Subtraction fluoroscopy method and apparatus
US4393402A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 8, 1981 |
| Grant date | Jul 12, 1983 |
| Priority date | — |
| Expiry date | Jun 8, 2001 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N5/3205
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Image frames produced consecutively with x-ray beams having different spectral bands or average energy levels are converted to analog video signals and then to digital data. The digital data for an image at one energy is stored in a memory and the ensuing data for the next image is subtracted from the stored data in an alternate or cyclic fashion. The resulting difference data is converted to analog video signals and displayed on a television monitor at standard frame rates. The same system can be used to store a digitized data mask frame and the digital data for ensuing frames can be subtracted from the mask. In some embodiments a buffer is used to allow removal of data from memory without having the data from a preceding frame overwritten by ensuing frames. Other embodiments use more than one memory and, in some cases, buffers to allow manipulating the data so snapshot, integrated and continuous or real-time subtraction images can be displayed individually on a single monitor or jointly on additional monitors.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.