What does the term “field strength” mean?
The strength of a magnetic field is measured in units of either Gauss or Tesla, where 10,000 Gauss units equal 1 Tesla. Based on these measurements, MRI scanners are often categorized as low-, mid- or high-field as follows: Low-field MRI: Under 0.2 Tesla (2,000 Gauss) Mid-field MRI: 0.2 to 0.6 Tesla (2,000 Gauss to 6,000 Gauss) High-field MRI: 1.0 to 1.5 Tesla (10,000 Gauss to 15,000 Gauss) For years, there was a debate among radiologists as to which range of field strengths was more effective diagnostically. High-field strength proponents would point to the fact that, other things being equal, the stronger the field, the stronger the amount of usable radio signal which can be elicited from the body’s atoms and, therefore, the higher the quality of the MRI image.
