Technical Note: MTF determination from a star bar pattern image

Abstract

The procedure presented provides a good method to investigate the MTF in any spatial direction. Finally, as the whole star bar pattern image is used for MTF computation, the high signal to noise ratio guarantees a good immunity against noise.

Performance of a new star‐bar phantom designed for MTF calculations in x‐ray imaging systems

“…[20][21][22] Also, it has been shown that the information of intermediate and high frequencies is encapsulated in a small area of the edge image. 23 A theoretical method for MTF calculations using star-bar phantoms has been presented in Ref. [23] Some aspects of the theory, like using higher order harmonics or determining its uncertainties have also been developed in Ref.…”

“…23 A theoretical method for MTF calculations using star-bar phantoms has been presented in Ref. [23] Some aspects of the theory, like using higher order harmonics or determining its uncertainties have also been developed in Ref. [21,22,24] One important result states that the SD of the MTF determination is proportional to the square root of the frequency, 21,22 a better behavior than that of the edge method.…”

“…First, to evaluate the feasibility of using this kind of phantoms and the method presented in Ref. [23] and [24] for calculating the MTF in a real x-ray imaging system. Second, the measurements carried out are used to verify the predictions of the theory previously developed.…”

Technical Note: An oversampling procedure to calculate the MTF of an imaging system from a bar‐pattern image

“…Calculating the modulation transfer function (MTF) of an imaging system is based on the analysis of the image of a test object. 1 Pinholes, 2 slits, 3 edges, 4 star bar-pattern, 5,6 and line-pair phantoms [7][8][9] have been used to investigate the spatial resolution of an imaging system.…”

“…Oversampling procedures have been developed for the analysis of the slit image, 3 the edge image, 4 and the star bar-pattern image. 6 These procedures aimed at overcoming aliasing 10 by obtaining a presampled MTF and to improve the signal to noise ratio (SNR) of the test object image. Line-pair resolution phantoms are often used to study the spatial resolution of imaging systems in radiology.…”