Direct Reconstruction of Proton Resonance Frequency-Shift Temperature Maps from K-Space Data for Highly Accelerated Thermometry

Pooja Gaur¹, William A. Grissom²

Real-time volumetric MR thermometry is desirable for several applications of MR-guided focused ultrasound. We propose a constrained temperature reconstruction method that estimates temperature changes directly from k-space data. Because we fit an image model comprising fully-sampled baseline images to the accelerated k-space data, temperature maps containing aliasing artefacts are removed from the solution space, and high acceleration factors can be achieved without temporal regularization that sacrifices temporal resolution. The method is demonstrated in 2D simulations and experiments. The method will readily extend to 3D, where it will enable accurate real-time volumetric thermometry at a high frame rate.