| 摘要 |
The model of the invention comprises an exterior cylindrical body provided with a central orifice and an interior cylindrical body that fits inside the central orifice of the exterior cylindrical body. Both the interior and the exterior cylindrical body comprise first through-orifices for receiving pencil- or Farmer-type ionization chambers and second, blind orifices for receiving test tubes containing a variety of materials of known mass and electronic densities, and also test objects for image quality control. Thus, a single model allows calibration not only of absorbed dose but also of electronic densities and image quality in a single study. |
