Real-time MR temperature mapping of rabbit liver in vivo during thermal ablation
Real-time MR temperature mapping of rabbit liver in vivo during thermal ablation
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DOI：
10.1002/mrm.10521
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发表时间：
2003-08-01
影响因子：
3.3
通讯作者：
Moonen, CTW
中科院分区：
文献类型：
--
作者：
Weidensteiner, C;Quesson, B;Moonen, CTW
研究表明，使用质子共振频率(PRF)方法的定量MRI测温技术可以无创监测组织温度的变化，指导基于局部热疗的微创肿瘤消融。虽然肝脏肿瘤是热消融的主要目标之一，但由于运动伪影、脂肪含量和低T-2*，基于PRF的肝脏温度磁共振成像很难执行。本研究在1.5T临床体温扫描仪上进行了活体兔肝实时测温的稳定性试验。将快速分段EPI原理与呼吸门控相结合，以减少呼吸运动伪影。通过二项式激发脉冲实现了对脂质信号的抑制。应用饱和板来抑制由于血液流动而产生的伪影。活体呼吸门控MR体温测量的标准偏差为1-3°C，时间分辨率为3 S/层，平面空间分辨率为1.4 mm×1.9 mm(层厚为5 mm)。该方法被用于指导临床红外激光的热消融实验。根据MR温度图计算的热剂量，估计的坏死区大小与组织学确定的实际病变大小和治疗5天后获得的常规MR图像很好地一致。这些结果表明，可以在活体肝脏内获得定量的MR温度图，并可用于实时控制热消融和预测病变大小。(C)2003年Wiley-Liss，Inc.
It has been shown that quantitative MRI thermometry using the proton resonance frequency (PRF) method can be used to non-invasively monitor the evolution of tissue temperature, and to guide minimally-invasive tumor ablation based on local hyperthermia. Although hepatic tumors are among the main targets for thermal ablation, PRF-based temperature MRI of the liver is difficult to perform because of motion artifacts, fat content, and low T-2*.. In this study the stability of real-time thermometry was tested on a clinical 1.5 T scanner for rabbit liver in vivo. The fast segmented EPI principle was used together with respiratory gating to limit respiratory motion artifacts. Lipid signal suppression was achieved with a binomial excitation pulse. Saturation slabs were applied to suppress artifacts due to flowing blood. The respiratory-gated MR thermometry in the rabbit liver in vivo showed a standard deviation (SD) of 1-3degreesC with a temporal resolution of 3 s per slice and 1.4 mm x 1.9 mm spatial resolution in plane (slice thickness = 5 mm). The method was used to guide thermal ablation experiments with a clinical infrared laser. The estimated size of the necrotic area, based on the thermal dose calculated from MR temperature maps, corresponded well with the actual lesion size determined by histology and conventional MR images obtained 5 days posttreatment. These results show that quantitative MR temperature mapping can be obtained in the liver in vivo, and can be used for real-time control of thermal ablation and for lesion size prediction. (C) 2003 Wiley-Liss, Inc.