JP7169157B2 - ULTRASOUND DIAGNOSTIC APPARATUS AND METHOD OF OPERATION THEREOF - Google Patents

Description

The present invention relates to an ultrasonic diagnostic apparatus and method of operation thereof, and more particularly to forming a transmit beam.

Recently, in the field of ultrasonic diagnosis, ultrasonic probes equipped with two-dimensional transducer arrays are becoming popular. According to the two-dimensional transducer array, the two-dimensional transmission aperture can form a transmission beam that is electronically focused in first and second directions orthogonal to the beam axis, and the two-dimensional reception aperture allows the first A receive beam that is electronically focused in a direction and a second direction can be formed.

In the ultrasonic diagnostic apparatus disclosed in Patent Document 1, a transmission aperture is fixedly set, and a plurality of reception apertures are sequentially set at a plurality of spatially different positions. Multiple scan data obtained using multiple receive apertures are combined.

JP-A-2001-245884

From the viewpoint of further improving biological safety or for other reasons, it is sometimes required to reduce the acoustic power of ultrasonic waves radiated into the living body during transmission. In that case, if the transmission voltage applied to each transducer element is lowered, the penetration, that is, the depth of penetration, worsens, making it impossible to observe deep parts of the living body. It is conceivable to reduce the acoustic power by reducing the transmission aperture instead of lowering the transmission voltage, but if the transmission aperture is simply reduced, the spatial resolution will decrease. Note that Patent Literature 1 does not describe switching between a plurality of transmission apertures or using a plurality of transmission beams having different forms.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an ultrasonic diagnostic apparatus capable of ensuring good spatial resolution even if the acoustic power is reduced, and an operating method thereof.

An ultrasonic diagnostic apparatus according to the present invention includes an ultrasonic probe having a two-dimensional transducer array, and a transmission/reception control unit that controls transmission and reception operations of the two-dimensional transducer array, wherein for each transmission beam direction, By sequentially setting a plurality of transmission apertures having different shapes on the two-dimensional transducer array, a plurality of transmission beams having the same transmission focus depth and different shapes are sequentially formed. a transmission/reception control unit for controlling the transmission operation; a synthesis unit for synthesizing a plurality of beam data obtained for each transmission beam orientation, thereby generating a plurality of synthesized beam data corresponding to the plurality of transmission beam orientations; and an image forming unit that forms an ultrasonic image based on the plurality of combined beam data.

A method of operating an ultrasonic diagnostic apparatus according to the present invention controls a transmission operation so that a plurality of transmission beams having the same transmission focus depth and different shapes are sequentially formed for each transmission beam orientation. controlling a reception operation so that a plurality of reception beams are sequentially formed in accordance with the sequential formation of the plurality of transmission beams; and synthesizing a plurality of beam data obtained for each of the transmission beam directions. , thereby generating a plurality of synthesized beam data corresponding to a plurality of transmission beam azimuths; and forming an ultrasonic image based on the plurality of synthesized beam data. .

According to the present invention, good spatial resolution can be obtained even if the acoustic power is reduced.

1 is a block diagram showing an ultrasonic diagnostic apparatus according to an embodiment; FIG. FIG. 5 is a conceptual diagram showing an aperture pair according to a comparative example; FIG. 10 is a diagram showing total transmission/reception sound pressure characteristics according to a comparative example; Fig. 2 shows two aperture pairs according to an embodiment; FIG. 3 is a diagram showing two combined transmission/reception sound pressure characteristics and synthesized sound pressure characteristics according to the embodiment; FIG. 3 is a diagram showing sound pressure characteristics of transmission beams; It is a figure which shows the beam data synthesizing process in 1st synthesizing mode. FIG. 10 is a diagram showing frame data synthesizing processing in the second synthesizing mode; FIG. 10 is a diagram showing volume data synthesizing processing in the third synthesizing mode; FIG. 3 is a diagram showing a first configuration example of a transmission/reception unit; FIG. 10 is a diagram showing a second configuration example of the transmission/reception unit; FIG. 12 is a diagram showing a third configuration example of the transmission/reception unit; 4 is a flowchart showing transmission/reception operations in the first synthesis mode; 9 is a flow chart showing transmission/reception operations in the second synthesis mode;

Hereinafter, embodiments will be described based on the drawings.

(1) Outline of Embodiment An ultrasonic diagnostic apparatus according to an embodiment includes an ultrasonic probe, a transmission/reception control section, a synthesizing section, and an image forming section. The ultrasound probe has a two-dimensional transducer array. The transmission/reception control unit is a transmission/reception control unit that controls the transmission operation and the reception operation of the two-dimensional transducer array, and sequentially creates a plurality of transmission apertures having mutually different forms on the two-dimensional transducer array for each transmission beam orientation. By setting, the transmission operation is controlled such that a plurality of transmission beams having the same transmission focal depth and different shapes are sequentially formed. The synthesizing unit synthesizes a plurality of beam data obtained for each transmission beam azimuth, thereby generating a plurality of synthesized beam data corresponding to the plurality of transmission beam azimuths. The image forming unit forms an ultrasound image based on the multiple combined beam data.

According to the above configuration, a plurality of synthesized beam data are generated, so even if the size of each transmission aperture is reduced to reduce acoustic power, it is possible to obtain good spatial resolution. That is, according to the above configuration, synthesized beam data equivalent to or close to beam data obtained when a transmission aperture having a large size is set can be obtained.

In an embodiment, the plurality of transmission apertures have a form elongated in a first direction, the first transmission aperture producing a first transmission beam and the form elongated in a second direction intersecting the first direction. a second transmit aperture having and producing a second transmit beam. According to this configuration, good spatial resolution can be obtained in both the first direction and the second direction.

In the embodiment, the transmission/reception control section sets the first reception aperture following the setting of the first transmission aperture, and sets the second reception aperture that is the same as the first reception aperture following the setting of the second transmission aperture. Since there is no problem of acoustic power during reception, it is generally desirable to set the reception aperture as large as possible.

In an embodiment, the plurality of transmit beams comprises a first transmit beam and a second transmit beam, wherein the formation of the first transmit beam is followed by the formation of the first receive beam, and the formation of the second transmit beam is followed by the formation of the second transmit beam. A reception beam is formed, and the transmission/reception control unit continuously forms a first beam pair consisting of a first transmission beam and a first reception beam and a second beam pair consisting of a second transmission beam and a second reception beam for each transmission beam orientation. It controls the transmitting and receiving operations of the two-dimensional transducer array so as to be formed systematically. With this configuration, the frame rate or volume rate is reduced by the number of times of transmission/reception for each transmission beam orientation, but the time resolution can be improved.

In an embodiment, the plurality of transmission beams are composed of a first transmission beam and a second transmission beam, one-dimensional scanning of the first transmission beam and one-dimensional scanning of the second transmission beam are alternately repeated, and the synthesizing unit First frame data consisting of a plurality of beam data obtained by one-dimensional scanning of the first transmission beam and a plurality of beam data obtained by one-dimensional scanning of the second transmission beam for every two one-dimensional scanning adjacent on the axis is combined with the second frame data consisting of a plurality of composite beam data to generate composite frame data consisting of a plurality of composite beam data. With this configuration, it is possible to prevent the frame rate from dropping. It is desirable to employ the above configuration when the time resolution is of little concern.

In an embodiment, the plurality of transmission beams are composed of a first transmission beam and a second transmission beam, two-dimensional scanning of the first transmission beam and two-dimensional scanning of the second transmission beam are alternately repeated, and the synthesizing unit First volume data consisting of a plurality of beam data obtained by two-dimensional scanning of the first transmission beam and a plurality of beams obtained by two-dimensional scanning of the second transmission beam for every two two-dimensional scanning adjacent on the axis Second volume data consisting of data are synthesized to generate synthesized volume data consisting of a plurality of synthesized beam data. This configuration can prevent a decrease in volume rate. It is desirable to employ the above configuration when the time resolution is of little concern.

An ultrasonic diagnostic apparatus according to an embodiment includes a transmission circuit that supplies a plurality of transmission signals in parallel to a two-dimensional transducer array, and a wiring switching circuit that is provided between the two-dimensional transducer array and the transmission circuit. and the transmission/reception control unit connects the transmission circuit to the transmission aperture selected from among the plurality of transmission apertures under the control of the wiring switching circuit. It is desirable to employ the above configuration when the number of transmission channels is smaller than the number of transducer elements. The two-dimensional transducer array and the receiving circuit may be connected via the wiring switching circuit.

A method of operating an ultrasonic diagnostic apparatus according to an embodiment includes a transmission control process, a reception control process, a synthesis process, and an image formation process. In the transmission control step, the transmission operation is controlled such that a plurality of transmission beams having the same transmission focal depth and different forms are sequentially formed for each transmission beam azimuth. In the reception control step, the reception operation is controlled such that a plurality of reception beams are formed along with the formation of the plurality of transmission beams. In the synthesizing step, a plurality of beam data obtained for each transmission beam azimuth are synthesized, thereby generating a plurality of synthetic beam data corresponding to the plurality of transmission beam azimuths. In the image forming step, an ultrasound image is formed based on the multiple combined beam data. The concept of ultrasound images includes tomographic images, three-dimensional images, blood flow images, and the like.

In an embodiment, the transmit beam orientation is a transmit beam address, and multiple transmissions and receptions are performed sequentially for each transmit beam address. In each transmission/reception, a transmit beam and a receive beam are continuously formed. The transmit and receive beams can be thought of as beam pairs or total transmit and receive beams. Beam data is obtained as sound ray data for each beam pair. Synthetic beam data is obtained for each sound ray by synthesizing a plurality of beam data corresponding to a plurality of transmission beams having mutually different shapes.

(2) Details of Embodiment FIG. 1 shows an ultrasonic diagnostic apparatus according to an embodiment. 2. Description of the Related Art An ultrasonic diagnostic apparatus is a medical apparatus that is installed in a medical institution such as a hospital and forms an ultrasonic image based on received data obtained by transmitting and receiving ultrasonic waves to and from a living body.

In FIG. 1, an ultrasonic probe 10, in the illustrated example, transmits and receives ultrasonic waves while in contact with the surface of a living body. The ultrasonic probe 10 has a two-dimensional transducer array 12 . The two-dimensional transducer array 12 consists of hundreds, thousands, tens of thousands or more transducers aligned in the x and y directions. The x-direction and the y-direction are directions perpendicular to the z-direction corresponding to the center axis of the probe, respectively, and the x-direction and the y-direction are perpendicular to each other. Either or both of the x-direction and y-direction may be curved.

An ultrasonic beam is formed by the two-dimensional transducer array 12 . An ultrasound beam is conceived as a combined transmit and receive beam that combines transmit and receive beams. In practice, a transmit beam is formed during the transmit process and a receive beam is formed during the subsequent receive process. However, the received beam is actually electronically formed by phasing and adding a plurality of received signals. Receive dynamic focus is applied in forming the receive beams.

In an embodiment, the ultrasound beam is electronically scanned using an electronic sector scanning scheme. Frame data corresponding to a two-dimensional data capturing area (beam scanning plane) can be obtained by one-dimensional scanning of an ultrasonic beam. Two-dimensional scanning of an ultrasonic beam provides volume data corresponding to a three-dimensional data capturing area. An electronic linear scanning method or the like may be employed instead of the electronic sector scanning method. As the two-dimensional transducer array 12, a C-MUT (Capacitive Micro-machined Ultrasound Transducer) may be used. As the ultrasonic probe 10, a body cavity insertion type ultrasonic probe may be used.

The ultrasonic diagnostic apparatus according to the embodiment has a first synthesis mode, a second synthesis mode, and a third synthesis mode, and can selectively execute any of the synthesis modes. In any synthesis mode, two transmission beams are formed in order for each transmission beam direction (transmission beam address), and two beam data obtained thereby are synthesized. However, the target and timing of synthesis processing differ depending on the synthesis mode. This will be detailed later.

In FIG. 1, the transmitted beam azimuth is indicated by θ. In the embodiment, as described above, the first transmission/reception and the second transmission/reception are continuously performed for each transmission beam azimuth θ (first combination mode), or the first transmission/reception and the second transmission/reception are performed at regular time intervals. Transmission and reception are performed alternately (second and third combination modes). In the first transmission/reception, a first transmission beam BT1 is formed, followed by a first reception beam. In the second transmission/reception, a second transmission beam BT2 is formed, followed by a second reception beam.

The first transmission beam BT1 is formed using the first transmission aperture T1 set on the two-dimensional transducer array 12, and the second transmission beam BT2 is formed using the second transmission aperture T1 set on the two-dimensional transducer array 12. It is formed by the transmit aperture T2. Both the first transmission aperture T1 and the second transmission aperture T2 correspond to a part of the two-dimensional transducer array 12, that is, they are partial apertures. Their centers (opening centers) are coincident.

However, the first transmission aperture T1 and the second transmission aperture T2 have different shapes. For example, the first transmission aperture T1 has a shape such as a rectangle or an ellipse extending in the x direction, and the second transmission aperture T2 has a shape such as a rectangle or an ellipse extending in the y direction. Therefore, the first transmission beam BT1 and the second transmission beam BT2 have different three-dimensional shapes. It has a narrowed form. The central axis of the first transmission beam BT1 and the central axis of the second transmission beam BT2 match the transmission beam azimuth θ1, and their transmission focal point depths also match. The transmission frequency (transmission center frequency) is the same between the first transmission and reception and the second transmission and reception. In addition, the first receiving aperture and the second receiving aperture have the same shape, so that the first receiving beam and the second receiving beam have the same three-dimensional shape.

As described above, in the embodiment, the first transmission beam BT1 and the second transmission beam BT2 having three-dimensional shapes different from each other are formed for each transmission beam azimuth. In other words, a first total transmission/reception beam and a second total transmission/reception beam having different three-dimensional forms are formed for each transmission beam azimuth θ1. However, the time intervals for forming the first transmission beam BT1 and the second transmission beam BT2 differ depending on the combination mode.

The transmission unit 14 is a transmission beamformer that supplies a plurality of transmission signals in parallel to a plurality of transducer elements forming a transmission aperture in the two-dimensional transducer array 12 at the time of transmission, and is configured as an electronic circuit. be done. The receiving unit 16 is a receiving beamformer that performs phasing addition (delayed addition) of a plurality of received signals output in parallel from a plurality of transducer elements forming a reception aperture in the two-dimensional transducer array 12 during reception. Yes, it is configured as an electronic circuit. The receiving section 16 includes a plurality of A/D converters, detection circuits, and the like. Beam data is generated by phasing addition of a plurality of received signals in the receiving unit 16 .

Each frame data is composed of a plurality of beam data arranged in the electronic scanning direction. Each volume data is composed of a plurality of beam data arranged in two electronic scanning directions. Each beam data is composed of a plurality of echo data arranged in the depth direction. A beam data processing unit is provided behind the receiving unit 16, but its illustration is omitted.

The delay data for transmission and the delay data for reception may be calculated in advance and stored in the storage unit. Alternatively, transmission delay data and reception delay data may be calculated in parallel with transmission and reception.

The synthesizing unit 18 is composed of a processor that synthesizes a plurality of beam data obtained for each transmission beam azimuth θ to generate synthesized beam data. In the first synthesis mode, two beam data adjacent on the time axis are synthesized as shown in FIG. 7 later. In the second synthesizing mode, as shown in FIG. 8 later, two frames of data adjacent to each other on the time axis are synthesized in units of frame data pairs. In the third synthesizing mode, as shown in FIG. 9 later, two pieces of volume data adjacent on the time axis are synthesized in units of volume data pairs.

In any case, two echo data obtained at certain time intervals are combined for each individual coordinate in the living body. At that time, preferably the minimum value is selected as the synthesized echo data. An average value, a median value, or the like may be calculated as the synthesized echo data. Three or more pieces of beam data may be obtained for each transmission beam azimuth θ and synthesized.

The combined beam data or frame data is sent to the tomographic image forming unit 20 . The combined beam data, frame data or volume data are stored in the memory 24 as required.

In the embodiment, the tomographic image forming unit 20 is configured by a processor or the like including a digital scan converter (DSC). A DSC has a coordinate conversion function, a pixel interpolation function, a frame rate conversion function, and the like. The tomographic image forming unit 20 forms a tomographic image based on frame data (a plurality of beam data). Data of the tomographic image (display frame data) is sent to the display processing unit. The data may be stored in memory 24 .

The memory 24 is a memory for storing volume data. The volume data is composed of a plurality of frame data arranged one-dimensionally, or composed of a plurality of beam data arranged two-dimensionally.

The rendering section 26 is a module that forms a three-dimensional ultrasound image based on the volume data in the memory 24 . It is for example constituted by a processor. A volume rendering method, a surface rendering method, and the like are known as rendering methods. Data of the three-dimensional ultrasound image is sent to the display processing unit 22 . Note that an MPR (Multi-Planar Reconstruction) image representing a designated cross section may be formed based on the volume data.

The display processing unit 22 is configured by a processor having a display image generation function, an image synthesis function, a color processing function, a graphic image generation function, and the like. A display image generated by the display processing unit 22 is displayed on the display unit 28 . For example, a tomographic image based on synthetic frame data is displayed there, or a three-dimensional ultrasound image based on synthetic volume data is displayed. A three-dimensional ultrasound image is an image that represents a tissue three-dimensionally. The display unit 28 is configured by an LCD, an organic EL display device, or the like.

The control unit 30 is composed of a CPU and an operation program. The control unit 30 controls the operation of each component shown in FIG. The control unit 30 has a transmission/reception control function, which is represented as a transmission/reception control unit 32 in FIG. The transmission/reception control unit 32 controls the transmission/reception of ultrasonic waves and controls the synthesis processing in the synthesis unit 18 according to the selected synthesis mode. An operation panel 34 connected to the control unit 30 is an input device, which has multiple switches, multiple buttons, a trackball, a keyboard, and the like.

General transmission/reception control will be described with reference to FIGS. 2 and 3 prior to description of transmission/reception control according to the embodiment.

FIG. 2 schematically shows a transmission aperture T0 and a reception aperture R0 set with respect to the two-dimensional transducer array 12. As shown in FIG. In the illustrated example, the transmit aperture T0 and the receive aperture R0 span the entire two-dimensional transducer array 12 and each have a square configuration. A transmit beam is formed using the transmit aperture T0, and a receive beam is formed using the receive aperture R0. Thereby, beam data 36 is obtained.

FIG. 3 shows the total transmission/reception sound pressure characteristic TR0 assuming the transmission aperture T0 and the reception aperture R0 shown in FIG. The x-direction and the y-direction are directions in which the vibrating elements are arranged. An axis orthogonal to them indicates the magnitude of sound pressure (sound power). In the illustrated example, the sound pressure characteristic TR0 has a mountain-like peak at the center of the two-dimensional transducer array. Usually a two-dimensional weighting function is applied to produce such mountain peaks. The sound pressure characteristic TR0 shown in FIG. 3 is, in a sense, an ideal characteristic. However, if the transmission voltage applied to each transducer element is lowered due to the need to reduce the acoustic power, the penetration will be worsened. To avoid this, simply reducing the transmission aperture size while maintaining the transmission voltage results in a decrease in spatial resolution.

In FIG. 4, the horizontal axis indicates the depth d, and the vertical axis indicates the sound pressure P. As shown in FIG. There, two sound pressure characteristics 100, 102 are shown conceptually and schematically. Specifically, sound pressure characteristics 100 are sound pressure characteristics of a transmission beam formed by a wide transmission aperture, and sound pressure characteristics 102 are sound pressure characteristics of a transmission beam formed by a narrow transmission aperture. The acoustic power limit at the depth of the transmit focus point F1 is indicated by P1. Using a wider transmission aperture results in a narrower beam width near the transmission focus point F1. Using a narrow transmit aperture results in a wider beam width near the transmit focus point F1. That is, the spatial resolution is lowered. From the viewpoint of spatial resolution, it is still advantageous to use a wide transmit aperture.

The embodiment based on the above is the embodiment, and its basic concept is shown in FIG. The upper part of FIG. 5 shows the first transmission aperture T1 and the first reception aperture R1 set for the two-dimensional transducer array 12 in the first transmission and reception. The lower part of FIG. 5 shows the second transmission aperture T2 and the second reception aperture R2 set for the two-dimensional transducer array 12 in the second transmission and reception. Note that the first reception aperture R1 and the second reception aperture R2 are the same and extend over the entire two-dimensional transducer array 12 . The transmission weighting function and reception weighting function are omitted from the drawing. The variable reception aperture size during reception is also omitted from the drawing.

In the first transmission aperture T1, the x direction is the longitudinal direction and the y direction is the lateral direction. The first transmission aperture T1 has the shape of a rectangle elongated in the x-direction. There are invalid regions that do not contribute to transmission on both sides of the first transmission aperture T1 in the y direction. On the other hand, in the second transmission aperture T2, the y direction is the longitudinal direction and the x direction is the lateral direction. The second transmission aperture T2 has a rectangular shape elongated in the y-direction. There are invalid regions that do not contribute to transmission on both sides of the second transmission aperture T2 in the x direction. The aperture centers of the first transmission aperture T1 and the second transmission aperture T2 are the same, and they are orthogonal to each other.

In an embodiment, the beam data 38 obtained in the first transmission/reception and the beam data 40 obtained in the second transmission/reception are combined (see numeral 42). Composite beam data 44 is thus obtained. Even when two frame data or two volume data are synthesized, two beam data are synthesized for each acoustic ray.

In FIG. 6, the total transmission/reception sound pressure characteristic TR1 occurs in the first transmission/reception shown in FIG. In the sound pressure characteristic TR1, the width in the y direction is wider than the width in the x direction, and a decrease in spatial resolution is recognized in the y direction. On the other hand, in FIG. 6, the total transmission/reception sound pressure characteristic TR2 occurs in the second transmission/reception shown in FIG. In the sound pressure characteristic TR2, the width in the x direction is wider than the width in the y direction, and a decrease in spatial resolution is recognized in the x direction. Synthesis of these sound pressure characteristics TR1 and TR2 (see reference numeral 46) is a synthesized sound pressure characteristic TR3 of the combined transmission and reception.

The synthesized sound pressure characteristic TR3 has a form close to the sound pressure characteristic shown in FIG. By combining two beam data obtained using two relatively small transmission apertures, it is possible to obtain beam data close to that obtained using a large transmission aperture. Of course, three or more beam data may be combined for each transmission beam azimuth. According to the embodiment, it is possible to ensure good penetration while limiting instantaneous acoustic power, and to improve spatial resolution.

FIG. 7 shows the first synthesis mode. In the first synthesis mode, two transmissions and receptions are continuously performed for each transmission beam orientation during one-dimensional scanning or two-dimensional scanning of the ultrasonic beam. In FIG. 7, reference numeral 48 denotes a plurality of beam data acquired in chronological order, and reference numeral 50 denotes a plurality of synthesized beam data generated in chronological order. At timing t1, beam data A is obtained by first transmission/reception for the transmission beam azimuth θi, and beam data B is obtained by second transmission/reception for the same transmission beam azimuth θi at timing t2. Synthetic beam data is obtained by synthesizing them. Similarly, at timing t3, beam data A is obtained by the first transmission/reception for the transmission beam azimuth θi+1, and beam data B is obtained by the second transmission/reception for the same transmission beam azimuth θi+1 at timing t4. Synthetic beam data is obtained by synthesizing them. According to the first composition mode, the frame rate is halved in the course of composition processing, but on the other hand, it is possible to increase the temporal resolution.

FIG. 8 shows the second synthesis mode. The switching of the transmission/reception conditions is performed in units of frames, that is, the first transmission/reception conditions and the second transmission/reception conditions are alternately set in units of frames. Focusing on individual transmission beam azimuths, the first transmission/reception and the second transmission/reception are alternately performed at intervals of the frame rate.

In FIG. 8, reference numeral 52 denotes a plurality of frame data acquired in chronological order, and reference numeral 54 denotes a plurality of synthesized frame data generated in chronological order. Frame data A is obtained by repeating the first transmission/reception at timing t1, and frame data B is obtained by repeating the second transmission/reception at timing t2 immediately after that. Synthetic frame data is obtained by synthesizing them. Subsequently, frame data B obtained at timing t2 and frame data A obtained at timing t3 are synthesized to obtain synthesized frame data. That is, according to the second combining mode, combined frame data is obtained for each pair of adjacent frame data on the time axis, in other words, each frame data can be used twice. As a result, the frame rate can be maintained without lowering during the synthesis process. This second synthesizing mode is a mode that functions when the time resolution is not so important.

FIG. 9 shows the third synthesis mode. The third synthesis mode is basically a mode close to the second synthesis mode. The transmission/reception conditions are switched in volume units, that is, the first transmission/reception conditions and the second transmission/reception conditions are alternately set in volume units. Focusing on individual transmission beam azimuths, the first transmission and reception and the second transmission and reception are alternately performed at intervals of the volume rate.

In FIG. 9, reference numeral 56 denotes a plurality of volume data acquired in chronological order, and reference numeral 58 denotes a plurality of synthesized volume data generated in chronological order. At timing t1, volume data A is obtained by repeating the first transmission/reception, and immediately after that, volume data B is obtained by repeating the second transmission/reception at timing t2. Synthetic volume data is obtained by synthesizing them. Subsequently, the volume data B obtained at timing t2 and the volume data A obtained at timing t3 are combined to obtain combined volume data. That is, according to the third synthesis mode, synthesized volume data is obtained for each adjacent volume data pair on the time axis, in other words, it is possible to use each volume data twice. As a result, the volume rate does not decrease in the process of synthesizing, and the volume rate can be maintained. This third synthesizing mode is a mode that functions when the time resolution is not so important.

Next, a specific configuration example of the transmitting/receiving section will be described with reference to FIGS. 10 to 12. FIG. The transmitting/receiving section corresponds to the transmitting section and the receiving section shown in FIG.

In the first configuration example shown in FIG. 10, reference numeral 60 indicates a probe head in the ultrasonic probe, and reference numeral 62 indicates a cable in the ultrasonic probe. Reference numeral 64 indicates the main body of the ultrasonic diagnostic apparatus. A two-dimensional transducer array 66 is provided within the probe head 60 . The two-dimensional transducer array 66 is configured as an aggregate of a plurality of sub-arrays, and a sub-beam former (SBF) 70 is provided for each individual sub-array. An SBF column 68 is provided corresponding to a plurality of subarrays. Each SBF 70 is one or both of a transmit sub-beamformer and a receive sub-beamformer. A plurality of SBFs 70 are connected to a main beam former (MBF) 72 . MBF 72 is one or both of a transmit main beamformer and a receive main beamformer. Each beamformer performs delay processing for beamforming, signal distribution processing, signal addition processing, and the like. Operation of the plurality of SBFs 70 is controlled by control signal 74 and operation of MBF 72 is controlled by control signal 76 .

In the second configuration example shown in FIG. 11, a wiring switching section 80 is provided between the SBF column 68 and the MBF 78 . In addition, the same reference numerals are assigned to the same components as those shown in FIG. 10, and the description thereof will be omitted. MBF 78 has a smaller number of channels than MBF 72 shown in FIG. It is connected to SBF70. When the transmission aperture (or reception aperture) is switched, the wiring switching section 80 connects the MBF 78 to the plurality of SBFs connected to the plurality of sub-arrays forming the switched transmission aperture. The operation of MBF 78 is controlled by control signal 84 , and the operation of wiring switching section 80 is controlled by control signal 82 .

In the third configuration example shown in FIG. 12, the two-dimensional transducer array 66 is provided in the ultrasonic probe 86 and the wiring switching section 90 is provided in the ultrasonic diagnostic apparatus body 88 . The wiring switching unit 90 exhibits a function of connecting a beam former (BF) 92 to a plurality of transducer elements forming a transmission aperture. BF 92 is controlled by control signal 96 , and wiring switching unit 90 is controlled by control signal 94 . According to the third configuration example, the circuit scale of the transmitter/receiver can be reduced.

FIG. 13 shows an operation example in the first synthesis mode as a flow chart. In this operation example, the ultrasonic beam is one-dimensionally scanned. N is a counter indicating a transmission beam address. N is initialized in S10. In S12, the first transmission/reception is performed with respect to the Nth transmission beam address. That is, a first transmit aperture T1 is set and used to form a first transmit beam, and then a first receive aperture R1 is set and used to form a first receive beam. . The beam data is thus obtained.

In S14, the second transmission/reception is performed with respect to the same N-th transmission beam address. That is, a second transmit aperture T2 is set and used to form a second transmit beam, and then a second receive aperture R2 is set and used to form a second receive beam. . The beam data is thus obtained. The two beam data obtained in S12 and S14 are synthesized. However, that process is not shown in FIG.

At S16, it is determined whether or not N has exceeded the maximum value Nmax. If not exceeded, N is incremented by one in S18, and each step from S12 is repeatedly executed. In S16, if N exceeds the maximum value Nmax, it is determined in S20 whether or not to continue this process, and in the case of continuation, N is reset in S10, and each step after S12 is executed. be done.

FIG. 14 shows an operation example in the second synthesis mode as a flow chart. In this operation example, an ultrasonic beam is scanned one-dimensionally. K indicates a frame number. K is initialized in S30. At S32, it is determined whether or not K is an even number. If K is an even number, frame data is obtained by repeating the first transmission/reception in S34. For each first transmission/reception, a first transmission aperture T1 is set and used to form a first transmission beam. A first receive aperture R1 is then set and used to form a first receive beam.

On the other hand, if it is determined in S32 that K is not an even number, that is, K is an odd number, in S36 frame data is obtained by repeatedly executing the second transmission/reception. For each second transmission/reception, a second transmission aperture T2 is set and used to form a second transmission beam. A second receive aperture R2 is then set and used to form a second receive beam. By alternately executing S34 and S36, a plurality of frame data arranged on the time axis are generated. At them individual adjacent frame data pairs are retrieved and adjacent frame data pairs are combined. In addition, in the third synthesis mode, a plurality of steps similar to the plurality of steps shown in FIG. 14 are executed. However, the composition target is volume data.

According to each of the synthesis modes described above, for example, in fetal ultrasound diagnosis in obstetrics, the spatial resolution can be increased while reducing the acoustic power. Moreover, according to the first synthesis mode, the temporal resolution can be enhanced. According to the second synthesis mode and the third synthesis mode, a drop in frame rate or volume rate can be avoided. Note that parallel reception may be performed in the above embodiments. Doppler information may also be acquired and harmonic imaging may be performed.

10 ultrasonic probe, 12 two-dimensional transducer array, 14 transmission unit, 16 reception unit, 18 synthesis unit, 20 image formation unit, 22 display processing unit, 30 control unit, and 32 transmission/reception control unit.

Claims (8)

an ultrasonic probe having a two-dimensional transducer array;
A transmission/reception control unit for controlling the transmission operation and the reception operation of the two-dimensional transducer array, wherein a plurality of transmission apertures having mutually different forms are sequentially set on the two-dimensional transducer array for each transmission beam orientation. a transmission/reception control unit that controls the transmission operation so that a plurality of transmission beams having the same transmission focal depth and different shapes are sequentially formed by
a synthesizing unit that synthesizes a plurality of beam data obtained for each of the transmission beam azimuths, thereby generating a plurality of synthesized beam data corresponding to the plurality of transmission beam azimuths;
an image forming unit that forms an ultrasound image based on the plurality of combined beam data;
including
The plurality of transmit apertures are
a first transmit aperture having a configuration elongated in a first direction and producing a first transmit beam;
a second transmit aperture having a configuration elongated in a second direction intersecting the first direction and generating a second transmit beam;
An ultrasonic diagnostic apparatus comprising: The ultrasonic diagnostic apparatus according to claim 1,
the center of the first transmission aperture and the center of the second transmission aperture are aligned;
An ultrasonic diagnostic apparatus characterized by: The ultrasonic diagnostic apparatus according to claim 1 ,
The transmission/reception control unit sets a first reception aperture following the setting of the first transmission aperture, and sets a second reception aperture that is the same as the first reception aperture following the setting of the second transmission aperture.
An ultrasonic diagnostic apparatus characterized by: The ultrasonic diagnostic apparatus according to claim 1,
The plurality of transmission beams are composed of a first transmission beam and a second transmission beam,
forming a first receive beam subsequent to forming the first transmit beam;
forming a second receive beam subsequent to forming the second transmit beam;
The transmission/reception control unit continuously controls a first beam pair consisting of the first transmission beam and the first reception beam and a second beam pair consisting of the second transmission beam and the second reception beam for each transmission beam orientation. controlling the transmitting and receiving operations of the two-dimensional transducer array so as to be formed systematically;
An ultrasonic diagnostic apparatus characterized by: The ultrasonic diagnostic apparatus according to claim 1,
The plurality of transmission beams are composed of a first transmission beam and a second transmission beam,
one-dimensional scanning of the first transmission beam and one-dimensional scanning of the second transmission beam are alternately repeated;
The synthesizing unit synthesizes first frame data including a plurality of beam data obtained by one-dimensional scanning of the first transmission beam and one-dimensional scanning of the second transmission beam for every two one-dimensional scanning adjacent on the time axis. synthesizing second frame data composed of a plurality of beam data obtained by scanning to generate synthesized frame data composed of the plurality of synthesized beam data;
An ultrasonic diagnostic apparatus characterized by: The ultrasonic diagnostic apparatus according to claim 1,
The plurality of transmission beams are composed of a first transmission beam and a second transmission beam,
two-dimensional scanning of the first transmission beam and two-dimensional scanning of the second transmission beam are alternately repeated;
The synthesizing unit generates first volume data composed of a plurality of beam data obtained by two-dimensional scanning of the first transmission beam and two-dimensional data of the second transmission beam for each two two-dimensional scanning adjacent on the time axis. synthesizing second volume data composed of a plurality of beam data obtained by scanning to generate synthesized volume data composed of the plurality of synthesized beam data;
An ultrasonic diagnostic apparatus characterized by: The ultrasonic diagnostic apparatus according to claim 1,
a transmission circuit that supplies a plurality of transmission signals in parallel to the two-dimensional transducer array;
a wiring switching circuit provided between the two-dimensional transducer array and the transmission circuit;
including
The transmission/reception control unit connects the transmission circuit to a transmission aperture selected from among the plurality of transmission apertures under control of the wiring switching circuit.
An ultrasonic diagnostic apparatus characterized by: By sequentially setting a plurality of transmission apertures having mutually different forms on the two-dimensional transducer array for each transmission beam orientation, a plurality of transmission beams having the same transmission focal depth and having mutually different forms are sequentially formed. controlling the transmission operation to form
a step of controlling a reception operation such that a plurality of reception beams are sequentially formed in accordance with the sequential formation of the plurality of transmission beams;
a step of synthesizing a plurality of beam data obtained for each transmission beam orientation, thereby generating a plurality of synthesized beam data corresponding to the plurality of transmission beam orientations;
forming an ultrasound image based on the plurality of combined beam data;
including
The plurality of transmit apertures are
a first transmit aperture having a configuration elongated in a first direction and producing a first transmit beam;
a second transmit aperture having a configuration elongated in a second direction intersecting the first direction and generating a second transmit beam;
including,
A method of operating an ultrasonic diagnostic apparatus, characterized by:

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