De Poorter J
MR Department, University Hospital, Gent, Belgium.
Magn Reson Med. 1995 Sep;34(3):359-67. doi: 10.1002/mrm.1910340313.
The temperature dependence of proton resonance frequency (PRF) is related to the temperature dependence of the screening constant and of the volume susceptibility constant. To evaluate the relative importance, an experimental setup was designed allowing quantification of both effects in different tissues, notably pure water in a gel structure, and porcine muscle and fat tissue. The temperature varied from 28 to 44 degrees C, a range significant for hyperthermia applications. Good agreement with results from the literature was obtained for water. Porcine muscle tissue behaves like water. Its screening constant varies linearly at a rate of 0.97 10(-8) (degree C)-1 and the effects of temperature-induced changes of the susceptibility constant are negligible for muscle thermometry applications. The PRF-temperature relation in fat tissue, however, is almost completely determined by susceptibility effects.
质子共振频率（PRF）对温度的依赖性与屏蔽常数和体积磁化率常数对温度的依赖性有关。为了评估相对重要性，设计了一种实验装置，用于量化不同组织中的这两种效应，特别是凝胶结构中的纯水以及猪肌肉和脂肪组织。温度范围为28至44摄氏度，这一范围对热疗应用具有重要意义。对于水，与文献结果取得了良好的一致性。猪肌肉组织的行为与水相似。其屏蔽常数以0.97×10⁻⁸（℃）⁻¹的速率线性变化，并且对于肌肉温度测量应用而言，温度引起的磁化率常数变化的影响可忽略不计。然而，脂肪组织中的PRF - 温度关系几乎完全由磁化率效应决定。
