Evaluation of resolution of a scintillation camera using presampling MTF

Resolution with the modulation transfer function (MTF) of planar images in nuclear medicine has been used to evaluate the function of the pre-reconstruction filter used in single photon emission computed tomography (SPECT), in order to obtain high quality of SPECT images. In this study we compared presampling MTF used for evaluation of medical image resolution in digital subtraction angiography (DSA) and computed radiography (CR), with MTF which was approximated to the Gauss function from the full width at half maximum (FWHM), which is normalized by the National Electrical Manufacturers Association (NEMA). As a result, relative error of MTF between the two methods was approximately 10%. The effect of distortion in LSF caused by the addition of scattering appeared to be greater at full width at tenth maximum (FWTM) than at FWHM. Therefore, evaluation of a scintillation camera with only FWHM is limited when the system includes scattering. Evaluation of resolution by the presampling MTF method is useful for radionuclide images. (author)