Yacine Noureddine1,2, Andreas K Bitz3,4, Mark E Ladd3,4, Markus Thürling3,5, Susanne C Ladd3,6, Gregor Schaefers7, Oliver Kraff3. 1. Erwin L. Hahn Institute for Magnetic Resonance Imaging, University Duisburg-Essen, Essen, Germany. noureddine@mrcomp.com. 2. MR:comp GmbH, MR Safety Testing Laboratory, Gelsenkirchen, Germany. noureddine@mrcomp.com. 3. Erwin L. Hahn Institute for Magnetic Resonance Imaging, University Duisburg-Essen, Essen, Germany. 4. Division of Medical Physics in Radiology (E020), German Cancer Research Center (DKFZ), Heidelberg, Germany. 5. Department of Neurology, University Hospital, University Duisburg-Essen, Essen, Germany. 6. Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital, University Duisburg-Essen, Essen, Germany. 7. MR:comp GmbH, MR Safety Testing Laboratory, Gelsenkirchen, Germany.
Abstract
OBJECT: Over the last decade, the number of clinical MRI studies at 7 T has increased dramatically. Since only limited information about the safety of implants/tattoos is available at 7 T, many centers either conservatively exclude all subjects with implants/tattoos or have started to perform dedicated tests for selected implants. This work presents our experience in imaging volunteers with implants/tattoos at 7 T over the last seven and a half years. MATERIALS AND METHODS: 1796 questionnaires were analyzed retrospectively to identify subjects with implants/tattoos imaged at 7 T. For a total of 230 subjects, the type of local transmit/receive RF coil used for examination, imaging sequences, acquisition time, and the type of implants/tattoos and their location with respect to the field of view were documented. These subjects had undergone examination after careful consideration by an internal safety panel consisting of three experts in MR safety and physics. RESULTS: None of the subjects reported sensations of heat or force before, during, or after the examination. None expressed any discomfort related to implants/tattoos. Artifacts were reported in 52% of subjects with dental implants; all artifacts were restricted to the mouth area and did not affect image quality in the brain parenchyma. CONCLUSION: Our initial experience at 7 T indicates that a strict rejection of subjects with tattoos and/or implants is not justified. Imaging can be conditionally performed in carefully selected subjects after collection of substantial safety information and evaluation of the detailed exposure scenario (RF coil/type and position of implant). Among the assessed subjects with tattoos, no side effects from the exposure to 7 T MRI were reported.
OBJECT: Over the last decade, the number of clinical MRI studies at 7 T has increased dramatically. Since only limited information about the safety of implants/tattoos is available at 7 T, many centers either conservatively exclude all subjects with implants/tattoos or have started to perform dedicated tests for selected implants. This work presents our experience in imaging volunteers with implants/tattoos at 7 T over the last seven and a half years. MATERIALS AND METHODS: 1796 questionnaires were analyzed retrospectively to identify subjects with implants/tattoos imaged at 7 T. For a total of 230 subjects, the type of local transmit/receive RF coil used for examination, imaging sequences, acquisition time, and the type of implants/tattoos and their location with respect to the field of view were documented. These subjects had undergone examination after careful consideration by an internal safety panel consisting of three experts in MR safety and physics. RESULTS: None of the subjects reported sensations of heat or force before, during, or after the examination. None expressed any discomfort related to implants/tattoos. Artifacts were reported in 52% of subjects with dental implants; all artifacts were restricted to the mouth area and did not affect image quality in the brain parenchyma. CONCLUSION: Our initial experience at 7 T indicates that a strict rejection of subjects with tattoos and/or implants is not justified. Imaging can be conditionally performed in carefully selected subjects after collection of substantial safety information and evaluation of the detailed exposure scenario (RF coil/type and position of implant). Among the assessed subjects with tattoos, no side effects from the exposure to 7 T MRI were reported.
Authors: Bob van den Bergen; Cornelis A T van den Berg; Dennis W J Klomp; Jan J W Lagendijk Journal: J Magn Reson Imaging Date: 2009-07 Impact factor: 4.813
Authors: Christoph Treutlein; Tobias Bäuerle; Armin M Nagel; Ali Guermazi; Arnd Kleyer; David Simon; Georg Schett; Tobias Hepp; Michael Uder; Frank W Roemer Journal: BMC Musculoskelet Disord Date: 2020-02-21 Impact factor: 2.362