Possibilities of low-field magnetic resonance imaging

Worldwide MRI is going up to higher field-strength. For imaging, magnets with a field-strength between 0.2 and about 2.5 Tesla are installed. Below 0.2 Tesla, low-field systems have been used in research projects to optimize image quality. New developments of 0.064 Tesla permanent-magnet MRI are hopeful for clinical work. Future possibilities of low-field MRI are shown. The advantages of this system are good image quality by low initial startup and operating costs as well as ease of siting and lack of need for cryogens. The open design has excellent patient acceptance and allows to examine patients with claustrophobia feelings. It allows easier monitoring during the examination especially children and patients with cancer or polytraumatic diseases. The introduction of more affordable MRI systems of low-field strength may decrease the cost of MRI to the point where it is competitive with computer tomography. (author)