[Modulation transfer function measurements on magnetic resonance imaging: use of the edge spread function].

A convenient, accurate method to measure the modulation transfer function (MTF) of magnetic resonance(MR) images is discussed. To avoid any distortion of the edge spread function(ESF) which is inadvertently produced by the magnitude operator, the MTF was calculated from the ESF obtained from the salad-oil/water interface. Our MTF findings closely correlated with the MTF findings as calculated by an alternate method (Steckner et al.). Our method was only adapted to some specific sequences and some specific encoding directions, however, MTF was successfully obtained by the magnitude operator without any errors. In our method, the production and arrangement of phantoms were also easier to control. Our new method is therefore considered to be useful for evaluating the resolution property of MR images from various institutions.