JP2012161554A - Ultrasound diagnostic apparatus and ultrasound image producing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ultrasound diagnostic apparatus and an ultrasound image producing method capable of efficiently obtaining data for producing a B mode image and data for measuring the sound speed to achieve production of both a B mode image and a sound speed map.SOLUTION: Transmission focuses are formed at lattice points E in a region of interest R to obtain reception data for measuring a sound speed, and the reception data for producing a B mode image is obtained by transmitting and receiving a wide ultrasonic beam B2 having a narrow width portion extending over a plurality of sound ray regions at a given depth L for each of the sound rays. Thus, both the B mode image and the sound speed map are produced.

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. The B mode is obtained by acquiring reception data for sound speed measurement by transmitting and receiving, for each sound ray, an ultrasonic beam that forms a narrow portion extending over a plurality of sound ray regions at a predetermined depth. A control unit that controls the transmission circuit and the reception circuit so as to acquire reception data for image generation, a sound speed map generation unit that generates a sound speed map in the region of interest based on the reception data for sound speed measurement, and a B-mode image And an image generation unit that generates a B-mode image based on the reception data for generation.

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, set multiple grid points in the area of interest, form transmission focal points at the multiple grid points, and transmit and receive ultrasonic beams respectively to obtain the reception data for sound speed measurement, and measure the sound speed A sound velocity map in the region of interest is generated based on the received data for transmission, and an ultrasonic beam forming a narrow portion extending over the plurality of sound ray regions at a predetermined depth is transmitted for each of the plurality of sound rays. Acquires received data for the B-mode image produced by Shin is a method for generating a B-mode image based on the received data for the B-mode image generation.

  According to the present invention, transmission focal points are formed at a plurality of lattice points set in a region of interest, and transmission and reception of ultrasonic beams are performed to acquire reception data for sound velocity measurement and Since reception data for generating a B-mode image is obtained by transmitting and receiving an ultrasonic beam forming a narrow portion extending over the sound ray region for each of a plurality of sound rays, data for generating a B-mode image and data for measuring a sound speed are obtained. It is possible to efficiently acquire data and perform both generation of a B-mode image and generation of a sound velocity map.

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. 4 is a diagram illustrating a position of a transmission focus and a state of an ultrasonic beam in the first embodiment. FIG. 10 is a diagram illustrating a position of a transmission focus and a state of an ultrasonic beam in the second embodiment. FIG. 11 is a diagram illustrating a position of a transmission focus and a state of an ultrasonic beam in a modification example of the second embodiment.

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, with reference to FIG. 3, the transmission focus and ultrasonic beam for measuring the sound velocity and the ultrasonic beam for generating the B-mode image in the first embodiment will be described. In FIG. 3, for the sake of simplicity, the transducer array 1 is shown as an array of nine ultrasonic transducers, and the sound rays S <b> 1 to S <b> 9 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 the sound rays S4 to S6 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.
By transmitting / receiving the ultrasonic beam B1 so as to form a transmission focus at each of the nine lattice points E set in the region of interest R, reception data for sound velocity measurement is acquired.

On the other hand, an ultrasonic beam B2 that forms a narrow portion at a predetermined depth L is used to generate a B-mode image. The narrow portion of the ultrasonic beam B2 only spans a plurality of sound ray regions. It has a width. FIG. 3 shows an ultrasonic beam B2 in which the narrow portion extends over three sound rays S1 to S3.
By using such a wide ultrasonic beam B2, reception data for generating a B-mode image for three sound rays can be acquired by transmitting and receiving the ultrasonic beam B2 once. For this reason, it is not necessary to transmit / receive the ultrasonic beam B2 to / from each sound ray, and it is sufficient to transmit / receive every three sound rays.

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 line, that is, the sound rays S4 to S6 in FIG.

Then, the transmission circuit 2 is transmitted by the control unit 12 so as to acquire reception data for measuring the sound velocity by forming transmission focal points at the nine lattice points E in the region of interest R and transmitting / receiving the ultrasonic beam B1. And the receiving circuit 3 is controlled.
The acquired reception 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 calculate a local sound speed value at each lattice point E and generate a sound speed map in the region of interest R.

In addition, the transmission circuit 2 and the reception circuit 3 are controlled by the control unit 12 such that a wide ultrasonic beam B2 that forms a narrow portion at a predetermined depth L is transmitted and received. The narrow portion of the ultrasonic beam B2 has a width that extends over three adjacent sound rays. First, an ultrasonic beam B2 is transmitted such that the narrow portion spans three sound rays S1 to S3 at a predetermined depth L, and thereby reception data for generating a B-mode image for the sound rays S1 to S3 is acquired. The Next, an ultrasonic beam B2 is transmitted such that the narrow portion extends over the three sound rays S4 to S6 at a predetermined depth L, thereby obtaining reception data for generating a B-mode image for the sound rays S4 to S6. Is done. Furthermore, the ultrasonic beam B2 is transmitted so that the narrow portion extends over the three sound rays S7 to S9 at a predetermined depth L, thereby receiving the reception data for generating the B-mode image for the sound rays S7 to S9. The
That is, by using the wide ultrasonic beam B2, the reception data for generating the B-mode image for the nine sound rays S1 to S9 can be acquired by transmitting and receiving the ultrasonic beam B2 three times.

  The reception data for B-mode image generation obtained in this way 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 addition, for example, an ultrasonic beam having a center frequency of 8 MHz with a numerical aperture of 96 channels is used as an ultrasonic beam B1 for measuring the speed of sound that is transmitted by forming a transmission focal point at nine lattice points E in the region of interest R. An ultrasonic beam having a center frequency of 3 MHz with a numerical aperture of 64 channels is used as a wide ultrasonic beam B2 for generating a B-mode image having a narrow portion that spans three sound rays at a predetermined depth L. Can do.
The ultrasonic beam B1 for measuring the speed of sound has a wider aperture for narrowing the transmission focus than the ultrasonic beam B2 for generating a B-mode image, and a higher center frequency for reducing the influence of side lobes. It is 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 B1 for sound velocity measurement is set low, for example, 2.5 MHz. Then, the influence of refraction can be reduced.

  In this way, reception data for sound speed measurement is obtained by forming transmission focal points at a plurality of lattice points E set in the region of interest R and transmitting and receiving the ultrasonic beam B1, respectively, while obtaining a predetermined depth L. The reception data for generating the B-mode image is obtained by transmitting and receiving a wide ultrasonic beam B2 that forms a narrow portion extending over a plurality of sound ray regions for each of the plurality of sound rays. It is possible to efficiently acquire the data and the data for measuring the sound speed, and perform both the generation of the B-mode image and the sound speed map.

  In Embodiment 1 described above, the wide ultrasonic beam B2 for generating the B-mode image has a narrow portion that spans three sound rays at a predetermined depth L. However, the present invention is not limited to this. What is necessary is just to acquire the reception data for B-mode image generation by transmitting / receiving the ultrasonic beam which forms the narrow part which spans a several sound ray area | region in the predetermined depth L for every several sound rays. .

Embodiment 2
In the first embodiment, a wide ultrasonic beam B2 for generating a B-mode image is transmitted also to the sound rays S4 to S6 in which nine lattice points E in the region of interest R for sound velocity measurement are located. Thus, the reception data for generating the B-mode image for each sound ray is acquired regardless of the acquisition of the reception data for measuring the sound velocity. However, for the sound rays S4 to S6 passing through the region of interest R, The ultrasonic beam B2 for generating the mode image is not transmitted, but transmitted to the lattice point E having a depth closest to the predetermined depth L for generating the B-mode image among the plurality of lattice points E in the region of interest R. A configuration in which the image generation unit 15 generates a B-mode image by using reception data for sound velocity measurement obtained by forming a focal point and transmitting and receiving an ultrasonic beam as reception data for generating a B-mode image. You can also

In other words, in FIG. 3, the reception data for sound velocity measurement obtained for the three lattice points E located at the deepest part closest to the predetermined depth L among the nine lattice points E in the region of interest R are represented as B. It can be used as reception data for mode image generation.
In this case, a predetermined depth L1 for generating the B-mode image may be set to be equal to the depth of any one of the plurality of grid points set in the region of interest R. .

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 “◯”.
Further, a predetermined depth L1 for generating a B-mode image is set to the depth of the lattice point E2 located in the center of the region of interest R in the depth direction.

Then, the reception data for sound velocity measurement is acquired by sequentially forming the transmission focal point and transmitting / receiving the ultrasonic beam B1 to the nine lattice points E1 and E2 in the region of interest R.
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. Are used to calculate local sound velocity values at the lattice points E1 and E2 and generate a sound velocity map in the region of interest R.

In addition, the ultrasonic beam B2 is transmitted such that the narrow portion extends over the three sound rays S1 to S3 at a predetermined depth L, and thereby reception data for generating a B-mode image for the sound rays S1 to S3 is acquired. After that, the ultrasonic beam B2 is transmitted so that the narrow portion extends over the three sound rays S7 to S9 at a predetermined depth L, whereby reception for generating a B-mode image for the sound rays S7 to S9 is performed. Data is acquired. The ultrasonic beam B2 is not transmitted to the sound rays S4 to S6 passing through the region of interest R.
The reception data for generating 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.

  Based on a command from the control unit 12, the signal processing unit 4 forms transmission focal points at three lattice points E2 in the region of interest R among the reception data sequentially input from the reception circuit 3, and generates the ultrasonic beam B1. The B-mode image signal is generated using the reception data acquired by performing transmission / reception of and the reception data acquired by the wide ultrasonic beam B2. That is, the B-mode image generation for the sound rays S4 to S6 is performed on the reception data for sound velocity measurement obtained by transmitting and receiving the ultrasonic beam B1 by forming the transmission focal point at the three lattice points E2 in the region of interest R. For generating B-mode images related to the sound rays S1 to S3 and S7 to S9 obtained by transmitting and receiving these reception data for generating the B-mode image and the wide ultrasonic beam B2. A B-mode image signal is generated based on the received data. 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 the ultrasonic beam B1 is used for generating a B-mode image. As a result, the number of times of transmission / reception of the wide ultrasonic beam B2 is reduced, and the reception data for B-mode image generation and the reception data for sound velocity measurement are obtained more efficiently. Both mode image generation and sound velocity map generation can be performed.

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. Also in this case, the transmission focal point is sequentially formed at each lattice point and the ultrasonic beam B1 is transmitted / received to acquire the reception data for the sound velocity measurement, while extending over a plurality of sound ray regions at a predetermined depth L. The reception data for generating the B-mode image may be acquired by transmitting and receiving the wide ultrasonic beam B2 forming the narrow portion for each of the plurality of sound rays.
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. A grid point E1 is also set on the lines S4, S5, S9, and S10.

By sequentially forming transmission focal points at all the lattice points E1 and E2 and transmitting / receiving the ultrasonic beam B1, reception data for sound velocity measurement is acquired, and sound rays S1 to S5 and S9 to pass outside the region of interest R are obtained. The reception data for generating the B-mode image is obtained by performing transmission / reception of the wide ultrasonic beam B2 with respect to S13.
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 performing transmission / reception of the ultrasonic beam B1 is used to generate B-mode images relating to the sound rays S6 to S8. B-mode image generation reception data for sound rays S1 to S5 and S9 to S13 obtained by transmitting / receiving these B-mode image generation reception data and a wide ultrasonic beam B2. A B-mode image signal is generated based on the above.

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 synthetic wave, R region of interest, S1-S13 sound ray, B1 for sound velocity measurement Ultrasonic beam, ultrasonic beam for B2 B-mode image generation, E lattice point, E1 lattice point where transmission focus dedicated to sound speed measurement is formed, and transmission focus used for both E2 B-mode image generation and sound speed measurement Lattice points to be 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 is configured to acquire reception data for generating a B-mode image by transmitting and receiving, for each of a plurality of sound rays, an ultrasonic beam that forms a narrow portion extending over a plurality of sound ray regions at a predetermined depth. And a control unit for controlling the receiving circuit;
A sound speed map generation unit that generates a sound speed map in the region of interest based on the reception data for sound speed measurement, and an image generation unit that generates a B mode image based on the reception data for B mode image generation. An ultrasonic diagnostic apparatus. 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.
Generating a sound speed map in the region of interest based on the received data for sound speed measurement;
Obtaining reception data for generating a B-mode image by transmitting and receiving an ultrasonic beam that forms a narrow portion spanning a plurality of sound ray regions at a predetermined depth for each of the plurality of sound rays,
An ultrasonic image generation method, wherein a B-mode image is generated based on the received data for generating a B-mode image.

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