MR-guided transcranial brain HIFU in small animal models
MR-guided transcranial brain HIFU in small animal models
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DOI：
10.1088/0031-9155/55/2/003
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发表时间：
2010-01-21
影响因子：
3.5
通讯作者：
Tanter, M.
中科院分区：
文献类型：
--
作者：
Larrat, B.;Pernot, M.;Tanter, M.
最近的研究已经证明了使用自适应聚焦技术的经颅高强度聚焦超声（HIFU）治疗大脑的可行性。然而，程序的复杂性要求提供这种新兴治疗方式的准确靶向、监测和控制，以确保治疗的安全性并避免超声对健康组织的潜在破坏作用。为了这些目的，一个完整的工作流程和设置磁共振（MR）的指导下的HIFU治疗提出并实施大鼠。第一次，由声辐射力引起的组织位移在体内脑组织中检测和定量测量使用运动敏感的MR序列。这样一个有价值的目标控制治疗前评估质量的聚焦模式在原位，使我们能够估计在焦点上的声强度。然后将该MR声辐射力成像与用于跟踪HIFU治疗期间的温度变化的常规MR温度测量序列相关联。最后，治疗前和治疗后的磁共振弹性成像（MRE）数据集的采集和评估作为一种新的潜在的方式来非侵入性地控制由于存在热坏死的刚度变化。作为概念的证明，MR引导的HIFU在体外火鸡乳房样本和体内经颅大鼠脑实验中进行。实验使用专用的MR兼容HIFU设置在高场MRI扫描仪（7 T）中进行。在大鼠身上获得的结果证实，无论是MR定位的US焦点和前和后的HIFU测量的组织硬度，连同温度控制在HIFU是可行的和有价值的技术，有效地监测HIFU在大脑中。脑弹性似乎对水肿的存在比对组织坏死更敏感。
Recent studies have demonstrated the feasibility of transcranial high-intensity focused ultrasound (HIFU) therapy in the brain using adaptive focusing techniques. However, the complexity of the procedures imposes provision of accurate targeting, monitoring and control of this emerging therapeutic modality in order to ensure the safety of the treatment and avoid potential damaging effects of ultrasound on healthy tissues. For these purposes, a complete workflow and setup for HIFU treatment under magnetic resonance (MR) guidance is proposed and implemented in rats. For the first time, tissue displacements induced by the acoustic radiation force are detected in vivo in brain tissues and measured quantitatively using motion-sensitive MR sequences. Such a valuable target control prior to treatment assesses the quality of the focusing pattern in situ and enables us to estimate the acoustic intensity at focus. This MR-acoustic radiation force imaging is then correlated with conventional MR-thermometry sequences which are used to follow the temperature changes during the HIFU therapeutic session. Last, pre- and post-treatment magnetic resonance elastography (MRE) datasets are acquired and evaluated as a new potential way to non-invasively control the stiffness changes due to the presence of thermal necrosis. As a proof of concept, MR-guided HIFU is performed in vitro in turkey breast samples and in vivo in transcranial rat brain experiments. The experiments are conducted using a dedicated MR-compatible HIFU setup in a high-field MRI scanner (7 T). Results obtained on rats confirmed that both the MR localization of the US focal point and the pre- and post-HIFU measurement of the tissue stiffness, together with temperature control during HIFU are feasible and valuable techniques for efficient monitoring of HIFU in the brain. Brain elasticity appears to be more sensitive to the presence of oedema than to tissue necrosis.