Antje Kickhefel1, Rares Salomir2,3,
Jrg Roland4, Patrick Gross4, Fritz Schick5,
Clifford R. Weiss6
1Eberhard-Karls-University Tbingen, Tbingen, Baden-Wrttemberg, Germany; 2University
Hospitals of Geneva, Switzerland; 3 University Hospitals of
Geneva; 4Siemens Healthcare, Erlangen, Germany; 5Eberhard-Karls-University
Tbingen, Tbingen, Baden-Wrttemberg,
Germany; 6Department of Radiology, The Johns Hopkins University
School of Medicine, Baltimore, United States
The
study demonstrates that susceptibility artifacts in GRE phase image induced
by ice ball can be corrected allowing the PRF method to be used to monitor
the near zero temperature during cryoablation. Susceptibility artifacts were
corrected in post-processing. First the susceptibility contrast between
frozen and melted meat was determined and second the magnetic perturbation
was calculated using a convolution filter in the k-space. The susceptibility
artifacts were fully corrected. In conclusion, using an in-line post
processing system, this method could be applied during clinical MR-guided
cryotherapy, and allow for the non-invasive monitoring of near zero
temperatures.