The use of Modulation Transfer Function as an Overall Quality Control parameter in PET/CT

Abstract

The Modulation Transfer Function (MTF) is an important parameter for the characterization of image quality and the signal transfer properties of an imaging system. To develop a new method for MTF determination of PET/CT in three dimensions (3D), a novel and highly uniform, film based flood source using 18F-FDG has been prepared. The source was placed between PMMA blocks of various thicknesses, and imaged in a GE Discovery-ST, PET/CT system. MTF was then calculated from the line spread function (LSF) profile of the film. The film was prepared by immersing silica gel matrix, Al foils (5×10cm Fluka) in 18F-FDG bath solution. The effects of different reconstruction algorithms and the shape of the scanned object on MTF were investigated. By this method the alignment of PET and CT in the fused image was investigated as well. Hence the MTF can be used as an overall quality control parameter in PET/CT