Bauer-Marschallinger Johannes, Höllinger Astrid, Jakoby Bernhard, Burgholzer Peter, Berer Thomas
Research Center for Non-Destructive Testing GmbH (RECENDT), Altenberger Straße 69, 4040 Linz, Austria.
Institute for Microelectronics and Microsensors, Johannes Kepler University, Altenberger Straße 69, 4040 Linz, Austria.
Photoacoustics. 2017 Jan 25;5:1-9. doi: 10.1016/j.pacs.2017.01.001. eCollection 2017 Mar.
We report on a novel imaging system for large depth of field photoacoustic scanning macroscopy. Instead of commonly used piezoelectric transducers, fiber-optic based ultrasound detection is applied. The optical fibers are shaped into rings and mainly receive ultrasonic signals stemming from the ring symmetry axes. Four concentric fiber-optic rings with varying diameters are used in order to increase the image quality. Imaging artifacts, originating from the off-axis sensitivity of the rings, are reduced by coherence weighting. We discuss the working principle of the system and present experimental results on tissue mimicking phantoms. The lateral resolution is estimated to be below 200 μm at a depth of 1.5 cm and below 230 μm at a depth of 4.5 cm. The minimum detectable pressure is in the order of 3 Pa. The introduced method has the potential to provide larger imaging depths than acoustic resolution photoacoustic microscopy and an imaging resolution similar to that of photoacoustic computed tomography.
我们报道了一种用于大景深光声扫描显微镜的新型成像系统。该系统采用基于光纤的超声检测，而非常用的压电换能器。光纤被制成环形，主要接收源自环形对称轴的超声信号。为提高图像质量，使用了四个直径不同的同心光纤环。通过相干加权减少了由环的离轴灵敏度产生的成像伪影。我们讨论了该系统的工作原理，并展示了在组织模拟体模上的实验结果。在1.5厘米深度处，横向分辨率估计低于200微米；在4.5厘米深度处，低于230微米。最小可检测压力约为3帕。所介绍的方法有可能提供比声学分辨率光声显微镜更大的成像深度，以及与光声计算机断层扫描相似的成像分辨率。
