ABSTRACT
It is well known that spatial variations in tissue magnetic susceptibility cause magnetic field inhomogeneity, leading to signal loss due to spin dephasing or hypointensity that is particularly prominent in gradient echo MRI (GRE MRI). In certain imaging protocols, the susceptibility source is a contrast agent and there is great desire to know how much contrast agent has arrived in particular regions. One option is to look at the percentage of hypointensity relative to a control region of known susceptibility. Percentage of hypointensity is a quantity, but how is this quantity related to the amount of susceptibility?
