A method of estimating the spatial variation in RF signal intensity within
magnetic resonance images of an object is described. The estimate can be
used to provide enhanced contrast in a magnetic resonance image by
correcting for spatial variation in RF intensities arising from
non-uniformities in RF receiving coils of an MRI machine acquiring the
image as well as distortions arising from the object and observation
itself. This is achieved through compound imaging of a medium of
essentially uniform spin density surrounding the object. From analysis of
the surrounding medium, and the location of notional points of RF signal
reception, a semi-empirical mathematical formulation of the decay profile
of the RF signal intensity within the object is determined. This is then
fitted to selected signal intensities from the medium surrounding the
object to obtain an estimate of the spatial variation in RF signal
intensity within the object.
