Technical Note: In vivo Young's modulus mapping of pancreatic ductal adenocarcinoma during HIFU ablation using harmonic motion elastography (HME).
Technical Note: In vivo Young's modulus mapping of pancreatic ductal adenocarcinoma during HIFU ablation using harmonic motion elastography (HME).
复制标题
技术说明：使用谐波运动弹性成像 (HME) 对 HIFU 消融过程中的胰腺导管腺癌进行体内杨氏模量测绘。
DOI：
10.1002/mp.13170
复制
发表时间：
2018
期刊：
影响因子：
3.8
通讯作者：
Konofagou,ElisaE
中科院分区：
文献类型：
--
作者：
Nabavizadeh,Alireza;Payen,Thomas;Saharkhiz,Niloufar;McGarry,Matthew;Olive,KennethP;Konofagou,ElisaE
目的在高强度聚焦超声(HIFU)消融术中对凝固组织进行无创性定量评估是肿瘤治疗的重要步骤之一，特别是对早期诊断概率低、晚期易形成化疗耐药的实体癌的胰腺导管腺癌(PDA)。这项基于谐波运动成像(HMI)的技术旨在非侵入性地绘制组织的杨氏模数或硬度。聚焦超声(FUS)换能器在其焦点区域产生振荡的声辐射力。通过跟踪在高帧速率下采集的射频(RF)信号来生成二维(2D)剪切波速以及相应的杨氏模量图。采用相同的方法将超声作用时间延长50多小时，重建二维杨氏模图，同时应用高强度聚焦超声对动脉导管未闭小鼠肿瘤进行消融。结果首次在模拟组织模型中评价了该技术测量局部杨氏模数的可行性。每个重建的杨氏模量图的对比度噪声比(CNR)均大于11.7dB.这项验证研究的平均误差被发现等于小于19%。然后将HME应用于两只胰腺导管腺癌转基因小鼠。高强度聚焦超声治疗开始时肿瘤的杨氏模数中位值为2.1kPa，而经S超声45h后，肿瘤的杨氏模数中位数约为6.7kPa3倍。结论HME通过测量组织内传播的剪切波速度并重建二维杨氏模量图，显示了其无创性测量组织硬度的能力。因此，在此首次报告了在HIFU期间活体应用该方法的情况。
PurposeNoninvasive quantitative assessment of coagulated tissue during high‐intensity focused ultrasound (HIFU) ablation is one of the essential steps for tumor treatment, especially in such cases as the Pancreatic Ductal Adenocarcinoma (PDA) that has low probability of diagnosis at the early stages and high probability of forming solid carcinomas resistant to chemotherapy treatment at the late stages.MethodsHarmonic motion elastography (HME) is a technique for the localized estimation of tumor stiffness. This harmonic motion imaging (HMI)‐based technique is designed to map the tissue Young's modulus or stiffness noninvasively. A focused ultrasound (FUS) transducer generates an oscillating, acoustic radiation force in its focal region. The two‐dimensional (2D) shear wave speed, and consequently the Young's modulus maps, is generated by tracking the radio frequency (RF) signals acquired at high frame rates. By prolonging the sonication for more than 50 s using the same methodology, the 2D Young's modulus maps are reconstructed while HIFU is applied and ablation is formed on PDA murine tumors.ResultsThe feasibility of this technique in measuring the regional Young's modulus was first assessed in tissue‐mimicking phantoms. The contrast‐to‐noise ratio (CNR) was found to be higher than 11.7 dB for each 2D reconstructed Young's modulus map. The mean error in this validation study was found to be equal to less than 19%. Then HME was applied on two transgenic mice with pancreatic ductal adenocarcinoma tumors. The Young's modulus median value of this tumor at the start of the HIFU application was equal to 2.1 kPa while after 45 s of sonication it was found to be approximately three times stiffer (6.7 kPa).ConclusionsThe HME was described herein and showed its capability of measuring tissue stiffness noninvasively by measuring the shear wave speed propagation inside the tissue and reconstructing a 2D Young's modulus map. Application of the methodologyin vivoand during HIFU were thus reported here for the first time.