Method for enhancing the diagnostic power of ultrasonic scanning systems by using real-time spectral maps, and device operating by said method

• US 6,066,098 A
• Filed: 06/12/1998
• Issued: 05/23/2000
• Est. Priority Date: 06/13/1997
• Status: Expired due to Term

• Current Assignee: Esoate S.p.A.
• Original Assignee: Esaote SpA
• Inventors: Bertini, Alberto, Giovannucci, Carlo, Bigagli, Andrea, Calzolai, Marco, Galardi, Leonardo, Masotti, Leonardo, Cerofolini, Marino, Biagi, Elena
• Primary Examiner(s): Jaworski, Francis J.
• Application Number:
  US09/097,166
• Time in Patent Office: 711 Days
• Field of Search: 600/442, 600/443, 73/602, 382/128, 382/132, 382/274, 382/276
• US Class Current: 600/443
• CPC Class Codes: G01S 7/52026 Extracting wanted echo signals Doppler systems G01S15/50; Doppler short range imaging systems G01S15/8979
• CPC Class Codes: G01S 7/52034 Data rate converters
• CPC Class Codes: G01S 7/52038 involving non-linear properties of the propagation medium or of the reflective target
• CPC Class Codes: G01S 7/52039 exploiting the non-linear response of a contrast enhancer, e.g. a contrast agent diagnostic techniques involving the use of contrast agents A61B8/481

Abstract

A method of analyzing an ultrasonic signal is described. The method is characterized in that the ultrasonic signal (f(t)) is sampled and digitized and in that a discrete wavelet transform is applied to the sampled and digitized signal to obtain a spectral map of the sampled signal

Claims

1. A method for producing an ultrasound image of a body, the method comprising the steps of:

transmitting an ultrasound signal in an investigated portion of the body;

receiving a response signal from the body;

filtering said response signal into a plurality of sub-band signals;

determining an energy content of each of said sub-band signals;

displaying spectral maps of said energy content of said sub-band signals.

2. The method in accordance with claim 1, wherein:

said response signal includes radio frequencies and said response signal is digitized to obtain a digitized signal, said digitized signal is filtered into said plurality of sub-bands.

3. The method in accordance with claim 1, wherein:

said spectral maps are separate from each other.

4. The method in accordance with claim 1, wherein:

said displaying includes displaying fewer than all said spectral maps at one time.

5. The method in accordance with claim 1, wherein:

said displaying includes superimposing two of said spectral maps.

6. A method for producing an ultrasound image of a body, the method comprising the steps of:

transmitting an ultrasound signal in an investigated portion of the body;

receiving a response signal from the body;

filtering said response signal into a plurality of sub-band signals;

applying a time-frequency transform to said plurality of sub-band signals to obtain a plurality of spectral maps, each of said spectral maps corresponding to one of said sub-band signals;

displaying said spectral maps.

7. The method in accordance with claim 6, wherein:

said time-frequency transform is a Discrete Wavelet Transform (DWT).

8. The method in accordance with claim 7, wherein:

said DWT is a Daubechies Wavelet transform of order 16.

9. The method in accordance with claim 6, wherein:

said spectral maps are separate from each other.

10. The method in accordance with claim 6, wherein:

said displaying includes displaying fewer than all said spectral maps at one time.

11. A method for producing an ultrasound image of a body, the method comprising the steps of:

transmitting an ultrasound signal in an investigated portion of the body;

receiving a response signal from the body;

filtering said response signal with a subband encoding algorithm to obtain a spectral content of said response signal at a plurality of frequency subbands;

generating a plurality of frequency maps, each of said frequency maps corresponding to said spectral content of one of said plurality of frequency subbands;

displaying said frequency maps.

12. The method in accordance with claim 11, wherein:

said frequency maps are separate from each other.

13. The method in accordance with claim 11, wherein:

said displaying includes displaying fewer than all said spectral maps at one time.

14. A method for producing an ultrasound image of a body, the method comprising the steps of:

transmitting an ultrasound signal in an investigated portion of the body;

receiving a response signal from the body;

filtering said response signal to obtain a plurality of sets of coefficients representing a spectral content of said response signal at a plurality of frequency bands;

generating a plurality of spectral maps, each of said spectral maps corresponding to one of said plurality of sets of coefficients.

15. The method in accordance with claim 14, wherein:

said filtering is performed with a subband encoding algorithm.

16. The method in accordance with claim 14, wherein:

said filtering is performed by applying a Discrete Wavelet Transform to said response signal.

17. The method in accordance with claim 14, wherein:

said spectral maps are separate from each other and display separate said sets of coefficients.

18. An ultrasonic imaging system comprising:

a transducer to emit an ultrasound signal into a body and receive a response signal from the body;

a filter for filtering said response signal into a plurality of sub-band signals and obtaining spectral content for each of said plurality of sub-band signals;

display means for generating and displaying spectral maps corresponding to said spectral content of said sub-band signals.

19. An ultrasonic imaging system comprising:

a transducer to emit an ultrasound signal into a body and receive a response signal from the body;

a filter means for applying a discrete wavelet transform to said response signal and obtaining a plurality of sets of coefficients representing a spectral content of each of said response signal at a plurality of frequency bands;

display means for generating and displaying spectral maps corresponding to said spectral content of said sub-band signals.

20. The system in accordance with claim 19, further comprising:

a sample and acquisition card connected to said transducer to sample and digitalize said response signal and generate a digitized signal, said filter means applying said discrete wavelet transform to said digitized signal.