Mougenot Charles, Quesson Bruno, de Senneville Baudouin Denis, de Oliveira Philippe Lourenco, Sprinkhuizen Sara, Palussière Jean, Grenier Nicolas, Moonen Chrit T W
Laboratory for Molecular and Functional Imaging: From Physiology to Therapy, UMR5231 Centre National de la Recherche Scientifique/Université Victor Segalen Bordeaux 2, Bordeaux, France.
Magn Reson Med. 2009 Mar;61(3):603-14. doi: 10.1002/mrm.21887.
High-intensity focused ultrasound (HIFU) is an efficient noninvasive technique for local heating. Using MRI thermal maps, a proportional, integral, and derivative (PID) automatic temperature control was previously applied at the focal point, or at several points within a plane perpendicular to the beam axis using a multispiral focal point trajectory. This study presents a flexible and rapid method to extend the spatial PID temperature control to three dimensions during each MR dynamic. The temperature in the complete volume is regulated by taking into account the overlap effect of nearby sonication points, which tends to enlarge the heated area along the beam axis. Volumetric temperature control in vitro in gel and in vivo in rabbit leg muscle was shown to provide temperature control with a precision close to that of the temperature MRI measurements. The proposed temperature control ensures heating throughout the volume of interest of up to 1 ml composed of 287 voxels with 95% of the energy deposited within its boundaries and reducing the typical average temperature overshoot to 1 degrees C.
高强度聚焦超声（HIFU）是一种用于局部加热的高效非侵入性技术。利用磁共振成像（MRI）热图，先前已采用比例积分微分（PID）自动温度控制在焦点处，或使用多螺旋焦点轨迹在垂直于束轴的平面内的多个点处进行温度控制。本研究提出了一种灵活且快速的方法，可在每次MR动态过程中将空间PID温度控制扩展到三维。通过考虑附近超声处理点的重叠效应来调节整个体积内的温度，这种重叠效应往往会沿束轴扩大加热区域。在凝胶中的体外和兔腿部肌肉中的体内体积温度控制显示，其提供的温度控制精度接近温度MRI测量的精度。所提出的温度控制确保在高达1 ml的感兴趣体积内进行加热，该体积由287个体素组成，95%的能量沉积在其边界内，并将典型的平均温度过冲降低至1摄氏度。
