Correlation between the temperature dependence of intrinsic MR parameters and thermal dose measured by a rapid chemical shift imaging technique.
Correlation between the temperature dependence of intrinsic MR parameters and thermal dose measured by a rapid chemical shift imaging technique.
复制标题
固有 MR 参数的温度依赖性与快速化学位移成像技术测量的热剂量之间的相关性。
DOI：
10.1002/nbm.1707
复制
发表时间：
2011
影响因子：
2.9
通讯作者：
Stafford,RJ
中科院分区：
文献类型：
--
作者：
Taylor,BA;Elliott,AM;Hwang,KP;Hazle,JD;Stafford,RJ
为了研究同时进行的MR温度成像和热治疗过程中组织损伤的直接验证，通过一种技术在体内组织中测量质子共振频率（PRF）位移、R2*值和T1加权振幅的温度依赖信号变化。利用多梯度回波采集和Stieglitz - McBride算法，在25 - 61°C的范围内，以高时空分辨率（1.6x1.6x4mm3,≤5sec）测量了这些参数在每个组织中的温度敏感系数。研究了磁共振参数的非线性变化，并将其与热损伤的Arrhenius率剂量模型相关联。使用逻辑回归，计算这些参数变化的概率作为热剂量的函数，以确定这些变化是否对应于热损伤。温度灵敏度R2*，在某些情况下，T1‐加权振幅在热损伤发生前后有统计学差异。观察到R2*的斜率随温度的显著变化。Logistic回归分析表明，使用Arrhenius速率剂量模型（Ω = 1.01±0.03）可以准确预测这些变化，从而表明R2*的变化可以作为蛋白质变性的直接标志。总的来说，通过同时使用温度估计、R2*成像和T1 - W成像的化学位移成像技术，研究表明，当热损伤预计发生时，体内组织中R2*的灵敏度变化以及较小程度的T1 - W振幅的变化是可以测量到的。与基于模型的预测相比，这些变化可能用于直接验证热损伤。版权所有©2011 John Wiley & Sons， Ltd
In order to investigate simultaneous MR temperature imaging and direct validation of tissue damage during thermal therapy, temperature‐dependent signal changes in proton resonance frequency (PRF) shifts, R2* values, and T1‐weighted amplitudes are measured from one technique inex vivotissue. Using a multigradient echo acquisition and the Stieglitz‐McBride algorithm, the temperature sensitivity coefficients of these parameters are measured in each tissue at high spatiotemporal resolutions (1.6x1.6x4mm3, ≤ 5sec) at the range of 25‐61 °C. Non‐linear changes in MR parameters are examined and correlated with an Arrhenius rate dose model of thermal damage. Using logistic regression, the probability of changes in these parameters is calculated as a function of thermal dose to determine if changes correspond to thermal damage. Temperature sensitivity of R2* and, in some cases, T1‐weighted amplitudes are statistically different before and after thermal damage occurred. Significant changes in the slopes of R2* as a function of temperature are observed. Logistic regression analysis shows that these changes could be accurately predicted using the Arrhenius rate dose model (Ω = 1.01 ± 0.03), thereby showing that the changes in R2* could be direct markers of protein denaturation. Overall, by using a chemical shift imaging technique with simultaneous temperature estimation, R2* mapping and T1‐W imaging, it is shown that changes in the sensitivity of R2* and, to a lesser degree, T1‐W amplitudes are measured inex vivotissue when thermal damage is expected to occur. These changes could possibly be used for direct validation of thermal damage in contrast to model‐based predictions. Copyright © 2011 John Wiley & Sons, Ltd.