Matrone Giulia, Ramalli Alessandro, Savoia Alessandro Stuart, Quaglia Fabio, Castellazzi Gloria, Morbini Patrizia, Piastra Marco
Department of Electrical, Computer and Biomedical Engineering, University of Pavia.
Department of Information Engineering, University of Florence.
J Vis Exp. 2017 Sep 24(127):55798. doi: 10.3791/55798.
The possibility to perform an early and repeatable assessment of imaging performance is fundamental in the design and development process of new ultrasound (US) probes. Particularly, a more realistic analysis with application-specific imaging targets can be extremely valuable to assess the expected performance of US probes in their potential clinical field of application. The experimental protocol presented in this work was purposely designed to provide an application-specific assessment procedure for newly-developed US probe prototypes based on Capacitive Micromachined Ultrasonic Transducer (CMUT) technology in relation to brain imaging. The protocol combines the use of a bovine brain fixed in formalin as the imaging target, which ensures both realism and repeatability of the described procedures, and of neuronavigation techniques borrowed from neurosurgery. The US probe is in fact connected to a motion tracking system which acquires position data and enables the superposition of US images to reference Magnetic Resonance (MR) images of the brain. This provides a means for human experts to perform a visual qualitative assessment of the US probe imaging performance and to compare acquisitions made with different probes. Moreover, the protocol relies on the use of a complete and open research and development system for US image acquisition, i.e. the Ultrasound Advanced Open Platform (ULA-OP) scanner. The manuscript describes in detail the instruments and procedures involved in the protocol, in particular for the calibration, image acquisition and registration of US and MR images. The obtained results prove the effectiveness of the overall protocol presented, which is entirely open (within the limits of the instrumentation involved), repeatable, and covers the entire set of acquisition and processing activities for US images.
在新型超声（US）探头的设计和开发过程中，能够对成像性能进行早期且可重复的评估至关重要。特别是，使用特定应用的成像目标进行更实际的分析，对于评估US探头在其潜在临床应用领域的预期性能可能极具价值。本文介绍的实验方案是专门为基于电容式微机械超声换能器（CMUT）技术的新开发US探头原型提供一种针对脑成像的特定应用评估程序而设计的。该方案结合使用固定在福尔马林中的牛脑作为成像目标，这确保了所描述程序的真实性和可重复性，以及借鉴神经外科的神经导航技术。实际上，US探头连接到一个运动跟踪系统，该系统获取位置数据并使US图像能够叠加到大脑的参考磁共振（MR）图像上。这为人类专家提供了一种对US探头成像性能进行视觉定性评估以及比较不同探头采集图像的方法。此外，该方案依赖于使用一个完整且开放的US图像采集研发系统，即超声高级开放平台（ULA - OP）扫描仪。本文详细描述了该方案中涉及的仪器和程序，特别是US图像与MR图像的校准、图像采集和配准。所获得的结果证明了所提出的整个方案的有效性，该方案完全开放（在所涉及仪器的限制范围内）、可重复，并且涵盖了US图像的整套采集和处理活动。
