Radiographic/fluoroscopic imaging system with reduced patient dose and faster transitions between radiographic and fluoroscopic modes
First Claim
1. In a diagnostic medical imaging system adapted for radiographic and fluoroscopic examinations of a patient, said system being capable of operating in a fluoroscopic examination mode at a selected fluoroscopic pulse rate employing frame integration at a selected frame integration rate, and in a radiographic examination mode, comprising:
- means for producing x-rays directed toward an examination region of interest;
means for receiving x-rays and producing therefrom image information relating to said examination region of interest;
means for detecting change in said image information relating to said examination region of interest; and
means responsive to said means for detecting change in said image information for causing a change in radiographic or fluoroscope or imaging operating parameters of said imaging system;
the improvement wherein said means for causing a change in radiographic or fluoroscopic or imaging operating parameter of said imaging system changes said frame integration rate.
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Accused Products
Abstract
A radiographic/fluoroscopic imaging system provides rapid transition from fluoroscopic to radiographic imaging mode by maintaining the X-ray tube high voltage, increasing the filament current, allowing X-ray tube current to increase toward the desired radiographic current, and terminating exposure when the desired X-ray dose has been achieved. Rapid transition from radiographic to fluoroscopic imaging mode is provided by reducing x-ray tube high voltage to produce an equivalent fluoroscopic-level x-ray output at high initial current, dropping filament current, and enabling ABS control of the high-voltage. As x-ray tube current drops, ABS correspondingly increase high voltage to maintain the desired output. The imaging system obtains movement-related information by analyzing a video signal (such as from fluoroscopic image or an image from an optical camera trained on the patient), or from operator movement requests. The imaging system uses movement-related information to responsively control fluoroscopic pulse rate or other imaging parameters. The imaging system can also use such information to initiate a radiographic exposure, or advance to the next step of an operator programmed examination consisting of interspersed fluoroscopic and radiographic exposures. This results in a lower dose to both the patient and the examiner, consistent with high image quality.
70 Citations
11 Claims
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1. In a diagnostic medical imaging system adapted for radiographic and fluoroscopic examinations of a patient, said system being capable of operating in a fluoroscopic examination mode at a selected fluoroscopic pulse rate employing frame integration at a selected frame integration rate, and in a radiographic examination mode, comprising:
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means for producing x-rays directed toward an examination region of interest; means for receiving x-rays and producing therefrom image information relating to said examination region of interest; means for detecting change in said image information relating to said examination region of interest; and means responsive to said means for detecting change in said image information for causing a change in radiographic or fluoroscope or imaging operating parameters of said imaging system; the improvement wherein said means for causing a change in radiographic or fluoroscopic or imaging operating parameter of said imaging system changes said frame integration rate.
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2. In a diagnostic medical imaging system adapted for radiographic and fluoroscopic examinations of a patient, said system being capable of operating in a fluoroscopic examination mode with edge enhancement at a selected level, and in a radiographic examination mode, comprising:
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means for producing x-rays directed toward an examination region of interest; means for receiving x-rays and producing therefrom image information relating to said examination region of interest; means for detecting change in said image information relating to said examination region of interest; and means responsive to said means for detecting change in said image information for causing a change in radiographic or fluoroscopic or imaging operating parameters of said imaging system; the improvement wherein said means for causing a change in radiographic or fluoroscopic or imaging operating parameter of said imaging system changes said edge enhancement level.
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3. In a diagnostic medical imaging system adapted for radiographic and fluoroscopic examinations of a patient, said system being capable of operating in a fluoroscopic examination mode and in a radiographic examination mode, comprising:
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means for producing x-rays directed toward an examination region of interest; means for receiving x-rays and producing therefrom image information relating to said examination region of interest; means for detecting change in said image information relating to said examination region of interest; means responsive to said means for detecting change in said image information for causing a change in radiographic or fluoroscopic or imaging operating parameter of said imaging system; the improvement wherein; said system further comprises means for determining a rate of relative motion between said patient and said imaging system; and said means responsive to said means for detecting change in said image information for causing a change in radiographic or fluoroscopic or imaging operating parameter of said imaging system varies said parameter by an amount related to said rate of relative motion.
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4. In a diagnostic medical imaging system adapted for radiographic and fluoroscopic examinations of a patient, said system being capable of operating in a fluoroscopic examination mode and in a radiographic examination mode, of the kind including:
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means for producing x-rays directed toward an examination region of interest; means for receiving x-rays and producing therefrom image information relating to said examination region of interest; means for detecting change in said image information relating to said examination region of interest; and means responsive to said means for detecting change in said image information for causing a change in radiographic or fluoroscopic or imaging operating parameters of said imaging system; the improvement wherein said means responsive to said means for detecting change in said image information for causing a change in radiographic or fluoroscopic or imaging operating parameters of said imaging system varies said radiographic or fluoroscopic or imaging operating parameter by an amount proportional to a rate of change of said image information detected by said means for detecting change.
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5. A diagnostic medical imaging system adapted for radiographic and fluoroscopic examinations of a patient, said system being capable of operating in a fluoroscopic examination mode and in a radiographic examination mode, comprising:
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means for producing x-rays directed toward an examination region of interest;
means for receiving x-rays and producing therefrom image information relating to said examination region of interest;means for storing at least first and second sets of fluoroscopic operating parameters; means for deriving movement related information producing an indication when movement of said patient with respect to said imaging system, requests for movement of said patient with respect to said imaging system, or change in a visible feature of said image information occur; and means responsive to said means for deriving movement related information for operating said imaging system using said first set of fluoroscopic operating parameters when said indication is absent and for operating said imaging system using said second set of fluoroscopic operating parameters when said indication is present wherein; said second set of fluoroscopic operating parameters includes a fluoroscopic pulse rate parameter; and said system further comprises; means for determining a rate of relative motion between said patient and said imaging system; and means for varying said fluoroscopic pulse rate parameter by an amount related to said rate of relative motion.
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6. A diagnostic medical imaging system adapted for radiographic and fluoroscopic examinations of a patient, said system being capable of operating in a fluoroscopic examination mode and in a radiographic examination mode, comprising:
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means for producing x-rays directed toward an examination region of interest; means for receiving x-rays and producing therefrom image information relating to said examination region of interest; means for storing at least first and second sets of fluoroscopic operating parameters; means for deriving movement related information producing an indication when movement of said patient with respect to said imaging system, requests for movement of said patient with respect to said imaging system, or change in a visible feature of said image information occur; and means responsive to said means for deriving movement related information for operating said imaging system using said first set of fluoroscopic operating parameters when said indication is absent and for operating said imaging system using said second set of fluoroscopic operating parameters when said indication is present wherein said means for varying said fluoroscopic pulse rate parameter by an amount related to said rate of relative motion varies said parameter by an amount proportional to said rate of relative motion.
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7. In a diagnostic medical imaging system adapted for radiographic and fluoroscopic examinations of a patient, said system being capable of operating in a fluoroscopic examination mode and in a radiographic examination mode, including:
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means for producing x-rays directed toward an examination region of interest; means for receiving x-rays and producing therefrom image information relating to said examination region of interest; means for deriving movement related information producing an indication when movement of said patient with respect to said imaging system, requests for movement of said patient with respect to said imaging system, or change in a visible feature of said image information occur; means responsive to said means for deriving movement related information for operating said imaging system in said fluoroscopic examination mode whole said indication is absent; and means responsive to said means for deriving movement related information for performing a radiographic exposure when said indication is received; the improvement wherein said means for deriving movement related information comprises; means for measuring a characteristic of said image information relating to said examination region of interest; digital means for storing, in the form of a digital word, said characteristic corresponding to said image information at an initial time; digital means for storing, in the form of a digital word, said characteristic corresponding to said image information at a subsequent time; digital word comparison means for comparing the stored digital word representing said characteristic determined at an initial time with the stored digital word representing said characteristic determined at a subsequent time to produce a digital indication of change in said image information; and means responsive to said indication of change in said image information for initiating a radiographic exposure when said indication exceeds a predetermined threshold.
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8. A method for use with a diagnostic medical imaging system adapted for radiographic and fluoroscopic examinations of a patient, said system being capable of operating in a fluoroscopic examination mode and in a radiographic examination mode, said system including means for deriving movement related information relating to movement of the patient or the imaging system or in an image obtained therefrom;
- the method comprising the steps of;
(a) establishing a first set of fluoroscopic and imaging operating parameters for use in non-movement conditions; (b) establishing a second set of fluoroscopic and imaging operating parameters for use in movement conditions said second set of fluoroscopic and imaging operating parameters including an edge enhancement level greater than that of said first set of fluoroscopic and imaging operating parameters; (c) causing said imaging system to initiate a fluoroscopic examination according to said first set of fluoroscopic and imaging operating parameters; (d) receiving said movement related information; and (e) causing said imagine system to operate according to said second set of fluoroscopic and imaging operating parameters.
- the method comprising the steps of;
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9. A method for use with a diagnostic medical imaging system adapted for radiographic and fluoroscopic examinations of a patient, said system being capable of operating in a fluoroscopic examination mode and in a radiographic examination mode, said system including means for deriving movement related information relating to movement of the patient or the imaging system or in an image obtained therefrom:
- the method comprising the steps of;
(a) establishing a first set of fluoroscopic and imaging operating parameters for use in non-movement conditions; (b) establishing a second set of fluoroscopic and imaging operating parameters for use in movement conditions, said second set of fluoroscopic and imaging operating parameters including a frame integration rate smaller than that of said first set of fluoroscopic and imaging operating parameters; (c) causing said imaging system to initiate a fluoroscopic examination according to said first set of fluoroscopic and imaging operating parameters; (d) receiving said movement related information; and (e) causing said imaging system to operate according to said second set of fluoroscopic and imaging operating parameters.
- the method comprising the steps of;
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10. In a diagnostic medical imaging system adapted for radiographic and fluoroscopic examinations of a patient, said system being capable of operating in a fluoroscopic examination mode and in a radiographic examination mode, including:
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means for producing x-rays directed toward an examination region of interest; means for receiving x-rays and producing therefrom image information relating to said examination region of interest; means for deriving movement related information producing an movement of said patient with respect to said imaging system, requests for movement of said patient with respect to said imaging system, or change in a visible feature of said image information occur; means responsive to said means for deriving movement related information for operating said is system in said fluoroscopic examination mode while said indication is absent; and means responsive to said means for deriving movement related information for performing a radiographic exposure when said indication is received; the improvement comprising; first image change detection means responsive to image change in a first selected image region for producing a first signal indicating said change; second image change detection means responsive to image change in a second selected image region for producing a second signal indicating said change; means for initially causing said imaging system to operate according to a first set of fluoroscopic and imaging operating parameters; means responsive to said first signal for causing said imaging system to operate according to a second set of fluoroscopic and imaging operating parameters non-identical with said first set; and means responsive to said second signal for initiating a radiographic exposure.
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11. In a method for use with a diagnostic medical imaging system adapted for radiographic and fluoroscopic examinations of a patient, said system being capable of operating on a fluoroscopic examination mode and in a radiographic examination mode, said system having means for collecting image information from said patient to form a representation of an image;
- the method comprising the steps of;
(a) establishing fluoroscopic and imaging operating parameters; (b) defining at least one region of said representation of an image; (c) performing the fluoroscopic examination; (d) detecting image change in at least one of said defined regions of said representation of an image; and (e) causing said imaging system to initiate a radiographic exposure; the improvement wherein; step (a) thereof further comprises the step of (a1) defining initial fluoroscopic and imaging examination parameters; step (b) thereof further comprises the step of (b1) defining first and second regions of said representation of an image; step (c) thereof further comprises the steps of; (c1) initiating the fluoroscopic examination according to the initial fluoroscopic and imaging examination parameters; and (c2) detecting image change in said first defined region of said representation of an image, and responsive thereto, causing said imaging system to operate according to adjusted fluoroscopic and imaging examination parameters; step (d) thereof further comprises the step of (d1) detecting image change in said second defined region of said representation of an image; and step (e) thereof further comprises the step of (e1) responsive thereto, causing said imaging system to initiate said radiographic exposure.
- the method comprising the steps of;
Specification