US5459769A
Expired / Lapsed
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Procedure for monitoring contrast agent application in a CT imaging system
Assignee: General Electric Co
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Filing: 1994-11-09
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Granted: 1995-10-17
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Expires: 2014-11-09
Abstract
Abstract In a CT imaging system a baseline image is acquired prior to the injection of a contrast agent into the subject and a series of monitoring images are acquired which enable the affects of the contrast agent to be observed in real time. Regions in the baseline image may be selected with a cursor and the contrast enhancement amounts in these regions are calculated and displayed in both graphic and numerical form. By observing the changes that occur in the displayed information, the operator can determine the moment to begin the image scan for optimal image contrast.
Inventors
- 👤 Barry D. Brown
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 21:54
CPC Classifications
A; A61; A61B; A61B6/00; A61B6/48; A61B6/481; A61B6/02; A61B6/03; A61B6/032; A61B6/488; A61B6/50; A61B6/504; Y; Y10; Y10S; Y10S378/00; Y10S378/901
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
150 words
A method for performing a scan with a CT imaging system using a contrast agent which is injected into a subject to enhance image contrast, the steps comprising: performing a baseline scan of the subject with the CT imaging system; displaying a baseline image reconstructed with data acquired in the baseline scan; selecting a region in the baseline image to be monitored; performing a monitoring operation after injection of the contrast agent into the subject which includes: a) performing a monitor scan of the subject; b) displaying a monitor image reconstructed from data acquired in the monitor scan; c) calculating a contrast enhancement amount using attenuation values in the monitor image from the selected region; d) displaying the contrast enhancement amount; and e) repeating steps a) through d) until an indication that the image scan should begin is received; and performing an image scan and reconstructing the contrast enhanced image.
Claim 2
Independent Claim
150 words
A method for performing a scan with a CT imaging system using a contrast agent which is injected into a subject to enhance image contrast, the steps comprising: performing a baseline scan of the subject with the CT imaging system; displaying a baseline image reconstructed with data acquired in the baseline scan; selecting a region in the baseline image to be monitored; performing a monitoring operation after injection of the contrast agent into the subject which includes: a) performing a monitor scan of the subject; b) displaying a monitor image reconstructed from data acquired in the monitor scan; c) calculating a contrast enhancement amount using attenuation values in the monitor image from the selected region; d) displaying the contrast enhancement amount; and e) repeating steps a) through d) until an indication that the image scan should begin is received; and performing an image scan and reconstructing the contrast enhanced image.
Claim 3
Dependent Claim
41 words
The method as recited in claim 1 in which a plurality of regions in the baseline image are selected to be monitored and the contrast enhancement amount for each selected region is calculated in step c) and displayed in step d).
Claim 4
Dependent Claim
18 words
The method as recited in claim 1 in which the contrast enhancement amount is displayed in a graph.
Claim 5
Dependent Claim
19 words
The method as recited in claim 3 in which the contrast enhancement amount is also displayed in numerical form.
Claim 6
Dependent Claim
54 words
The method as recited in claim 1 in which the contrast enhancement amount is calculated in step c) by determining the mean value of the attenuation values within the selected region of the monitor image and subtracting therefrom the mean value of the attenuation values within the corresponding selected region of the baseline image.
Claim 7
Dependent Claim
21 words
The method as recited in claim 1 in which a contrast enhancement threshold is selected and is displayed in step d).
Claim 8
Dependent Claim
29 words
The method as recited in claim 6 in which the contrast enhancement amount is displayed in a graph, and the contrast enhancement threshold is also displayed in said graph.
Claim 9
Dependent Claim
21 words
The method as recited in claim 1 in which the baseline scan and the monitor scan are low x-ray dose scans.
Claim 10
Dependent Claim
37 words
The method as recited in claim 8 in which the baseline scan and the monitor scan are half scans in which a gantry on the CT imaging system revolves less than a full revolution during the scans.
Claim 11
Dependent Claim
24 words
The method as recited in claim 1 which includes displaying the total elapsed time since the injection of the contrast agent into the subject.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-10-16 | 1999-04-17 | 1999-10-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-10-16 | 2003-04-17 | 2003-10-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-10-16 | 2007-04-17 | 2007-10-17 | $7700.00 | Window Closed / Lapsed |