Xia Wenfeng, West Simeon J, Mari Jean-Martial, Ourselin Sebastien, David Anna L, Desjardins Adrien E
Department of Medical Physics and Biomedical Engineering, University College London, Gower Street, London WC1E 6BT, UK.
Department of Anaesthesia, Main Theatres, Maple Bridge Link Corridor, Podium 3, University College Hospital, 235 Euston Road, London NW1 2BU, UK.
Med Image Comput Comput Assist Interv. 2016 Oct;9900:353-361. doi: 10.1007/978-3-319-46720-7_41.
Ultrasound image guidance is widely used in minimally invasive procedures, including fetal surgery. In this context, maintaining visibility of medical devices is a significant challenge. Needles and catheters can readily deviate from the ultrasound imaging plane as they are inserted. When the medical device tips are not visible, they can damage critical structures, with potentially profound consequences including loss of pregnancy. In this study, we performed 3D ultrasonic tracking of a needle using a novel probe with a 1.5D array of transducer elements that was driven by a commercial ultrasound system. A fiber-optic hydrophone integrated into the needle received transmissions from the probe, and data from this sensor was processed to estimate the position of the hydrophone tip in the coordinate space of the probe. Golay coding was used to increase the signal-to-noise (SNR). The relative tracking accuracy was better than 0.4 mm in all dimensions, as evaluated using a water phantom. To obtain a preliminary indication of the clinical potential of 3D ultrasonic needle tracking, an intravascular needle insertion was performed in an pregnant sheep model. The SNR values ranged from 12 to 16 at depths of 20 to 31 mm and at an insertion angle of 49° relative to the probe surface normal. The results of this study demonstrate that 3D ultrasonic needle tracking with a fiber-optic hydrophone sensor and a 1.5D array is feasible in clinically realistic environments.
超声图像引导在包括胎儿手术在内的微创手术中被广泛应用。在此背景下，保持医疗设备的可视性是一项重大挑战。针和导管在插入时很容易偏离超声成像平面。当医疗设备尖端不可见时，它们可能会损伤关键结构，可能产生包括妊娠丢失在内的严重后果。在本研究中，我们使用一种由商用超声系统驱动的具有1.5D换能器元件阵列的新型探头对针进行了三维超声跟踪。集成在针内的光纤水听器接收来自探头的传输信号，并对该传感器的数据进行处理，以估计水听器尖端在探头坐标空间中的位置。使用格雷编码来提高信噪比（SNR）。使用水模评估时，在所有维度上相对跟踪精度均优于0.4毫米。为了初步了解三维超声针跟踪的临床潜力，在孕羊模型中进行了血管内针插入操作。在深度为20至31毫米且相对于探头表面法线的插入角度为49°时，SNR值范围为12至16。本研究结果表明，使用光纤水听器传感器和1.5D阵列进行三维超声针跟踪在临床实际环境中是可行的。
