Il'yasov K A, Hennig J
Department of Radiology, University Hospital of Freiburg, Germany.
J Magn Reson Imaging. 1998 Nov-Dec;8(6):1296-305. doi: 10.1002/jmri.1880080617.
A diffusion-sensitive single-shot RARE (rapid acquisition with relaxation enhancement) sequence was implemented on a 2T whole-body MRI system. The sequence was optimized for diffusion-based MR thermometry, both on a conventional whole-body gradient system and on a high-performance gradient insert. The use of spin-echo versus stimulated-echo diffusion weighting is discussed as a function of gradient performance. Diffusion-based temperature mapping was used to observe the effect of the geometry of the antenna used for radiofrequency (RF) hyperthermia on the temperature distribution. Temperature changes of +/-.5 degrees C in gel and +/-2 degrees C in a muscle sample in vitro could be detected within 16 seconds (gel) or 1 minute (muscle) at a spatial resolution of 2 x 2 x 8 mm. Temperature changes in vivo were also observed on human muscle cooled with ice with comparable sensitivity for the measured apparent diffusion coefficient (ADC) values.
在一台2T全身MRI系统上实施了一种扩散敏感的单次激发RARE（弛豫增强快速采集）序列。该序列在传统的全身梯度系统和高性能梯度插入件上均针对基于扩散的磁共振测温进行了优化。讨论了自旋回波与受激回波扩散加权的使用与梯度性能的关系。基于扩散的温度映射用于观察用于射频（RF）热疗的天线几何形状对温度分布的影响。在凝胶中，温度变化±0.5℃，在体外肌肉样本中温度变化±2℃，在空间分辨率为2×2×8mm的情况下，16秒（凝胶）或1分钟（肌肉）内即可检测到。在用冰冷却的人体肌肉上也观察到了体内温度变化，对测量的表观扩散系数（ADC）值具有可比的灵敏度。
