Surgery – Diagnostic testing – Detecting nuclear – electromagnetic – or ultrasonic radiation
Reexamination Certificate
1999-06-11
2001-01-16
Lateef, Mauvin M. (Department: 3737)
Surgery
Diagnostic testing
Detecting nuclear, electromagnetic, or ultrasonic radiation
Reexamination Certificate
active
06174287
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention relates to a medical diagnostic ultrasound system and method for imaging contrast agents in tissues, organs and/or blood. In particular, continuous monitoring of a contrast agent infused target allowing for contrast enhanced periodic imaging is provided.
Contrast agents are injected or introduced into human or animal tissue organs and/or blood to enhance the contrast of ultrasonic images. Contrast agents may take various forms. For example, perfluorocarbon gas-filled microbubbles encapsulated by an albumin shell are used. These contrast agents provide strong reflection of ultrasonic energy.
Ultrasonic energy may destroy contrast agents. U.S. Pat. Nos. 5,560,364 and 5,685,310 disclose suspending ultrasonic transmissions for a period of time to avoid such destruction. Once ultrasonic transmission is resumed, the enhancement of contrast provided by the contrast agents is significant, but diminishes as imaging and resulting destruction continues. Using an ECG signal, interrupted two dimensional B-mode imaging was used to provide contrast enhanced images. However, by suspending ultrasonic transmission between the triggers, diagnostic information capturing all of the dynamics of the motion of the heart musculature valves and blood flow is not obtained.
In order to avoid losing information between triggered images, low power ultrasonic energy has been transmitted for generating two dimensional B-mode images in between the triggered images (high power). This low power imaging provides an indication of the location of the target tissue or organ while minimally destroying or interacting with the contrast agent. When the high power imaging is momentarily resumed, contrast enhancement remains visible. Transmit parameters other than power may be changed to avoid destruction of contrast agents, such as lower ultrasound line density, different frequency transmission and shorter transmit burst durations.
In this method, the images are generated using the same imaging mode, such as B-mode imaging. For example, triggered high powered B-mode images are generated with substantially continuous low power B-mode images. In one embodiment, a continuous two dimensional Doppler and B-mode image is generated with a triggered amplitude detected two dimensional contrast agent image. However, the lower power results in lower quality B-mode images.
Alternating between two different imaging modes may be desirable. Triggered B-mode imaging of the heart has been displayed with a substantially continuous pulse wave (PW) Doppler strip image. By positioning the PW gate in the heart chamber, the PW strip image revealed the time course of a contrast enhanced increase in the intensity of the Doppler data. The triggered B-mode image was displayed above the PW strip.
Another mode for imaging contrast agents is the M-mode (motion mode). For example, Doppler energy M-mode is sensitive to tissue perfusion.
SUMMARY OF THE INVENTION
The present invention is defined by the following claims, and nothing in this section should be taken as a limitation on those claims. By way of introduction, the preferred embodiment described below includes a method and system for imaging contrast agent within human or animal tissue, organs and/or blood. Contrast agents, such as perfluorocarbon gas-filled albumin microbubbles which exhibit contrast enhancement when exposed to ultrasound, are injected into a patient. Periodic images are generated to avoid reduction in the contrast provided by the contrast agents due to ultrasound destruction. Between the periodic images, an M-mode image is substantially continuously updated to allow the user to better locate and maintain imaging of a region of interest, determine dynamic movement within the region of interest, assess attenuation, determine an appropriate trigger point, and view perfusion of the contrast agent between the periodic images while minimizing destruction of contrast agent.
In one embodiment, an ultrasound system alternates between triggered firings of a two-dimensional B-mode image and substantially continuous updating of an M-mode image. The M-mode image is displayed as a strip revealing the time course of reflected ultrasound echoes along a scan line within the B-mode image plane. The B-mode image is displayed adjacent to the M-mode image.
In a second embodiment, two dimensional B-mode and color Doppler images are triggered. M-mode bursts are fired substantially continuously, and the Doppler energy of the received signals from these M-mode bursts is used for generating the adjacent and substantially continuous M-mode image. In a third embodiment, two dimensional B-mode and color Doppler images are triggered, with M-mode bursts fired substantially continuously, and the B-mode processor is used to generate a substantially continuous M-mode image. In alternative embodiments, some data is used for both two dimensional and M-mode imaging.
In a first aspect, a medical diagnostic ultrasound method is provided for imaging contrast agents injected into a patient during an imaging session with an ultrasound system. An M-mode image is generated on a display. The M-mode image is substantially continuously updated during the imaging session. A periodic image is generated on the display adjacent to the M-mode image, where the periodic image is responsive to the contrast agents. The periodic image is periodically updated during the imaging session.
In a second aspect, a medical diagnostic ultrasound system is provided for imaging contrast agents injected into a patient during an imaging session. An M-mode processor and a periodic image processor operatively connect with a display. A controller is operative to cause the M-mode processor to substantially continuously update the M-mode image, to cause the periodic image processor to periodically update the periodic image, and to cause alternating between updating the M-mode image and updating the periodic image during the imaging session.
In a third aspect, a medical diagnostic ultrasound method for imaging contrast agents with an ultrasound system is provided. An ultrasonic burst is transmitted along a first scan line. This transmission step is repeated substantially continuously. In response to the substantially continuous ultrasonic burst transmissions, an M-mode image is generated. Transmission of ultrasonic bursts along a plurality of scan lines is triggered. A triggered image is generated in response to the triggered transmissions. The triggered image is displayed substantially simultaneously with the M-mode image at each trigger.
Further aspects and advantages of the invention are described below in conjunction with the preferred embodiments.
REFERENCES:
patent: 4398540 (1983-08-01), Takemura et al.
patent: 4501277 (1985-02-01), Hongo
patent: 5090411 (1992-02-01), Higuchi
patent: 5255683 (1993-10-01), Monaghan
patent: 5560364 (1996-10-01), Porter
patent: 5685310 (1997-11-01), Porter
patent: 5694937 (1997-12-01), Kamiyama
patent: 5735281 (1998-04-01), Rafter et al.
patent: 5820561 (1998-10-01), Olstad et al.
patent: 5833613 (1998-11-01), Averkiou et al.
Gerhard Kronik et al., Contrast M-Mode Echocardiography in Diagnosis of Atrial Septal Defect in Acyanotic Patients; Feb., 1979; pp. 372-378.
Richard E. Kerber, M.D., et al., Use of an Ultrasonic Method in the Diagnosis of Valvular Regurgitation and Inracardiac Shunts; Nov., 1974; pp. 722-727.
Lilliam M. Valdes-Cruz M.D., et al., Echocardiographic Detection of Intracardiac Right-to-Left Shunt following Peripherai Vein Injections; Mar., 1976; pp. 558-562.
Carmal M. Moran, et al., Potential applications of color-Doppler imaging of the myocardium in assessing contractility and perfusion; 1993; pp. 359-374.
Bennett Richard M.
Davidson John A.
Holley Gregory L.
Krishnan Sriram
Main Joan C.
Acuson Corporation
Brinks Hofer Gilson & Lione
Lateef Mauvin M.
Patel Mavlin
Summerfield Craig A.
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