For more than 20 years, the clinical standard for MR imaging has been either 1.5T or 3T. While many of the physical advantages of low field have been well known in the scientific community, the push for higher SNR favored higher fields. However, in the light of technical improvements, other metrics may be favored. Improvements in image reconstruction – from parallel imaging and compressed sensing to deep learning – mean that clinicians can make optimal use of the available signal while exploiting the physical advantages of low-field MRI, such as reduced artifacts. If SNR is sufficient at two different fields, then the focus may fall instead on diagnostic or financial value. Scientific literature
even back in the mid 1990s showed no significant difference in diagnostic
sensitivity or specificity between 1.5T and lower-field systems1.
As scanner costs typical scales with field strength,
lower field scanners offer opportunities given the cost pressure in many
healthcare systems. All these factors could
help bring MRI to places it has not been before – spreading into new geographical and clinical areas.