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.