Institut für Radiologie, Charité, Universitätsmedizin Berlin, Germany.
J Magn Reson Imaging. 2010 Jun;31(6):1499-503. doi: 10.1002/jmri.22197.
To validate an unspoiled gradient-recalled echo pulse sequence with dual echo acquisition as a means to increase temperature sensitivity while monitoring intradiscal laser ablation therapy.
Phantom experiments as well as in vitro thermal ablation simulations were performed in an open 1.0T magnetic resonance (MR) scanner. Three methods of noninvasive MR-thermometry based on the signal void decrease caused by T1-relaxation time increase (T1), the temperature-dependent proton resonance frequency (PRF) shift, and a combination of both methods with complex differences (CD) were compared. Temperature accuracy and reliability of temperature distribution were the main assessment criteria.
The optimum temperature sensitivity was found using CD in phantom experiments. During in vitro experiments the PRF showed the smallest margin of error (T1: +/-1.64 degrees C, PRF: +/-1.23 degrees C, CD: +/-1.29 degrees C) and the best qualitative evaluation of temperature.
Intradiscal temperature monitoring with an unspoiled dual-echo sequence is most accurate with PRF-thermometry in combination with the long echo time. Magnitude images with an initial short echo time permit high image detail of the heat-induced lesion.
验证一种未受污染的梯度回波脉冲序列，采用双回波采集，以提高温度灵敏度，同时监测椎间盘内激光消融治疗。
在开放式 1.0T 磁共振（MR）扫描仪中进行了体模实验和体外热消融模拟。比较了三种基于 T1 弛豫时间增加引起的信号缺失减少（T1）、与温度相关的质子共振频率（PRF）偏移以及两者结合的复杂差值（CD）的非侵入性 MR 测温方法。主要评估标准是温度准确性和温度分布的可靠性。
在体模实验中，使用 CD 找到了最佳的温度灵敏度。在体外实验中，PRF 显示出最小的误差幅度（T1：+/-1.64°C，PRF：+/-1.23°C，CD：+/-1.29°C）和最佳的温度定性评估。
未受污染的双回波序列进行椎间盘内温度监测时，PRF 测温与长回波时间相结合最准确。初始短回波时间的幅度图像允许对热诱导损伤进行高图像细节成像。
