Dual‐wavelength hybrid optoacoustic‐ultrasound biomicroscopy for functional imaging of large‐scale cerebral vascular networks

Abstract

A critical link exists between pathological changes of cerebral vasculature and diseases affecting brain function. Microscopic techniques have played an indispensable role in the study of neurovascular anatomy and functions. Yet, investigations are often hindered by suboptimal trade-offs between the spatiotemporal resolution, field-of-view (FOV) and type of contrast offered by the existing optical microscopy techniques. We present a hybrid dual-wavelength optoacoustic (OA) biomicroscope capable of rapid transcranial visualization of large-scale cerebral vascular networks. The system offers 3-dimensional views of the morphology and oxygenation status of the cerebral vasculature with single capillary resolution and a FOV exceeding 6 × 8 mm , thus covering the entire cortical vasculature in mice. The large-scale OA imaging capacity is complemented by simultaneously acquired pulse-echo ultrasound (US) biomicroscopy scans of the mouse skull. The new approach holds great potential to provide better insights into cerebrovascular function and facilitate efficient studies into neurological and vascular abnormalities of the brain.

Cortex‐wide microcirculation mapping with ultrafast large‐field multifocal illumination microscopy

“…Finally, optical-resolution optoacoustic microscopy has recently demonstrated label-free imaging of murine cerebrovascular dynamics with high resolution [10]. Yet, imaging of large FOVs implied the use of mechanical transducer scanning, which resulted in effective acquisition times in the minutes range, for example, when imaging the entire mouse cortex [11,12].…”

Wearable optical resolution photoacoustic microscopy

“…Optical resolution photoacoustic microscopy (ORPAM), featuring high spatial resolution, deep penetration depth and large FOV, is a noninvasive and label‐free imaging approach capable of monitoring brain hemodynamics at microscale level . Current developments of ORPAM mainly focus on miniaturization of the device using new scanning mechanisms and optical/acoustic scanners .…”

Optical-Resolution Photoacoustic Microscopy Using Transparent Ultrasound Transducer

“…The focused light is directly delivered through a hole at the center of the transducer, or coupled using a single-mode fiber integrated with a gradient-index (GRIN) lens. The imaging head is then two-dimensionally raster-scanned using mechanical stages to generate volumetric images [8][9][10][11][12]. Although the imaging head is miniaturized in these OR-PAM systems, the FOV, numerical aperture, and imaging speed (due to physical scanning of the imaging head) are still limited.…”