System and method for strain image display

• US 6,558,324 B1
• Filed: 11/20/2001
• Issued: 05/06/2003
• Est. Priority Date: 11/22/2000
• Status: Active Grant

• Current Assignee: Siemens Medical Solutions USA Incorporated (Siemens AG)
• Original Assignee: Siemens Medical Solutions USA Incorporated (Siemens AG)
• Inventors: Liu, Dong-Cyuan, Chen, Jian-Feng, Von Behren, Patrick L.
• Primary Examiner(s): Jaworski, Francis J.
• Assistant Examiner(s): Jung, William C.
• Application Number:
  US09/994,589
• Time in Patent Office: 532 Days
• Field of Search: 600/437-472
• US Class Current: 600/440
• CPC Class Codes: A61B 8/08 Detecting organic movements or changes, e.g. tumours, cysts, swellings A61B8/02 - A61B8/06 take precedence
• CPC Class Codes: A61B 8/0825 for diagnosis of the breast, e.g. mammography
• CPC Class Codes: A61B 8/463 characterised by displaying multiple images or images and diagnostic data on one display composite display in devices for short-range imaging with acoustic waves G01S7/52074
• CPC Class Codes: A61B 8/485 involving measuring strain or elastic properties
• CPC Class Codes: A61B 8/5276 due to motion
• CPC Class Codes: G01S 15/8993 Three dimensional imaging systems
• CPC Class Codes: G01S 7/52034 Data rate converters
• CPC Class Codes: G01S 7/52042 determining elastic properties of the propagation medium or of the reflective target diagnostic techniques involving the measurement of strain A61B8/485
• CPC Class Codes: G01S 7/52069 Grey-scale displays
• CPC Class Codes: G01S 7/52071 Multicolour displays; using colour coding; Optimising colour or information content in displays, e.g. parametric imaging
• CPC Class Codes: G01S 7/52074 Composite displays, e.g. split-screen displays; Combination of multiple images or of images and alphanumeric tabular information

Abstract

A region of interest (ROI) of a patient'"'"'s body is repeatedly scanned using an ultrasound transducer array. Data sets representing an image property, such as intensity, from portions of the ROI are used to calculate a representation of the displacement profile within the ROI at different stress levels. From the displacement profile, a function of strain is also preferably calculated. According to one aspect of the invention, a data set representing an estimate of the elasticity profile within the ROI is color-coded and is displayed along with a B-mode display in a single, overlaid display. According to another aspect of the preferred embodiment of the invention, the display of elasticity is adaptively persisted as a function of, for example, a measure of image quality. The invention also provides an on-screen guide that indicates to a user a measure of quality of each of a series of estimated displacement data sets.

Claims

1. An ultrasonic imaging method comprising the following steps:

repeatedly scanning a region of interest (ROI) of a body with an ultrasound transducer and thereby acquiring a first and a second set of intensity values, each intensity value representing an imaging property of a respective portion of the ROI;

generating a gray-scale representation of the first set of intensity values;

calculating an elasticity data set of elasticity values as a function of differences between corresponding intensity values in the first and second sets of intensity values;

generating a color representation of the elasticity data set by color-coding the elasticity values;

simultaneously displaying the gray-scale representation and the color representation as a single, overlaid display.

2. A method as in claim 1, further comprising the following steps:

generating the overlaid display as a linear combination of the gray-scale representation and the color representation; and

adjusting a display visibility of the gray-scale representation and the color representation, respectively, as a first and second function of a transmission coefficient.

3. A method as in claim 2, in which the transmission coefficient is user-adjustable.

4. A method as in claim 2, in which the step of generating the overlaid display comprises computing the linear combination according to:

5. A method as in claim 1, further comprising the step of generating the overlaid display as a non-linear combination of the gray-scale representation and the color representation.

6. A method as in claim 1, further comprising the following steps:

adaptively persisting the elasticity data set,

repeating the step of calculating the elasticity data set for a plurality scans of the ROI and, for each scan, generating a corresponding one of the elasticity data sets; and

for at least a current one of the elasticity data sets, calculating a quality factor;

in which;

the step of generating the color representation comprises color-coding the elasticity values in the persisted elasticity data set; and

the step of adaptively persisting the elasticity data set includes generating a persisted elasticity frame as a persistence function that has, as arguments, the current elasticity data set, the quality factor, and at least one earlier generated elasticity data set.

7. A method as in claim 1, further comprising:

calculating a quality value that indicates an estimated measure of quality of the elasticity data set;

displaying a graphical representation of the quality value along with the overlaid display.

8. An ultrasonic imaging system comprising:

an ultrasound transducer;

control means for controlling transmission and reception of ultrasound by the transducer and thereby for controlling repeated scanning of a region of interest (ROI) of a body with ultrasound generated by the transducer and for acquiring a first and a second set of intensity values, each intensity value representing an imaging property of a respective portion of the ROI;

a processing system including;

means for generating a gray-scale representation of the first set of intensity values;

elasticity estimation means for calculating an elasticity data set of elasticity values as a function of differences between corresponding intensity values in the first and second sets of intensity values;

remapping means of generating a color representation of the elasticity data set by color-coding the elasticity values; and

overlay generation means for generating a single, overlaid display of the gray-scale representation and the color representation; and

display means for displaying the single, overlaid display.

9. A system as in claim 8,

in which the overlay generation means is provided for generating the overlaid display as a linear combination of the gray-scale representation and the color representation;

further including means for adjusting a display visibility of the gray-scale representation and the color representation, respectively, as a first and second function of a transmission coefficient.

10. A system as in claim 9, in which the means for adjusting the display visibility is user-adjustable.

11. A system as in claim 8, further comprising persistence means:

for adaptively persisting the elasticity data set before the remapping means generates the color representation of the elasticity data set by color-coding, and

for calculating a quality factor of the elasticity data set and for adaptively persisting the elasticity data set as a persistence function that has, as arguments, the elasticity data set itself, the quality factor, and at least one earlier generated elasticity data set.

12. A system as in claim 8, further comprising guide generation means for generating a graphical representation of a quality value along with the overlaid display, the quality value indicating an estimated measure of quality of the elasticity data set.

13. An ultrasonic imaging method comprising the following steps:

repeatedly scanning a region of interest (ROI) of a body with an ultrasound transducer and acquiring first and second data sets of echo values, each echo value representing an imaging property of a respective portion of the ROI;

calculating an elasticity data set of elasticity values as a function of differences between corresponding echo values in the first and second data sets;

generating a display of the elasticity data set;

adaptively persisting the generated display;

repeating the step of calculating the elasticity data set for a plurality scans of the ROI and, for each scan, generating a corresponding one of the elasticity data sets; and

for at least a current one of the elasticity data sets, calculating a quality factor;

in which;

the step of adaptively persisting the display includes generating a persisted elasticity frame as a persistence function that has, as arguments, the current elasticity data set, the quality factor, and at least one earlier generated elasticity data set; and

the step of generating the display comprises displaying a representation of the persisted elasticity frame.

14. A method as in claim 13, further comprising generating the persisted elasticity frame as a linear combination of the current elasticity data set and at least one previous elasticity data set.

15. A method as in claim 14, in which the previous elasticity data set is an immediately preceding persisted elasticity data set.

16. A method as in claim 14, in which the linear combination is a sum of a first term and a second term, in which:

the first term is the product of the current elasticity data set and a quality factor;

the second term is the product of the preceding persisted elasticity data set and a function of the quality factor that decreases as the quality factor increases.

17. A method as in claim 13, which the step of calculating the quality factor comprises calculating a quality metric as a function of a mean value of the plurality of elasticity values in the current elasticity frame.

18. A method as in claim 17, in which the function of the mean value of the plurality of elasticity values increases from a minimum to a maximum metric value as the means value increases.

19. A method as in claim 17, in which the step of calculating the quality factor comprises calculating a quality metric as a function of a measure of change between the current elasticity data set and a preceding elasticity data set.

20. A method as in claim 19, in which the function of the measure of change decreases from a maximum to a minimum metric value as the measure of change increases.

21. An ultrasonic imaging system comprising:

an ultrasound transducer;

control means for controlling transmission and reception of ultrasound by the transducer and thereby for controlling repeated scanning of a region of interest (ROI) of a body with ultrasound generated by the transducer, and for acquiring a first and a second set of intensity values, each intensity value representing an imaging property of a respective portion of the ROI;

a processing system including;

elasticity estimation means for calculating an elasticity data set of elasticity values as a function of differences between corresponding intensity values in the first and second sets of intensity values;

persistence means;

for adaptively persisting the generated display;

for calculating a quality factor for at least a current one of the elasticity data sets; and

for generating a persisted elasticity frame as a persistence function that has, as arguments, the current elasticity data set, the quality factor, and at least one earlier generated elasticity data set;

display means for displaying a representation of the persisted elasticity frame.

22. A system as in claim 21, in which the persistence means is provided for calculating a mean value of the plurality of elasticity values in the current elasticity frame and for calculating the quality factor as a function of the mean value.

23. A system as in claim 21, in which the persistence means is provided for calculating a measure of change between the current elasticity data set and a preceding elasticity data set and for calculating the quality factor as a function of the measure of change.

24. An ultrasonic imaging method comprising:

repeatedly scanning a region of interest (ROI) of a body with an ultrasound transducer and thereby acquiring a plurality of intensity data sets of intensity values, each intensity value representing an imaging property of a respective portion of the ROI;

for each of at least one pair of the intensity data sets, calculating a corresponding displacement data set having displacement elements, each displacement element quantifying displacement of a respective ROI portion over a time interval between the respective pair of intensity data sets;

for each displacement data set, calculating a display data set as a function of the displacement elements in the respective displacement data set;

selecting one of the display data sets for display; and

displaying both the selected display data set and a graphical representation of a quality value that indicates an estimated measure of quality of the selected display data set.

25. A method as in claim 24, further comprising:

for each display data set, calculating a guide parameter; and

displaying a graphical representation of the guide parameter along with the selected display data set and graphical representation of the current quality value.

26. A method as in claim 25, in which the guide parameter is calculated as a mean value of the displacement elements in the displacement data set corresponding to the display data set.

27. A method as in claim 26, in which the quality value is calculated as a function of the change of the mean values of the displacement elements in displacement data sets corresponding to a plurality of sequential scans.

28. A method as in claim 25, further comprising:

calculating the guide parameter and quality value for each display data set; and

displaying a composite display guide that comprises a composite graphical representation of the guide parameters and corresponding quality values.

29. A method as in claim 24, further including the following steps:

for each displacement data set, calculating an elasticity data set as a function of the displacement data set; and

calculating each display data set as a function of the calculated elasticity data set corresponding to the respective displacement data set.

30. An ultrasonic imaging system comprising:

an ultrasound transducer;

control means for controlling transmission and reception of ultrasound by the transducer and thereby for controlling repeated scanning of a region of interest (ROI) of a body with ultrasound generated by the transducer, and for acquiring a first and a second set of intensity values, each intensity value representing an imaging property of a respective portion of the ROI;

a processing system including;

displacement estimation means for calculating, for each of at least one pair of the intensity data sets, a corresponding displacement data set having displacement elements, each displacement element quantifying displacement of a respective ROI portion over a time interval between the respective pair of intensity data sets, and, for each displacement data set, for calculating a display data set as a function of the displacement elements in the respective displacement data set;

guide generation means for generating a graphical representation of a quality value, the quality value indicating an estimated measure of quality of the elasticity data set; and

display means for displaying both a selected display data set and the graphical representation of the corresponding quality value.

31. A system as in claim 30, in which:

the guide generation means is further provided for calculating a respective guide parameter for each display data set; and

the display means is further provided for displaying a representation of the guide parameter along with the selected display data set and the graphical representation of the current quality value.

32. A system as in claim 31, further comprising frame selection means for presenting to a user a displayed indicator of the guide parameter, for sensing user selection of one of the display data sets for display, and for directing the display means to display the selected display data set.