Ultrasonic spectral contrast imaging
AssigneeBracco Research S.A.
InventorMarcel Arditi
Life of this patent
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Abstract
Echographic imaging (such as used for medical diagnosis) uses the injection of specific contrast agents in the body, or more generally in the region to be imaged. Different frequency dependent echographic behavior of the ultrasound contrast agents containing microbubbles as compared to echographic behavior of tissue without contrast agents is exploited by providing separated spectral echo responses and then combining them in ways to enhance image contrast. These imaging principles exploit certain physical "signatures" of the contrast agent responses, allowing increased contrast with respect to tissue background. This contrast enhancement is much larger than what is determined from direct echo amplitude monitoring.
Claims42
An ultrasonic imaging method for ultrasonic imaging of tissues located in a tissue image region including a contrast agent in at least a portion of said tissue image region, said method comprising the steps of:
- (a) projecting an ultrasound beam into said tissue image region;
- (b) receiving ultrasound reflections from said tissue image region and transducing said reflections into corresponding electrical echo signals;
- (c) first processing said electrical echo signals to derive a plurality of frequency component signals, each frequency component signal representing an electrical echo signal parameter associated with a pre-determined frequency component of said electrical echo signals;
- (d) second processing said plural frequency component signals to combine them into a single enhanced contrast image data signal;
- (e) repeating steps (a) through (d) to derive an ordered array of enhanced contrast image data signals representing an image of said tissue image region;
- and
- (f) displaying said ordered array of enhanced contrast image data signals as a visual image of said tissue image region.
A realtime method of ultrasonic imaging of organs and tissue by detection of ultrasound backscatter of a region containing a contrast agent, the method comprising:
- projecting an ultrasound beam to a zone of tissue to be imaged,
- receiving the echo reflected from the tissue as a radiofrequency response signal,
- processing the radiofrequency response signal into a video output by
- (a) passing the response signal to at least two independent channels with frequency pass-bands respectively tuned to one of at least two selected frequencies in a range lying between the lower and upper bounds of (i) the 6 dB bandwidth of the contrast agent response and (ii) the 6 dB bandwidth of the tissue response, and
- (b) demodulating signals passing each of said independent channels and processing the resulting demodulated signals to combine them into a single output signal wherein the echoes reflected by tissues containing contrast agent are significantly enhanced in comparison to those echoes reflected by tissue without contrast agent,
- storing the output in a video scan converter, and
- scanning the tissue to produce a video image of a region under investigation.
An ultrasonic imaging system for ultrasonic imaging of tissues located in a tissue image region including a contrast agent in at least a portion of said tissue image region, said system comprising:
- (a) means for projecting an ultrasound beam into said tissue image region;
- (b) means for receiving ultrasound reflections from said tissue image region and transducing said reflections into corresponding electrical echo signals;
- (c) means for first processing said electrical echo signals to derive a plurality of frequency component signals, each frequency component signal representing an electrical echo signal parameter associated with a pre-determined frequency component of said electrical echo signals;
- (d) means for second processing said plural frequency component signals to combine them into a single enhanced contrast image data signal;
- (e) means for repeatedly operating means (a) through (d) to derive an ordered array of enhanced contrast image data signals representing an image of said tissue image region;
- and
- (f) means for displaying said ordered array of enhanced contrast image data signals as a visual image of said tissue image region.
A system for ultrasonic imaging of organs and tissue by detection of ultrasound backscatter of a region containing a contrast agent, the system comprising:
- an ultrasonic transducer and electronic circuitry for transmitting and receiving ultrasonic signals,
- signal processing means including
- (a) means for separating the received ultrasonic signal into at least two independent channels with frequency pass-bands which can be tuned independently to one of at least two pre-selected frequencies selected in the range between the upper and lower bounds of (i) the 6 dB bandwidth of the contrast agent response and (ii) the 6 dB bandwidth of the tissue response,
- (b) a radiofrequency demodulator for each of said independent channels, and
- (c) means for processing the demodulated signals from said independent channels into a single output wherein the echoes reflected by tissue containing contrast agent are significantly enhanced in comparison to those reflected by the tissue itself;
- means for storing the processed signals, and
- a display element connected to display the stored processed signals.
Dependencies are inferred from the claim text.