ULTRASONIC DIAGNOSTIC APPARATUS AND THREE-DIMENSIONAL ELASTIC RATIO CALCULATING METHOD

• US 20120269416A1
• Filed: 11/11/2010
• Published: 10/25/2012
• Est. Priority Date: 11/18/2009
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi Medical Corporation (Hitachi, Ltd.)
• Inventors: Waki, Koji, Iimura, Takashi
• Granted Patent: US 9,044,175 B2
• Time in Patent Office: Days
• US Class Current: 382/131
• 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 8/14 Echo-tomography
• CPC Class Codes: A61B 8/4254 using sensors mounted on the probe
• CPC Class Codes: A61B 8/469 for selection of a region of interest
• CPC Class Codes: A61B 8/483 involving the acquisition of a 3D volume of data
• CPC Class Codes: A61B 8/485 involving measuring strain or elastic properties
• CPC Class Codes: G01S 15/8993 Three dimensional imaging systems
• CPC Class Codes: G01S 7/52036 using analysis of echo signal for target characterisation
• 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 7/52063 Sector scan display
• CPC Class Codes: G01S 7/52087 using synchronization techniques control of medical diagnostic ultrasound devices involving acquisition triggered by a physiological signal A61B8/543

Abstract

In order to three-dimensionally quantify the elastic information indicating the hardness or softness of tissue of an object with a simple operation, two three-dimensional regions of interest are set on a displayed elastic rendering image. A three-dimensional distortion ratio measuring unit 52 calculates a ratio between elastic information in the set first three-dimensional region of interest and elastic information in the set second three-dimensional region of interest and displays the ratio on an image display device 13.

Claims

1. An ultrasonic diagnostic apparatus comprising:

an ultrasonic probe which transmits and receives an ultrasonic wave to and from an object;

an elastic information calculating unit which generates elastic frame data by calculating elastic information indicating the hardness or softness on the basis of a reflected echo signal measured by the ultrasonic probe;

an elastic volume data generating unit which generates elastic volume data on the basis of plural sets of elastic frame data;

a display unit which displays at least either one of elastic slice images of a plurality of cross sections and an elastic rendering image generated on the basis of the elastic volume data;

an input unit which sets a plurality of three-dimensional regions of interest through at least either one of the displayed elastic slice images of the plurality of cross sections and the displayed elastic rendering image; and

a three-dimensional elastic ratio measuring unit which calculates a three-dimensional elastic ratio between the elastic information in a set first three-dimensional region of interest and the elastic information in a set second three-dimensional region of interest,

wherein the calculated three-dimensional elastic ratio is displayed on the display unit.

2. The ultrasonic diagnostic apparatus according to claim 1,

wherein the three-dimensional elastic ratio measuring unit calculates a two-dimensional elastic ratio between elastic information of a region corresponding to the first three-dimensional region of interest and elastic information of a region corresponding to the second three-dimensional region of interest in each of the plural sets of elastic frame data of the elastic rendering image, and calculates the three-dimensional elastic ratio on the basis of the two-dimensional elastic ratio in each set of the elastic frame data.

3. The ultrasonic diagnostic apparatus according to claim 2,

wherein the three-dimensional elastic ratio measuring unit calculates the three-dimensional elastic ratio by averaging the two-dimensional elastic ratio calculated in each set of the elastic frame data.

4. The ultrasonic diagnostic apparatus according to claim 2,

wherein the three-dimensional elastic ratio measuring unit calculates the three-dimensional elastic ratio between elastic information of a region corresponding to the first three-dimensional region of interest and elastic information of a region corresponding to the second three-dimensional region of interest in the plurality of elastic frame data sets with the same pressure state of tissue of the object.

5. The ultrasonic diagnostic apparatus according to claim 4,

wherein the three-dimensional elastic ratio measuring unit detects a section, in which pressure is applied to tissue of the object, and a section, in which no pressure is applied to tissue of the object, on the basis of a temporal change in the pressure state of tissue of the object, and calculates the three-dimensional elastic ratio on the basis of the elastic information of only one of the section in which pressure is applied and the section in which no pressure is applied in the first and second three-dimensional regions of interest.

6. The ultrasonic diagnostic apparatus according to claim 1,

wherein when the elastic volume data is generated in an RΘ

Φ

coordinate system, an elastic three-dimensional scan conversion unit which converts the elastic volume data from the RΘ

Φ

coordinate system to an XYZ coordinate system, an elastic slice image generating unit which generates an MPR image of orthogonal three cross sections of the elastic volume data converted to the XYZ coordinate system, and a coordinate transformation unit which converts the first and second three-dimensional regions of interest, which are set on the MPR image in the XYZ coordinate system displayed on the display unit, from the XYZ coordinate system to the RΘ

Φ

coordinate system are provided, and

the three-dimensional elastic ratio measuring unit calculates the three-dimensional elastic ratio on the basis of the elastic information of the first three-dimensional region of interest and the elastic information of the second three-dimensional region of interest converted to the RΘ

Φ

coordinate system.

7. The ultrasonic diagnostic apparatus according to claim 1,

wherein when the elastic volume data is generated in an RΘ

Φ

coordinate system, an elastic three-dimensional scan conversion unit which converts the elastic volume data from the RΘ

Φ

coordinate system to an XYZ coordinate system, an elastic volume rendering unit which generates the elastic rendering image on the basis of the elastic volume data converted to the XYZ coordinate system, and a coordinate transformation unit which converts the first and second three-dimensional regions of interest, which are set on the elastic rendering image in the XYZ coordinate system displayed on the display unit, from the XYZ coordinate system to the RΘ

Φ

coordinate system are provided, and

the three-dimensional elastic ratio measuring unit calculates the three-dimensional elastic ratio on the basis of the elastic information of the first three-dimensional region of interest and the elastic information of the second three-dimensional region of interest converted to the RΘ

Φ

coordinate system.

8. The ultrasonic diagnostic apparatus according to claim 6,

wherein the first and second three-dimensional regions of interest converted to the RΘ

Φ

coordinate system are displayed on the display unit in the RΘ

Φ

coordinate system so that at least one of the first and second three-dimensional regions of interest displayed in the RΘ

Φ

coordinate system is adjustable on an image.

9. The ultrasonic diagnostic apparatus according to claim 6,

wherein the three-dimensional elastic ratio measuring unit detects sections with the same pressure state in the first and second regions of interest on the basis of a temporal change in the pressure state of tissue of the object in the RΘ

Φ

coordinate system, and calculates a three-dimensional elastic ratio on the basis of elastic information of the detected sections with the same pressure state.

10. The ultrasonic diagnostic apparatus according to claim 6,

wherein the three-dimensional elastic ratio measuring unit calculates an integrated value of the elastic information in the first and second three-dimensional regions of interest on the basis of a temporal change in the pressure state of tissue of the object in the RΘ

Φ

coordinate system, estimates a distance between the tissue of the object and a pressure start position on the basis of the calculated integrated value, and calculates the three-dimensional elastic ratio on the basis of elastic information of a section with the estimated distance which is larger or smaller than a distance threshold value set in advance.

11. The ultrasonic diagnostic apparatus according to claim 6,

wherein the three-dimensional elastic ratio measuring unit detects a section, in which pressure is applied to tissue of the object, and a section, in which no pressure is applied to tissue of the object, on the basis of a temporal change in the pressure state of tissue of the object in the RΘ

Φ

coordinate system, and calculates the three-dimensional elastic ratio on the basis of the elastic information of a peak of the section in which pressure is applied or the section in which no pressure is applied in the first and second three-dimensional regions of interest.

12. The ultrasonic diagnostic apparatus according to claim 1,

wherein the three-dimensional elastic ratio measuring unit calculates the three-dimensional elastic ratio on the basis of two-dimensional elastic ratios in a plurality of remaining tomographic planes after excluding a two-dimensional elastic ratio, which deviates from an elastic ratio threshold value range set in advance, among two-dimensional elastic ratios calculated in a plurality of tomographic planes with the same pressure states of tissue of the object.

13. A three-dimensional elastic ratio calculating method comprising:

a step of transmitting and receiving an ultrasonic wave to and from an object;

a step of generating elastic frame data by calculating elastic information indicating the hardness or softness on the basis of a reflected echo signal;

a step of generating elastic volume data on the basis of the plural sets of elastic frame data;

a step of displaying at least either one of elastic slice images of a plurality of cross sections and an elastic rendering image generated on the basis of the elastic volume data;

a step of setting a plurality of three-dimensional regions of interest through at least either one of the displayed elastic slice images of the plurality of cross sections and the displayed elastic rendering image; and

a step of calculating a three-dimensional elastic ratio between the elastic information in a set first three-dimensional region of interest and the elastic information in a set second three-dimensional region of interest.

14. The three-dimensional elastic ratio calculating method according to claim 13, further comprising:

a step of calculating a two-dimensional elastic ratio between elastic information of a region corresponding to the first three-dimensional region of interest and elastic information of a region corresponding to the second three-dimensional region of interest in each of the plural sets of elastic frame data of the elastic rendering image; and

a step of calculating the three-dimensional elastic ratio on the basis of the two-dimensional elastic ratio in each set of the elastic frame data.

15. The three-dimensional elastic ratio calculating method according to claim 14, further comprising:

a step of calculating the three-dimensional elastic ratio by averaging the two-dimensional elastic ratio calculated in each set of the elastic frame data.