JP2012161569A - Ultrasound diagnostic apparatus and ultrasound image producing method - Google Patents

Abstract

An ultrasonic diagnostic apparatus capable of efficiently acquiring B-mode image generation data and sound speed measurement data to perform both B-mode image generation and sound speed map generation.
A transmission focal point is formed at a lattice point E in a region of interest R to preferentially acquire reception data for sound velocity measurement, and a sound velocity in the region of interest R is obtained based on the acquired reception data for sound velocity measurement. While generating the map, the transmission focus is formed at the point F located at the predetermined depth L on each of the sound rays S1 to S7, and the reception data for generating the B-mode image is obtained. Generation and sound velocity map are both performed.
[Selection] Figure 3

Description

  The present invention relates to an ultrasonic diagnostic apparatus and an ultrasonic image generation method, and more particularly, to generate both a B-mode image and a sound velocity map in a region of interest by transmitting and receiving ultrasonic waves from a transducer array of an ultrasonic probe. The present invention relates to an ultrasonic diagnostic apparatus.

  Conventionally, in the medical field, an ultrasonic diagnostic apparatus using an ultrasonic image has been put into practical use. In general, this type of ultrasonic diagnostic apparatus has an ultrasonic probe with a built-in transducer array and an apparatus main body connected to the ultrasonic probe. An ultrasonic image is generated by transmitting a sound beam, receiving an ultrasonic echo from the subject with an ultrasonic probe, and electrically processing the received signal with the apparatus main body.

In recent years, in order to more accurately diagnose a diagnostic site in a subject, the speed of sound at the diagnostic site has been measured.
For example, in Patent Document 1, a plurality of lattice points are set around a diagnostic region, and a local sound velocity value is calculated based on reception data obtained by transmitting and receiving an ultrasonic beam to each lattice point. An ultrasonic diagnostic apparatus has been proposed.

JP 2010-99452 A

With the apparatus of Patent Document 1, a local sound velocity value at a diagnostic site can be obtained by transmitting and receiving an ultrasonic beam from an ultrasonic probe into a subject. For example, information on a local sound velocity value is superimposed on a B-mode image. Can be displayed.
By the way, when a diagnosis is performed on a specific region in the subject, it is effective to display a sound velocity map indicating the distribution of local sound velocity values at each point in the region in addition to the B-mode image. .
However, if both the generation of the B-mode image and the generation of the sound velocity map of the diagnostic region are to be performed, the ultrasonic beam must be transmitted and received many times, and the data for generating the B-mode image and the sound velocity measurement For this reason, it takes a lot of time and labor to acquire data.

  The present invention has been made to solve such a conventional problem, and efficiently obtains B-mode image generation data and sound speed measurement data to generate a B-mode image and a sound speed map. It is an object to provide an ultrasonic diagnostic apparatus and an ultrasonic image generation method capable of performing both of the above.

  An ultrasonic diagnostic apparatus according to the present invention transmits an ultrasonic beam from a transducer array of an ultrasonic probe toward a subject and receives an ultrasonic echo from the subject based on a drive signal supplied from a transmission circuit. An ultrasonic diagnostic apparatus that generates an ultrasonic image based on reception data obtained by processing a reception signal output from a transducer array of an ultrasonic probe using a reception circuit. A region of interest setting unit for setting, a plurality of lattice points in the region of interest set by the region of interest setting unit, a transmission focal point is formed at the plurality of lattice points, and an ultrasonic beam is transmitted and received respectively. Is used to acquire reception data for sound velocity measurement, and to form a transmission focal point at a predetermined depth for each sound ray and transmit / receive an ultrasonic beam, thereby receiving reception data for B-mode image generation. A control unit that controls the transmission circuit and the reception circuit so as to obtain a sound speed, a sound speed map generation unit that generates a sound speed map in the region of interest based on reception data for sound speed measurement, and reception data for B-mode image generation An image generation unit that generates a B-mode image based on the received image data, and the control unit receives the reception data for B-mode image generation while the sound speed map generation unit performs generation of the sound speed map after acquiring reception data for sound speed measurement. The transmission circuit and the reception circuit are controlled so as to acquire data.

The control unit controls the transmission circuit and the reception circuit so as to acquire the reception data for generating the B-mode image only for the sound ray passing outside the region of interest, and the image generation unit transmits the sound passing through the inside of the region of interest. For the line, the reception data for sound velocity measurement obtained by forming a transmission focal point at a lattice point having a depth closest to a predetermined depth among a plurality of lattice points and transmitting and receiving an ultrasonic beam is B mode. It can also be configured to generate a B-mode image using the received data for image generation.
In this case, the control unit may set the predetermined depth to be equal to any one of the plurality of grid points. Furthermore, the control unit can set the predetermined depth to be equal to the depth of a lattice point located at the center in the depth direction of the region of interest among the plurality of lattice points.

  In the ultrasonic image generation method according to the present invention, an ultrasonic beam is transmitted from a transducer array of an ultrasonic probe toward a subject based on a drive signal supplied from a transmission circuit, and an ultrasonic echo by the subject is transmitted. An ultrasonic image generation method for generating an ultrasonic image based on reception data obtained by processing a reception signal output from a transducer array of a received ultrasonic probe by a reception circuit, and in the imaging region Set the area and set multiple grid points in the area of interest, form the transmission focal point at the multiple grid points, and send and receive the ultrasonic beam respectively to acquire the reception data for sound velocity measurement Generation of a sound velocity map in the region of interest is started based on the received sound velocity measurement data, and transmission focus is transmitted to one predetermined depth for a plurality of sound rays during the generation of the sound velocity map. Acquires received data for the B-mode image generated by performing transmission and reception of the formed ultrasonic beam, a method for generating a B-mode image based on the received data for the acquired B-mode image generation.

  According to the present invention, reception data for sound speed measurement is preferentially acquired, and reception for generating a B-mode image is performed during generation of a sound speed map in the region of interest based on the acquired reception data for sound speed measurement. Since the data is acquired, it is possible to efficiently acquire the B-mode image generation data and the sound speed measurement data to perform both the B-mode image generation and the sound speed map generation.

1 is a block diagram showing a configuration of an ultrasonic diagnostic apparatus according to Embodiment 1 of the present invention. 3 is a diagram schematically illustrating the principle of sound speed calculation in Embodiment 1. FIG. FIG. 6 is a diagram illustrating a transmission focal point position and an ultrasonic beam transmission / reception order in the first embodiment. It is a figure which shows the position of the transmission focus in Embodiment 2, and the order of ultrasonic beam transmission / reception. It is a figure which shows the position of the transmission focus in the modification of Embodiment 2, and the order of ultrasonic beam transmission / reception.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
Embodiment 1
FIG. 1 shows the configuration of an ultrasonic diagnostic apparatus according to Embodiment 1 of the present invention. The ultrasonic diagnostic apparatus includes a transducer array 1 to which a transmission circuit 2 and a reception circuit 3 are connected. A signal processing unit 4, a DSC (Digital Scan Converter) 5, and an image processing unit 6 are sequentially connected to the receiving circuit 3, and a display unit 8 is connected to the image processing unit 6 via a display control unit 7. An image memory 9 is connected.
Further, a cine memory 10 and a sound velocity map generator 11 are respectively connected to the receiver circuit 3, and a control unit is connected to the transmitter circuit 2, receiver circuit 3, signal processor 4, DSC 5, display controller 7, cine memory 10 and sound velocity map generator 11. 12 is connected. Furthermore, an operation unit 13 and a storage unit 14 are connected to the control unit 12.

  The transducer array 1 has a plurality of ultrasonic transducers arranged one-dimensionally or two-dimensionally. Each of these ultrasonic transducers transmits an ultrasonic wave according to the drive signal supplied from the transmission circuit 2 and receives an ultrasonic echo from the subject and outputs a received signal. Each ultrasonic transducer is, for example, a piezoelectric ceramic represented by PZT (lead zirconate titanate), a polymer piezoelectric element represented by PVDF (polyvinylidene fluoride), or PMN-PT (magnesium niobate / lead titanate). It is constituted by a vibrator in which electrodes are formed on both ends of a piezoelectric body made of a piezoelectric single crystal represented by a solid solution).

  When a pulsed or continuous wave voltage is applied to the electrodes of such a vibrator, the piezoelectric body expands and contracts, and pulsed or continuous wave ultrasonic waves are generated from the respective vibrators, and the synthesis of those ultrasonic waves. As a result, an ultrasonic beam is formed. In addition, each transducer generates an electric signal by expanding and contracting by receiving propagating ultrasonic waves, and these electric signals are output as ultrasonic reception signals.

  The transmission circuit 2 includes, for example, a plurality of pulsars, and an ultrasonic wave transmitted from the plurality of ultrasonic transducers of the transducer array 1 based on a transmission delay pattern selected according to a control signal from the control unit 12. The delay amount of each drive signal is adjusted so that the sound wave forms an ultrasonic beam, and then supplied to a plurality of ultrasonic transducers.

  The reception circuit 3 amplifies the reception signal transmitted from each ultrasonic transducer of the transducer array 1 and performs A / D conversion, and then, based on the reception delay pattern selected according to the control signal from the control unit 12. According to the set sound speed or distribution of sound speed, the reception focus process is performed by adding each received signal with a delay. By this reception focus processing, reception data (sound ray signal) in which the focus of the ultrasonic echo is narrowed is generated.

The signal processing unit 4 corrects attenuation by distance according to the depth of the reflection position of the ultrasonic wave on the reception data generated by the reception circuit 3, and then performs an envelope detection process so that the inside of the subject is detected. A B-mode image signal, which is tomographic image information related to the tissue of, is generated.
The DSC 5 converts (raster conversion) the B-mode image signal generated by the signal processing unit 4 into an image signal according to a normal television signal scanning method.
The image processing unit 6 performs various necessary image processing such as gradation processing on the B-mode image signal input from the DSC 5, and then outputs the B-mode image signal to the display control unit 7 or stores it in the image memory 9. Store.
These signal processing unit 4, DSC 5, image processing unit 6 and image memory 9 form an image generation unit 15 of the present invention.

The display control unit 7 causes the display unit 8 to display an ultrasound diagnostic image based on the B-mode image signal that has been subjected to image processing by the image processing unit 6.
The display unit 8 includes, for example, a display device such as an LCD, and displays an ultrasound diagnostic image under the control of the display control unit 7.

The cine memory 10 sequentially stores the reception data output from the reception circuit 3. Further, the cine memory 10 stores information related to the frame rate input from the control unit 12 (for example, parameters indicating the reflection position depth, the scanning line density, and the visual field width) in association with the received data.
The sound velocity map generation unit 11 calculates a local sound velocity value in the tissue in the subject to be diagnosed based on the received data stored in the cine memory 10 under the control of the control unit 12 and generates a sound velocity map. To do.
The control unit 12 controls each part of the ultrasonic diagnostic apparatus based on a command input from the operation unit 13 by the operator.

The operation unit 13 is for an operator to perform an input operation. The operation unit 13 constitutes a region of interest setting unit of the present invention, and can be formed from a keyboard, a mouse, a trackball, a touch panel, and the like.
The storage unit 14 stores an operation program and the like, and a recording medium such as a hard disk, a flexible disk, an MO, an MT, a RAM, a CD-ROM, and a DVD-ROM can be used.
The signal processing unit 4, the DSC 5, the image processing unit 6, the display control unit 7, and the sound speed map generation unit 11 are composed of a CPU and an operation program for causing the CPU to perform various processes. You may comprise with a circuit.

  The operator can select one of the following three display modes from the operation unit 13. That is, a mode in which a B-mode image is displayed alone, a mode in which a sound speed map is superimposed on a B-mode image (for example, a display in which color coding or luminance is changed according to a local sound speed value, or a point where local sound speed values are equal) Among the modes in which the B-mode image and the sound velocity map image are displayed side by side, display in a desired mode can be performed.

  When displaying a B-mode image, first, ultrasonic waves are transmitted from a plurality of ultrasonic transducers of the transducer array 1 in accordance with a drive signal supplied from the transmission circuit 2, and each ultrasonic echo received from a subject is received. A reception signal is output from the ultrasonic transducer to the reception circuit 3, and reception data is generated by the reception circuit 3. Further, a B-mode image signal is generated by the signal processing unit 4 to which the received data is input, and the B-mode image signal is raster-converted by the DSC 5 and various image processes are performed on the B-mode image signal by the image processing unit 6. After that, an ultrasonic diagnostic image is displayed on the display unit 8 by the display control unit 7 based on the B-mode image signal.

On the other hand, the calculation of the local sound velocity value can be performed, for example, by the method described in Japanese Patent Application Laid-Open No. 2010-99452 filed by the applicant of the present application.
As shown in FIG. 2A, this method focuses on a received wave Wx that reaches the transducer array 1 from a lattice point X that is a reflection point of the subject when an ultrasonic wave is transmitted into the subject. 2B, a plurality of lattice points A1, A2,... Are arranged at equal intervals at a position shallower than the lattice point X, that is, a position close to the transducer array 1, as shown in FIG. The combined wave Wsum of the received waves W1, W2,... Received from the plurality of grid points A1, A2,... Received from the point X is received from the grid point X according to Huygens' principle. This is a method of obtaining a local sound velocity value at the lattice point X by utilizing the fact that it matches the wave Wx.

  First, optimum sound speed values for all lattice points X, A1, A2,. Here, the optimum sound speed value means that, for each lattice point, an ultrasonic image is formed by performing a focus calculation based on the set sound speed and shooting, and the contrast and sharpness of the image are changed when the set sound speed is changed variously. Is the highest sound speed value. For example, as described in JP-A-8-317926, the optimum sound speed value can be determined based on the contrast of the image, the spatial frequency in the scanning direction, the variance, and the like.

Next, the waveform of the virtual received wave Wx emitted from the lattice point X is calculated using the optimum sound velocity value for the lattice point X.
Further, the hypothetical local sound velocity value V at the lattice point X is variously changed to calculate virtual composite waves Wsum of the received waves W1, W2,... From the lattice points A1, A2,. . At this time, it is assumed that the sound velocity in the region Rxa between the lattice point X and each lattice point A1, A2,... Is uniform and equal to the local sound velocity value V at the lattice point X. The time until the ultrasonic wave propagated from the lattice point X reaches the lattice points A1, A2,... Is XA1 / V, XA2 / V,. Here, XA1, XA2,... Are the distances between the lattice points A1, A2,. Therefore, a virtual composite wave Wsum can be obtained by synthesizing the reflected waves emitted from the lattice points A1, A2,... Delayed by times XA1 / V, XA2 / V,. .

Next, errors between the plurality of virtual synthesized waves Wsum calculated by variously changing the hypothetical local sound velocity value V at the lattice point X and the virtual received wave Wx from the lattice point X are respectively calculated. The hypothetical local sound velocity value V that minimizes the error is calculated and determined as the local sound velocity value at the lattice point X. Here, as a method of calculating an error between the virtual synthesized wave Wsum and the virtual received wave Wx from the lattice point X, a method of obtaining a cross-correlation with each other, a delay obtained from the synthesized wave Wsum on the received wave Wx is used. A method of performing phase matching addition by multiplying, a method of performing phase matching addition by multiplying the synthesized wave Wsum by a delay obtained from the reception wave Wx, and the like can be employed.
As described above, the local sound velocity value in the subject can be calculated with high accuracy based on the reception data generated by the reception circuit 3. Furthermore, similarly, a sound speed map showing the distribution of local sound speed values within the set region of interest can be generated.

Here, the transmission focus for generating the B-mode image and the transmission focus for measuring the sound speed in the first embodiment will be described with reference to FIG. In FIG. 3, for simplification, the transducer array 1 is shown as an array of seven ultrasonic transducers, and the sound rays S1 to S7 are formed at the arrangement pitch of these ultrasonic transducers. It is shown. In the region of interest R, a plurality of lattice points E indicated by “●” are set on the sound ray passing through the region of interest R and spaced from each other in the depth direction. In FIG. 3, nine grid points E set on sound rays S3 to S5 passing through the region of interest R are shown, and all of these nine grid points E are transmitted to generate a sound velocity map. Become the focus.
On the other hand, the transmission focus for generating the B-mode image is set to a point F located on each sound ray S1 to S7 and at a predetermined depth. In FIG. 3, the point F is indicated by “Δ”, and a transmission focal point is formed at each of the seven points F located at a predetermined depth L on the sound rays S1 to S7.

  The reception data is acquired by forming the transmission focal point at each of the nine lattice points E and the seven points F set as described above and transmitting and receiving the ultrasonic beam. First, reception data for sound velocity measurement is obtained by forming a transmission focal point at each of nine lattice points E in the region of interest R and performing transmission and reception of ultrasonic beams, and the obtained sound velocity measurement data is obtained. While calculating the local sound velocity value and generating the sound velocity map based on the received data, a transmission focus is formed at each of the seven points F to transmit / receive ultrasonic beams, thereby generating a B-mode image. Get received data.

Next, the operation of the first embodiment will be described.
First, an ultrasonic beam is transmitted from a plurality of ultrasonic transducers of the transducer array 1 in accordance with a drive signal from the transmission circuit 2, and reception signals are received from the ultrasonic transducers that have received ultrasonic echoes from the subject to the reception circuit 3. The received data is generated by the output, and the B-mode image is displayed on the display unit 8 by the display control unit 7 based on the B-mode image signal generated by the image generation unit 15.

Here, when the region of interest R is set on the B-mode image displayed on the display unit 8 by the operation of the operation unit 13 by the operator, the control unit 12 causes the sound passing through the inside of the region of interest R. Nine lattice points E are set in the region of interest R so as to be spaced apart from each other by a distance H in the depth direction on the sound lines S3 to S5 in FIG.
Next, a total of seven points F positioned at a predetermined depth L on the sound rays S1 to S7 are set by the control unit 12.

Then, after transmitting ultrasonic waves are transmitted and received by forming transmission focal points at the nine lattice points E in the region of interest R, the transmission focal points are respectively transmitted to the seven points F. The transmission circuit 2 and the reception circuit 3 are controlled by the control unit 12 so as to acquire reception data for generating a B-mode image by transmitting and receiving an ultrasonic beam.
At this time, for example, as shown in FIG. 3, for nine grid points E in the region of interest R, transmission focal points are sequentially formed at the three grid points E set on the sound ray S3 in the process P1. Then, an ultrasonic beam is transmitted / received, a transmission focal point is sequentially formed at the three lattice points E set on the sound ray S4 in the next process P2, and the ultrasonic beam is transmitted / received. An ultrasonic beam is transmitted / received by sequentially forming a transmission focal point at three lattice points E set on the sound ray S5. Thereby, the reception data for sound velocity measurement is acquired.

  The received data for measuring the sound speed is sequentially output from the receiving circuit 3 to the cine memory 10 and stored therein. When all the received data for the nine grid points E are acquired and stored in the cine memory 10, the sound speed map generating unit 11 receives the sound speed measurement received data stored in the cine memory 10 based on a command from the control unit 12. Is used to start the calculation of the local sound speed value at each lattice point E and the generation of the sound speed map in the region of interest R.

While the calculation of the local sound speed value and the generation of the sound speed map are executed by the sound speed map generation unit 11 in this way, this time, for the seven points F, from the point F on the sound ray S1 in step P4. The transmission focal point is sequentially formed up to the point F on the sound ray S7 to transmit / receive the ultrasonic beam. Thereby, the reception data for B mode images is acquired.
The acquired reception data for the B-mode image is sequentially output from the reception circuit 3 to the signal processing unit 4 of the image generation unit 15 and stored in the cine memory 10. In the signal processing unit 4, a B-mode image signal is generated using reception data for B-mode images sequentially input from the receiving circuit 3, and this B-mode image signal is raster-converted by the DSC 5, and the image processing unit 6 After various image processing is performed, the image is sent to the display control unit 7.

  On the other hand, when the sound speed map in the region of interest R is generated by the sound speed map generation unit 11, the data related to the sound speed map is raster-converted by the DSC 5, subjected to various image processing by the image processing unit 6, and then displayed. It is sent to the control unit 7. Then, according to the display mode input from the operation unit 13 by the operator, the B-mode image is displayed on the display unit 8 with the sound velocity map superimposed thereon, or the B-mode image and the sound velocity map image are arranged side by side. Is displayed.

  In this manner, the reception data for sound speed measurement is preferentially acquired, and the sound speed map generation unit 11 performs generation of the sound speed map in the region of interest R based on the acquired reception data for sound speed measurement. Since the reception data for generating the mode image is acquired, it is possible to efficiently acquire the data for generating the B mode image and the data for measuring the sound speed, and perform both the generation of the B mode image and the sound speed map. .

It should be noted that an ultrasonic beam for generating a B-mode image that is transmitted after forming a transmission focal point at seven points F, and a sound velocity measurement that is transmitted after forming a transmission focal point at nine lattice points E in the region of interest R. As the ultrasonic beams for use, those having different center frequencies and numerical apertures of the transducer array 1 can be used. For example, an ultrasonic beam having a central frequency of 3 MHz with a numerical aperture of 64 channels is used as an ultrasonic beam for generating a B-mode image, and an ultrasonic wave having a central frequency of 8 MHz with a numerical aperture of 96 channels is used as an ultrasonic beam for measuring the speed of sound. A beam can be used.
The ultrasonic beam for measuring the speed of sound may have a wider aperture for narrowing the transmission focus than the ultrasonic beam for generating the B-mode image, and the center frequency may be set higher to reduce the influence of side lobes. preferable. In the case where there is a high possibility of being affected by refraction due to the abdominal wall or the like as in the case where the liver is to be diagnosed, the center frequency of the ultrasonic beam for sound velocity measurement is set to a low value, for example, 2.5 MHz. , The influence of refraction can be reduced.

  In the first embodiment, for the nine grid points E set in the region of interest R, a transmission focal point is sequentially formed at the three grid points E set on the sound ray S3 in the step P1, In step P2, transmission focal points are sequentially formed at the three lattice points E set on the sound ray S4, and in step P3, transmission focal points are sequentially formed at the three lattice points E set on the sound ray S5. However, the present invention is not limited to this, but the transmission focus is sequentially formed at the three lattice points E located at the same depth on the sound rays S3 to S5, and then the sound rays S3 to S3 are transmitted. The ultrasonic beams may be transmitted and received in such an order that the transmission focal points are sequentially formed at the three lattice points E located at other depths on S5.

Embodiment 2
In the first embodiment, the seven points F serving as the transmission focus for generating the B-mode image are set regardless of the nine lattice points E in the region of interest R. The transmission circuit 2 and the reception circuit 3 are controlled so as to acquire reception data dedicated to B-mode image generation only for sound rays that pass outside the R region. An ultrasonic beam is transmitted and received by forming a transmission focal point at a lattice point having a depth closest to a predetermined depth L that forms a transmission focal point for generating a B-mode image among a plurality of lattice points in the region R. It is also possible to configure the image generation unit 15 to generate a B-mode image using the reception data for sound velocity measurement acquired in step (B) as reception data for B-mode image generation.
In this case, a predetermined depth L that forms a transmission focal point for B-mode image generation is further set to be equal to the depth of any one of the plurality of grid points set in the region of interest R. It may be set.

For example, as shown in FIG. 4, nine lattice points are set in the region of interest R, and among these lattice points, a total of six lattice points located at the shallowest part and the deepest part are dedicated to sound velocity measurement. In addition to the grid point E1 used, the three grid points located in the center of the region of interest R in the depth direction are set as the grid point E2 used for both the generation of the B-mode image and the sound speed measurement. In FIG. 4, the lattice point E1 is indicated by “●” and the lattice point E2 is indicated by “◯”.
In addition, a total of four points F are set on the sound rays S1, S2, S6, and S7 that pass outside the region of interest R and at a depth L equal to the depth of the lattice point E2.

Then, with respect to the nine lattice points E1 and E2 in the region of interest R, a transmission focal point is sequentially formed at the three lattice points set on the sound ray S3 in the step P1, and the ultrasonic beam is transmitted and received. In the next process P2, transmission focal points are sequentially formed at the three lattice points set on the sound ray S4 to transmit / receive the ultrasonic beam, and in the next process P3, three set on the sound ray S5. The transmission focal point is sequentially formed at the lattice points to transmit / receive the ultrasonic beam. Thereby, reception data for sound velocity measurement is acquired in the same manner as in the first embodiment.
The received data for measuring the sound speed is sequentially output from the receiving circuit 3 to the signal processing unit 4 and output to the cine memory 10 and stored therein. The sound speed map generating unit 11 is used for measuring the sound speed stored in the cine memory 10. Using the received data, the calculation of the local sound speed value at each of the lattice points E1 and E2 and the generation of the sound speed map in the region of interest R are started.

  While the calculation of the local sound speed value and the generation of the sound speed map are executed by the sound speed map generation unit 11 in this way, this time, for the four points F, the points on the sound rays S1 and S2 in step P4. A transmission focal point is sequentially formed in F to transmit / receive ultrasonic beams, and in a subsequent process P5, a transmission focal point is sequentially formed at point F on the sound rays S6 and S7 to transmit / receive ultrasonic beams.

  Based on the command from the control unit 12, the signal processing unit 4 forms a transmission focal point at three lattice points E2 in the region of interest R among the reception data sequentially input from the reception circuit 3, and generates an ultrasonic beam. A B-mode image signal is obtained by using the reception data acquired by performing transmission and reception and the reception data acquired by transmitting and receiving an ultrasonic beam by forming a transmission focal point at four points F outside the region of interest R. Generate. That is, the reception data for sound velocity measurement obtained by forming transmission focal points at three lattice points E2 in the region of interest R and transmitting / receiving ultrasonic beams is used for generating B-mode images related to the sound rays S3 to S5. The sound rays S1, S2, S6 acquired by forming the transmission focal point at the four points F and transmitting / receiving the ultrasonic beam, A B-mode image signal is generated based on the reception data for B-mode image generation relating to S7. This B-mode image signal is raster-converted by the DSC 5, subjected to various image processing by the image processing unit 6, and then sent to the display control unit 7.

  On the other hand, when the sound speed map in the region of interest R is generated by the sound speed map generation unit 11, the data related to the sound speed map is raster-converted by the DSC 5, subjected to various image processing by the image processing unit 6, and then displayed. It is sent to the control unit 7. Then, according to the display mode input from the operation unit 13 by the operator, the B-mode image is displayed on the display unit 8 with the sound velocity map superimposed thereon, or the B-mode image and the sound velocity map image are arranged side by side. Is displayed.

  In the second embodiment, reception data for sound velocity measurement obtained by forming a transmission focal point at three lattice points E2 in the region of interest R and transmitting / receiving an ultrasonic beam is used for generating a B-mode image. By using it also as reception data, it is possible to more efficiently acquire reception data for B-mode image generation and reception data for sound velocity measurement, and perform both generation of a B-mode image and generation of a sound velocity map. .

As shown in FIG. 5, for the convenience of calculating the local sound velocity value of each lattice point in the region of interest R, lattice points are added outside the region of interest R, and the sound velocity is also applied to these outer lattice points. A transmission focus for measurement may be formed. In this case as well, the reception data for the B-mode image may be acquired while the reception data for sound speed measurement is preferentially acquired and the sound speed map generation unit 11 generates the sound speed map.
In FIG. 5, among the sound rays S1 to S13, the sound rays S6 to S8 pass through the region of interest R, and the sound rays S1 to S5 and S9 to S13 pass outside the region of interest R. Grid points E1 are also set on the lines S3 to S5 and S9 to S11.
Further, a total of ten points F are set on the sound lines S1 to S5 and S9 to S13 passing through the outside of the region of interest R and at a depth L equal to the depth of the lattice point E2.

  In step P1, transmission focal points are sequentially formed at the lattice points E1 on the sound rays S3 to S5 to transmit / receive ultrasonic beams, and in step P2, transmission focal points are sequentially applied to the three lattice points set on the sound rays S6. The transmission focal point is formed and the ultrasonic beam is transmitted / received, the transmission focal point is sequentially formed at the three lattice points set on the sound ray S7 in the process P3, and the ultrasonic beam is transmitted / received. The transmission focal point is sequentially formed at the three lattice points set to ## EQU3 ## to transmit / receive the ultrasonic beam, and further, in step P5, the transmission focal point is sequentially formed at the lattice point E1 on the sound rays S9 to S11. Send and receive. Thereby, the reception data for sound velocity measurement is acquired.

Then, while the calculation of the local sound velocity value and the generation of the sound velocity map are being executed by the sound velocity map generation unit 11, a transmission focal point is sequentially formed at the points F on the sound rays S1 to S5 in step P6, and the ultrasonic beam In the subsequent process P7, transmission focal points are sequentially formed at points F on the sound rays S9 to S13, and ultrasonic beams are transmitted and received.
The reception data for sound velocity measurement obtained by forming a transmission focal point at three lattice points E2 in the region of interest R and transmitting / receiving an ultrasonic beam is received for generating a B-mode image for the sound rays S6 to S8. Used as data, the received data for generating the B-mode image and the sound rays S1 to S5 and S9 to S13 obtained by transmitting and receiving the ultrasonic beam by forming the transmission focal point at the ten points F A B-mode image signal is generated based on the reception data for generating the B-mode image.

In the first and second embodiments described above, the reception data output from the reception circuit 3 is temporarily stored in the cine memory 10, and the sound velocity map generation unit 11 uses the reception data stored in the cine memory 10 to store the reception data in the region of interest R. The sound speed map in the region of interest R is generated by calculating the local sound speed value at each lattice point of the sound field, but the sound speed map generation unit 11 directly inputs the reception data output from the receiving circuit 3 to generate the sound speed map. You can also.
The cine memory 10 stores not only received data used for sound velocity measurement but also received data for generating a B-mode image. Therefore, the control unit 12 controls the cine memory 10 from the cine memory 10 as necessary. It is also possible to read out reception data for image generation and generate a B-mode image by the image generation unit 15.

  In the first and second embodiments described above, for the sake of simplicity, the numerical aperture of the transducer array 1 illustrated, that is, the number of sound rays, the number of lattice points in the region of interest R, and the like are shown as small values. However, the present invention is not limited to this, and it is preferable to set the numerical aperture and the number of lattice points suitable for diagnosis using a B-mode image and measurement of sound speed.

  1 transducer array, 2 transmitting circuit, 3 receiving circuit, 4 signal processing unit, 5 DSC, 6 image processing unit, 7 display control unit, 8 display unit, 9 image memory, 10 cine memory, 11 sound velocity map generation unit, 12 control Unit, 13 operation unit, 14 storage unit, 15 image generation unit, X, A1, A2 lattice points, W1, W2, Wx received wave, Wsum synthesized wave, R region of interest, S1-S13 sound ray, P1-P7 process, E Lattice point, E1 Lattice point where a transmission focus dedicated to sound velocity measurement is formed, E2 Lattice point where a transmission focus used for both B-mode image generation and sound velocity measurement is formed, Transmission focus dedicated to FB mode image generation Where L is formed, L predetermined depth, H interval.

Claims (5)

Based on the drive signal supplied from the transmission circuit, an ultrasonic beam is transmitted from the transducer array of the ultrasonic probe toward the subject and the ultrasonic echo by the subject is received from the transducer array of the ultrasonic probe. An ultrasonic diagnostic apparatus that generates an ultrasonic image based on reception data obtained by processing an output reception signal in a reception circuit,
A region-of-interest setting unit for setting a region of interest in the imaging region;
By setting a plurality of grid points in the region of interest set by the region of interest setting unit, forming a transmission focal point at the plurality of grid points, and transmitting and receiving an ultrasonic beam, respectively, reception data for sound velocity measurement is obtained. The transmission circuit and the reception circuit are controlled so as to acquire reception data for generating a B-mode image by acquiring and transmitting and receiving an ultrasonic beam by forming a transmission focus at a predetermined depth for each sound ray. A control unit,
A sound speed map generating unit for generating a sound speed map in the region of interest based on the received data for sound speed measurement;
An image generation unit that generates a B-mode image based on the reception data for generating a B-mode image, and the control unit obtains the reception data for sound speed measurement, and then the sound speed map generated by the sound speed map generation unit. An ultrasonic diagnostic apparatus, wherein the transmission circuit and the reception circuit are controlled so as to acquire the reception data for generating a B-mode image during execution of generation. The control unit controls the transmission circuit and the reception circuit so as to acquire the reception data for generating a B-mode image only for a sound ray that passes outside the region of interest,
The image generation unit transmits and receives an ultrasonic beam by forming a transmission focal point at a lattice point having a depth closest to the predetermined depth among the plurality of lattice points for a sound ray passing through the inside of the region of interest. The ultrasonic diagnostic apparatus according to claim 1, wherein a B-mode image is generated by using the reception data for sound velocity measurement acquired by performing as reception data for generating a B-mode image.   The ultrasonic diagnostic apparatus according to claim 2, wherein the control unit sets the predetermined depth to be equal to any one of the plurality of lattice points.   The ultrasonic diagnosis according to claim 3, wherein the control unit sets the predetermined depth to be equal to a depth of a lattice point located in a central portion in a depth direction of the region of interest among the plurality of lattice points. apparatus. Based on the drive signal supplied from the transmission circuit, an ultrasonic beam is transmitted from the transducer array of the ultrasonic probe toward the subject and the ultrasonic echo by the subject is received from the transducer array of the ultrasonic probe. An ultrasonic image generation method for generating an ultrasonic image based on reception data obtained by processing an output reception signal in a reception circuit,
Setting a region of interest in the imaging region and setting a plurality of grid points in the region of interest;
Obtaining reception data for sound velocity measurement by forming transmission focal points at the plurality of lattice points and transmitting and receiving ultrasonic beams respectively.
Start generating a sound speed map in the region of interest based on the received data for sound speed measurement obtained;
During the generation of the sound velocity map, reception data for B-mode image generation is acquired by forming a transmission focal point at a predetermined depth for a plurality of sound rays and transmitting and receiving an ultrasonic beam,
An ultrasonic image generation method, wherein a B-mode image is generated based on the acquired reception data for generating a B-mode image.

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