TY - JOUR A1 - Wu, Mingming A1 - Mulder, Hendrik T. A1 - Baron, Paul A1 - Coello, Eduardo A1 - Menzel, Marion Irene A1 - van Rhoon, Gerard C. A1 - Haase, Axel T1 - Correction of motion-induced susceptibility artifacts and B0 drift during proton resonance frequency shift-based MR thermometry in the pelvis with background field removal methods JF - Magnetic Resonance in Medicine N2 - Purpose The linear change of the water proton resonance frequency shift (PRFS) with temperature is used to monitor temperature change based on the temporal difference of image phase. Here, the effect of motion-induced susceptibility artifacts on the phase difference was studied in the context of mild radio frequency hyperthermia in the pelvis. Methods First, the respiratory-induced field variations were disentangled from digestive gas motion in the pelvis. The projection onto dipole fields (PDF) as well as the Laplacian boundary value (LBV) algorithm were applied on the phase difference data to eliminate motion-induced susceptibility artifacts. Both background field removal (BFR) algorithms were studied using simulations of susceptibility artifacts, a phantom heating experiment, and volunteer and patient heating data. Results Respiratory-induced field variations were negligible in the presence of the filled water bolus. Even though LBV and PDF showed comparable results for most data, LBV seemed more robust in our data sets. Some data sets suggested that PDF tends to overestimate the background field, thus removing phase attributed to temperature. The BFR methods even corrected for susceptibility variations induced by a subvoxel displacement of the phantom. The method yielded successful artifact correction in 2 out of 4 patient treatment data sets during the entire treatment duration of mild RF heating of cervical cancer. The heating pattern corresponded well with temperature probe data. Conclusion The application of background field removal methods in PRFS-based MR thermometry has great potential in various heating applications and body regions to reduce motion-induced susceptibility artifacts that originate outside the region of interest, while conserving temperature-induced PRFS. In addition, BFR automatically removes up to a first-order spatial B0 drift. UR - https://doi.org/10.1002/mrm.28302 KW - B0 drift KW - background field removal KW - hyperthermia KW - motion KW - MR thermometry KW - susceptibility Y1 - 2020 UR - https://doi.org/10.1002/mrm.28302 UR - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:573-18776 SN - 1522-2594 VL - 84 IS - 5 SP - 2495 EP - 2511 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Wu, Mingming A1 - Mulder, Hendrik T. A1 - Zur, Yuval A1 - Lechner-Greite, Silke A1 - Menzel, Marion Irene A1 - Paulides, Margarethus M. A1 - Rhoon, Gerard C. van A1 - Haase, Axel T1 - A phase-cycled temperature-sensitive fast spin echo sequence with conductivity bias correction for monitoring of mild RF hyperthermia with PRFS JF - Magnetic Resonance Materials in Physics, Biology and Medicine UR - https://doi.org/10.1007/s10334-018-0725-5 KW - MR thermometry KW - Hyperthermia KW - Proton resonance frequency shift KW - Fast spin echo KW - Double echo gradient echo KW - Intervention KW - Conductivity Y1 - 2018 UR - https://doi.org/10.1007/s10334-018-0725-5 SN - 1352-8661 VL - 32 IS - 3 SP - 369 EP - 380 PB - Springer CY - Heidelberg ER -