MRI System Safety Evaluation
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Simulations of induced MRI RF eddy current patterns in virtual human models.

 

 

Full EM simulations are applied to high-resolution anatomical models, in this case a pregnant woman.

 

 

MRI3

Comparison of RF coil-induced SAR and corresponding temperature rise, considering thermoregulated and basal perfusion as well as thermal properties of tissues.

MRI System Safety Evaluation

 
Expertise & Infrastructure

The radio frequency (RF) and gradient coil fields from commercial scanners present a number of potential health risks for the patients. To develop the methodology for assessing MRI risks, IT'IS initiated the EUREKA Project MRI+, and several follow-up projects, with various partners from industry and academia. IT'IS performs customized evaluations of MRI exposure scenarios for a wide range of MR transmit technologies and patient populations. Based on the results, the critical parameters can be identified to improve overall patient safety. IT'IS has cooperated with major MRI manufacturers, including GE, Siemens and Philips, and actively contributes to the IEC 60601-2-33 safety requirements for medical MRI.

The group’s Yellow Submarine Laboratory is equipped with a range of benchtop MRI testing equipment including a PiX system, a MITS 1.5 and 3T system, the latest DASY6 RX90L with DASY52NEO licenses, and a wide range of specialized probes, including hardened probes designed specifically for MRI environments. With more than 100 Sim4Life licenses, including the Virtual Population 3.x and multiple animal models, and several High Performance Computers (HPC) ranging from Graphics Processing Unit (GPU) clusters to supercomputers, our interdisciplinary research team can tackle highly specific and complex research tasks with superior innovation and efficiency – while ensuring compliance to national and international standards.

 

Select Customized Research Projects of the Past Years
  • Collaborated with several major MRI manufacturers to measure full MRI systems with the aid of MRI-hardened acquisition systems developed by IT'IS together with SPEAG;
  • Developed benchtop MRI testbeds, the MITS platforms, together with ZMT Zurich MedTech AG and in collaboration with a leading implant manufacturer, to study a range of MRI configurations, exposure conditions and tissue phantoms;
  • Developed software tools for design of birdcage coils and parallel transmit coils, as well as an MR system simulator, together with ZMT Zurich MedTech AG;
  • Developed the Birdcage Library (BCLib) of precomputed RF coil exposures on the Virtual Population over a range of exposure conditions for 1.5T and 3T;
  • Developed the IMAnalytics shimming tool for benchtop high-throughput exposure assessments.

 

Solutions Beyond State-of-the-Art

As new MRI technologies evolve, risk assessment becomes significantly more complex. As the current methods for demonstrating MR safety are still highly empirical, it is important to continue to protect higher-risk populations, such as patients with medical implants or impaired thermoregulation, without resorting to overly conservative risk estimates which stifle innovation and technological progress. The IT'IS Foundation is committed to expanding its MR safety activities collectively with potential partners.

 

Contact

We look forward to discussing with you how we can best support your R&D initiatives and regulatory submissions – simply call us at +41 44 245 96 96 or send us an email at customized@itis.swiss.

 

RELEVANT PUBLICATIONS

Yao, A., Zastrow, E., Cabot, E., Lloyd, B., Schneider, B., Kainz, W. & Kuster, N. Anatomical Model Uncertainty for RF Safety Evaluation of AIMD under MRI Exposure. Bioelectromagnetics,
Yao, A., Zastrow, E. & Kuster, N. Data‐Driven Experimental Evaluation Method for the Safety Assessment of Implants With Respect to RF‐Induced Heating During MRI. Radio Science, 53(6):700-709, 2018
Corcoles, J., Zastrow, E. & Kuster, N. On the estimation of the worst-case implant-induced RF-heating in multi-channel MRI. Physics in Medicine and Biology, 62(12):4711-4727, 2017
Murbach, M., Neufeld, E., Cabot, E., Zastrow, E., Corcoles, J., Kainz, W. & Kuster, N. Virtual Population-Based Assessment of the Impact of 3 Tesla Radiofrequency Shimming and Thermoregulation on Safety and B1+ Uniformity. Magnetic Resonance in Medicine, 76(3):986-997, 2016
Corcoles, J., Zastrow, E. & Kuster, N. Convex Optimization of MRI Exposure for Mitigation of RF-Heating from Active Medical Implants. Physics in Medicine and Biology, 60(18):7293-7308, 2015
Murbach, M., Zastrow, E., Neufeld, E., Cabot, E., Kainz, W. & Kuster, N. Heating and Safety Concerns of the Radio-Frequency Field in MRI. In Current Radiology ReportsCurrent Radiology Reports, 3(12), Springer, 2015
Neufeld, E., Fütterer, M., Murbach, M. & Kuster, N. Rapid Method for Thermal Dose-Based Safety Supervision during MR Scans. Bioelectromagnetics, 36(5):398-407, 2015
Murbach, M., Neufeld, E., Capstick, M., Kainz, W., Brunner, D., Samaras, T., Prüssmann, K. & Kuster, N. Thermal Tissue Damage Model Analyzed for Different Whole-Body SAR and Scan Durations for Standard MR Body Coils. Magnetic Resonance in Medicine, 71(1):421-431, 2014
Murbach, M., Neufeld, E., Kainz, W., Prüssmann, K. & Kuster, N. Whole Body and Local RF Absorption in Human Models as a Function of Anatomy and Position within 1.5T MR Body Coil. Magnetic Resonance in Medicine, 71(2):839-845, 2014
van Rhoon, G., Samaras, T., Yarmolenko, P., Dewhirst, M., Neufeld, E. & Kuster, N. CEM43 Thermal Dose Thresholds: A Potential Guide for Magnetic Resonance Radiofrequency Exposure Levels? European Radiology, 23(8):2215-2227, 2013
Murbach, M., Cabot, E., Neufeld, E., Gosselin, M.C., Christ, A., Prüssmann, K. & Kuster, N. Local SAR Enhancements in Anatomically Correct Children and Adult Models as a Function of Position Within 1.5 T MR Body Coil. Progress in Biophysics and Molecular Biology, 107(3):428-433, 2011
Neufeld, E., Gosselin, M.C., Murbach, M., Christ, A., Cabot, E. & Kuster, N. Analysis of the Local Worst-Case SAR Exposure Caused by an MRI Multi-transmit Body Coil in Anatomical Models of the Human Body. Physics in Medicine and Biology, 56(15):4649-4659, 2011
Neufeld, E., Kühn, S., Szekely, G. & Kuster, N. Measurement, Simulation and Uncertainty Assessment of Implant Heating During MRI. Physics in Medicine and Biology, 54(13):4151-4169, 2009

 
CONTACT INFORMATION