: On 7 mar, 11:56,
[email protected] (Bruce Condine) wrote:
: > Would anyone happen to know why 362 MHz is a standard frequency for
: > NMRI?
: gamma = larmor constant, for hydrogen about 42.57 MHz/T
: So there are no specific frequencies that have to be used.
: Your frequency probably belongs to a B0 field of 8.5 T. (85000
: Gauss).
8.5 teslas sound quite high for a MRI system with a significantly
sized magnet bore, like those made for medical imaging. An example
of a device of such caliber is the french Neurospin facility
http://tinyurl.com/yahy59o . We happen to collaborate with them,
although not in the high-field MRI stuff.
For small sample sizes 8.5T is approximately the highest field
that can be obtained by simple Nb-Ti superconducting magnets operated
at 4.2K . For higher fields you'd need more expensive and hard-to-
manufacture materials and/or lower temperature. Maybe the 8.5T is
adopted as some sort of a standard, eg. in MRI-based chemical
analysis.
Regards,
Mikko
