Transfer function measurement and analysis for an MR imager

This paper reports on high contrast resolution in MR imaging expected to be dominated by pixel size. Recommendations have been made to verify this assumption for MR imagers. The transfer function characteristics of the author's imager have been measured and compared with theoretical expectations. An edge response function (ERF) was obtained from a water-Plexiglas interface at various pixel widths ranging from 0.312 to 1.0 mm. A spin-echo pulse sequence was used with a 5-mm transaxial section. The ERF was smoothed (1,2,1), differentiated, and Fourier-transformed to obtain modulation transfer function (MTF) curves. The LSF was analyzed for skewness and kurtosis. The areas under the MTF amplitude curves (MTFA) and MTF energy curves (equivalent band pass or Ke) were calculated