Radbook 2017

◼  MAGNETIC RESONANCE IMAGING MRI safety in practice Missing standardized MR labeling information – related to EN IEC 62570 “MR Safe” / ”MR Conditional” labeling requirements for medical devices and MR accessories – endangers MR user and MR patient safety. Commercially available accessories such as furniture, wheel chairs, instruments, gas cylinders, etc. can be ferromagnetic or electrically conductive. Those are not designed, thus contraindicated to be used in the MR environment (MRE). Several health injuries have been reported by use of incorrect or unlabeled MR devices. EN IEC 625701 standards address “MR Safe” / “MR Conditional” marking and identii cation of test requirements for all items with intended use inside the MRE3. After technical training, the MR personnel, MR authorized person or MR worker must learn the terminology of the MR environment and how it is applied. MR user education for MR safety is o(cid:30) ered by training cours- es as “MR safety expert (MRSE)”, www.mrcomp.com/mr-education.html, Germany, DIN 68762 and OENORM 1125-1/-2 at AHK Wien. 96 commercial available MRI products (www.MRI-tec.com, one-shop- stop, Germany) have been selected randomly and from throughout the daily use of MR clinical application: • Audio and video systems • Gurneys • Goggles • Injection systems • Suction pumps • Monitoring system • Positioning • Wheel chairs • Anesthesia machines The product documentation has been investigated for any existing MR labeling and the completeness of it. From 96 Products that have been analyzed, more than half of the investigated products have never been properly tested and assessed for safety in the MR environment. Relevant MR interactions to consider: MR safety • Magnetically-induced displacement force exist for devices consisting of ferromagnetic materials • Magnetically-induced torque aligns the device to the orientation of the (cid:31) eld • Gradient- & RF-induced heating / voltages • Gradient-induced vibration • Malfunction induced by all three (cid:31) elds MR compatibility • Image artefacts: can distort or misplace image information. • Amongst further image quality interferences disturbing the MR image quality are e.g.: • B0-inhomogeneities by ferromagnetic masses • Eddy currents by induced currents in electrically conductive components • RF noise emitted from unshielded accessories • Proton signals generated by hydrogen protons in plastics More sophisticated electrical/active devices need additional consul- tation of ISO/TS 10974 test methods. Implant MR safety labeling can be found in MR safety implant databases such as www.MagResource.eu MR Safe MR Conditional MR Unsafe Fig 1: Standardized symbols and terms used in MR labeling, which are created for MR product approval at worldwide regulatory agencies 1 35 60 ◾ never been tested ◾ tested but without certii cate ◾ tested by MR testing laboratory Fig. 2: Within the investigated 96 products 60 have never been properly tested and assessed for safety in the MR environment, 35 were tested but without any certii cate, 1 was approved by MR testing laboratory There could be fatal consequences if products contain ferromag- netic materials, be conductive, thus hurt the patient or have its function a(cid:30) ected as well as disturbing the MR system, if a device is not fully tested. Individual MR Statements of manufacturers lead to caution, but cannot be considered as being su(cid:29) cient for use in the daily clinical MR routine due to many factors resulting in unclear situations. Comprehensive testing of all MR interactions is necessary and is only given by the international standards, which have reached now- adays a useful and comprehensive quality level. Only then MR user and MR patient safety is guaranteed. www.mri-tec.com · www.mrcomp.com 1 IEC 62570:2014 Standard practice for marking medical devices and other items for safety in the magnetic resonance environment 2 DIN 6876. Operation of medical magnetic resonance systems. Berlin: German Institute for Standardization; 2014. 3 Curr Radiol Rep (2016) Planning an MR Suite: What can be done to ensure MR safety? Gregor Schaefers, Björn Mierau Published online: 10 May 2016, Springer 30 RADBOOK 2017

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