional and molecular information of living tissues. This imaging system integrated photoacoustic microscopy (PAM), optical coherence tomography (OCT), optical Doppler tomography (ODT) and confocal fluorescence microscopy in one platform. By taking advantage of the depth resolving capability of OCT, we developed a novel OCT-guided surface contour scanning methodology for dynamic focusing adjustment. We have conducted phantom, in vivo, and ex vivo tests to demonstrate the capability of the multimodal imaging system for providing comprehensive microscopic information of biological tissues. Integrating all the aforementioned imaging modalities with OCT-guided dynamic focusing for simultaneous multimodal imaging has promising potential for preclinical research and clinical practice in the future.

Integrating photoacoustic microscopy, optical coherence tomography, OCT angiography, and fluorescence microscopy for multimodal imaging

“…Details of the imaging system can be found in our previous publications. 17,18 In brief, a broadband superluminescent diode-based near-infrared (NIR) light source (T-840 Broadlighter, Superlum Diodes Ltd, Ireland) and a Q-switched frequency-doubled Nd:YAG laser (SPOT-10–200-532, Elforlight Ltd, wavelength: 532 nm, maximum pulse energy: 20 µJ, pulse duration: 2 ns, maximum pulse repetition rate (PRR): 30 kHz) were used for OCT/OCTA and PAM/CFM, respectively. The NIR and visible light were combined by a dichroic mirror and scanned together by a X-Y galvanometer scanner.…”

“…Multimodal imaging techniques 13–16 can overcome such limitations by providing complementary contrasts for imaging. In our previous publications, 17,18 we reported a simultaneous multimodal imaging platform, which integrated PAM, OCT, CFM, and optical Doppler tomography (ODT) 18 to offer multimodal multi-contrast imaging of biological tissues in vivo.…”

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

“…15 We have achieved OCT-guided dynamic focusing for multimodal PAM imaging and demonstrated the capability by imaging biological samples in vivo. 16 OCT-guided dynamic focusing intrinsically has better guiding accuracy and faster guiding speed due to the better spatial resolution and much faster imaging speed.…”

“…The performances of all the subimaging systems are similar to that in our previous publication. 16 We combined optical scanning with mechanical scanning to increase the imaging speed and the FOV. The scanning directions of the galvanometer mirrors are aligned with the mechanical scan.…”

Progress in Multimodal En Face Imaging: feature introduction

“…Arash Dadkhah et al [11] present a multimodal microscopic optical imaging system with the capability of providing comprehensive structural, functional and molecular information of living tissues. This imaging system integrated photoacoustic microscopy, OCT, optical Doppler tomography and confocal fluorescence microscopy in one platform.…”