Localised hyperthermia in rodent models using an MRI-compatible high-intensity focused ultrasound system.
Localised hyperthermia in rodent models using an MRI-compatible high-intensity focused ultrasound system.
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DOI：
10.3109/02656736.2015.1094833
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
Chopra R
中科院分区：
文献类型：
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作者：
Bing C;Nofiele J;Staruch R;Ladouceur-Wodzak M;Chatzinoff Y;Ranjan A;Chopra R
由于目标尺寸较小，啮齿动物研究中的局部高温具有挑战性。本研究描述了一种MRI兼容的高强度聚焦超声（HIFU）系统的开发和表征，用于在啮齿动物模型中进行局部轻度高温治疗。热疗平台由MRI兼容的小动物HIFU系统、具有扇形涡旋透镜的聚焦换能器、定制的接收线圈和维持啮齿动物全身温度的方法组成。该系统被集成到3T MR成像仪中。开发了控制软件，用于采集图像、处理温度图并使用比例-积分-微分反馈控制算法调节输出功率。在组织模拟模型和啮齿动物模型中进行高温暴露（n = 9）。在加热期间，在加热区域中分配ROI用于温度控制，目标温度为42 ° C;对每只动物进行30分钟轻度高温治疗，然后进行10分钟冷却程序。3D打印的扇形涡旋透镜成功地创建了环形聚焦区域，从而能够定制加热体积。在大鼠中进行的局部轻度高温产生的平均ROI温度为42.1 ± 0.3 ° C。T10和T90温度分别为43.2 ± 0.4 ℃和41.0 ± 0.3 ℃。对于30分钟的治疗，ROI内41 - 45 ° C之间的平均持续时间为31.1分钟。MRI兼容的HIFU系统成功地适用于在啮齿动物模型中进行局部轻度高温治疗。在大鼠大腿模型中将42 ° C的目标温度良好地维持30分钟。
Localised hyperthermia in rodent studies is challenging due to the small target size. This study describes the development and characterisation of an MRI-compatible high-intensity focused ultrasound (HIFU) system to perform localised mild hyperthermia treatments in rodent models. The hyperthermia platform consisted of an MRI-compatible small animal HIFU system, focused transducers with sector-vortex lenses, a custom-made receive coil, and means to maintain systemic temperatures of rodents. The system was integrated into a 3T MR imager. Control software was developed to acquire images, process temperature maps, and adjust output power using a proportional-integral-derivative feedback control algorithm. Hyperthermia exposures were performed in tissue-mimicking phantoms and in a rodent model (n = 9). During heating, an ROI was assigned in the heated region for temperature control and the target temperature was 42 °C; 30 min mild hyperthermia treatment followed by a 10-min cooling procedure was performed on each animal. 3D-printed sector-vortex lenses were successful at creating annular focal regions which enables customisation of the heating volume. Localised mild hyperthermia performed in rats produced a mean ROI temperature of 42.1 ± 0.3 °C. The T10 and T90 percentiles were 43.2 ± 0.4 °C and 41.0 ± 0.3 °C, respectively. For a 30-min treatment, the mean time duration between 41–45 °C was 31.1 min within the ROI. The MRI-compatible HIFU system was successfully adapted to perform localised mild hyperthermia treatment in rodent models. A target temperature of 42 °C was well-maintained in a rat thigh model for 30 min.