A novel easy-to-use phantom for the determination of MTF in SPECT scanners

Abstract

The method presented here is novel and easy to implement, requiring materials commonly found in clinical practice. Furthermore, this technique which is based on the LSF method reduces measurement noise levels due to the larger amount of data averaging than in the conventional PSF method. Furthermore, MTF can be assessed easily, in three dimensions (3D), by placing the flood source either in sagittal or coronal direction.

A new PET resolution measurement method through Monte-Carlo simulations

“…For angles greater than 8°, the dimensions of the vertical LSFs will be different from those of the true LSFs by more than 1%, and geometrical corrections should then be applied [14]. Since the plane source was positioned either clockwise or counter clockwise in a 3°a ngle, a custom-made software was used for angle correction [15,29]. The final LSF was obtained by averaging all line LSF profiles after angle correction.…”

“…The plane source, which is introduced in this study following the works of Boone [14] for CT and Fountos et al [15] for SPECT systems, is based on the excellent binding of 18 i.e., the radioactive plate) was simulated within a phantom, consisting of two semicylindrical polyethylene blocks with a 20 cm diameter and a 70 cm length, in the horizontal (parallel to coronal) and vertical (parallel to sagittal) directions.…”

“…This method is robust to aliasing when used for MTF calculation and is more resilient to noise because of greater data averaging when compared with the conventional point source method [14]. Fountos et al [15] recently introduced a similar method for single-photon emission computed tomography (SPECT) scanners by immersing an Agfa MammoRay HDR Medical X-ray film in a solution of dithiothreitol/Tc-99m(III)-DMSA to obtain the MTF through the plane source method. Building on the work of Fountos and colleagues, this study introduces a plane source phantom to estimate the MTF through the LSF by simulating a thin-layer chromatography (TLC) plate, which can be implemented by a layer of silica gel on Al foil substrates, immersed in an 18 F-FDG bath solution.…”

3D tomographic imaging with the γ-eye planar scintigraphic gamma camera

“…To do this a Gaussian fit was applied to the line profile of each reconstructed image from which the full-width-half-maximum (FWHM) could be extracted. While there are other methods that can provide optimised fitting for the point spread function [12], Gaussian fitting is sufficient for comparison purposes. The mean FWHM of numerous line profiles along the length of the capillary were used to give a value for the spatial resolution of each reconstruction [13].…”

Resolution Properties of a Calcium Tungstate (CaWO4) Screen Coupled to a CMOS Imaging Detector

“…Images of the edge, placed at a slight angle (less than 3 o ), were obtained under radiographic imaging conditions. In IEC 62220-1-1:2015 [20,21] the method to obtain the final MTF has been restricted and only averaging of the oversampled ESFs is used, in order to obtain the final MTF [20][21][22][23][24]. The pixel values of the linearized data of N consecutive lines (i.e.…”