A combination of RF heating and MR imaging equipment has been constructed in a fashion that allows simultaneous heating and MR diffusion imaging. Isolation between the RF heating and RF imaging frequencies is accomplished by means of filtering. This system has allowed a systematic estimate of temperature resolution and spatial resolution to be made using noninvasive MR tomography in a phantom model. The initial data indicates that 0.8°C resolution in ≤ 1 cm3 voxel is feasible using standard imaging techniques and an acquisition time of approximately 2 minutes.