Several parameters used in MRI are sensitive to temperature changes, including the proton density, the T1 and T2 relaxation times, the diffusion coefficient, and the proton resonance frequency (PRF). The PRF method is most commonly used to measure temperatures within aqueous tissues. It works by measuring a phase shift between two MRI images, which results from the temperature-dependent frequency of hydrogen protons in water. The measured phase change is linearly correlated with the change in temperature. Our lab has developed several techniques that use the PRF method to volumetrically measure temperatures in real time.
The lack of hydrogen bonding within fat-based tissues renders the PRF method very insensitive. However, there is a strong clinical need to monitor temperature in fat for FUS treatments in the breast. Our lab has developed hybrid MR temperature imaging techniques that simultaneously measure both PRF and T1-based temperature measurements. This novel technique allows for dynamic quantitative acquisition of two parameters to allow improved monitoring and control of breast focused ultrasound treatments.
Related Publications
McLean M, Parker DL, Odéen H, Payne A (2021). A T1-based correction method for proton resonance frequency shift thermometry in breast tissue. Med Phys, 48(9), 4719-4729.
Svedin BT, Payne A, Parker DL (2019). Simultaneous proton resonance frequency shift thermometry and T1 measurements using a single reference variable flip angle T1 method. Magn Reson Med, 81(5), 3138-3152.
Svedin BT, Payne A, Bolster BD Jr, Parker DL (2017). Multiecho pseudo-golden angle stack of stars thermometry with high spatial and temporal resolution using k-space weighted image contrast. Magn Reson Med, 79(3), 1407-1419.
Svedin BT, Payne A, Parker DL (2016). Respiration artifact correction in three-dimensional proton resonance frequency MR thermometry using phase navigators. Magn Reson Med, 76(1), 206-13.
Todd N, Diakite M, Payne A, Parker DL (2014). In vivo evaluation of multi-echo hybrid PRF/T1 approach for temperature monitoring during breast MR-guided focused ultrasound surgery treatments. Magn Reson Med, 72(3), 793-9.