Roel Deckers1, Sara M. Sprinkhuizen1, Bart J. Crielaard2, J H. Ippel3, R Boelens3, Twan Lammers2,4, C. J. Bakker1, L W. Bartels1
1Image Sciences Institute, University Medical Center Utrecht, Utrecht, Netherlands; 2Department of Pharmaceutics, Utrecht University, Utrecht, Netherlands; 3Department of NMR Spectroscopy, Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, Netherlands; 4Department of Experimental Molecular Imaging, RWTH Aachen, Aachen, Germany
Dynamic absolute MR thermometry may be of great interest for the precise and accurate spatio-temporal control of hyperthermia in local drug delivery applications using MR guided HIFU. In this study we evaluate the use an mFFE sequence in combination with polyethylene glycol (PEG) labeled liposomes for dynamic absolute MR thermometry. PEG provides a temperature insensitive proton resonance frequency (PRF) that can serve as reference for the temperature sensitive PRF of water. The frequency difference between the PRFs of PEG and water, and thus the absolute temperature, can be deduced from the signal evolution in time over 32 echoes acquired with the mFFE sequence.