Compensating for magnetic field inhomogeneity in multigradient-echo-based MR thermometry.

摘要: PURPOSE: MR thermometry (MRT) is a noninvasive method for measuring temperature that can potentially be used radio frequency (RF) safety monitoring. This application requires absolute temperature. In this study, multigradient-echo (mGE) MRT sequence was purpose. A drawback of sequence, however, its accuracy affected by background gradients. article, we present to minimize effect and improve measurements using MRI. THEORY: By determining gradients B0 map or combining data acquired with two opposing readout directions, the error removed in homogenous phantom, thus improving maps. METHODS: All scans were performed on 3T system ethylene glycol-filled phantoms. Background varied, one phantom uniformly heated validate both compensation approaches. Independent recordings made optical probes. RESULTS: Errors correlated closely all experiments. Temperature distributions showed much smaller standard deviation when corrections applied (0.21°C vs. 0.45°C) well thermo-optical CONCLUSION: The offer possibility measure RF heating phantoms more precisely. allows mGE become valuable tool assessment.