Significant precision improvement for temperature mapping

MR temperature measurements are important for applications such as the eval uation of thermal therapies and radiofrequency (RF) coil heating effects. I n this work the spherical mean value (SMV) method has been applied to signi ficantly improve the precision of MR temperature mapping in a homogeneous g el phantom. Temperature-increase maps of the phantom were obtained with thr ee-dimensional (3D) MR phase difference mapping after heating with the RIF coil. The temperature-increase distribution in most regions in the phantom is a harmonic function with the mean value property. Based on this property , the precision of temperature-increase maps was improved up to sixfold wit h the SMV method. Comparison of this method with conventional smoothing, fu rther precision improvement, and the in vivo application of the SMV method are discussed. (C) 2001 Wiley-Liss, Inc.