Magnetic resonance guided high intensity focused ultrasound (MRgHIFU) is a noninvasive therapy that is approved in Canada for thermal ablation of bone and soft tissue. MRgHIFU transmits ultrasound energy from outside the body and focuses that energy within the body, producing a thermal lesion as small as a rice kernel (8 mm long x 2 mm diameter). This focus is steered electronically and mechanically to cover a large volume, without repositioning the target. Since energy delivery is nonionizing and incisionless, the risk of infection and long-term side effects are minimal. The energy delivery is monitored in soft tissues with MR thermometry (MRT) by measuring signal changes in heated water molecules. Under ideal conditions, namely non-moving soft-tissue targets, MRT monitors temperature in a very fast and repeatable manner with an uncertainty less than 1˚C. However, there are many conditions, such as the treatment of bone and fat-based tissues that can lead to temperature uncertainties greater than 10˚C. Our lab is developing a simulation platform for MRgHIFU procedures that incorporates a mathematical model of sound wave propagation with tissue-specific properties of bone and soft tissues. These simulations involve segmentation of inner and outer bone surfaces from MRI scans, and an acoustic simulation of the ultrasound wave interaction throughout the bone tissue. It uses a modified solution of the Rayleigh integral, which is capable of solving for the longitudinal and shear components of the reflected and transmitted waves at each medium interface, and then propagating these waves into their respective tissues to find the deposited energy. The wave and temperature models are both implemented in a computationally efficient manner using the CUDA libraries for parallel computing on a graphical processing unit. This enables full 3D simulation of an MRgHIFU sonication in less than one minute.