Development and validation of a MRgHIFU non-invasive tissue acoustic property estimation technique
Development and validation of a MRgHIFU non-invasive tissue acoustic property estimation technique
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DOI：
10.1080/02656736.2016.1216184
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发表时间：
2016-01-01
影响因子：
3.1
通讯作者：
Payne, Allison
中科院分区：
文献类型：
--
作者：
Johnson, Sara L.;Dillon, Christopher;Payne, Allison
MR引导的高强度聚焦超声（MRgHIFU）非侵入性消融手术已进入临床试验，用于治疗许多病理和癌症。这些手术的剩余挑战是在面对患者特定的组织动态声学特性的情况下准确规划和监测组织加热。目前，在MRgHIFU治疗计划和监测程序中尚未实施声学特性的非侵入性测量。该方法驱动的研究提出了一种在低温HIFU声处理期间使用MR温度成像（MRTI）的技术，以非侵入性地估计组织模拟体模中的样本特定声吸收和声速值。使用测得的热性能，比吸收率（SAR）模式计算的MRTI数据和模拟SAR模式迭代生成的混合角谱（HAS）方法相比。一旦模拟和测量模式之间的误差最小化，估计的声学特性值与通过独立技术获得的真实体模值进行比较。估计值，然后用于模拟温度分布的幻影，并与实验温度分布。这项研究表明，在声吸收和声速的趋势可以非侵入性估计的平均误差分别为21%和1%。此外，使用估计的属性进行的温度预测平均在1.2摄氏度的实验峰值温度上升的幻影内匹配。在本研究中提出的组织模拟体模中取得的积极结果表明，该技术可以扩展到体内应用，改善HIFU超声处理温升预测和治疗评估。
MR-guided high-intensity focussed ultrasound (MRgHIFU) non-invasive ablative surgeries have advanced into clinical trials for treating many pathologies and cancers. A remaining challenge of these surgeries is accurately planning and monitoring tissue heating in the face of patient-specific and dynamic acoustic properties of tissues. Currently, non-invasive measurements of acoustic properties have not been implemented in MRgHIFU treatment planning and monitoring procedures. This methods-driven study presents a technique using MR temperature imaging (MRTI) during low-temperature HIFU sonications to non-invasively estimate sample-specific acoustic absorption and speed of sound values in tissue-mimicking phantoms. Using measured thermal properties, specific absorption rate (SAR) patterns are calculated from the MRTI data and compared to simulated SAR patterns iteratively generated via the Hybrid Angular Spectrum (HAS) method. Once the error between the simulated and measured patterns is minimised, the estimated acoustic property values are compared to the true phantom values obtained via an independent technique. The estimated values are then used to simulate temperature profiles in the phantoms, and compared to experimental temperature profiles. This study demonstrates that trends in acoustic absorption and speed of sound can be non-invasively estimated with average errors of 21% and 1%, respectively. Additionally, temperature predictions using the estimated properties on average match within 1.2 degrees C of the experimental peak temperature rises in the phantoms. The positive results achieved in tissue-mimicking phantoms presented in this study indicate that this technique may be extended to in vivo applications, improving HIFU sonication temperature rise predictions and treatment assessment.