Imaging of Single Transducer-Harmonic Motion Imaging-Derived Displacements at Several Oscillation Frequencies Simultaneously.
Imaging of Single Transducer-Harmonic Motion Imaging-Derived Displacements at Several Oscillation Frequencies Simultaneously.
复制标题
DOI：
10.1109/tmi.2022.3178897
复制
发表时间：
2022-11
影响因子：
10.6
通讯作者：
中科院分区：
文献类型：
--
作者：
根据运动频率绘制力学特性图与诊断、监测治疗反应或术中手术切除计划相关。虽然在不同频率下的剪切波速度已在其他地方进行了描述，但频率对“轴上”声辐射力（ARF）引起的位移的影响以前尚未研究过。提出了一种新颖的多频激励脉冲，用于同时产生100-1000 Hz的峰间位移图像，而不是产生特定频率下的单换能器谐波运动成像（ST-HMI）衍生的峰间位移（P2PD）图像。建议的激发脉冲的性能进行比较，ARFI通过成像16个不同的夹杂物（杨氏模量为6，9，36，70千帕和直径为1.6，2.5，6.5，和10.4毫米）嵌入在18千帕的背景。根据夹杂物的大小和硬度，在不同的频率下达到最大CNR和对比度，并且总是高于ARFI。达到最大CNR和对比度的频率随固定夹杂物尺寸的刚度而增加，随固定刚度的尺寸而减少。通过在注射肿瘤细胞后第6、12和19天对4 T1乳腺癌小鼠肿瘤成像来测试体内可行性。与幻影相似，ST-HMI图像的CNR高于ARFI，并且在第6天随着肿瘤频率的增加而增加。此外，在100-1000 Hz下的P2PD表明，随着时间的推移，肿瘤相对于邻近的非癌组织变得更硬。这些结果表明，使用多频激励脉冲以多个频率同时产生位移以更好地描绘内含物或肿瘤的重要性。
Mapping of mechanical properties, dependent on the frequency of motion, is relevant in diagnosis, monitoring treatment response, or intra-operative surgical resection planning. While shear wave speeds at different frequencies have been described elsewhere, the effect of frequency on the “on-axis” acoustic radiation force (ARF)-induced displacement has not been previously investigated. Instead of generating single transducer-harmonic motion imaging (ST-HMI)-derived peak-to-peak displacement (P2PD) image at a particular frequency, a novel multi-frequency excitation pulse is proposed to generate P2PD images at 100–1000 Hz simultaneously. The performance of the proposed excitation pulse is compared with the ARFI by imaging 16 different inclusions (Young’s moduli of 6, 9, 36, 70 kPa and diameters of 1.6, 2.5, 6.5, and 10.4 mm) embedded in an 18 kPa background. Depending on inclusion size and stiffness, the maximum CNR and contrast were achieved at different frequencies and were always higher than ARFI. The frequency, at which maximum CNR and contrast were achieved, increased with stiffness for fixed inclusion’s size and decreased with size for fixed stiffness. In vivo feasibility is tested by imaging a 4T1 breast cancer mouse tumor on Day 6, 12, and 19 post-injection of tumor cells. Similar to phantoms, the CNR of ST-HMI images was higher than ARFI and increased with frequency for the tumor on Day 6. Besides, P2PD at 100–1000 Hz indicated that the tumor became stiffer with respect to the neighboring non-cancerous tissue over time. These results indicate the importance of using a multi-frequency excitation pulse to simultaneously generate displacement at multiple frequencies to better delineate inclusions or tumors.