Towards Motion-Robust Magnetic Resonance Thermometry

Magnetic Resonance Imaging allows for minimally invasive targeting and thermal ablation of tumors while monitoring the temperature distribution. Conventional MR thermometry procedures are hampered by either low accuracy or high sensitivity to motion artifacts due to the use of a reference temperature image. A new, dual-echo technique has been developed to obtain the temperature distribution within a single MR-acquisition. The acquired phase images were post-processed using noise filtering and advanced phase unwrapping, to obtain the two-dimensional temperature distribution. In vitro calibration experiments showed that the accuracy of our newly developed technique is similar to existing thermometry approaches. There was a good linear relationship (r=0.99) between the measured phase difference and the recorded temperature up to at least 65°C. The reproducibility of the temperature coefficient (∆φ /∆T) was within 5%. Real-time temperature mapping and solving susceptibility inhomogeneity are under investigation.