Huang Xinyue, Hooshangnejad Hamed, China Debarghya, Feng Ziwei, Lee Junghoon, Bell Muyinatu A Lediju, Ding Kai
Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21287, USA.
Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University, Baltimore, MD 21287, USA.
Cancers (Basel). 2023 Jun 22;15(13):3294. doi: 10.3390/cancers15133294.
Pancreatic cancer with less than 10% 3-year survival rate is one of deadliest cancer types and greatly benefits from enhanced radiotherapy. Organ motion monitoring helps spare the normal tissue from high radiation and, in turn, enables the dose escalation to the target that has been shown to improve the effectiveness of RT by doubling and tripling post-RT survival rate. The flexible array transducer is a novel and promising solution to address the limitation of conventional US probes. We proposed a novel shape estimation for flexible array transducer using two sequential algorithms: (i) an optical tracking-based system that uses the optical markers coordinates attached to the probe at specific positions to estimate the array shape in real-time and (ii) a fully automatic shape optimization algorithm that automatically searches for the optimal array shape that results in the highest quality reconstructed image. We conducted phantom and in vivo experiments to evaluate the estimated array shapes and the accuracy of reconstructed US images. The proposed method reconstructed US images with low full-width-at-half-maximum (FWHM) of the point scatters, correct aspect ratio of the cyst, and high-matching score with the ground truth. Our results demonstrated that the proposed methods reconstruct high-quality ultrasound images with significantly less defocusing and distortion compared with those without any correction. Specifically, the automatic optimization method reduced the array shape estimation error to less than half-wavelength of transmitted wave, resulting in a high-quality reconstructed image.
三年生存率低于10%的胰腺癌是最致命的癌症类型之一，强化放疗对其有很大益处。器官运动监测有助于使正常组织免受高剂量辐射，进而能够提高对靶区的照射剂量，已证明这可使放疗后的生存率提高两倍甚至三倍，从而提高放疗效果。柔性阵列换能器是解决传统超声探头局限性的一种新颖且有前景的方案。我们提出了一种针对柔性阵列换能器的新颖形状估计方法，该方法使用两种顺序算法：（i）基于光学跟踪的系统，该系统利用附着在探头特定位置的光学标记坐标实时估计阵列形状；（ii）一种全自动形状优化算法，该算法自动搜索能产生最高质量重建图像的最佳阵列形状。我们进行了体模和体内实验，以评估估计的阵列形状以及重建超声图像的准确性。所提出的方法重建的超声图像具有点散射的低半高宽（FWHM）、囊肿的正确纵横比以及与真实情况的高匹配分数。我们的结果表明，与未进行任何校正的图像相比，所提出的方法重建的超声图像散焦和失真明显更少。具体而言，自动优化方法将阵列形状估计误差降低到小于发射波的半波长，从而得到高质量的重建图像。
