Transcranial phase aberration correction using beam simulations and MR- ARFI
Transcranial phase aberration correction using beam simulations and MR- ARFI
复制标题
DOI：
10.1118/1.4865778
复制
发表时间：
2014-03-01
期刊：
影响因子：
3.8
通讯作者：
Pauly, Kim Butts
中科院分区：
文献类型：
--
作者：
Vyas, Urvi;Kaye, Elena;Pauly, Kim Butts
目的：经颅磁共振引导的聚焦超声手术是一种非侵入性的技术，用于造成选择性组织坏死。颅骨的密度、厚度和形状的变化导致聚焦区的位置和形状的畸变。在本文中，作者提出了一种混合模拟-MR-ARFI技术，以实现经颅MR引导聚焦超声手术的像差校正。该技术使用超声波束传播模拟和MR声辐射力成像（MR-ARFI）来校正颅骨引起的相位畸变。研究方法：从MR引导聚焦超声患者治疗中获得基于颅骨的数值像差，并在传输过程中将其添加到InSightec适形骨聚焦超声手术换能器的所有元件中。在第一个实验中，1024畸变来自人类头骨被压缩成16畸变平均超过64个元件的换能器区域。在第二个实验中，所有1024个像差被施加到换能器。混合模拟-MR-ARFI技术中使用的像差MR-ARFI图像，以找到16个估计的像差。从原始像差中减去这些估计的像差，得到校正图像。每个畸变实验（16-畸变和1024-畸变）重复三次。结果：在每个实验中，将校正的MR-ARFI图像与畸变图像和理想图像（零畸变图像）进行比较。混合模拟-MR-ARFI技术导致16像差和1024像差情况下的局灶MR-ARFI相位平均增加44%和52%，并且分别恢复了16像差和1024像差情况下理想MR-ARFI相位的83%和39%。结论：混合模拟-MR-ARFI技术利用一幅MR-ARFI图像，在没有相位像差先验信息的情况下，提高了光束焦点的最大MR-ARFI相位。(C)2014年美国医学物理学家协会。
Purpose: Transcranial magnetic resonance-guided focused ultrasound surgery is a noninvasive technique for causing selective tissue necrosis. Variations in density, thickness, and shape of the skull cause aberrations in the location and shape of the focal zone. In this paper, the authors propose a hybrid simulation-MR-ARFI technique to achieve aberration correction for transcranial MR-guided focused ultrasound surgery. The technique uses ultrasound beam propagation simulations with MR Acoustic Radiation Force Imaging (MR-ARFI) to correct skull-caused phase aberrations. Methods: Skull-based numerical aberrations were obtained from a MR-guided focused ultrasound patient treatment and were added to all elements of the InSightec conformal bone focused ultrasound surgery transducer during transmission. In the first experiment, the 1024 aberrations derived from a human skull were condensed into 16 aberrations by averaging over the transducer area of 64 elements. In the second experiment, all 1024 aberrations were applied to the transducer. The aberrated MR-ARFI images were used in the hybrid simulation-MR-ARFI technique to find 16 estimated aberrations. These estimated aberrations were subtracted from the original aberrations to result in the corrected images. Each aberration experiment (16-aberration and 1024-aberration) was repeated three times. Results: The corrected MR-ARFI image was compared to the aberrated image and the ideal image (image with zero aberrations) for each experiment. The hybrid simulation-MR-ARFI technique resulted in an average increase in focal MR-ARFI phase of 44% for the 16-aberration case and 52% for the 1024-aberration case, and recovered 83% and 39% of the ideal MR-ARFI phase for the 16-aberrations and 1024-aberration case, respectively. Conclusions: Using one MR-ARFI image and no a priori information about the applied phase aberrations, the hybrid simulation-MR-ARFI technique improved the maximum MR-ARFI phase of the beam's focus. (C) 2014 American Association of Physicists in Medicine.