Low-Field Permanent Magnet MR Systems in the Developing World:  A Review of Clinical and Research Applications
Christina Louise Sammet1,2, Godwin Ogbole3, and Steffen Sammet4

1Radiology, Northwestern University, Chicago, IL, United States, 2Medical Imaging, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, IL, United States, 3Department of Radiology, University of Ibadan, Ibadan, Nigeria, 4Department of Radiology, University of Chicago, Chicago, IL, United States

Synopsis

Low-field permanent magnet MR systems will be increasingly utilized in resource-limited settings due to their independence from helium and power supply infrastructure. Optimization of available systems for clinical imaging will greatly improve diagnostics and lead to unique opportunities to study health concerns in developing countries. This exhibit summarizes the state-of-the art in permanent magnet MRI to encourage interest in the improvement of existing systems and their utilization for collaborative imaging research in the developing world.

Purpose

This educational exhibit will explore the imaging capabilities and challenges of low-field, permanent magnet MR imaging technologies increasingly utilized in developing countries (Figure 1). Limited access to helium and the infrastructure necessary to support superconducting magnets in resource-limited settings has spurred the development of commercially available, low-field permanent magnet MR systems. As the MR community dedicates itself to optimizing neuroimaging at ultra-high field, the challenges of low-field permanent magnet imaging (<0.4T) are infrequently discussed. The advancement of low-field permanent magnet technology is necessary to extend magnetic resonance imaging to a large part of the world’s population, and it can also provide unique opportunities to research health concerns of the developing world 1,2.

Outline of Content

1.) A review of the technical abilities and limitations of existing low-field MR systems

• Limitation of the main field (B0) strength for permanent magnets

• Unique installation challenges

• RF receiver chain design and coil availability

• Gradient system performance

2.) Available MR pulse sequences for clinical imaging and research

• Structural imaging capabilities and example images (Figure 2)

• Functional imaging – what we can and cannot do

• Contrast agent performance considerations at low-field

3.) Feasibility of imaging research in resource-limited settings

• Current state of research utilizing low-field MRI

• PACS and post-processing in settings with limited digital infrastructure.

4.) The state of quality control procedure for low-field MR systems

• The state of accreditation for low-field systems

• Existence of phantoms for low-field Quality Control procedures

Summary

Low-field permanent magnet MR systems will be increasingly utilized in resource-limited settings due to their independence from helium and power supply infrastructure. Optimization of available systems for clinical imaging will greatly improve diagnostics and lead to unique opportunities to study health concerns in developing countries. This exhibit summarizes the state-of-the art in permanent magnet MRI to encourage interest in the improvement of existing systems and their utilization for collaborative imaging research in the developing world.

Acknowledgements

This educational exhibit is supported in part by NIH/NINDS Grant #R25NS080949 and NIH/FIC Grant #R24TW008878.

References

1. Ogbole GI, et al. Magnetic resonance imaging: Clinical experience with an open low-field-strength scanner in a resource challenged African state. J Neurosci Rural Pract. 2012 May-Aug; 3(2): 137-143.

2. Ogbole GI, et al. Low field MR imaging of sellar and parasellar lesions: experience in a developing country hospital. Eur J Radiol. 2012 Feb;81(2):e139-46. Epub 2011 Feb 5.

Figures

Figure 1: Example of Low-field permanent magnet MRI system (0.2 T).

Figure 2: Lumbosacral magnetic resonance images showing an extensive intra-spinal tumor. MR images are from the University College Hospital, Ibadan, Nigeria acquired on a 0.2T permanent magnet MRI system.



Proc. Intl. Soc. Mag. Reson. Med. 24 (2016)
3633