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.