
US Patent No: 4,633,307
Number of patents in Portfolio can not be more than 2000
Digital subtraction fluorographic method and apparatus
Stats
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Dec 30, 1986
Issued date -
Sep 5, 1985
filing date -
06/772,861
serial no -
Expired
status
Importance
Abstract
In a digital intravenous subtraction fluorographic system, X-ray subtraction images obtained by performing a subtraction between the precontrast images and the post-contrast images are processed by comparing, for each pixel, the value of the pixel image data in the difference image with a predetermined threshold intensity value, and recognizing the time until the value of the pixel image data reaches the threshold intensity value. The resulting time data so determined in the processor is used for displaying the distribution of contrast medium in the vessel in relation to the time periods it takes for each pixel to attain the predetermined threshold intensity. In effect, the time data for each pixel is itself converted to an intensity signal dependent on the amount of time it takes for each pixel to cross the predetermined threshold intensity, and it is the time period derived intensity signal which is displayed.
First Claim
Related Publications
International Classification(s)
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Cited Art
| Patent Info | (Count) | # Cites | Year |
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| 4,504,908 Matched filter for X-ray temporal subtraction | 19 | 1982 | |
| 4,542,459 Matched filter for x-ray hybrid subtraction | 28 | 1982 | |
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| 4,204,226 Real-time digital X-ray time interval difference imaging | 54 | 1978 | |
| 4,204,225 Real-time digital X-ray subtraction imaging | 66 | 1978 | |
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| 4,436,095 Method and apparatus for imaging a body | 10 | 1981 | |