Patent ID: 8633450

Claim:
An apparatus for assisting determination of at least one of modulation transfer function (MTF) and detective quantum efficiency (DQE) of an ionizing radiation imaging system, the ionizing radiation imaging system including an ionizing radiation detector for detecting an ionizing radiation beam received from an ionizing radiation source, the apparatus comprising, a box comprising a front window and rear window, the front window and the rear window being generally aligned and defining a space there between within the box, each of the front window and the rear window being generally transparent to ionizing radiation and of an area substantially similar to the ionizing radiation beam such that, when said box is placed in front of the detector, the ionizing radiation beam may substantially pass through said front window and said rear window, and into said detector; a KERMA (kinetic energy released in medium) module, contained within said box between said front window and said rear window, for measuring at least one of incident free-air exposure and incident free-air KERMA of the ionizing radiation beam when the ionizing radiation beam passes through said space, said KERMA module comprising a scatter baffle and an ionization chamber residing substantially in an aperture through said scatter baffle, said aperture being smaller than the front window, said scatter baffle comprising a sheet of ionizing radiation absorbing material for further preventing scatter of the ionizing radiation within said box; at least one backscatter baffle located between said KERMA module and said rear window for preventing backscatter of the ionizing radiation beam from the detector into the KERMA module, when said KERMA module is in use; at least one MTF module, contained within said box, for enabling acquisition of at least one edge image by the ionizing radiation imaging system, each said KERMA module, said at least one backscatter baffle and said at least one MTF module being independently moveable in and out of said space, such that at least one open image, a dark image, and said at least one edge image may be independently acquired by the ionizing radiation imaging system when the ionizing radiation beam passes through said box, and KERMA module measurements may be performed independent of image acquisition, such that said images and said KERMA module measurements may be processed to determine DQE; an interface for acquiring data from said KERMA module, and for controlling moving of each said KERMA module, said at least one backscatter baffle, and said at least one MTF module in and out of said space; and a self-contained unit comprising said box, said KERMA module, said at least one backscatter baffle, and said at least one MTF module.