Optical ultrasound image correction with fibre-optic shape sensors - data

<b>Significance:</b> Optical ultrasound (OpUS) imaging, in which ultrasound is generated and received optically, is well suited to guiding minimally procedures. 2D images can be synthesized by translation of an OpUS probe within the body. If the probe positions are not known precisely, spatial distortions in the images may occur. Fibre-optic shape sensors offer the possibility to reduce distortions by providing real-time probe positions in an all-optical, miniaturized device.<b>Aim:</b> We aimed to correct 2D OpUS images acquired with a forward-looking OpUS probe during scanning at non-uniform speeds, using tip position data from a fibre-optic shape sensor.<b>Approach:</b> An OpUS probe was combined with a fibre-optic shape sensor to allow for real-time acquisition of both ultrasound depth scans and probe tip positions, as the probe was scanned at varying speed across a wire grille imaging phantom. The resulting distorted OpUS images were corrected using the shape sensor position data.<b>Results:</b> The corrected images corresponded well to the true positions of the wires in the phantom, and distortions in the raw images caused by pauses and varying speeds of the probe movement were largely removed.<b>Conclusions:</b> Fibre-optic shape sensing is a promising modality for reducing distortions during 2D OpUS images acquired by translating single-element optical transducers.

**研究意义：** 光学超声（Optical Ultrasound, OpUS）成像技术通过光学方式生成并接收超声，非常适合辅助微创操作。通过在体内平移光学超声探头，可合成二维超声图像。若探头位置无法精确获知，则可能导致图像出现空间畸变。光纤形状传感器能够以全光学、小型化的设备实时获取探头位置，从而有望减少此类图像畸变。

**研究目标：** 本研究旨在借助光纤形状传感器获取的探头尖端位置数据，校正以非匀速扫描的前视型光学超声探头采集到的二维OpUS图像。

**研究方法：** 本研究将光学超声探头与光纤形状传感器集成，当探头以变速扫过金属丝格栅成像体模时，可同步采集超声深度扫描数据与探头尖端位置信息。随后利用形状传感器的位置数据，对采集到的畸变OpUS图像进行校正。

**研究结果：** 校正后的图像与体模中金属丝的真实位置高度吻合，原始图像中因探头暂停与变速运动导致的畸变已基本消除。

**研究结论：** 光纤形状传感技术在通过平移单元件光学换能器采集二维OpUS图像的过程中，具备降低图像畸变的良好应用前景。