Radiographic imaging system quality monitor
US4239395A · kind A · utility
Inventor
Key dates
| Filing date | Aug 7, 1978 |
| Grant date | Dec 16, 1980 |
| Priority date | — |
| Expiry date | Aug 7, 1998 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B42/02
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The present invention is an apparatus and a method for using the apparatus to maintain quality control over a radiographic imaging system by precisely exposing two areas of a film to even illumination from a light source attenuated by different precisely known amounts. Both exposures are chosen to fall on the linear portion of the film's density-log exposure curve. The film is developed and the densities of the exposed areas are sensed photometrically. The film's base plus fog density, gamma and "processor quality factor" (which is a measure of the sensed film's deviation from the gamma and speed of a reference film processed in a reference processor) are automatically calculated. The processor quality factor allows faulty radiographic technique to be detected apart from faulty film or faulty processing without re-exposing the patient to additional radiation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.