Ultrasonic diagnostic apparatus and elasticity image display method

• US 9,161,736 B2
• Filed: 09/09/2010
• Issued: 10/20/2015
• Est. Priority Date: 09/10/2009
• Status: Active Grant

• Current Assignee: FUJIFILM Healthcare Corp. (Fujifilm Holdings Corporation)
• Original Assignee: Hitachi Medical Corporation (Hitachi, Ltd.)
• Inventors: Waki, Koji
• Primary Examiner(s): Chen, Tse
• Assistant Examiner(s): Brutus, Joel F
• Application Number:
  US13/392,652
• Publication Number:
  US 20120157831A1
• Time in Patent Office: 1,867 Days
• Field of Search: 600/427, 600/407, 600/437
• US Class Current: 1/1
• 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 8/4461 Features of the scanning mechanism, e.g. for moving the transducer within the housing of the probe
• CPC Class Codes: A61B 8/466 adapted to display 3D data 3D imaging and stereoscopic displays in devices for short-range imaging with acoustic waves G01S15/8993 and G01S7/52068, respectively; 3D image rendering G06T15/00; manipulating 3D models for computer graphics G06T19/00
• 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 15/8934 using a dynamic transducer configuration
• 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 7/52071 Multicolour displays; using colour coding; Optimising colour or information content in displays, e.g. parametric imaging

Abstract

Disclosed is an ultrasonic diagnostic apparatus provided with: an ultrasonic probe which transmits/receives ultrasonic waves to/from an object while being in contact with the object; a transmission/reception unit which, in a process in which pressing force applied to the object by the ultrasonic probe is changed and the tomographic position at which the ultrasonic waves are transmitted/received to/from the object is moved in a short axis direction, periodically transmits/receives the ultrasonic waves to/from the object, performs reception processing on a reflection echo signal from the object, and measures RF signal frame data at the tomographic position; a displacement measurement unit which, on the basis of two pieces of RF signal frame data, between which the difference in measurement time falls within a set range, selected from among multiple pieces of RF signal frame data sequentially measured by the transmission/reception unit, finds the displacement of a living tissue at the tomographic position and sequentially generates displacement frame data; an elasticity information calculation unit which on the basis of the displacement frame data sequentially generated by the displacement measurement unit, finds elasticity information relating to the living tissue at the tomographic position, and sequentially generates elasticity frame data; and an elasticity image construction unit which on the basis of the elasticity frame data sequentially generated by the elasticity information calculation unit, sequentially constructs elasticity images.

Claims

1. An ultrasonic diagnostic apparatus for use with a living tissue, the ultrasonic diagnostic apparatus comprising:

an ultrasonic probe which transmits ultrasonic waves to an object and receives a reflected echo signal from the object while being in contact with the object; and

an ultrasonic diagnostic system including circuitry, memory and a display, the ultrasonic diagnostic system being programmed to;

transmit periodically the ultrasonic waves to the object through the ultrasonic probe, and receive the reflected echo signal and receive the reflection echo signal from the object through the ultrasonic probe, in a process in which a pressing force applied to the object by the ultrasonic probe is changed and a cross-sectional position to transmit or receive ultrasonic waves to or from the object is continuously moved in a short-axis direction of the ultrasonic probe;

obtain a displacement of the living tissue between two pieces of RF signal frame data selected from among a plurality of pieces of RF signal frame data captured at a plurality of different cross-sectional positions sequentially received by the ultrasonic probe and selected within a set range of a difference in measurement time, and generate sequentially a plurality of displacement frame data;

calculate elasticity information of the living tissue at the cross-sectional position based on the displacement frame data, and generate elasticity frame data sequentially based on the calculated elasticity information; and

construct elasticity images sequentially based on the generated elasticity frame data.

2. The ultrasonic diagnostic apparatus according to claim 1, wherein the ultrasonic diagnostic system is programmed to:

store the constructed elastic images in the memory together with respective pieces of positional information of the cross-sectional position; and

construct a three-dimensional elasticity image by rendering the volume data of the elasticity images stored in the memory and display the three-dimensional elasticity image on the display.

3. The ultrasonic diagnostic apparatus according to claim 1, wherein

a change of the pressing force applied to the object and a movement of the cross-sectional position in the short-axis direction are manually performed while the ultrasonic probe is grasped.

4. The ultrasonic diagnostic apparatus according to claim 1, wherein

the ultrasonic probe is assembled to a swing apparatus which arcuately or linearly guides the cross-sectional position to transmit or receive ultrasonic waves.

5. The ultrasonic diagnostic apparatus according to claim 1, wherein:

the ultrasonic probe is formed to include a plurality of two-dimensionally arranged transducers,

the ultrasonic diagnostic system is programmed to move the cross-sectional position by electronically scanning the plurality of transducers in the short-axis direction of the ultrasonic probe, and

a change of the pressing force applied to the object can be manually performed in response to the ultrasonic probe being grasped.

6. The ultrasonic diagnostic apparatus according to claim 1, further comprising:

a swing device including;

a swing mechanism which swings the ultrasonic probe in the short-axis direction,

a motor which swings and drives the ultrasonic probe via the swing mechanism, and

a motor control unit which senses a swing angle of the ultrasonic probe from a rotational position of the motor and controls a rotational speed of the motor;

wherein the ultrasonic diagnostic system is programmed to;

store the constructed elastic images in the memory in association with respective swing angles of the ultrasonic probe; and

construct a three-dimensional elasticity image by rendering the volume data of the elasticity images stored in the memory and display the three-dimensional elasticity image on the display.

7. The ultrasonic diagnostic apparatus according to claim 6, wherein the motor control unit performs at least one of:

first control that controls speed of the motor in a pattern with a swing speed decreasing from a center of a swing range of the ultrasonic probe toward two ends;

second control that controls the swing speed of the ultrasonic probe according to a depth for one of a plurality of depth sections into which a range in a depth direction is divided;

third control that controls the swing speed of the ultrasonic probe according to depth of a part-of-interest desired to be observed in the three-dimensional elasticity image;

fourth control that periodically controls the swing speed of the ultrasonic probe to increase and decrease;

fifth control that controls the swing speed of the ultrasonic probe to be low in a specific swing section corresponding to a plurality of cross-sectional positions including a part-of-interest desired to be observed in the three-dimensional elasticity image and controls the swing speed to be high outside the specific swing section; and

sixth control that performs control according to variably set swing speed of the ultrasonic probe in the specific swing section corresponding to the plurality of cross-sectional positions including a part-of-interest desired to be observed in the three-dimensional elasticity image.

8. The ultrasonic diagnostic apparatus according to claim 6, wherein the ultrasonic diagnostic system is programmed to:

detect whether a part-of-interest desired is present in the three-dimensional elasticity image based on the elasticity frame data and a preset condition, and

control a swing speed of the ultrasonic probe to be low in response to a signal indicating the presence of the part-of-interest and control the swing speed of the ultrasonic probe to be high in response to a signal indicating the presence of the part-of-interest.

9. The ultrasonic diagnostic apparatus according to claim 6, wherein the ultrasonic diagnostic system is programmed to:

construct a tomographic image based on the RF signal frame data,

transmit or receive ultrasonic waves for measuring the RF signal frame data at a plurality of the cross-sectional positions a plurality of times,

detect a part-of-interest that meets a preset condition as a part to be observed in the three-dimensional elasticity image based on the tomographic image obtained by initial measurement of the RF signal frame data,

switch swing speed of the ultrasonic probe at a plurality of cross-sectional positions including a part-of-interest to a low speed at the time of measurement of the RF signal frame data after part-of-interest is detected, and

construct the elasticity images based on the RF signal frame data measured at the plurality of cross-sectional positions including a part-of-interest within a swing range of the ultrasonic probe.

10. The ultrasonic diagnostic apparatus according to claim 6, wherein the ultrasonic diagnostic system is programmed to:

transmit or receive ultrasonic waves to measure the RF signal frame data at a plurality of the cross-sectional positions a plurality of times,

detect a part-of-interest that meets a preset condition as a part to be observed in the three-dimensional elasticity image based on the elasticity images obtained by initial measurement of the RF signal frame data,

switch the swing speed of the ultrasonic probe at a plurality of cross-sectional positions including a part-of-interest to a low speed at the time of measurement of the RF signal frame data after a part-of-interest is detected, and

construct the elasticity images based on the RF signal frame data measured at the plurality of cross-sectional positions including a part-of-interest within a swing range of the ultrasonic probe.

11. The ultrasonic diagnostic apparatus according to claim 1, wherein

the set range of the difference in measurement time between the two pieces of RF signal frame data is selected based on a difference in measurement time that causes diameters of ultrasonic reception beams of the reflection echo signals at a plurality of cross-sectional positions to overlap with each other.

12. The ultrasonic diagnostic apparatus according to claim 11, wherein

the set range for the difference in measurement time between two selected pieces of RF signal frame data is based on:

(i) a difference in measurement time that causes diameters of ultrasonic reception beams of the reflection echo signals at adjoining ones of the cross-sectional positions to overlap with each other;

or

(ii) if three or more pieces of RF signal frame data are measured within the set range for the difference in measurement time, obtains a correlation of a latest one of the three or more pieces of RF signal frame data as a reference with each of the other three or more pieces of RF signal frame data measured within the set range is obtained and the displacement frame data between the two pieces of RF signal frame data having a greatest correlation is obtained.

13. The ultrasonic diagnostic apparatus according to claim 12, wherein the ultrasonic diagnostic system is programmed to:

input and set the part-of-interest desired to be observed in the three-dimensional elasticity image if three or more pieces of RF signal frame data are measured within the set range for the difference in measurement time; and

the motor control unit controls swing speed of the ultrasonic probe to be low in the part-of-interest input from the input setting unit and controls the swing speed of the ultrasonic probe to be high outside the part-of-interest.

14. The ultrasonic diagnostic apparatus according to claim 1, wherein the ultrasonic diagnostic system is programmed to:

transmit preset ultrasonic waves for elasticity image acquisition and preset ultrasonic waves for tomographic image acquisition as a set to a plurality of the consecutive cross-sectional positions and one subsequent cross-sectional position, respectively, and a period of transmission of ultrasonic waves for elasticity image acquisition is set to a period that causes diameters of ultrasonic reception beams of sequentially received reflection echo signals to overlap with each other, and

construct a tomographic image based on measured RF signal frame data in response to the ultrasonic waves for tomographic image acquisition.

15. An elasticity image display method for use with a living tissue, the elasticity image display method comprising:

a first step of periodically transmitting ultrasonic waves to the object and receiving a measured reflection echo signal by the ultrasonic probe, in a process in which a pressing force applied to an object by the ultrasonic probe is changed and a cross-sectional position for transmission of ultrasonic waves is continuously moved in a short-axis direction of the ultrasonic probe;

a second step of performing reception processing on the reflection echo signal captured in the first step and periodically measuring RF signal frame data;

a third step of obtaining displacements of the living tissue at a plurality of the cross-sectional positions and sequentially generating pieces of displacement frame data on the basis of two pieces of RF signal frame data, between which a difference in measurement time falls within a set range, selected from among a plurality of pieces of RF signal frame data periodically measured in the second step and selected within a set range of a difference in measurement time;

a fourth step of on the basis of a plurality of the pieces of displacement frame data obtained in the third step, calculating elasticity information of the living tissue at the plurality of cross-sectional positions and sequentially generating elasticity frame data; and

a fifth step of, on the basis of the elasticity frame data sequentially generated in the fourth step, sequentially constructing elasticity images.