Eva Oberacker1, Katharina Paul1, Lukas Winter1, Celal Oezerdem1, Antje Els1, Andreas Pohlmann1, Laura Boehmert1, Stefanie Kox1, Min-Chi Ku1, Till Huelnhagen1, Oliver Stachs2, Jens Heufelder3,4, Andreas Weber3,4, and Thoralf Niendorf1,5
1Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany, 2Department of Ophthalmology, University of Rostock, Rostock, Germany, 3Department of Ophthalmology, Charité University Medicine, Berlin, Germany, 4BerlinProtonen, Helmholtz Zentrum Berlin, Berlin, Germany, 5Experimental and Clinical Research Center (ECRC), a joint cooperation between the Charité Medical Faculty and the Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
This
work examines the MR safety of intraocular tantalum markers used in proton beam
therapy of uveal melanoma. RF power deposition induced heating was studied
using electromagnetic field and temperature simulations. Magnetic
force acting on the marker was investigated and image artifacts were assessed. Minor local increase of RF power deposition was observed
for SAR0.075g but not detectable for SAR1g. Measurements
showed no detectable magnetic attraction of the implant. FSE based imaging showed only small artifacts barely exceeding the thickness of the
sclera. Our studies indicate that intraocular tantalum markers do not
constitute a per se contraindication
for 7.0T MRI.
