The b-value is a factor of diffusion weighted sequences. The b factor summarizes the influence of the gradients on the diffusion weighted images. The higher the value b, the stronger the diffusion weighting.
[B0] A conventional symbol for the main magnetic field strength (magnetic flux density or induction) in a MRI system. Although historically used, H0 (units of magnetic field strength, ampere//meter) should be distinguished from the more appropriate B0 [units of magnetic induction, tesla].
In current MR systems it has a constant value over time varying from 0.02 to 4 T. Field strengths of 0.5 T and above are generated with superconductive magnets. High field strengths have a better signal to noise ratio (SNR). The optimal imaging field strength for clinical imaging is between 0.5 and 2.0 T.
[B1] A conventional symbol for the radio frequencyfield strength (another symbol historically used, is H1). In MRI, B1 labels the field produced by the radio frequency coil.
The B1 field is often conceived of two vectors rotating in opposite directions, usually in a plane transverse to B0. At the Larmor frequency, the vector rotating in the same direction as the precessing spins will interact strongly with the spins.
Short name: B22956, generic name: Gadocoletic acid, chemical compound: Gadocoletic acid trisodium salt, central moiety: Gd, phase: II
A blood pool agent for magnetic resonancecoronary angiography and first pass myocardial perfusion imaging under development (Bracco Diagnostics Inc). The small molecules of gadolinium-based B22956 are bound after injection to large human serum albumin molecules in coronary vessels with the result of high vessel/muscle contrast.
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