ULTRASONIC DIAGNOSTIC APPARATUS AND ELASTICITY IMAGE DISPLAY METHOD

• US 20120157831A1
• Filed: 09/09/2010
• Published: 06/21/2012
• 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
• Granted Patent: US 9,161,736 B2
• Time in Patent Office: Days
• US Class Current: 600/427
• 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, comprising:

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 a cross-sectional position for transmitting/receiving ultrasonic waves to/from the object is moved in a short axis direction, periodically transmits/receives 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 cross-sectional position;

a displacement measurement unit which obtains a displacement of a living tissue at the cross-sectional position and sequentially generates displacement frame data on the basis of two pieces of RF signal frame data within a set time range, selected from among a plurality of pieces of RF signal frame data sequentially measured by the transmission/reception unit;

an elasticity information calculation unit which obtains elasticity information of the living tissue at the cross-sectional position and sequentially generates elasticity frame data on the basis of the displacement frame data sequentially generated by the displacement measurement unit; and

an elasticity image construction unit which sequentially constructs elasticity images on the basis of the elasticity frame data sequentially generated by the elasticity information calculation unit.

2. The ultrasonic diagnostic apparatus according to claim 1, further comprising;

a volume data generating unit which sequentially registers the elastic images constructed by the elasticity image construction unit in a memory together with respective pieces of positional information of the cross-sectional position; and

a three-dimensional elasticity image construction unit which constructs a three-dimensional elasticity image by rendering on the basis of volume data of the elasticity images registered in the volume data generating unit and displays the three-dimensional elasticity image on a monitor screen.

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

the change of the pressing force applied to the object and the 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 3, wherein

the ultrasonic probe is assembled to a swing apparatus which arcuately or linearly guides the cross-sectional position for transmitting/receiving 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 transmission/reception unit has a function of electronically scanning the plurality of transducers in the short axis direction of the ultrasonic probe,

the change of the pressing force applied to the object is manually performed while the ultrasonic probe is grasped, and

the movement of the cross-sectional position in the short axis direction comprises swinging the cross-sectional position for transmitting/receiving ultrasonic waves in the short axis direction through the electronic scanning by the transmission/reception unit.

6. The ultrasonic diagnostic apparatus according to claim 2, 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;

a volume data generating unit which sequentially registers the, elastic images constructed by the elasticity image construction unit in a memory in association with respective swing angles of the ultrasonic probe; and

a three-dimensional elasticity image construction unit which constructs a three-dimensional elasticity image by rendering on the basis of volume data of the elasticity images registered in the volume data generating unit and displays the three-dimensional elasticity image on a monitor screen.

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

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

8. The ultrasonic diagnostic apparatus according to claim 7, wherein

the displacement measurement unit obtains the displacement frame data such that the set range for the difference in measurement time between the two selected pieces of RF signal frame data is based on 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, 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 pieces of RF signal frame data as a reference with each of the other pieces of RF signal frame data measured within the set range and obtains the displacement frame data between the two pieces of RF signal frame data with a highest correlation.

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

10. The ultrasonic diagnostic apparatus according to claim 6, wherein

the elasticity information calculation unit includes a part-of-interest detection unit which detects on the basis of the elasticity frame data and in light of a preset condition whether a part of interest desired to be observed in the three-dimensional elasticity image,

the motor control unit controls swing speed of the ultrasonic probe to be low in response to a signal indicating detection of the part of interest output from the part-of-interest detection unit and controls the swing speed of the ultrasonic probe to be high when the signal indicating detection of the part of interest is not output from the part-of-interest detection unit.

11. The ultrasonic diagnostic apparatus according to claim 8, comprising

an input setting unit which inputs and sets a 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.

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

a tomographic image construction unit which constructs a tomographic image on the basis of the RF signal frame data, wherein

the transmission/reception unit performs transmission/reception of ultrasonic waves for measuring the RF signal frame data at a plurality of the cross-sectional positions a plurality of times,

the tomographic image construction unit includes a part-of-interest detection unit which detects a part of interest meeting a preset condition as a part to be observed in the three-dimensional elasticity image on the basis of the tomographic image obtained by initial measurement of the RF signal frame data,

the motor control unit switches swing speed of the ultrasonic probe at a plurality of cross-sectional positions including the part of interest to a low speed at the time of measurement of the RF signal frame data after the part-of-interest detection unit detects the part of interest, and

the elasticity image construction unit constructs the elasticity images on the basis of the RF signal frame data measured at the plurality of cross-sectional positions including the part of interest within a swing range of the ultrasonic probe.

13. The ultrasonic diagnostic apparatus according to claim 6, wherein

the transmission/reception unit performs transmission/reception of ultrasonic waves for measuring the RF signal frame data at a plurality of the cross-sectional positions a plurality of times,

the tomographic image construction unit includes a part-of-interest detection unit which detects a part of interest meeting a preset condition as a part to be observed in the three-dimensional elasticity image on the basis of the elasticity images obtained by initial measurement of the RF signal frame data,

the motor control unit switches the swing speed of the ultrasonic probe at a plurality of cross-sectional positions including the part of interest to a low speed at the time of measurement of the RF signal frame data after the part-of-interest detection unit detects the part of interest, and

the elasticity image construction unit constructs the elasticity images on the basis of the RF signal frame data measured at the plurality of cross-sectional positions including the part of interest within a swing range of the ultrasonic probe.

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

the transmission/reception unit transmits 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 the 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

the apparatus further comprises a tomographic image construction unit which constructs a tomographic image on the basis of RF signal frame data measured by the transmission/reception unit in response to the ultrasonic waves for tomographic image acquisition.

15. An elasticity image display method, comprising:

a first step of, in a process in which pressing force applied to an object by an ultrasonic probe is changed and a cross-sectional position for transmission/reception of ultrasonic waves is moved in a short axis direction, periodically transmitting/receiving ultrasonic waves to/from the object and capturing a measured reflection echo signal by 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, 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, obtaining displacements of a living tissue at a plurality of the cross-sectional positions and sequentially generating pieces of displacement frame data;

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.