Optoacoustic imaging at kilohertz volumetric frame rates.

Daniel Razansky,Ali Özbek,Xosé Luís Deán-Ben

doi:10.1364/optica.5.000857

Abstract

State-of-the-art optoacoustic tomographic imaging systems have been shown to attain three-dimensional (3D) frame rates of the order of 100 Hz. While such a high volumetric imaging speed is beyond reach for other bio-imaging modalities, it may still be insufficient to accurately monitor some faster events occurring on a millisecond scale. Increasing the 3D imaging rate is usually hampered by the limited throughput capacity of the data acquisition electronics and memory used to capture vast amounts of the generated optoacoustic (OA) data in real time. Herein, we developed a sparse signal acquisition scheme and a total-variation-based reconstruction approach in a combined space-time domain in order to achieve 3D OA imaging at kilohertz rates. By continuous monitoring of freely swimming zebrafish larvae in a 3D region, we demonstrate that the new approach enables significantly increasing the volumetric imaging rate by using a fraction of the tomographic projections without compromising the reconstructed image quality. The suggested method may benefit studies looking at ultrafast biological phenomena in 3D, such as large-scale neuronal activity, cardiac motion, or freely behaving organisms.

Highlights

State-of-the-art optoacoustic tomographic imaging systems have been shown to attain threedimensional (3D) frame rates of the order of 100 Hz
Volumetric data acquisition (DAQ) and real-time 3D image rendering at 100 Hz frame rates have been demonstrated with high-end Optoacoustic tomography (OAT) systems employing matrix detection arrays and GPU-based processing of the generated data flows in the gigabits per second range [7,8,9]
Performance of the sparse acquisition total variation (TV)-based reconstruction algorithm was first validated by numerically simulating volumetric imaging of the moving absorbing sphere

Summary

Introduction

State-of-the-art optoacoustic tomographic imaging systems have been shown to attain threedimensional (3D) frame rates of the order of 100 Hz. Volumetric data acquisition (DAQ) and real-time 3D image rendering at 100 Hz frame rates have been demonstrated with high-end OAT systems employing matrix detection arrays and GPU-based processing of the generated data flows in the gigabits per second range [7,8,9] With this volumetric imaging speed it became possible to efficiently monitor fast biological phenomena, such as calcium transients in the brain [10] or cardiovascular dynamics [9,11], whereas spiral volumetric optoacoustic tomography (SVOT) further enabled scaling of temporal resolution with the field of view to attain multiscale dynamic imaging capabilities [12]. We take this approach one step further by incorporating a total variation (TV) regularization term in the combined spatio-temporal domain in order to achieve significant acceleration of 3D imaging frame rates with negligible effects on the resulting image quality

Methods

Results

Conclusion