Modulation Transfer Function (MTF) is one of several key parameters that determine the overall performance capability of an x-ray image intensifier. The measurement of MTF described is made by illuminating the intensifier with a narrow line (Sifunction) of x-radiation and recording the line spread function of the resultant output illumination. The Fourier transform of this line spread is calculated to obtain the MTF. Measured MTF's are given from some typical intensifiers, on and off axis, in both the radial and tangen-tial directions.
R. J. Doyle, R. J. Doyle,
"X-Ray Image Intens If Ier Modulation Transfer Function Measurement", Proc. SPIE 0056, Medical X-Ray Photo-Optical Systems Evaluation, (1 May 1974); doi: 10.1117/12.954277; https://doi.org/10.1117/12.954277