JP2008245981A - Ultrasonic diagnostic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To generate a three-dimensional image having little rough and fine parts in the insertion axial direction of an ultrasonic probe and less visual field depth irregularity. <P>SOLUTION: A radial ultrasonic vibrator array 14 arranged in the ultrasonic probe 11 radiates ultrasonic beams simultaneously in a plurality of directions by the first and second MUXes 23, 24. A probe speed detecting device 13 detects the movement speed of the ultrasonic probe 11 in the insertion axial direction, on the basis of a signal from a reception antenna 33 arranged in the ultrasonic probe 11. A control part 25 controls the number of directions of the ultrasonic beams, the scan ranges of the respective ultrasonic beams, and scan timing of each ultrasonic beam, on the basis of the detected movement speed, and then, changes the acquisition time of a tomographic image, while keeping the scan speed of the ultrasonic beams fixed. Consequently, the acquisition time interval of the tomographic image is fixed regardless of the change of the movement speed, thereby generating the three-dimensional image having little rough and fine parts in the insertion axial direction and less eyesight depth irregularity. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an ultrasound diagnostic apparatus that acquires an ultrasound image by inserting an ultrasound probe into a body cavity, scanning an ultrasound beam into a body part, and receiving a reflected wave (reflected echo). In particular, the present invention relates to a radial scanning ultrasonic diagnostic apparatus.

  In recent years, ultrasonic diagnostic apparatuses have been put into practical use in the medical field. An ultrasound diagnostic device inserts an ultrasound probe equipped with multiple ultrasound transducers that transmit and receive ultrasound into the body cavity of the subject, and acquires an ultrasound image in the body cavity by scanning the ultrasound beam To do. As a configuration of the ultrasonic probe, there is known a radial scanning method in which an ultrasonic beam is scanned radially (360 ° rotation scanning) in a direction perpendicular to the insertion axis direction. In this radial scanning method, a perpendicular direction to the insertion axis direction is known. A tomographic image can be obtained.

  In addition, as an ultrasonic diagnostic apparatus using the above-described radial scanning method, tomographic images are sequentially acquired according to the movement of the ultrasonic probe in the insertion axis direction, and these tomographic images are arranged along the insertion axis direction. Thus, a simple three-dimensional image can be generated. However, since the ultrasonic probe is manually moved by the operator, there is a problem in that the moving speed is uneven, and in accordance with this, the three-dimensional image becomes dense along the insertion axis direction. It was.

In order to solve such a problem, it is also possible to reduce the density by detecting the position information of the ultrasonic probe and performing image processing (interpolation processing or thinning-out processing) on the three-dimensional image in comparison with the detected position information. In this method, the image is blurred by image processing and the image quality is deteriorated. Therefore, in Patent Document 1, the moving speed of the ultrasonic probe in the insertion axis direction is detected, and the detected moving speed is determined according to the detected moving speed. There has been proposed a technique for reducing the density in the insertion axis direction that occurs in a three-dimensional image by changing the scanning speed (rotational scanning speed) of the ultrasonic beam.
JP 2003-310618 A

  However, although the technique of Patent Document 1 can construct a three-dimensional image with less roughness in the insertion axis direction of the ultrasonic probe, in order to change the scanning speed, the depth of field in the direction perpendicular to the insertion axis ( There is a problem of unevenness in the penetration depth. For example, as shown in FIG. 12, the moving speed of the ultrasonic probe in the insertion axis direction changes from V1 → V2 → V2 → V1 (V1 <V2), and the scan speed is maintained so that the tomographic image acquisition interval is kept constant. Is changed from ω1 → ω2 → ω2 → ω1 (ω1 <ω2), the depth of field changes from D1 → D2 → D2 → D1 (D1> D2) in inverse proportion to the scanning speed.

  The reason why the visual field depth changes according to the scanning speed is that the ultrasonic transducer repeatedly transmits and receives ultrasonic waves, and the reception time needs to be changed to change the scanning speed. . If the reception time is shortened in order to increase the scanning speed, the reflected echo from a distant place cannot be received, and the depth of field is reduced.

  In the case of the radial electronic scanning method in which a plurality of ultrasonic transducers are arranged on the circumferential surface, a method of increasing the scanning speed without changing the reception time by thinning out the ultrasonic transducers that are driven at the time of scanning can be considered. In this method, the resolution of the tomographic image is lowered.

  The present invention has been made in consideration of the above circumstances, and an ultrasonic diagnostic apparatus capable of generating a three-dimensional image with less roughness and less unevenness of the depth of field in the insertion axis direction of the ultrasonic probe. The purpose is to provide.

  In order to achieve the above object, an ultrasonic diagnostic apparatus of the present invention is an ultrasonic diagnostic apparatus that sequentially acquires tomographic images by rotating and scanning an ultrasonic beam radially about an insertion axis of an ultrasonic probe. Movement speed detection means for detecting the movement speed of the ultrasonic probe in the insertion axis direction, ultrasonic irradiation means capable of simultaneously irradiating an ultrasonic beam in a plurality of directions, and movement speed detected by the movement speed detection means Based on the above, the number of directions of the ultrasonic beam irradiated by the ultrasonic irradiation means, the scanning range of each ultrasonic beam, and the scanning timing of each ultrasonic beam are controlled, and the scanning speed of the ultrasonic beam is kept constant. And a scanning control means for changing a tomographic image acquisition time. As a result, the tomographic image acquisition time interval can be made constant regardless of changes in the moving speed.

The ultrasonic irradiation means can irradiate an ultrasonic beam simultaneously in two directions,
The scanning control means scans the entire range with only one ultrasonic beam when the detected moving speed is equal to or lower than the predetermined speed, and when the detected moving speed is higher than the predetermined speed, the first control is performed. It is preferable to perform control so that the remaining range is scanned with the second ultrasonic beam while the predetermined range is scanned with the ultrasonic beam.

  Further, the scanning control means may cause the scanning range of the first ultrasonic beam to be inversely proportional to the moving speed when the detected moving speed is larger than the predetermined speed and not more than twice the predetermined speed. It is preferable to perform control.

  The scanning control unit preferably performs timing control so that directions of the first and second ultrasonic beams are 180 ° rotationally symmetric. This prevents interference between ultrasonic beams and reflected echoes emitted simultaneously in two directions.

  The ultrasonic irradiation means is preferably a radial ultrasonic transducer array in which ultrasonic transducers are arranged at a constant pitch in a circumferential direction around the insertion axis.

  According to the ultrasonic diagnostic apparatus of the present invention, the moving speed detecting means for detecting the moving speed of the ultrasonic probe in the insertion axis direction, the ultrasonic irradiation means capable of simultaneously irradiating the ultrasonic beam in a plurality of directions, the moving Based on the moving speed detected by the speed detecting means, the number of directions of the ultrasonic beam irradiated by the ultrasonic irradiating means, the scanning range of each ultrasonic beam, and the scanning timing of each ultrasonic beam are controlled. And a scanning control unit that changes the tomographic image acquisition time while keeping the scanning speed constant, and generates a three-dimensional image with less roughness and less unevenness in the depth of field in the insertion axis direction of the ultrasonic probe. be able to.

In FIG. 1, an ultrasonic diagnostic apparatus 10 includes an ultrasonic probe 11, a processor apparatus 12,
And the probe speed detection device 13. The ultrasonic probe 11 is a small-diameter probe inserted into a forceps opening of an electronic endoscope or a so-called ultrasonic endoscope integrated with an electronic endoscope, and is used by being inserted into a body cavity of a subject. Is done.

  In FIG. 2, the ultrasonic probe 11 is provided with a radial ultrasonic transducer array 14 at the tip. The ultrasonic transducer array 14 is composed of a plurality of strip-shaped ultrasonic transducers 16 disposed adjacent to each other on a peripheral surface of a cylindrical support 15 centering on the insertion axis S via a backing material 15a. A filler 17 is interposed between the ultrasonic transducers 16. The ultrasonic transducer 16 is disposed such that the longitudinal direction thereof follows the insertion axis S. Further, as shown in FIG. 3, 360 ultrasonic transducers 16 are arranged in the circumferential direction around the insertion axis S at a constant pitch in the range of θ = 0 ° to 360 °. In order to show this arrangement, each ultrasonic transducer 16 is given a number n (n = 1 to 360), and θ indicates the ultrasonic transducer 16 with n = 1.

  Returning to FIG. 2, an acoustic matching layer 18 is provided on the ultrasonic transducer array 14, and an acoustic lens 19 is provided on the acoustic matching layer 18. The acoustic matching layer 18 is a resin film having a thickness of about ¼ of the wavelength of the sound wave emitted from the ultrasonic transducer 16, and relaxes the difference in acoustic impedance between the living body and the living body. The acoustic lens 19 is a resin film having a convex cross section along the insertion axis S direction, and converges sound waves emitted from the ultrasonic transducer 16 with respect to the insertion axis S direction. With the configuration described above, the ultrasonic probe 11 can transmit and receive ultrasonic waves radially in a direction perpendicular to the insertion axis S.

  A cable 20 is connected to the tip of the ultrasonic probe 11, and wirings 21 and 22 (see FIG. 1) are inserted into the cable 20. A connector portion (not shown) is provided at the rear end of the cable 20. By inserting this connector portion into a connector portion (not shown) of the processor device 12, the ultrasonic probe 11, the processor device 12, Are electrically connected. Excitation pulses and echo signals, which will be described later, are transmitted through the wirings 21 and 22.

  Returning to FIG. 1, the ultrasonic transducer array 14 is connected to first and second multiplexers (hereinafter referred to as MUX) 23 and 24 provided in the processor device 12 via wirings 21 and 22. . The first MUX 23 is connected to all (n = 1 to 360) ultrasonic transducers 16 via the wiring 21, and any nth ultrasonic wave from n = 1 to 360 based on the control of the control unit 25. The vibrator 16 is selected. The second MUX 24 is connected to the half (n = 181 to 360) ultrasonic transducers 16 via the wiring 22, and any nth ultrasonic wave from n = 181 to 360 based on the control of the control unit 25. The vibrator 16 is selected. The ultrasonic transducer 16 selected by the second MUX 24 is limited to a range of 180 ° ≦ θ <360 ° (see FIG. 3).

  First and second transmission / reception units 26 and 27 are connected to the first and second MUXs 23 and 24, respectively. That is, the first and second MUXs 23 and 24 are selection circuits for selecting the ultrasonic transducer 16 that connects the first and second transmission / reception units 26 and 27, respectively. The first and second MUXs 23 and 24 have the same configuration, and include a transmission-side pulser 28, a reception-side amplifier 29 and receiver 30, and a switch circuit 31. The pulser 28 outputs an excitation pulse for causing the ultrasonic transducer 16 to generate an ultrasonic wave. The amplifier 29 amplifies the echo signal received by the ultrasonic transducer 16. The receiver 30 receives the echo signal amplified by the amplifier 29. The switch circuit 31 connects the pulsar 28 to the first and second MUXs 23 and 24 at the time of transmission, transmits the excitation pulse to the ultrasonic transducer 16, and at the time of reception, connects the amplifier 29 and the first and second MUXs 23 and 24 to each other. By connecting, the echo signal output from the ultrasonic transducer 16 is transmitted to the amplifier 29.

  The operation timing of the first and second MUXs 23 and 24 and the first and second transmission / reception units 26 and 27 are controlled by the control unit 25. The control unit 25 basically controls the first MUX 23 to select the ultrasonic transducers 16 in order from n = 1 every predetermined time, and drives the first transmission / reception unit 26 to switch between transmission / reception of ultrasonic waves. Are performed sequentially. When the moving speed of the ultrasonic probe 11 in the direction of the insertion axis S detected by the probe speed detection device 13 exceeds a predetermined speed, the second MUX 24 is controlled together with the first MUX 23, and the second transmitting / receiving section together with the first transmitting / receiving section 26. 27 is driven. In this case, not all the ultrasonic transducers 16 are scanned (selected in order) by the first MUX 23, but are scanned up to the mth (m ≧ 180) th ultrasonic transducer 16 according to the moving speed, and the remaining The mth and subsequent ultrasonic transducers 16 are scanned by the second MUX 24. In this way, the control unit 25 adjusts the scan time according to the moving speed of the ultrasonic probe 11.

  The moving speed of the ultrasonic probe 11 in the direction of the insertion axis S is such that a magnetic field emitted from the transmitting antenna 32 arranged in the vicinity of the use area of the ultrasonic probe 11 is caused by the receiving antenna 33 provided at the distal end of the ultrasonic probe 11. The signal is received and detected by the probe speed detector 13 analyzing the received signal. The transmission antenna 32, the reception antenna 33, and the probe speed detection device 13 constitute a position measurement system disclosed in Japanese Patent No. 2945756. Each of the transmission antenna 32 and the reception antenna 33 includes three antennas (X, Y, and Z axis antennas), and the position of the reception antenna 33 with respect to the transmission antenna 32 is set to three-dimensional six degrees of freedom (3 orthogonal to each other). The axial direction and the rotational direction around each axis). The probe speed detection device 13 continuously obtains position information from the receiving antenna 33 and performs a difference calculation to obtain the moving speed of the ultrasonic probe 11 in the insertion axis S direction. In addition to the above, various forms of the position measurement system are known and can be appropriately applied.

  First and second memories 34 and 35 are connected to the first and second transmission / reception units 26 and 27, respectively. The first and second memories 34 and 35 temporarily store the echo signals received by the receiver 30 and input them to the first and second phase matching operation units 36 and 37, respectively. After the first and second phase matching calculation units 36 and 37 give a delay corresponding to the time difference to each echo signal from the first and second memories 34 and 35 under the control of the control unit 25. Add each echo signal.

  The echo signals added by the first and second phase matching calculators 36 and 37 are input to the tomographic image generator 38. The tomogram generation unit 38 combines the echo signals from the first and second phase matching calculation units 36 and 37 to generate a tomogram in a direction orthogonal to the insertion axis S. As described above, when the moving speed of the ultrasonic probe 11 in the insertion axis S direction exceeds a predetermined speed, the tomographic images are shared by the first and second transmitting / receiving units 26 and 27. The image generation unit 38 performs the synthesis process. However, when the moving speed is equal to or lower than the predetermined speed, the tomographic image is acquired only by the first transmission / reception unit 26, and thus the synthesis process is not performed.

  The tomographic image output from the tomographic image generator 38 is input to the three-dimensional image generator 39. The three-dimensional image generation unit 39 stores the input tomographic images in the image memory 40 as needed, and arranges the stored tomographic images along the insertion axis S direction based on the position information of the ultrasonic probe 11. Thus, a three-dimensional image is generated. This three-dimensional image is input to the display processing unit 41. The display processing unit 41 converts the input three-dimensional image into a television signal scanning method (NTSC method). The monitor 42 displays the three-dimensional image (ultrasonic image) converted into the NTSC system by the display processing unit 41.

  An operation unit 43 is connected to the control unit 25. The operation unit 43 includes a keyboard and a mouse. The control unit 25 operates each unit in response to an operation input signal from the operation unit 43.

  In order to perform ultrasonic diagnosis of an observation site using the ultrasonic diagnostic apparatus 10 described above, first, an operator inserts an ultrasonic probe 11 into a body cavity of a subject through a forceps port of an electronic endoscope. (If the ultrasonic probe 11 is an ultrasonic endoscope, the ultrasonic probe 11 itself is inserted), and an electronic endoscope (if the ultrasonic probe 11 is an ultrasonic endoscope, an image is arranged at the tip) While observing the inside of the body cavity with the device, the site to be observed is searched. Then, the operator gives an instruction to acquire an ultrasonic image using the operation unit 43 and then moves the ultrasonic probe 11 in the direction of the insertion axis S (manually pushes and pulls it), so that the ultrasonic image becomes 3 A dimensional image is output to the monitor 42.

Next, scan control of the ultrasonic transducer array 14 accompanying the movement of the ultrasonic probe 11 in the insertion axis S direction will be described with reference to the flowchart of FIG. When the ultrasonic image acquisition operation starts, first, the moving speed V of the ultrasonic probe 11 in the direction of the insertion axis S is detected from the probe speed detection device 13 and input to the control unit 25 (step S1). The control unit 25 compares the input moving speed V with the predetermined speed V ₀ (step 2). If the moving speed V is equal to or lower than the predetermined speed V ₀ , only the first transmitting / receiving unit 26 is operated and the first MUX 23 is operated. And one-way scanning is performed (step S3). As shown in FIG. 5, the one-way scan is performed by scanning an irradiation ultrasonic wave around the insertion axis S between θ = 0 ° and 360 ° (radially rotating scan) with only one direction being applied. This is a conventional scanning method. Hereinafter, the scan using the first MUX 23 is referred to as a first scan, and the scan using the second MUX 24 is referred to as a second scan.

In step S2, the moving speed V is determined to be greater than the predetermined speed V _0, the control unit 25, a scan range of the first scan is determined based on the graph of FIG. 6 (step S4). Figure 6 shows a maximum angle theta _m scanning range of the first scan. The remaining range exceeding this maximum angle theta _m is assigned to the second scan. When determining the scan range, the control unit 25 drives the first transmission / reception unit 26 and the first MUX 23 to perform the first scan, and drives the second transmission / reception unit 27 and the second MUX 24 during the execution of the first scan. A second scan is executed (step S5). That is, during execution of the first scan and the second scan, the ultrasonic beam is irradiated in two directions simultaneously. Note that the scan speeds of the first scan and the second scan (corresponding to the transmission / reception time for each ultrasonic transducer 16) are equal, and the scan speed is constant regardless of the moving speed V.

More specifically, when V ₀ ≦ V ≦ 2V ₀ , the control unit 25 calculates the maximum angle θ _m of the first scan based on the formula “θ _m = 360 ° V ₀ / V”. , V> 2V ₀ , θ _m = 180 °. FIG. 7 shows the scan ranges of the first and second scans when V = (4/3) V ₀ . In this case, as shown in FIG. 7A, first, the first scan starts from the first ultrasonic transducer 16 (from θ = 0 °), and as shown in FIG. When the first ultrasonic transducer 16 is reached (when θ = 90 °), the second scan starts from the 271st ultrasonic transducer 16 (from θ = 270 °) together with the first scan. As shown in FIG. 8, the scan time in this case is shortened to 3/4 times the scan time when V = V ₀ .

Further, FIG. 9 shows a first and a second scan of scanning range in the case of V = 2V _0, this case, the first scan is the first ultrasonic oscillator 16 (θ = 0 ° And the second scan starts from the 181st ultrasonic transducer 16 (from θ = 180 °). Since the scan speeds of the first and second scans are equal, the scan time in this case is shortened to ½ times that in the case of V = V ₀ as shown in FIG. As described above, the scan time for generating one tomographic image can be adjusted between t and 0.5 t according to the change in the moving speed V, where t is the case of only the first scan.

Returning to FIG. 4, when the scan in step S3 or step S5 is completed, a tomographic image is generated by the tomographic image generator 38 and stored in the image memory 40 (step S6). Then, the control unit 25 repeats the tomographic image acquisition control in steps S1 to S6 until a predetermined time elapses or the ultrasonic probe 11 is moved a predetermined distance. When the end condition is satisfied (Yes determination in step S7), a three-dimensional image is generated by the three-dimensional image generation unit 39 and output to the monitor 42 by the display processing unit 41. Note that the time interval of the acquired tomographic image is a constant value (= t · V ₀ ) when V ₀ ≦ V ≦ 2V ₀ . In the case of V <V ₀ , tomographic images are acquired at shorter time intervals. In this case, the three-dimensional image generation unit 39 may perform thinning processing or the like. However, when V> 2V ₀ , the time interval of the acquired tomographic image becomes larger than the certain value. In this case, the three-dimensional image generation unit 39 may perform interpolation processing as appropriate.

  As described above, the scan range of the first scan is determined according to the change in the moving speed V of the ultrasonic probe 11, and the remaining scan range is scanned by the second scan during the execution of the first scan. Therefore, it is possible to change the scan time for generating one tomographic image without changing the scan speed. Thereby, it is possible to generate a three-dimensional image with less roughness and less unevenness of the depth of field in the insertion axis S direction of the ultrasonic probe. When the first scan and the second scan are performed simultaneously, there is a problem of interference between ultrasonic beams emitted in two directions and between reflected echoes. In the above embodiment, the beam direction is symmetric with respect to the insertion axis S by 180 °. Therefore, interference can be prevented.

In the above embodiment, since simultaneous scanning in two directions is possible, with respect to the density in the insertion axis direction of the three-dimensional image, only changes up to the range of V ≦ 2V ₀ can be handled. By increasing the number of beam directions, it is possible to widen the response range of the speed change. However, since the above interference becomes a problem due to the increase in the number of beam directions, the maximum allowable number of beam directions is about four. FIG. 10 shows the maximum angle θ _m of the first scan when simultaneous scanning in a maximum of four directions is possible as shown in FIG. 11, and in the case of V ₀ ≦ V ≦ 4V ₀ , the maximum angle θ _m is calculated based on the formula “θ _m = 360 ° V ₀ / V”. If V> 4V ₀ , θ _m = 90 °. 1 direction scan in the case of _{V ≦ V 0, V 0 <} V 2 direction scanning in the case of ≦ _{2V 0,} 2V ₀ <3 direction scanning in the case of a V ≦ _{3V 0,} 3V ₀ <a V ≦ 4V ₀ In this case, the time interval of the acquired tomographic image is set to a constant value (= t · V ₀ ) in the range of V ₀ ≦ V ≦ 4V ₀ by sequentially increasing the number of beam directions in four directions. it can.

  In the above embodiment, the method of driving the ultrasonic transducers 16 one by one with respect to one beam direction is described as an example. However, the present invention is not limited to this, and a plurality of adjacent transducers are adjacent to each other. The present invention can also be applied to a system in which (for example, 40) ultrasonic transducers 16 are driven collectively and the ultrasonic beam scan is performed while shifting the driven transducer group.

  In the above embodiment, 360 ultrasonic transducers 16 are arranged on the circumferential surface. However, the present invention is not limited to this, and the total number of ultrasonic transducers 16 is 120. , 240 or the like may be changed as appropriate.

  Further, in the above-described embodiment, a description is given by taking as an example a radial electronic scanning type ultrasonic probe that scans an ultrasonic beam by electrically switching a plurality of ultrasonic transducers arranged on the circumferential surface. However, the present invention is not limited to this, and it is also possible to use a mechanical scanning ultrasonic probe that performs scanning by mechanically rotating an ultrasonic transducer with a motor or the like. When this mechanical scanning method is employed, it is only necessary to provide ultrasonic transducers as many as the maximum number of simultaneous scans, and to enable each ultrasonic transducer to rotate independently around the same axis.

It is a block diagram which shows the structure of an ultrasound diagnosing device. It is a partially cutaway perspective sectional view showing the configuration of the ultrasonic probe. It is a schematic diagram which shows the arrangement | sequence of an ultrasonic vibrator. It is a flowchart explaining the scan control accompanying the movement to the insertion axis direction of an ultrasonic probe. It is an explanatory view showing a scanning method in the case of V ≦ V _0. It is a graph which shows the maximum angle of a 1st scan. It is an explanatory view showing a scanning method in the case of _V = (4/3) V _0. FIG. 6 is a timing diagram of first and second scans. It is an explanatory view showing a scanning method in the case of V = 2V _0. It is a graph which shows the maximum angle of the 1st scan at the time of enabling simultaneous scanning to a maximum of 4 directions. It is explanatory drawing which shows 4 direction scanning. It is explanatory drawing explaining a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Ultrasonic diagnostic apparatus 11 Ultrasonic probe 12 Processor apparatus 13 Probe speed detection apparatus (movement speed detection means)
14 Ultrasonic transducer array (Ultrasonic irradiation means)
16 Ultrasonic vibrator 23 First multiplexer (scanning control means)
24 Second multiplexer (scanning control means)
25 Control unit (scanning control means)
26 First Transmitter / Receiver 27 Second Transmitter / Receiver 28 Pulser 29 Amplifier 30 Receiver 31 Switch Circuit 32 Transmitting Antenna (Moving Speed Detection Means)
33 Receiving antenna (moving speed detection means)
36 First phase matching calculation unit 37 Second phase matching calculation unit 38 Tomographic image generation unit 39 Three-dimensional image generation unit

Claims (5)

In an ultrasonic diagnostic apparatus that sequentially obtains tomographic images by rotating and scanning an ultrasonic beam radially about the insertion axis of an ultrasonic probe,
A moving speed detecting means for detecting a moving speed of the ultrasonic probe in the insertion axis direction;
Ultrasonic irradiation means capable of simultaneously irradiating an ultrasonic beam in a plurality of directions;
Based on the moving speed detected by the moving speed detecting unit, the number of directions of the ultrasonic beam irradiated by the ultrasonic irradiation unit, the scanning range of each ultrasonic beam, and the scanning timing of each ultrasonic beam are controlled. Scanning control means for changing the acquisition time of the tomographic image while keeping the scanning speed of the sound beam constant;
An ultrasonic diagnostic apparatus comprising: The ultrasonic irradiation means is capable of simultaneously irradiating an ultrasonic beam in two directions,
The scanning control means scans the entire range with only one ultrasonic beam when the detected moving speed is equal to or lower than the predetermined speed, and when the detected moving speed is higher than the predetermined speed, the first control is performed. 2. The ultrasonic diagnostic apparatus according to claim 1, wherein control is performed so that the remaining range is scanned with the second ultrasonic beam while the predetermined range is scanned with the ultrasonic beam. .   The scanning control means controls the scanning range of the first ultrasonic beam to be inversely proportional to the moving speed when the detected moving speed is greater than a predetermined speed and not more than twice the predetermined speed. The ultrasonic diagnostic apparatus according to claim 2, wherein:   The ultrasonic diagnostic apparatus according to claim 3, wherein the scanning control unit performs timing control so that directions of the first and second ultrasonic beams are 180 ° rotationally symmetric.   The ultrasonic irradiation means is a radial ultrasonic transducer array in which ultrasonic transducers are arranged at a constant pitch in a circumferential direction around the insertion axis. 5. The ultrasonic diagnostic apparatus according to any one of 4 to 4.

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