Zhao Jim, Nozdriukhin Daniil, Razansky Daniel, Dean-Ben Xose Luis
Opt Lett. 2025 May 1;50(9):2966-2969. doi: 10.1364/OL.557507.
Localization optoacoustic tomography (LOT) has recently been suggested for enhancing spatial resolution in optoacoustic imaging beyond the acoustic diffraction barrier and further enabling measuring blood flow velocity. LOT relies on tracking highly absorbing particles in a sequence of images acquired following intravenous injection. Much like for other high-resolution imaging methods, the achievable resolution is afflicted by physiological motion. Inter-frame displacements further hamper particle tracking and accurate velocity measurements. Herein, we propose a geometric-transformation-based approach to align motion-affected frames to a reference frame. This is achieved with a singular value decomposition (SVD) clutter filter, clustering the acquired sequence into low-order singular vectors representing blood-vessel background and high-order singular values related to flowing particles. Motion estimation is then performed in the background sequence, and localization and tracking are subsequently done in the flowing-particle sequence after motion correction. The enhanced performance achieved with the suggested approach is demonstrated in phantom experiments and LOT images of the mouse brain.
局部光声层析成像（LOT）最近被提出用于在光声成像中提高空间分辨率，突破声学衍射极限，并进一步实现血流速度测量。LOT依赖于在静脉注射后采集的一系列图像中跟踪高吸收性粒子。与其他高分辨率成像方法类似，可实现的分辨率受到生理运动的影响。帧间位移进一步阻碍了粒子跟踪和精确的速度测量。在此，我们提出一种基于几何变换的方法，将受运动影响的帧与参考帧对齐。这通过奇异值分解（SVD）杂波滤波器实现，将采集到的序列聚类为表示血管背景的低阶奇异向量和与流动粒子相关的高阶奇异值。然后在背景序列中进行运动估计，随后在运动校正后的流动粒子序列中进行定位和跟踪。在体模实验和小鼠大脑的LOT图像中证明了所提方法实现的增强性能。
