{'fraction_non_alphanumeric': 0.03391384051329056, 'fraction_numerical': 0.027497708524289642, 'mean_word_length': 5.033149171270718, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Measurement of the presampled MTF of computed radiography using an edge test device

Objective:To design a high-precision edge test device and to measure the presampled MTF of computed radiography system.Methods:An edge device had been designed and constructed from a m-thick lead foil laminated between two thin slabs of acrylic.The device was placed on the surface of IP,and the polished edge was parallel to the X-ray beam.A radiograph of the device was taken with an exposure,the image of the edge device was acquired and processed to obtain the presampled MTF.The image processing include calculation of the relative deposited-energy data,automated determination of the edge angle,reprojection,smoothing of the edge spread function(ESF),and MTF synthesis from ESF.Results:The presampled MTF of CR in horizontal and vertical directions were 0.67 and 0.58 at 0.4 cycle/mm,0.085 and 0.063 at 1.5 lp/mm,0.0033 and 0.0011 at 3.0 lp/mm.Conclusion:The simplicity and practicality of edge test method allows routine and accurate determination of presampled MTF for digital radiographic systems.