JP2009297399A - Ultrasonic diagnostic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ultrasonic diagnostic apparatus improving an overall image quality of a three-dimensional ultrasonic image while retaining a volume rate. <P>SOLUTION: A scanning section of this ultrasonic diagnostic apparatus scans a subject along a first direction (a) by ultrasonic beams Bs and Bb having different beam widths in a focus position F to form a scanning face T1 or T2 and also scans a three-dimensional region by forming a plurality of scanning faces T1 and T2 along a second direction different from the first direction. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an ultrasonic diagnostic apparatus, and more particularly to an ultrasonic diagnostic apparatus that displays a three-dimensional image.

  The ultrasonic diagnostic apparatus includes an ultrasonic probe that transmits / receives ultrasonic waves to / from a subject and a transmission / reception unit that drives the ultrasonic probe. The ultrasonic probe includes a transducer array, ultrasonic waves are transmitted from the transducer array, and reflected waves are received by the transducer.

Among such ultrasonic diagnostic apparatuses, an ultrasonic diagnostic apparatus that displays a three-dimensional ultrasonic image scans with an ultrasonic beam along a first direction to form a scanning surface, Is configured to scan a three-dimensional region by forming a plurality of scanning planes along different second directions (see, for example, Patent Document 1).
JP 2006-271594 A

  By the way, the beam width at the focus position of the ultrasonic beam can be adjusted by changing the aperture width of the transducer array. Specifically, the beam width at the focus position can be reduced as the aperture width of the transducer array is increased, while the beam width at the focus position is increased as the aperture width of the transducer array is decreased. can do.

  Here, there is an advantage that the azimuth resolution near the focus is improved as the aperture width of the transducer array is increased to reduce the beam width at the focus position. However, as the distance from the focus position increases, the beam width increases, so the azimuth resolution decreases. In addition, since the beam width is small at the focus position, a region where no ultrasonic beam exists in the surrounding area becomes large.

  On the other hand, the smaller the aperture width of the transducer array and the larger the beam width at the focus position, the smaller the aperture of the beam. Compared with the case where the beam width is reduced, there is an advantage that the difference in azimuth resolution in the depth direction of the ultrasonic beam is reduced. Further, since the beam width at the focus position is large, it is possible to reduce a region where no beam exists. However, the azimuth resolution near the focus decreases.

  As described above, when the beam width at the focus position is reduced and when it is increased, the advantages and disadvantages are reversed.

  When the beam width at the focus position is reduced, as a technique for preventing a decrease in azimuth resolution in a portion away from the focus position, there is a technique of forming a plurality of focus positions in the depth direction. However, since it is necessary to perform scanning a plurality of times at the same position, the volume rate is lowered, particularly when a three-dimensional image is obtained.

  The problem to be solved by the present invention is to provide an ultrasonic diagnostic apparatus capable of improving the overall image quality of a three-dimensional ultrasonic image while maintaining the volume rate.

  The present invention has been made to solve the above-mentioned problems. The invention of the first aspect is that a scan surface is formed by performing scanning with an ultrasonic beam a plurality of times along a first direction on a subject. In addition, the ultrasonic diagnostic apparatus includes a scanning unit that scans a three-dimensional region by forming a plurality of scanning planes along a second direction different from the first direction. An ultrasonic diagnostic apparatus that performs scanning with ultrasonic beams having different beam widths at a focus position.

  In the first aspect of the invention, ultrasonic waves having different beam widths at the focus position are transmitted and received in the three-dimensional region.

  The invention of the second aspect is characterized in that, in the invention of the first aspect, the scanning unit scans ultrasonic beams having different beam widths at a focus position in a predetermined cycle along the first direction. This is an ultrasonic diagnostic apparatus.

  In the second aspect of the invention, each scanning plane includes ultrasonic beams having different beam widths at the focus position.

  According to a third aspect of the invention, in the invention of the second aspect, the scanning unit scans the scanning pattern in the first direction of the ultrasonic beam having a different beam width at the focus position with one scanning plane adjacent to the other and the other. The ultrasonic diagnostic apparatus is characterized in that a different pattern is used for a scanning plane.

  In the invention according to the third aspect, the scanning pattern of the ultrasonic beam having a different beam width at the focus position is different between one scanning plane and another scanning plane that are adjacent to each other.

  According to a fourth aspect of the present invention, in the first aspect of the invention, the scanning unit has the same width of the ultrasonic beam when performing scanning along the first direction, and one scanning plane adjacent to each other. The ultrasonic diagnostic apparatus is characterized in that the beam width is changed with another scanning plane.

  In the invention according to the fourth aspect, the ultrasonic beam scanning each scanning plane has the same beam width at the focus position, and the beam width differs between one scanning plane and another scanning plane that are adjacent to each other.

  According to a fifth aspect of the present invention, in the invention according to any one of the first to fourth aspects, the scanning unit scans so that the scanning position of the ultrasonic beam in the first direction is the same position on each scanning plane. It is an ultrasonic diagnostic apparatus characterized by performing.

  In the fifth aspect of the invention, the scanning position of the ultrasonic beam in the first direction is the same on each scanning plane.

  The invention according to a sixth aspect is the invention according to any one of the first to fourth aspects, wherein the scanning unit has a scanning position of an ultrasonic beam between one scanning surface and another scanning surface adjacent to each other, An ultrasonic diagnostic apparatus that performs scanning so as to shift in a first direction.

  In the invention according to the sixth aspect, the scanning position of the ultrasonic beam is different in the first direction between the one scanning surface and the other scanning surface that are adjacent to each other.

  The invention of the seventh aspect is the invention of any one of the first to sixth aspects, wherein the beam width at the focus position is adjusted by adjusting the aperture width of the transducer array of the ultrasonic probe constituting the scanning unit. The ultrasonic diagnostic apparatus is characterized by being adjusted.

  In the seventh aspect of the invention, the beam width at the focus position of the ultrasonic beam is changed by changing the aperture width of the transducer array of the ultrasonic probe.

  According to the present invention, since ultrasonic waves having different beam widths at the focus position are transmitted and received in the three-dimensional region, it is possible to create a three-dimensional ultrasonic image based on echo data of ultrasonic waves having different beam widths. . As a result, the disadvantages of the ultrasonic beams having the respective beam widths are negated, and the overall image quality of the three-dimensional ultrasonic image can be improved. Since the same position is not scanned a plurality of times, the volume rate can be maintained.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing a schematic configuration of an embodiment of an ultrasonic diagnostic apparatus according to the present invention, FIG. 2 is a perspective view showing a schematic configuration of an ultrasonic probe of the ultrasonic diagnostic apparatus shown in FIG. 1, and FIG. FIG. 4 is a conceptual diagram showing scanning of a three-dimensional region of a subject by the transducer array of the ultrasonic diagnostic apparatus shown in FIG. 1, and FIG. 4 is an ultrasonic beam transmitted and received by the transducer array of the ultrasonic diagnostic apparatus shown in FIG. FIG. 5 is a conceptual diagram for explaining creation of an ultrasonic image based on echo signals of ultrasonic beams having different beam widths at the focus position on one scanning plane and another scanning plane.

  The ultrasonic diagnostic apparatus 1 includes an ultrasonic probe 2, a transmission / reception unit 3, an image creation unit 4, an image display unit 5, a control unit 6, and an operation unit 7.

  The above-described configuration will be described. First, the ultrasonic probe 2 drives a transducer array 200 described later by a drive signal input from the transmission / reception unit 3, and transmits an ultrasonic beam to a subject. ing. The ultrasonic beam reflected from the subject is received, converted into an echo signal by the transducer array 200, and the echo signal is output to the transmission / reception unit 3.

  A schematic configuration of the ultrasonic probe 2 will be described with reference to FIG. The ultrasonic probe 2 has a transducer array 200, a damper 210, and a motor 220, and is configured by housing them in a protective case 230. The vibrator array 200 is formed by arranging a plurality of vibrators 200a formed of a piezoelectric material such as PZT (titanium (Ti) zirconate (Zr) acid lead) ceramics along the first direction a. It is configured. By driving a plurality of transducers 200a of the transducer array 200, an ultrasonic beam is transmitted. Then, by sequentially switching the vibrator 200a to be driven, electronic scanning is performed in the first direction a, and the scanning surface T1 or T2 is formed.

  The damper 210 suppresses free vibration of the transducer array 200 after driving the transducer array 200 and transmitting an ultrasonic beam to the subject. The damper 210 is made of a material having a sound absorbing effect, and suppresses unnecessary propagation of ultrasonic waves from the damper 210 to the connection side with the probe cable 300 behind. .

  The motor 220 mechanically moves the transducer array 200 in a second direction b orthogonal to the arrangement direction of the transducers 200a. Thereby, in the second direction b, a plurality of scanning planes T1 and T2 can be formed, and a three-dimensional area can be scanned. However, the present invention is not limited to the one that mechanically scans the three-dimensional region as described above, and includes one that electronically scans the three-dimensional region.

  The transmission / reception unit 3 is connected to the ultrasonic probe 2, and based on a command signal from the control unit 6, gives a drive signal to the ultrasonic probe 2 to transmit an ultrasonic beam. Yes. Further, when the echo signal from the ultrasonic probe 2 is input, the transmission / reception unit 3 performs processing such as amplification, delay, and addition on the echo signal and outputs the processed signal to the image creation unit 4. ing. The transmission / reception unit 3 and the ultrasonic probe 2 are an example of an embodiment of a scanning unit that performs scanning by transmission / reception of an ultrasonic beam in the present invention.

  Here, the beam width of the ultrasonic beam at the focus position F is adjusted by changing the number of transducers 200 a driven by the transceiver 3 and adjusting the aperture width of the transducer array 200. The beam width at the focus position F can be reduced by increasing the number of vibrators 200a to be driven to increase the opening width of the vibrator array 200. On the other hand, the beam width at the focus position F can be increased by reducing the number of transducers 200a to be driven to reduce the aperture width of the transducer array 200. In this example, as will be described later, when scanning is performed along the first direction a, an ultrasonic beam having a small beam width at the focus position F and an ultrasonic beam having a large beam width at the focus position F are alternately transmitted and received. It has come to be.

  The image creation unit 4 is connected to the transmission / reception unit 3. The image creation unit 4 creates a three-dimensional ultrasonic image of the subject based on the echo signal from the transmission / reception unit 3.

  The image display unit 5 is connected to the image creation unit 4. The image display unit 5 receives an image signal from the image creation unit 4 and displays a three-dimensional ultrasonic image based on the image signal.

  The control unit 6 is connected to the above-described units in the ultrasonic diagnostic apparatus 1 and outputs control signals to these units to control the operation. The control unit 6 includes a CPU (Central Processing Unit).

  The operation unit 7 is connected to the control unit 6. The operation unit 7 includes an input device such as a keyboard or a pointing device. The operation unit 7 receives operation information from an operator and outputs a command to the control unit 6 based on the operation information.

  Now, the operation of the ultrasonic diagnostic apparatus 1 will be described. In the ultrasonic diagnostic apparatus 1, scanning with an ultrasonic beam having a different beam width at the focus position F is performed in a three-dimensional region of the subject. In this example, scanning of an ultrasonic beam having a different beam width at the focus position F is performed in a predetermined cycle along the first direction a, and the scanning pattern of the beam is different between the scanning surface T1 and the scanning surface T2. ing. More specifically, in this example, in the scanning of the ultrasonic beam in the first direction a, the ultrasonic beam Bs having a small beam width at the focus position F and the ultrasonic wave having a large beam width at the focus position F. The beam Bb is transmitted and received alternately. Incidentally, the focus position F of the ultrasonic beam Bs and the ultrasonic beam Bb is the same in the depth direction (transmission / reception direction of ultrasonic waves). The scanning plane T1 and the scanning plane T2 are different in the scanning pattern of the ultrasonic beam, that is, the transmission / reception order of the ultrasonic beam Bs and the ultrasonic beam Bb. Specifically, in FIGS. 3 and 4, scanning is performed from the right side to the left side, and on the scanning surface T1, the ultrasonic beam Bs is first transmitted and received, and then the ultrasonic beam. Bb is transmitted and received, and the ultrasonic beam Bs and the ultrasonic beam Bb are transmitted and received in this order. On the other hand, on the scanning surface T2, the ultrasonic beam Bb is first transmitted / received, and then the ultrasonic beam Bs is transmitted / received, and the ultrasonic beam Bb and the ultrasonic beam Bs are transmitted / received in this order. Then, the ultrasonic beam is scanned so that the scanning surface T1 and the scanning surface T2 are alternately formed in the three-dimensional region in the subject.

  The scanning position of the ultrasonic beam in the first direction a is the same on the scanning surface T1 and the scanning surface T2. Therefore, the ultrasonic beam Bs and the ultrasonic beam Bb are alternately arranged in the second direction b, that is, in the arrangement direction of the scanning surfaces T1 and T2.

  The transmission / reception unit 3 is obtained by scanning the three-dimensional region of the subject so that the ultrasonic beam Bs and the ultrasonic beam Bb are alternately arranged in both the first direction a and the second direction b. The echo signal is output to the image creation unit 4. The image creation unit 4 creates a three-dimensional image based on the input echo signal, and the three-dimensional image is displayed on the image display unit 5.

  Here, the image creating unit 4 performs an interpolation process on a portion between the scanning surface T1 and the scanning surface T2 (a portion where no ultrasonic beam exists) in the three-dimensional region where the ultrasonic beam is scanned. To create an image. The interpolation processing is performed using echo signals respectively obtained based on ultrasonic beams on adjacent scanning planes. That is, in this example, the interpolation process is performed using an echo signal obtained based on the ultrasonic beam on the scanning plane T1 and an echo signal obtained based on the ultrasonic beam on the scanning plane T2. At this time, the echo signals used in the interpolation processing are the echo signals of the ultrasonic beams having different beam widths, that is, the echo signal of the ultrasonic beam Bb and the echo signal of the ultrasonic beam Bs. Created images. That is, as shown in FIG. 5, as the distance from the focus position F in the transmission / reception direction is reached, the beam width of the ultrasonic beam Bs becomes extremely larger than the beam width at the focus position F, and reverses the beam width of the ultrasonic beam Bb. Thus, it is wider than the ultrasonic beam Bb. Accordingly, in an area where the beam width of the ultrasonic beam Bs and the beam width of the ultrasonic beam Bb are reversed, by creating an image from the echo signal of the ultrasonic beam Bb and the echo signal of the ultrasonic beam Bs, Compared to the case where an image is created only from the echo signal of the ultrasonic beam Bs, the azimuth resolution can be improved.

  On the other hand, if an image is created only from the echo signal of the ultrasonic beam Bb, the azimuth resolution decreases near the focus position F. However, it is possible to improve the azimuth resolution by creating an image using the echo signal of the ultrasonic beam Bs. When attention is paid to the ultrasonic beam Bs, the region where the beam does not exist is large in the vicinity of the focus position F. However, by creating an image using the echo signal of the ultrasonic beam Bs and the echo signal of the ultrasonic beam Bb, the image quality can be improved in a region where no beam exists.

  According to the ultrasonic diagnostic apparatus 1 of this example described above, the respective disadvantages of the ultrasonic beam Bs and the ultrasonic beam Bb are negated, and the overall image quality of the three-dimensional ultrasonic image can be improved. Since the same position does not need to be scanned a plurality of times, the volume rate can be maintained.

  It is sufficient that the ultrasonic beams Bs and Bb are scanned in the first direction a at a predetermined cycle on each scanning plane T1 and T2. For example, after transmitting and receiving the ultrasonic beam Bs twice, It is not restricted to what is alternately transmitted / received as mentioned above, such as transmitting / receiving sound wave beam Bb twice.

  Next, a modification of the present embodiment will be described with reference to FIG. In this modification, the width of the ultrasonic beam when scanning along the first direction a is the same, and the scanning surface T1 and the scanning surface T2 have different beam widths. Specifically, the ultrasonic beam Bs is transmitted and received on the scanning plane T1. Further, the ultrasonic beam Bb is transmitted and received on the scanning plane T2.

  Also in this modified example, the scanning position of the ultrasonic beam in the first direction a is the same on the scanning surface T1 and the scanning surface T2. Therefore, the ultrasonic beam Bs and the ultrasonic beam Bb are alternately arranged in the second direction b, that is, in the arrangement direction of the scanning surfaces T1 and T2. As described above, also in this modification, the image creating unit 4 uses the echo signal obtained based on the ultrasonic beam on the scanning surface T1 and the echo signal obtained based on the ultrasonic beam on the scanning surface T2. When performing the interpolation processing, the echo signal of the ultrasonic beam Bs and the echo signal of the ultrasonic beam Bb can be used. Thereby, an image in which the demerits of both beams are canceled can be created.

  As mentioned above, although this invention was demonstrated by the said embodiment, this invention can be variously implemented in the range which does not change the main point. For example, in the embodiment, the scanning position of the ultrasonic beam in the first direction a is the same position on the scanning surface T1 and the scanning surface T2, but the scanning position of the ultrasonic beam on the scanning surface T1; The scanning position of the ultrasonic beam on the scanning surface T2 may be shifted in the first direction a. However, even in this case, the interpolation process using the echo signal obtained based on the ultrasonic beam on the scanning plane T1 and the echo signal obtained based on the ultrasonic beam on the scanning plane T2 is performed by the ultrasonic beam Bs. This is performed using the echo signal and the echo signal of the ultrasonic beam Bb. Therefore, when performing the interpolation process based on the echo signal obtained based on the ultrasonic beam on the scanning plane T1 and the echo signal obtained based on the ultrasonic beam on the scanning plane T2, the echo signal of the ultrasonic beam Bs is performed. It is desirable that the ultrasonic beam Bs and the ultrasonic beam Bb are arranged in the three-dimensional region so that interpolation processing using the echo signal of the ultrasonic beam Bb is performed.

  In FIGS. 4 and 6, transmission / reception of the ultrasonic beams Bs and Bb adjacent in the first direction a is performed using different vibrators 200a. Of course, overlapping vibrators 200a may be used.

1 is a block diagram showing a schematic configuration of an embodiment of an ultrasonic diagnostic apparatus according to the present invention. It is a perspective view which shows schematic structure of the ultrasonic probe of the ultrasonic diagnosing device shown in FIG. FIG. 2 is a conceptual diagram showing scanning of a three-dimensional region of a subject by the transducer array of the ultrasonic diagnostic apparatus shown in FIG. It is a figure which shows the ultrasonic beam transmitted / received by the vibrator | oscillator array of the ultrasonic diagnosing device shown in FIG. It is a conceptual diagram for demonstrating preparation of the ultrasonic image based on the echo signal of the ultrasonic beam from which the beam width of a focus position differs in one scanning surface and another scanning surface. It is a figure which shows the ultrasonic beam transmitted / received by the vibrator | oscillator array of the ultrasonic diagnostic apparatus of a modification.

Explanation of symbols

1 Ultrasonic diagnostic device 2 Ultrasonic probe (scanning unit)
3 Transmission / reception unit (scanning unit)
200 transducer array Bs, Bb ultrasonic beam a first direction b second direction F focus position T1, T2 scanning plane

Claims (7)

By scanning the subject with the ultrasonic beam a plurality of times along the first direction to form a scanning surface, and forming the plurality of scanning surfaces along a second direction different from the first direction. , An ultrasonic diagnostic apparatus comprising a scanning unit for scanning a three-dimensional region,
The ultrasonic diagnostic apparatus, wherein the scanning unit performs scanning with ultrasonic beams having different beam widths at a focus position. The ultrasonic diagnostic apparatus according to claim 1, wherein the scanning unit scans ultrasonic beams having different beam widths at a focus position in a predetermined cycle along the first direction. 3. The scanning unit according to claim 2, wherein the scanning patterns in the first direction of the ultrasonic beams having different beam widths at the focus positions are different from each other in one scanning surface and another scanning surface. An ultrasonic diagnostic apparatus according to 1. The scanning unit is characterized in that the width of the ultrasonic beam when scanning along the first direction is the same width, and the beam width is changed between one scanning surface and another scanning surface that are adjacent to each other. The ultrasonic diagnostic apparatus according to claim 1. The ultrasonic wave according to any one of claims 1 to 4, wherein the scanning unit performs scanning so that the scanning position of the ultrasonic beam in the first direction is the same position on each scanning plane. Diagnostic device. 5. The scanning unit according to claim 1, wherein the scanning unit performs scanning so that a scanning position of the ultrasonic beam is shifted in a first direction between one scanning surface and another scanning surface that are adjacent to each other. The ultrasonic diagnostic apparatus according to claim 1. The beam width at the focus position is adjusted by adjusting the aperture width of the transducer array of the ultrasonic probe that constitutes the scanning unit. Ultrasonic diagnostic equipment.

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