JP2016007315A - Ultrasonic diagnostic equipment and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide ultrasonic diagnostic equipment capable of acquiring an elastic image that reflects the elasticity of a biological tissue more accurately than ever before.SOLUTION: Ultrasonic diagnostic equipment includes a transmission control part for controlling the transmission of an ultrasonic push pulse to a biological tissue of a subject and the transmission of an ultrasonic pulse for detection for detecting a shear elastic wave generated in the biological tissue by the push pulse, which causes a first push pulse PP1 and a second push pulse PP2 whose positions of focuses F1 and F2 are different in different sound rays to be transmitted as ultrasonic push pulses.

Description

  The present invention relates to an ultrasonic diagnostic apparatus and program for measuring the elasticity of a living tissue by transmitting an ultrasonic push pulse.

  An elastic measurement technique is known in which the elasticity of a living tissue is measured by transmitting an ultrasonic pulse (push pulse) having a high sound pressure from the ultrasound probe to the living tissue (see, for example, Patent Document 1). More specifically, a shear elastic wave generated in a living tissue by a push pulse is detected by a detection ultrasonic pulse, and a propagation velocity of the shear elastic wave and an elastic value of the living tissue are calculated to obtain elastic data. It is done. Then, an elasticity image having a color corresponding to the elasticity data is displayed in the two-dimensional region of interest. In this case, the ultrasonic detecting pulses are transmitted / received at a plurality of sound rays in the two-dimensional region of interest, and shear elastic waves are detected at a plurality of points in each of the plurality of sound rays.

JP2012-100997A

  The shear elastic wave is a transverse wave that propagates in a direction (lateral direction) intersecting the transmission direction of the push pulse. The amplitude of this shear elastic wave differs in the depth direction in the living tissue (transmission direction of the push pulse). Specifically, the amplitude of the shear elastic wave is greatest at the same depth position as the vicinity of the focus of the push pulse, and decreases with increasing distance from this position in the depth direction. If the amplitude of the shear elastic wave is small, an elastic image that accurately reflects the elasticity of the living tissue may not be obtained.

  In addition, since the shear elastic wave is attenuated as the distance from the push pulse is increased, the elastic image of the portion far from the push pulse in the region of interest may not accurately reflect the elasticity of the living tissue.

  One aspect of the invention made to solve the above-described problem is to transmit an ultrasonic push pulse to a living tissue of a subject and to detect a shear elastic wave generated in the living tissue by the push pulse. A transmission control unit that controls transmission of ultrasonic pulses for detection, and includes a transmission control unit that transmits, as the ultrasonic push pulses, a plurality of ultrasonic push pulses having different focus positions in different sound rays. This is an ultrasonic diagnostic apparatus.

  According to the first aspect of the invention, since a plurality of ultrasonic push pulses having different focus positions are transmitted as the ultrasonic push pulse, the difference in amplitude of the shear elastic wave in the depth direction is It will disappear than before. Further, since the ultrasonic push pulse is transmitted in different sound rays, when the shear elastic wave is detected in a two-dimensional region, the distance from the shear elastic wave detection point to the ultrasonic push pulse is changed. The bias can be made smaller than before. Thereby, it is possible to obtain an elasticity image that more accurately reflects the elasticity of the living tissue than before.

1 is a block diagram illustrating a schematic configuration of an ultrasonic diagnostic apparatus that is an example of an embodiment of the present invention. It is a block diagram which shows the structure of an echo data processing part. It is a block diagram which shows the structure of a display process part. It is a figure which shows the display part on which the B mode image and the elasticity image were displayed. It is a flowchart which shows the effect | action of 1st embodiment. It is a figure which shows the display part by which the region of interest was set to the B mode image. It is a figure explaining transmission of the 1st push pulse. It is a figure explaining transmission and reception of the ultrasonic pulse for the 1st detection. It is explanatory drawing which shows the part from which a propagation velocity is calculated. It is a figure explaining transmission of the 2nd push pulse. It is a figure explaining transmission and reception of the ultrasonic pulse for the 2nd detection. It is a figure explaining transmission of the 1st push pulse in the 1st modification of a 1st embodiment. It is a figure explaining transmission of the 2nd push pulse in the 1st modification of a first embodiment. It is a figure explaining other examples of transmission of the 1st push pulse in the 1st modification of a first embodiment. It is a figure explaining other examples of transmission of the 2nd push pulse in the 1st modification of a first embodiment. It is a figure explaining transmission of the 3rd push pulse in the 1st modification of a first embodiment. It is a figure explaining transmission of the 4th push pulse in the 1st modification of a first embodiment. It is a block diagram which shows the structure of the echo data process part in the 2nd modification of 1st embodiment. It is a flowchart which shows the effect | action of the 2nd modification of 1st embodiment. It is a flowchart which shows the effect | action of 2nd embodiment. It is a figure explaining the transmission of the 1st push pulse and 2nd push pulse in 2nd embodiment. It is a figure explaining transmission and reception of the ultrasonic pulse for detection in a second embodiment. It is a figure explaining transmission of the 1st push pulse and the 2nd push pulse in the 1st modification of a 2nd embodiment. It is a figure explaining transmission of the 1st push pulse in the 1st modification of a 2nd embodiment, the 2nd push pulse, the 3rd push pulse, and the 4th push pulse. It is a flowchart which shows the effect | action of the 2nd modification of 2nd embodiment.

Hereinafter, embodiments of the present invention will be described.
(First embodiment)
First, the first embodiment will be described. An ultrasonic diagnostic apparatus 1 illustrated in FIG. 1 includes an ultrasonic probe 2, a transmission / reception beam former 3, an echo data processing unit 4, a display processing unit 5, a display unit 6, an operation unit 7, a control unit 8, and a storage unit 9.

  The ultrasonic probe 2 is an example of an embodiment of an ultrasonic probe according to the present invention, and transmits ultrasonic waves to a living tissue of a subject. The ultrasonic probe 2 transmits an ultrasonic pulse (push pulse) for generating a shear elastic wave in the living tissue. The ultrasonic probe 2 transmits a detection ultrasonic pulse for detecting a shear elastic wave and receives an echo signal thereof.

  The ultrasonic probe 2 transmits an ultrasonic pulse for an image for creating a B-mode image, and receives an echo signal thereof.

  The transmission / reception beamformer 3 drives the ultrasonic probe 2 based on a control signal from the control unit 8 to transmit the various ultrasonic pulses having predetermined transmission parameters (transmission control function). ). The transmission / reception beamformer 3 performs signal processing such as phasing addition processing on the ultrasonic echo signal. The transmission / reception beamformer 3 and the control unit 8 are an example of an embodiment of a transmission control unit in the present invention. The transmission control function is an example of an embodiment of the transmission control function in the present invention.

  The echo data processing unit 4 includes a B-mode processing unit 41, a propagation velocity calculation unit 42, an elastic value calculation unit 43, and a selection unit 44, as shown in FIG. The B-mode processing unit 41 performs B-mode processing such as logarithmic compression processing and envelope detection processing on the echo data output from the transmission / reception beamformer 3 to create B-mode data.

  The propagation velocity calculation unit 42 calculates the propagation velocity of the shear elastic wave based on the echo data output from the transmission / reception beamformer 3. The elastic value calculation unit 43 calculates the elastic value of the living tissue to which the push pulse is transmitted based on the propagation speed. Details will be described later. The propagation velocity calculation unit 42 and the elastic value calculation unit 43 are an example of an embodiment of a measurement value calculation unit in the present invention. The propagation velocity and the elasticity value are an example of an embodiment of a measurement value relating to the elasticity of the living tissue in the present invention.

  Incidentally, only the propagation velocity is calculated, and the elasticity value is not necessarily calculated. The propagation velocity data or the elasticity value data is referred to as elasticity data.

  As will be described later, in this example, the first push pulse PP1 and the second push pulse PP2 are transmitted as the push pulse. Accordingly, two pieces of elasticity data, that is, elasticity data corresponding to the first push pulse PP1 and elasticity data corresponding to the second push pulse PP2 are obtained for the same part of the living tissue. The selection unit 44 selects one of a plurality of elasticity data obtained for the same part of the living tissue according to a predetermined criterion. Details will be described later. The selection unit 44 is an example of an embodiment of a selection unit in the present invention.

  The display processing unit 5 includes an image display processing unit 51 and a region setting unit 52, as shown in FIG. The image display processing unit 51 scan-converts the B-mode data with a scan converter to create B-mode image data, and causes the display unit 6 to display a B-mode image based on the B-mode image data. . The image display processing unit 51 scans the elasticity data with a scan converter to create elasticity image data, and causes the display unit 6 to display an elasticity image based on the elasticity image data. The image display processing unit 51 is an example of an embodiment of an elastic image data creation unit in the present invention.

  As shown in FIG. 4, the elasticity image EI is a two-dimensional image displayed in the region of interest R set in the B-mode image BI. The elasticity image EI is a color image having a color corresponding to the propagation speed or the elasticity value. The image display processing unit 51 generates composite image data by combining the B-mode image data and the elastic image data, and causes the display unit 6 to display an image based on the combined image data. Therefore, the elastic image EI is a translucent image through which the background B-mode image BI is transmitted.

  The region of interest R is set by the region setting unit 52. More specifically, the region setting unit 52 sets the region of interest R based on an input from the operation unit 7 by an operator. The region of interest R is a region where shear elastic waves are detected, and the ultrasonic pulse for detection is transmitted and received in this region. The region of interest R is an example of an embodiment of a two-dimensional region in the present invention.

  The display unit 6 is an LCD (Liquid Crystal Display), an organic EL (Electro-Luminescence) display, or the like. The display unit 6 is an example of an embodiment of a display unit in the present invention.

  Although not particularly illustrated, the operation unit 7 includes a keyboard for inputting instructions and information by an operator, a pointing device such as a trackball, and the like.

  The control unit 8 is a processor such as a CPU (Central Processing Unit). The control unit 8 reads the program stored in the storage unit 9 and controls each unit of the ultrasonic diagnostic apparatus 1. For example, the control unit 8 reads a program stored in the storage unit 9 and causes the functions of the transmission / reception beamformer 3, the echo data processing unit 4, and the display processing unit 5 to be executed by the read program. .

  The control unit 8 executes all the functions of the transmission / reception beamformer 3, all of the functions of the echo data processing unit 4, and all of the functions of the display processing unit 5 by a program. Alternatively, only some functions may be executed by a program. When the control unit 8 executes only some functions, the remaining functions may be executed by hardware such as a circuit.

  The functions of the transmission / reception beamformer 3, the echo data processing unit 4, and the display processing unit 5 may be realized by hardware such as a circuit.

  The storage unit 9 is an HDD (Hard Disk Drive), a semiconductor memory (RAM) such as a RAM (Random Access Memory) or a ROM (Read Only Memory).

  Next, the operation of the ultrasonic diagnostic apparatus 1 of this example will be described based on the flowchart of FIG. First, in step S1, the operator transmits / receives ultrasonic waves by the ultrasonic probe 2 to / from the living tissue of the subject, and displays a B-mode image BI based on the echo signal as shown in FIG. Then, the operator performs an input to set the region of interest R in the B-mode image BI in the operation unit 7. Thereby, the region of interest R is set in the B-mode image BI. This region of interest R is set to a region where an elastic image is to be displayed.

  Next, in step S2, a first push pulse PP1 is transmitted from the ultrasonic probe 2 as shown in FIG. The first push pulse PP1 is transmitted, for example, when an operator inputs to display an elastic image on the operation unit 7. The first push pulse PP1 is transmitted outside the region of interest R and in the vicinity of one end portion of the region of interest R in the lateral direction (X direction).

  The first push pulse PP1 has a first focus F1 having a predetermined depth, as shown in FIG.

  A first shear elastic wave W1 (not shown) is generated in the living tissue T by the first push pulse PP1. In the region of interest R, the first shear elastic wave W1 propagates in a direction away from the first push pulse PP1 (direction of arrow A1 from left to right in FIG. 7).

  Next, in step S3, as shown in FIG. 8, the first ultrasonic detecting pulse DP1 for detecting the first shear elastic wave W1 (not shown) in the region of interest R is transmitted, and its echo is transmitted. A signal is received. The transmission / reception of the first ultrasonic detecting pulse DP1 is performed for a plurality of sound rays in the region of interest R. FIG. 8 shows a sound ray through which the first detection pulse DP1 is transmitted.

  In FIG. 8, the first ultrasonic detecting pulses DP1 for a plurality of sound rays in the region of interest R are shown, but the first ultrasonic detecting pulses DP1 are transmitted and received one sound ray at a time. Is called. For example, transmission / reception of the first ultrasonic detecting pulse DP1 may be performed in order from a sound ray close to the first push pulse PP1. Transmission / reception of the first ultrasonic detecting pulse DP1 is performed a plurality of times for each sound ray.

  Next, in step S4, first elasticity data D1 is created based on the echo signal of the first ultrasonic detecting pulse DP1. The first elastic data D1 is data on the propagation speed of the first shear elastic wave W1 or data on an elastic value calculated based on the propagation speed. More specifically, the propagation velocity calculation unit 42 calculates the propagation velocity of the first shear elastic wave W1 detected in the echo signal of the first ultrasonic detecting pulse DP1. The elastic value calculation unit 43 calculates an elastic value (Young's modulus (Pa: Pascal)) based on the propagation velocity of the first shear elastic wave W1. However, the elasticity value is not calculated, and only the propagation velocity may be calculated.

  As shown in FIG. 9, the first elasticity data D1 is created for a plurality of portions p in each of the sound rays l where the first ultrasonic detecting pulse DP1 is transmitted and received. These portions p are portions corresponding to pixels, for example.

  When the first elasticity data D1 is calculated in step S4, a second push pulse PP2 is transmitted from the ultrasonic probe 2 in step S5 as shown in FIG.

  The transmission of the second push pulse PP2 does not have to be performed after the creation of the first elasticity data D1 in the step S4, and may be performed during the calculation of the first elasticity data D1, for example. In this case, for example, when the transmission / reception of the first detection ultrasonic pulse DP1 is performed a predetermined number of times in the step S3, the second push pulse PP2 may be transmitted.

  The second push pulse PP2 is transmitted to a sound ray different from the first push pulse PP1. Specifically, the second push pulse PP2 is outside the region of interest R, and the other end of the region of interest R in the lateral direction (X direction) (what is the transmission position of the first push pulse PP1? Sent to the vicinity of the opposite end). Accordingly, the positional relationship between the first push pulse PP1, the second push pulse PP2, and the region of interest R is between the transmission position of the first push pulse PP1 and the transmission position of the second push pulse PP2. The region R is in a positional relationship.

  The second push pulse PP2 has a second focus F2, which is a position different from the first focus F1 in the first push pulse PP1 in the depth direction (sound ray direction). The position of the second focus F2 is a shallower position (on the body surface side) in the body tissue T of the subject than the position of the first focus F1.

  A second shear elastic wave W2 (not shown) is generated in the living tissue T by the second push pulse PP2. In the region of interest R, the second shear elastic wave W2 propagates in the direction away from the second push pulse PP2 (the direction of the arrow A2 from right to left in FIG. 10).

  Next, in step S6, as shown in FIG. 11, the second ultrasonic detecting pulse DP2 for detecting the second shear elastic wave W2 in the region of interest R is transmitted and the echo signal is received. The The transmission / reception of the second ultrasonic detecting pulse DP2 is performed for a plurality of sound rays in the region of interest R. In FIG. 11, a sound ray through which the second detection pulse DP2 is transmitted and received is shown. The position of the sound ray at which the second ultrasonic detecting pulse DP2 is transmitted / received may be the same position on the subject as the position of the sound ray at which the first ultrasonic detecting pulse DP1 is transmitted / received.

  In FIG. 11, the second ultrasonic detecting pulses DP2 for all the sound rays in the region of interest R are shown, but the second ultrasonic detecting pulses DP2 are transmitted and received one by one. Is called. For example, the transmission / reception of the second ultrasonic detecting pulse DP2 may be performed in order from a sound ray close to the second push pulse PP2. The transmission / reception of the second ultrasonic detecting pulse DP2 is performed a plurality of times for each sound ray.

  Next, in step S7, second elasticity data D2 is created based on the echo signal of the second ultrasonic detecting pulse DP2. The second elastic data D2 is data on the propagation speed of the second shear elastic wave W2 or data on an elastic value calculated based on the propagation speed. More specifically, the propagation velocity calculation unit 42 calculates the propagation velocity of the second shear elastic wave W2 detected in the echo signal of the second ultrasonic detecting pulse DP2. The elastic value calculation unit 43 calculates an elastic value based on the propagation speed of the second shear elastic wave W2. However, the elasticity value is not calculated, and only the propagation velocity may be calculated.

  The second elasticity data D2 is created for a plurality of portions p in each of the sound rays through which the second ultrasonic detecting pulse DP2 is transmitted and received (see FIG. 9). Thereby, the first elastic data D1 and the second elastic data D2 exist for each of the plurality of portions p. In other words, there exist two elasticity data, the first elasticity data D1 and the second elasticity data D2, for the same part in the subject.

  Next, in step S8, the selection unit 44 selects either the first elasticity data D1 or the second elasticity data D2 for each of the plurality of portions p. In this example, the selection unit 44 selects elastic data corresponding to a shear elastic wave having a larger amplitude.

  Specifically, the selection unit 44 first determines the amplitude of the first shear elastic wave W1 detected in the echo signal of the first ultrasonic detecting pulse DP1 in the step S4, and the first in the step S7. The amplitude of the second shear elastic wave W2 detected in the echo signal of the two detection ultrasonic pulses DP2 is compared.

  Next, the selection unit 44 selects elastic data corresponding to a shear elastic wave having a larger amplitude among the first shear elastic wave W1 and the second shear elastic wave W2. Specifically, the selection unit 44 selects the first elastic data D1 if the amplitude of the first shear elastic wave W1 is larger than the amplitude of the second shear elastic wave W2. On the other hand, the selection unit 44 selects the second elastic data D1 if the amplitude of the second shear elastic wave W2 is larger than the amplitude of the first shear elastic wave W1.

  For example, the amplitude of the first shear elastic wave W1 may be larger than that of the second shear elastic wave W2 at the portion p in the relatively deep region close to the first push pulse PP1 in the region of interest R. The first elasticity data D1 is selected. On the other hand, the amplitude of the second shear elastic wave W2 may be larger than that of the first shear elastic wave W1 at the portion p in the region of interest R that is close to the second push pulse PP2 and is relatively shallow. The second elasticity data D2 is selected.

  Next, in step S9, elasticity image data is created based on the elasticity data selected in step S8, and an elasticity image EI based on this elasticity image data is displayed in the region of interest R (FIG. 4). reference).

  According to this example, the first push pulse PP1 and the second push pulse PP2 having different focus positions are transmitted, and an elastic image based on elastic data corresponding to a shear elastic wave having a larger amplitude is created. For example, in the region of interest R, the position in the depth direction is closer to the depth position of the first focus F1 than the depth position of the second focus F2, and the amplitude is larger than the amplitude of the second shear elastic wave W2. For the portion where the amplitude of the first shear elastic wave W1 is larger, an elastic image based on the first elastic data D1 is created. In the region of interest R, the position in the depth direction is closer to the depth position of the second focus F2 than the depth position of the first focus F1, and the amplitude is larger than the amplitude of the first shear elastic wave W1. For the portion where the amplitude of the second shear elastic wave W2 is larger, an elastic image based on the second elastic data D2 is created. Therefore, in the region of interest R, the range in which a shearing elastic wave having a large amplitude can be detected is wider than before, so that the region in which an elastic image reflecting the elasticity of living tissue can be obtained more accurately can be widened. it can.

  Further, since the transmission positions of the first push pulse PP1 and the second push pulse PP2 are one end side and the other end side of the region of interest R, the first push pulse PP1 and the second push pulse PP2 are the same sound ray. As compared with the case where the transmission is performed in FIG. 5, the deviation of the distance between each of the plurality of portions p and the push pulse can be reduced. Therefore, compared with the case where a push pulse is transmitted in the same sound ray, the distance between each of the plurality of portions P and the push pulse is close, and a shear elastic wave in which attenuation is suppressed can be detected. Therefore, an elastic image accurately reflecting the elasticity of the living tissue can be obtained.

  Next, a modification of the first embodiment will be described. First, the first modification will be described. In this first modification, the first push pulse PP1 and the second push pulse PP2 are transmitted on different sound rays in the region of interest R. In the step S2, the first push pulse PP1 is transmitted to a position closer to the one end side than the other end side in the region of interest R, for example, as shown in FIG. The second push pulse PP2 is transmitted in the step S5 to a position closer to the other end side than the one end side in the region of interest R, for example, as shown in FIG.

  Within the region of interest R, a first shear elastic wave W1 propagating in directions A1 and A2 away from the first push pulse PP1 is detected. In the region of interest R, a second shear elastic wave W2 propagating in the directions A1 and A2 away from the second push pulse PP2 is detected.

  For example, when the region of interest R is wider than those shown in the above figures, push pulses having different focus positions are transmitted on more different sound rays as shown in FIGS. Also good. In each of FIGS. 14 to 17, the first push pulse PP1, the second push pulse PP2, the third push pulse PP3, and the fourth push pulse PP4 are transmitted in the region of interest R.

  14 to 17, the first focus F1 in the first push pulse PP1 and the position in the depth direction of the third focus F3 in the third push pulse PP3 are the same. Further, the positions in the depth direction of the second focus F3 in the second push pulse PP2 and the fourth focus F4 in the fourth push pulse PP4 are the same. However, the positions in the depth direction of the first focus F1 and the third focus F3 and the second focus F2 and the fourth focus F4 are different.

  However, the positions of the first focus F1, the second focus F2, the third focus F3, and the fourth focus F4 in the depth direction may all be different.

  Although not particularly shown in the flowchart, after the first push pulse PP1 is transmitted, the first ultrasonic detecting pulse DP1 for detecting the first shear elastic wave W1 generated by the first push pulse PP1 is transmitted. An echo signal is received. And the 1st elasticity data D1 is created based on this echo signal. Further, after the second push pulse PP2 is transmitted, the second ultrasonic detecting pulse DP2 for detecting the second shear elastic wave W2 generated by the second push pulse PP2 is transmitted and the echo signal is received. The Then, second elasticity data D2 is created based on this echo signal. In addition, after the third push pulse PP3 is transmitted, the third ultrasonic detecting pulse DP3 for detecting the third shear elastic wave W3 generated by the third push pulse PP3 is transmitted and the echo signal is received. The Then, the third elasticity data D3 is created based on this echo signal. Further, after the fourth push pulse PP4 is transmitted, the fourth ultrasonic detecting pulse DP4 for detecting the fourth shear elastic wave W4 generated by the fourth push pulse PP4 is transmitted and the echo signal is received. The And the 4th elasticity data D4 is created based on this echo signal.

  Accordingly, the first elasticity data D1, the second elasticity data D2, the third elasticity data D3, and the fourth elasticity data D4 are created in each of the plurality of portions p in the region of interest R. In step S8, the selection unit 44 selects the elastic data corresponding to the shear elastic wave having the largest amplitude among the elastic data D1 to D4.

  In this way, by transmitting the first push pulse PP1 to the fourth push pulse PP4 having the first focus F1 to the fourth focus F4 on different sound rays, a relatively wide region of interest R can be obtained. In addition, it is possible to obtain an elastic image based on the elastic data created by detecting the shear elastic wave whose attenuation is suppressed.

  Next, a second modification will be described. In the second modification, the echo data processing unit 4 includes an addition averaging unit 45 instead of the selection unit 44 as shown in FIG. The addition averaging unit 45 is an example of an embodiment of the addition averaging unit in the present invention.

  In the second modified example, in step S8 ′ of the flowchart shown in FIG. 19, the addition averaging unit 45 averages the first elastic data D1 and the second elastic data D2 for each of the plurality of portions p. Create elasticity data. The addition averaging unit 45 may calculate an average value based on a simple average, or may calculate an average value by weighted addition of the first elasticity data D1 and the second elasticity data D2. In the weighted addition, the addition averaging unit 45 uses a weighting coefficient corresponding to the amplitudes of the first shear elastic wave W1 and the second shear elastic wave W2. Specifically, the amplitude of the first shear elastic wave W1 and the amplitude of the second shear elastic wave W2 are compared, and the weight coefficient for the elastic data corresponding to the shear elastic wave having the larger amplitude is determined as the other elasticity. Make it larger than the weighting factor for the data. For example, if the amplitude of the first shear elastic wave W1 is larger than the amplitude of the second shear elastic wave W2, the weight coefficient for the first elastic data D1 is set larger than the weight coefficient for the second elastic data D2. To do. On the other hand, if the amplitude of the second shear elastic wave W2 is larger than the amplitude of the first shear elastic wave W1, the weight coefficient for the second elastic data D2 is set larger than the weight coefficient for the first elastic data D1. To do.

  In addition, when said 1st elasticity data D1- said 4th elasticity data D4 are produced, the addition average of said 1st elasticity data D1-said 4th elasticity data D4 is performed.

  When the elasticity data averaged in the step S8 'is created, the elasticity image data is created in the step S9 based on the elasticity data, and the elasticity image is displayed.

(Second embodiment)
Next, a second embodiment will be described. The configuration of the ultrasonic diagnostic apparatus of this example is the same as that of the first embodiment, and the operation will be described below based on the flowchart of FIG. The echo data processing unit 4 is assumed to have the configuration shown in FIG.

  In this example, the first push pulse PP1 and the second push pulse PP2 are transmitted simultaneously. This will be specifically described with reference to FIG. First, in step S11, as in step S1, the B-mode image BI is displayed and the region of interest R is set.

  Next, in step S12, for example, when an operator inputs to display an elastic image in the operation unit 7, as shown in FIG. 21, the first push pulse PP1 and the second push pulse are sent from the ultrasonic probe 2. Are sent simultaneously. The first push pulse PP1 and the second push pulse PP2 have the first focus F1 and the second focus F2 at different positions in the depth direction, and are transmitted to different sound rays. In FIG. 21, the first push pulse PP <b> 1 is transmitted outside one end portion of the region of interest R, as in FIG. 7 of the first embodiment. Further, the second push pulse PP2 is transmitted to the outside of the other end portion of the region of interest R as in FIG. 10 of the first embodiment.

  Next, in step S13, a first shear elastic wave W1 generated by the first push pulse PP1 and a second shear elastic wave W2 generated by the second push pulse PP2 are detected in the region of interest R. An ultrasonic pulse DP for detection is transmitted. The detection pulse DP is transmitted as shown in FIG. 22, and the echo signal is received. The detection ultrasonic pulse DP is sequentially performed one sound line at a time, similarly to the transmission / reception of the first detection ultrasonic pulse DP1 and the second detection ultrasonic pulse DP2.

  Next, in step S14, first elasticity data D1 and second elasticity data D2 are created based on the echo signal of the detection ultrasonic pulse DP. The first elasticity data D1 and the second elasticity data D2 are created for each of the plurality of portions p in the region of interest R, as in the first embodiment.

  The first elastic data D1 is data on the propagation speed of the first shear elastic wave W1 or data on an elastic value calculated based on the propagation speed. The second elastic data D2 is data on the propagation speed of the second shear elastic wave W2 or data on an elastic value calculated based on this propagation speed. The first elasticity data D1 and the second elasticity data D2 are created for a plurality of portions p in each of the sound rays through which the detection ultrasonic pulse DP is transmitted and received.

  The propagation speed is calculated by the propagation speed calculator 42. More specifically, the propagation velocity calculation unit 42 calculates the propagation velocity of the first shear elastic wave W1 detected in the echo signal of the detection ultrasonic pulse DP. Further, the propagation velocity calculation unit 42 calculates the propagation velocity of the second shear elastic wave W2 detected in the echo signal of the detection ultrasonic pulse DP.

  Here, in the echo signal of the ultrasonic pulse DP for detection, the first shear elastic wave W1 and the second shear elastic wave W2 are detected. The first shear elastic wave W1 propagates in the direction of arrow A1 shown in FIG. On the other hand, the second shear elastic wave W2 propagates in the region of interest R in the direction of the arrow A2 opposite to the arrow A2. Therefore, the propagation velocity calculation unit 42 determines whether the shear elastic wave detected by the detection ultrasonic pulse DP is the first shear elastic wave W1 or the second shear elastic wave W2. Identified by a national filter. The directional filter is a filter that identifies the first shear elastic wave W1 and the second shear elastic wave W2 based on the propagation directions of the first shear elastic wave W1 and the second shear elastic wave W2.

  Similar to the first embodiment, the elastic value calculation unit 43 calculates an elastic value based on the propagation velocity of the first shear elastic wave W1, and elasticizes based on the propagation velocity of the second shear elastic wave W2. Calculate the value. However, the elasticity value may not be calculated as in the first embodiment.

  Next, in step S15, the selection unit 44 selects either the first elasticity data D1 or the second elasticity data D2 for each of the plurality of portions p in the same manner as in the first embodiment. .

  Next, in step S16, elasticity image data is created based on the elasticity data selected in step S15, and an elasticity image EI based on this elasticity image data is displayed in the region of interest R (FIG. 4). reference).

  According to this example, the same effect as in the first embodiment can be obtained, and the first push pulse PP1 and the second push pulse PP2 are transmitted at the same time, so that they are transmitted at different timings. The frame rate can be improved compared to the case.

  Next, a modification of the second embodiment will be described. First, the first modification will be described. In the first modification, as in the first modification of the first embodiment, as shown in FIG. 23, the first push pulse PP1 and the second push pulse PP2 are in the region of interest R. Sent on different sound rays. However, unlike the first embodiment, the first push pulse PP1 and the second push pulse PP2 are transmitted simultaneously. Then, the first shear elastic wave W1 and the second shear elastic wave W2 detected in the echo signal of the detection ultrasonic pulse DP are identified by the directional filter, and their propagation speeds are calculated.

  As shown in FIG. 24, in the region of interest R, the first push pulse PP1, the second push pulse PP2, the third push pulse PP3, and the fourth push pulse PP4 may be transmitted simultaneously. The positions of the first push pulse PP1 to the fourth push pulse PP4 are the same positions as those shown in FIGS.

  Next, a second modification will be described. In the second modified example, the echo data processing unit 4 has the addition averaging unit 45 as in the second modified example of the first embodiment (FIG. 18). Then, processing according to the flowchart shown in FIG. 25 is performed.

  In step S15 ′ of the flowchart of FIG. 25, similarly to step S8 ′ in the first embodiment, the addition averaging unit 45 adds and averages the first elasticity data D1 and the second elasticity data D2. Create When the first elasticity data D1 to the fourth elasticity data D4 are created, these are averaged. In step S16, elasticity image data is created based on the elasticity data obtained by averaging.

  As mentioned above, although this invention was demonstrated by the said embodiment, of course, this invention can be variously implemented in the range which does not change the main point.

DESCRIPTION OF SYMBOLS 1 Ultrasonic diagnostic apparatus 3 Transmission / reception beam former 8 Control part 6 Display part 42 Propagation velocity calculation part 43 Elasticity value calculation part 44 Selection part 45 Addition averaging part

Claims (13)

  A transmission control unit that controls transmission of an ultrasonic push pulse to a biological tissue of a subject and transmission of an ultrasonic pulse for detection for detecting a shear elastic wave generated in the biological tissue by the push pulse. An ultrasonic diagnostic apparatus comprising: a transmission control unit configured to transmit a plurality of ultrasonic push pulses having different focus positions in different sound rays as the ultrasonic push pulses.   The ultrasonic diagnostic apparatus according to claim 1, wherein the push pulses are transmitted at different timings.   The ultrasonic diagnostic apparatus according to claim 1, wherein the push pulses are transmitted simultaneously.   The apparatus includes a display unit configured to display an elasticity image having a display form corresponding to a measurement value related to elasticity of a biological tissue calculated based on an echo signal of the detection ultrasonic pulse in a two-dimensional region. The ultrasonic diagnostic apparatus as described in any one of 1-3.   The ultrasonic diagnostic apparatus according to claim 4, wherein the two-dimensional region is located between the different sound rays.   The ultrasonic diagnostic apparatus according to claim 4, wherein the different sound rays are located in the two-dimensional region. A measurement value calculation unit that calculates a measurement value related to elasticity of the living tissue based on an echo signal of the detection ultrasonic pulse, the detection ultrasonic pulse corresponding to each of the plurality of ultrasonic push pulses A measurement value calculation unit that calculates the measurement value for each part of the biological tissue based on each of the echo signals, and obtains a plurality of measurement values for the same part of the biological tissue;
A selection unit that selects any one of the plurality of measurement values obtained in the same part of the living tissue according to a predetermined standard;
An elastic image data creation unit that creates data of an elastic image having a display form corresponding to the measurement value selected by the selection unit;
The ultrasonic diagnostic apparatus according to any one of claims 1 to 6, further comprising: A measurement value calculation unit that calculates a measurement value related to elasticity of the living tissue based on an echo signal of the detection ultrasonic pulse, the detection ultrasonic pulse corresponding to each of the plurality of ultrasonic push pulses A measurement value calculation unit that calculates the measurement value for each part of the biological tissue based on each of the echo signals, and obtains a plurality of measurement values for the same part of the biological tissue;
An averaging unit that calculates an average value by averaging each of the plurality of measurement values obtained in the same portion of the biological tissue;
An elastic image data creation unit for creating data of an elastic image having a display form according to the average value;
The ultrasonic diagnostic apparatus according to any one of claims 1 to 6, further comprising:   The addition averaging unit calculates an average value by weighting and adding each of the measured values using a weighting factor corresponding to the amplitude of the shear elastic wave detected in the echo signal of the detection ultrasonic pulse. The ultrasonic diagnostic apparatus according to claim 8, characterized in that:   The ultrasonic diagnostic apparatus according to claim 7, wherein the measured value is a propagation speed of the shear elastic wave.   The ultrasonic diagnostic apparatus according to claim 7, wherein the measured value is an elastic value of a living tissue calculated based on a propagation velocity of the shear elastic wave.   A transmission control function for controlling transmission of an ultrasonic push pulse to a biological tissue of a subject and transmission of an ultrasonic pulse for detection for detecting a shear elastic wave generated in the biological tissue by the push pulse. An ultrasonic diagnostic apparatus comprising: a processor that executes, as a program, a transmission control function for transmitting a plurality of ultrasonic push pulses having different focus positions in different sound rays as the ultrasonic push pulses.   A transmission control function for controlling transmission of an ultrasonic push pulse to a biological tissue of a subject and transmission of an ultrasonic pulse for detection for detecting a shear elastic wave generated in the biological tissue by the push pulse. A program for causing a processor of an ultrasonic diagnostic apparatus to execute a transmission control function for transmitting a plurality of ultrasonic push pulses having different focus positions in different sound rays as the ultrasonic push pulse.

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