Oh Sukhoon, Webb Andrew G, Neuberger Thomas, Park BuSik, Collins Christopher M
Department of Radiology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033, USA.
Magn Reson Med. 2010 Jan;63(1):218-23. doi: 10.1002/mrm.22174.
It is important to accurately characterize the heating of tissues due to the radiofrequency energy applied during MRI. This has led to an increase in the use of numerical methods to predict specific energy absorption rate distributions for safety assurance in MRI. To ensure these methods are accurate for actual MRI coils, however, it is necessary to compare to experimental results. Here, we report results of some recent efforts to experimentally map temperature change and specific energy absorption rate in a phantom and in vivo where the only source of heat is the radiofrequency fields produced by the imaging coil. Results in a phantom match numerical simulation well, and preliminary results in vivo show measurable temperature increase. With further development, similar methods may be useful for verifying numerical methods for predicting specific energy absorption rate distributions and in some cases for directly measuring temperature changes and specific energy absorption rate induced by the radiofrequency fields in MRI experiments.
准确描述由于磁共振成像（MRI）过程中施加的射频能量而导致的组织加热情况非常重要。这使得数值方法在预测MRI中用于安全保障的比吸收率分布方面的应用有所增加。然而，为确保这些方法对实际的MRI线圈准确无误，有必要与实验结果进行比较。在此，我们报告了一些近期的研究成果，这些研究通过实验绘制了模型和活体中的温度变化及比吸收率，其中唯一的热源是成像线圈产生的射频场。模型中的结果与数值模拟吻合良好，并在活体中得到的初步结果显示有可测量的温度升高。随着进一步发展，类似方法可能有助于验证预测比吸收率分布的数值方法，并且在某些情况下可直接测量MRI实验中射频场引起的温度变化和比吸收率。
