Fig. 3.
Phase map subtraction to calculate PRF temperature maps. Two orthogonal views from a focused ultrasound heating in porcine muscle. By subtracting the reference phase map acquired before the start of the heating from the phase map of the current time frame and scaling according to ΔT = Δφ/ϒαB0TE the PRF temperature map can be calculated. It can be noted that by using complex subtraction, phase wraps occurring in the phase images (red arrows) get subtracted out and do not occur in the temperature map. From Chapter 15 in Theory and Applications of Heat Transfer in Humans. Henrik Odéen and Dennis L Parker, Non-Invasive Thermometry with Magnetic Resonance Imaging. Devashish Shrivastava (Editor). John Wiley and Sons 2018. Reprinted with permission.