Measuring local RF heating in MRI: Simulating perfusion in a perfusionless phantom.
Measuring local RF heating in MRI: Simulating perfusion in a perfusionless phantom.
复制标题
测量 MRI 中的局部射频加热：模拟无灌注模型中的灌注。
DOI：
10.1002/jmri.21161
复制
发表时间：
2007
期刊：
影响因子：
--
通讯作者：
Atalar,Ergin
中科院分区：
文献类型：
--
作者：
Akca,ImranB;Ferhanoglu,Onur;Yeung,ChristopherJ;Guney,Sevin;Tasci,TOnur;Atalar,Ergin
PurposeTo overcome conflicting methods of local RF heating measurements by proposing a simple technique for predicting in vivo temperature rise by using a gel phantom experiment.Materials and MethodsIn vivo temperature measurements are difficult to conduct reproducibly; fluid phantoms introduce convection, and gel phantom lacks perfusion. In the proposed method the local temperature rise is measured in a gel phantom at a timepoint that the phantom temperature would be equal to the perfused body steady‐state temperature value. The idea comes from the fact that the steady‐state temperature rise in a perfused body is smaller than the steady‐state temperature increase in a perfusionless phantom. Therefore, when measuring the temperature on a phantom there will be the timepoint that corresponds to the perfusion time constant of the body part.ResultsThe proposed method was tested with several phantom and in vivo experiments. Instead, an overall average of 30.8% error can be given as the amount of underestimation with the proposed method. This error is within the variability of in vivo experiments (45%).ConclusionWith the aid of this reliable temperature rise prediction the amount of power delivered by the scanner can be controlled, enabling safe MRI examinations of patients with implants. J. Magn. Reson. Imaging 2007;26:1228–1235. © 2007 Wiley‐Liss, Inc.
