1. A method of magnetic resonance (MR) B1 field mapping with a magnetic resonance imaging (MRI) system comprising: transmitting with a plurality of MR imaging radio frequency (RF) coils, both a radio frequency (RF) pulse sequence and a gradient pulse sequence, in order to excite a linear projection that passes through a volume of interest; transmitting with the plurality of MR imaging RF coils a radio frequency (RF) pulse sequence in order to impart B1 sensitive phase into the linear projection; acquiring a one dimensional spatially encoded signal along the linear projection with the MRI system; and generating a B1 field map of the MRI system, based on the one dimensional spatially encoded signal that has been acquired along the linear protection; wherein the volume of interest is defined by a geometric placement, of the plurality of the RF coils at specified locations, within the MRI system; wherein the linear projection is in the form of one or more vector-like columns extending from one or more of the plurality of RF coils, that passes through the volume of interest; and wherein each of the one or more vector-like columns, of the linear projection have a column geometry, while also being individually spaced according to an estimated RF wavelength that passes through the volume of interest.