Rectangular and radial region of interests on the edge of cylindrical phantom for spatial resolution measurement

<span lang="EN-US">The purpose of this study was to evaluate the effect rectangular region interest (ROI) size on modulation transfer function (MTF), develop radial ROI, and compare both ROIs performances for MTF measurement using a cylindrical polymethyl methacrylate (PMMA) phantom. The PMMA phantom used in rotated 45°. Four ROI were created measure value. sizes 3×41, 21×41, 41×41, 61×41 pixels; each placed at upper edge. ROI’s length 41 pixels several points calculation automatically conducted MATLAB. MTFs from then compared. comparison also three different filters. which smoother than those all This indicated that more resistant noise ROI. Rectangular with 41×41 had similar 50% 10% values value obtained is accurate robust ROI.</span>