Laboratory for Molecular and Functional Imaging: From Physiology to Therapy, FRE 3313 CNRS/Université Bordeaux 2, Bordeaux, France.
NMR Biomed. 2012 Apr;25(4):556-62. doi: 10.1002/nbm.1771.
Online MR temperature monitoring during radiofrequency (RF) ablation of cardiac arrhythmias may improve the efficacy and safety of the treatment. MR thermometry at 1.5 T using the proton resonance frequency (PRF) method was assessed in 10 healthy volunteers under normal breathing conditions, using a multi-slice, ECG-gated, echo planar imaging (EPI) sequence in combination with slice tracking. Temperature images were post-processed to remove residual motion-related artifacts. Using an MR-compatible steerable catheter and electromagnetic noise filter, RF ablation was performed in the ventricles of two sheep in vivo. The standard deviation of the temperature evolution in time (TSD) was computed. Temperature mapping of the left ventricle was achieved at an update rate of approximately 1 Hz with a mean TSD of 3.6 ± 0.9 °C. TSD measurements at the septum showed a higher precision (2.8 ± 0.9 °C) than at the myocardial regions at the heart-lung and heart-liver interfaces (4.1 ± 0.9 °C). Temperature rose maximally by 9 °C and 16 °C during 5 W and 10 W RF applications, respectively, for 60 s each. Tissue temperature can be monitored at an update rate of approximately 1 Hz in five slices. Typical temperature changes observed during clinical RF application can be monitored with an acceptable level of precision.
在线磁共振（MR）温度监测可提高心脏心律失常射频（RF）消融的疗效和安全性。在 10 名健康志愿者中，在正常呼吸条件下使用多切片、心电图门控、回波平面成像（EPI）序列结合切片跟踪，评估了使用质子共振频率（PRF）方法在 1.5 T 下的 MR 测温。使用与 MR 兼容的可控导管和电磁噪声滤波器，在两只绵羊的体内进行了 RF 消融。计算了温度随时间变化的标准偏差（TSD）。以大约 1 Hz 的更新率实现了左心室的温度图，平均 TSD 为 3.6±0.9°C。与心脏-肺和心脏-肝界面的心肌区域相比，室间隔的 TSD 测量值具有更高的精度（2.8±0.9°C）。在 60 s 内，分别施加 5 W 和 10 W RF 应用时，温度最大升高 9°C 和 16°C。可以以大约 1 Hz 的更新率监测五个切片中的组织温度。可以用可接受的精度监测到在临床 RF 应用中观察到的典型温度变化。
