Oliver Kraff1,2, Karsten H. Wrede1,3,
Stephan Orzada1,2, Philipp Dammann1,3, Mark E. Ladd1,2,
Andreas K. Bitz1,2
1Erwin L. Hahn Institute
for MRI, University Duisburg-Essen, Essen, Germany; 2Department of
Diagnostic & Interventional Radiology & Neuroradiology, University
Hospital Essen, Essen, Germany; 3Clinic for Neurosurgery,
University Hospital Essen, Essen, Germany
Examination of patients with implants has become relevant at research facilities with ultra-high field strength systems. In this study we focus on miniplate implants used for refixation of the bone flap after craniotomy. Since typical temperature measurements performed with fiber-optic probes to assess potential heating yield only point-wise information, a much more detailed assessment of MRI-related heating due to interactions of the RF field with the implants was performed. The test protocol included full wave simulations on different numerical models as well as external measurements of the H and E field and SAR distribution using a 7T head coil.
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