Optoacoustic tomography systems have attained un-precedented volumetric imaging speeds, thus enabling insights into rapid biological dynamics and marking a milestone in the clinical translation of this modality. Fast imaging performance often comes at the cost of limited field-of-view, which may hinder potential applications looking at larger tissue volumes. The imaged field-of-view can potentially be expanded via scanning and using additional hardware to track the position of the imaging probe. However, this approach turns impractical for high-resolution volumetric scans performed in a freehand mode along arbitrary trajectories. We have developed an accurate framework for spatial compounding of time-lapse optoacoustic data. The method exploits the frequency-domain properties of vascular networks in optoacoustic images and estimates the relative motion and orientation of the imaging probe. This allows rapidly combining sequential volumetric frames into large area scans without additional tracking hardware. The approach is universally applicable for compounding volumetric data acquired with calibrated scanning systems but also in a freehand mode with up to six degrees of freedom. Robust performance is demonstrated for whole-body mouse imaging with spiral volumetric optoacoustic tomography and for freehand visualization of vascular networks in humans using volumetric imaging probes. The newly introduced capability for angiographic observations at multiple spatial and temporal scales is expected to greatly facilitate the use of optoacoustic imaging technology in pre-clinical research and clinical diagnostics. The technique can equally benefit other biomedical imaging modalities, such as scanning fluorescence microscopy, optical coherence tomography or ultrasonography, thus optimizing their trade-offs between fast imaging performance and field-of-view.

中文翻译：

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体积数据的空间复合实现了大规模血管网络的徒手光学血管造影。

光声层析成像系统已达到前所未有的体积成像速度，因此能够洞察快速的生物动力学，并标志着该模式在临床翻译中的一个里程碑。快速成像性能通常是以有限的视野为代价的，这可能会妨碍潜在的应用，例如寻找更大的组织体积。可以通过扫描并使用其他硬件跟踪成像探头的位置来扩展成像的视野。但是，这种方法对于以徒手模式沿着任意轨迹执行的高分辨率体积扫描变得不切实际。我们已经为时移光声数据的空间复合开发了一个精确的框架。该方法利用了光声图像中血管网络的频域特性，并估计了成像探头的相对运动和方向。这允许将连续的体积帧快速组合到大面积扫描中，而无需其他跟踪硬件。该方法普遍适用于复合使用校准的扫描系统获取的体积数据，但也适用于具有多达六个自由度的徒手模式。使用螺旋式体积光声层析成像对全身小鼠成像以及使用体积成像探针对人的血管网络进行徒手可视化，证明了其强大的性能。预期新引入的在多个时空尺度上进行血管造影观察的功能将极大地促进光声成像技术在临床前研究和临床诊断中的使用。该技术同样可以使其他生物医学成像方式受益，例如扫描荧光显微镜，光学相干断层扫描或超声检查，从而优化了它们在快速成像性能和视野之间的权衡。