An MRI-compatible system for focused ultrasound experiments in small animal models
An MRI-compatible system for focused ultrasound experiments in small animal models
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DOI：
10.1118/1.3115680
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发表时间：
2009-05-01
期刊：
影响因子：
3.8
通讯作者：
Hynynen, Kullervo
中科院分区：
文献类型：
--
作者：
Chopra, Rajiv;Curiel, Laura;Hynynen, Kullervo
MRI引导的新型治疗性超声方法的发展，包括增强药物输送和靶向热消融，需要在小动物如大鼠和小鼠身上进行广泛的测试，因为这些物种被广泛用作疾病模型。构建了一种与MRI兼容的、计算机控制的三轴定位系统，以将聚焦的超声照射精确地传递到小动物的目标解剖结构，以进行高通量的临床前药物传递研究。每个轴由定制的非磁性直线球台组成，由压电致动器和光学编码器驱动。实现了5x5x2.5厘米(3)的运动范围，最初的工作台特征表明，能够以0.3 mm的空间精度将超声波传递到大脑。该定位系统在临床3T磁共振成像仪的钻孔内操作是可行的，同时运动和磁共振成像不会导致任何相互干扰。该系统在以下方面进行了评估：在小鼠大脑内提供精确的超声波，在大鼠大脑中进行线性扫描以破坏血屏障，并在MR温度反馈下进行循环扫描以控制加热。初步结果表明，在小动物临床前模型中，这是一种用于研究基于超声的新治疗策略的可靠和精确的设备。
The development of novel MRI-guided therapeutic ultrasound methods including potentiated drug delivery and targeted thermal ablation requires extensive testing in small animals such as rats and mice due to the widespread use of these species as models of disease. An MRI-compatible, computer-controlled three-axis positioning system was constructed to deliver focused ultrasound exposures precisely to a target anatomy in small animals for high-throughput preclinical drug delivery studies. Each axis was constructed from custom-made nonmagnetic linear ball stages driven by piezoelectric actuators and optical encoders. A range of motion of 5x5x2.5 cm(3) was achieved, and initial bench top characterization demonstrated the ability to deliver ultrasound to the brain with a spatial accuracy of 0.3 mm. Operation of the positioning system within the bore of a clinical 3 T MR imager was feasible, and simultaneous motion and MR imaging did not result in any mutual interference. The system was evaluated in its ability to deliver precise sonications within the mouse brain, linear scanned exposures in a rat brain for blood barrier disruption, and circular scans for controlled heating under MR temperature feedback. Initial results suggest that this is a robust and precise apparatus for use in the investigation of novel ultrasound-based therapeutic strategies in small animal preclinical models.