1. A radiographing information management system comprising: an image analysis unit that analyzes a radiological image, which is obtained by a radiographing system, to derive an image quality evaluation value indicating quality of the image; a storage processing unit that stores the image quality evaluation value derived by the image analysis unit and radiographing information, which includes an item of a radiation dose or an equivalent amount equivalent to the radiation dose, in a storage unit so as to be associated with each other; a search unit that searches for radiographing information, which has an item designated in search conditions, and an image quality evaluation value, which is associated with the radiographing information, from the storage unit; a statistical data generation unit that generates statistical data, which has an image quality evaluation value and a radiation dose or an equivalent amount as parameters, based on the radiographing information and the image quality evaluation value associated with the radiographing information that have been searched for by the search unit; and a display unit that displays the statistical data generated by the statistical data generation unit, wherein the image quality evaluation value is granularity of a region of interest of a radiological image.