HYBRID REFERENCELESS AND MULTIBASELINE PRF-SHIFT MAGNETIC RESONANCE THERMOMETRY

摘要

The invention relates to MR PRF shift thermometry wherein the phase background (i.e. the component of the phase not attributable to the temperature change) is compensated for by a hybrid approach which combines multi -baseline, thermometry with referenceless thermometry. According to an embodiment of the invention, the phase background of a thermal treatment image is modeled by a combination of baseline images acquired prior to treatment, and a linear combination of smooth basis functions (e.g. polynomials) that are fitted to a region of the treatment image surrounding the thermally hot spot and extrapolated into the region of the hot spot. Compared to pure multi -baseline methods, the hybrid approach is not undermined by main field drifts during treatment. Compared to referenceless methods, it accommodates rapidly varying anatomical phase, and does not require the user to have a priori knowledge of the location of the hot spot.