Systems and methods for rapid calculation of parameters for delivering ultrasound energy to selected locations in the brain. An example method for delivering ultrasound energy to a region of a blood-brain barrier may comprise generating a model of the region of the blood-brain barrier and surrounding tissues. The method may also comprise determining a plurality of intermediate parameters by simulating acoustic paths of a plurality of ultrasound beams propagating from the region of the blood-brain barrier to a plurality of locations. The method may also comprise determining transmission parameters for ultrasound beams to be emitted from a plurality of ultrasound transducers based on the intermediate parameters and measured locations of the ultrasound transducers.