JP2009112491A - Ultrasonic diagnostic system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ultrasonic diagnostic system capable of generating an image wherein a level difference due to a time difference is less likely to be distinct. <P>SOLUTION: A scan control part 91 gathers a plurality of scanning lines arranged along a main scanning direction in one individual area. With respect to the scanning lines included in the individual area, a transmission and reception part 3 transmits and receives ultrasonic waves once to each scanning line in order until the number of times of the transmission and reception becomes a predetermined number respectively. When the number of times of the transmission and reception to the scanning lines becomes a predetermined number respectively, the transmission and reception part 3 is allowed to perform scanning same as the scanning in another individual area in a sub-scanning direction generally orthogonal to the main scanning direction. An image generation part 6, on the basis of a received signal obtained by the scanning, generates a color Doppler image data of a surface parallel to the sub-scanning direction. A display control part 7 makes a display part 81 display a color Doppler image. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an ultrasonic diagnostic apparatus that transmits ultrasonic waves to a subject and generates motion information of a moving body in the subject based on a received signal.

  2. Description of the Related Art An ultrasonic diagnostic apparatus capable of Doppler scanning is known in order to acquire blood flow information in a subject. Doppler scan is a technique for obtaining blood flow information in a subject based on the principle of ultrasonic Doppler method. The ultrasonic diagnostic apparatus executes a CFM (Color Flow Mapping) method (or “color Doppler method”) to acquire a 2D image or a 3D image representing blood flow information and display it in color. Is possible.

  When the CFM method is performed, ultrasonic waves are transmitted a plurality of times in the same direction, and information on each point on one scanning line is acquired by a plurality of transmissions / receptions. In order to acquire blood flow information in a desired imaging region (for example, a tomographic plane), transmission / reception of ultrasonic waves is repeated for all the scanning lines constituting the imaging region (tomographic plane).

  By the way, in order to detect a low blood flow velocity, it is necessary to reduce the pulse repetition frequency (PRF) and transmit / receive ultrasonic waves. That is, it is necessary to lengthen the sampling cycle (sampling interval). However, if the sampling period is lengthened, the time required to generate one frame of blood flow information is lengthened. For example, if the sampling period is simply quadrupled, it takes four times longer to scan the entire imaging area, resulting in a frame rate of ¼.

  Here, a method of transmitting and receiving ultrasonic waves according to the prior art will be described with reference to FIG. FIG. 3 is a diagram for explaining a method of transmitting and receiving ultrasonic waves according to the prior art. As an example, a case where a color Doppler image is composed of 16 scanning lines will be described. In FIG. 3, scanning lines A, B, C,..., P correspond to each of 16 scanning lines. The column numbers in each scanning line indicate the order of transmission. In the example shown in FIG. 3, the first order “1” in the column of the scanning line A represents the Doppler information obtained by the first transmission / reception. Then, transmission / reception of ultrasonic waves is performed six times on one scanning line A, and data of each point on one scanning line A is generated based on reception data acquired by each transmission / reception. This order of transmission and reception corresponds to the numbers “1” to “6” shown in FIG. Then, similarly to the scanning line A, ultrasonic waves are transmitted and received for the scanning line B, and data of each point on the scanning line B is generated. The transmission / reception order corresponds to the numbers “7” to “12” shown in FIG. Then, transmission / reception of ultrasonic waves is repeated from the first line (scanning line A) to the 16th line (scanning line P).

  In this method, if the interval between transmissions is increased in order to measure a low blood flow velocity, the time required to generate an image is proportionally increased. That is, when the sampling period is quadrupled, the time interval between the order “1” indicating the first transmission and the order “2” indicating the second transmission is quadrupled. Usually, when the sampling period is T, the sampling period is 4T, and the frame rate is ¼.

  Therefore, a method has been proposed in which the substantial pulse repetition frequency is reduced and the sampling period is extended without reducing the frame rate (for example, Patent Document 1). This method divides a tomographic plane, which is an imaging region, into a plurality of regions, and transmits and receives ultrasonic waves one by one within the region in order for each of the plurality of scanning lines. Send ultrasonic waves multiple times. Hereinafter, the scanning method described in Patent Document 1 may be referred to as “alternate scanning”.

  Here, the alternate scanning described in Patent Document 1 will be described with reference to FIG. FIG. 4 is a diagram for explaining a method of transmitting and receiving ultrasonic waves according to the prior art. For example, a case where the cross section 100 shown in FIG. 4 is scanned will be described. The number of scanning lines in one cross section is 16 and the number of transmission / reception of ultrasonic waves for each scanning line is 6. One section is divided into four individual areas, and the number of scanning lines included in each individual area is four. Thereby, the number of times of transmission / reception of ultrasonic waves for each individual area is {number of scanning lines (4)} × {number of transmission / reception for one scanning line (6 times)} = 24 times. In the alternate scan, ultrasonic waves are transmitted and received once in order for four scanning lines included in one individual region, and ultrasonic waves are transmitted and received six times for each scanning line. Then, after transmitting / receiving ultrasonic waves to / from one individual region 24 times, transmitting / receiving ultrasonic waves to / from the adjacent individual region 24 times. As described above, in the alternate scan, ultrasonic waves are transmitted and received 24 times for each individual region.

  For example, the cross section 100 is divided into four individual regions 110, 120, 130, and 140. Since the number of scanning lines in one cross section 100 is 16, the individual area 110 includes four scanning lines A, B, C, and D. Similarly, the individual area 120 includes four scanning lines E to H, the individual area 130 includes four scanning lines I to L, and the individual area 140 includes four scanning lines M to P. It is included.

  As described above, in the alternate scan, the scanning lines A to D are combined into one area. Then, ultrasonic waves are transmitted and received one by one in order for the scanning lines A to D included in one individual region 110. Then, the ultrasonic waves are transmitted and received in order from the scanning line A to the scanning line D until the total number of transmissions from the scanning line A to the scanning line D reaches six. For example, ultrasonic waves are transmitted once to the scanning line A (corresponding to the order “1”), then ultrasonic waves are transmitted once to the scanning line B (corresponding to the order “2”), and then the scanning line Ultrasonic waves are transmitted once to C (corresponding to the order “3”), and then ultrasonic waves are transmitted once to the scanning line D (corresponding to the order “4”). Then, after transmitting the ultrasonic wave to the scanning line D, the second transmission to the scanning line A is performed again (corresponding to the order “5”). Then, after transmitting and receiving ultrasonic waves six times for each scanning line included in the individual area 110, the ultrasonic waves are sequentially transmitted once to the scanning lines E to H included in the adjacent individual area 120. Send and receive. And the image data in the whole cross section 100 is acquired by transmitting / receiving an ultrasonic wave with respect to each individual area | region in the order of the individual area | region 110,120,130,140.

  According to this alternate scanning, the transmission interval of each time is the same as that of the prior art shown in FIG. 3, but the sampling period on each scanning line is quadrupled. For example, the first transmission with respect to the scanning line A is in the order “1” and the second transmission is in the order “5”, so the sampling period on the scanning line is 4T. In other words, it is possible to increase the sampling period and reduce the blood flow velocity without reducing the frame rate.

  By applying the ultrasonic diagnostic apparatus described in Patent Literature 1 to a three-dimensional region, it is possible to acquire a three-dimensional color Doppler image representing a low blood flow velocity without reducing the volume rate. .

Japanese Patent Publication No. 7-71557

  However, according to the alternating scan described in Patent Document 1, the time interval (time difference) at which data is acquired becomes large at the boundaries between the individual regions, and a step due to the time difference occurs in the image. There was a problem. In particular, when the time difference becomes large at the boundary of each individual area, there is a problem that the step is conspicuous on the image. When acquiring a three-dimensional color Doppler image, a plurality of cross sections are scanned with ultrasonic waves. However, there is a problem in that a step generated at the boundary of each individual region occurs across a plurality of cross sections, so that the step is conspicuous in the three-dimensional color Doppler image, and as a result, diagnosis becomes difficult.

  Here, the time difference between the individual regions will be described with reference to FIGS. FIG. 5 is a diagram for explaining a time when data on each scanning line is acquired in the ultrasonic transmission / reception method according to the related art. In FIG. 5, the horizontal axis indicates the position in the cross section, and the vertical axis indicates the time when transmission / reception is performed.

  For example, the case where the three-dimensional imaging region S shown in FIG. 4 is scanned with ultrasonic waves will be described. In the example illustrated in FIG. 4, image data of the three-dimensional imaging region S is acquired by scanning four cross sections 100, 200, 300, and 400 with ultrasonic waves. As described above, the cross section 100 is divided into four individual regions 110, 120, 130, and 140, and the cross section 100 is scanned with ultrasonic waves. When the transmission / reception with respect to the cross section 100 is completed, the same transmission / reception with respect to the cross section 100 is performed next with respect to the cross section 200. That is, the cross section 200 is divided into four individual areas, and ultrasonic waves are transmitted and received for each individual area. And the image data of the whole imaging area | region S is acquired by transmitting / receiving an ultrasonic wave in order of the cross section 100,200,300,400.

  However, according to the alternate scan according to the prior art, the time interval (time difference) at which data is acquired becomes large at the boundary of each individual region, and a large time difference occurs every 24 transmissions / receptions. If the scanning lines are in the same individual area, the time interval (time difference) at which the data is acquired is constant, but the time difference becomes large at the boundary of the individual areas. The time difference at the boundary between the individual areas is displayed as a conspicuous step on the image.

  For example, as shown in FIG. 5, in the scanning lines A to D in the individual area 110, the time interval (time difference) at which data is acquired is constant between adjacent scanning lines. Further, also in the scanning lines E to H in the individual region 120, the time interval (time difference) at which data is acquired is constant between adjacent scanning lines.

  However, at the boundaries between the individual areas, the time interval (time difference) at which the data is acquired becomes large. For example, a large time difference occurs between the scanning line D included in the individual area 110 and the scanning line E included in the individual area 120. Similarly, at the boundary between the individual area 120 and the individual area 130, the time interval (time difference) at which the data is acquired increases. In this way, a portion where the time difference becomes large (between individual areas) is displayed as a conspicuous step on the image.

  If the time interval (time difference) at which data is acquired is constant between the scanning lines, the level difference is not noticeable on the image. However, when there is a part where the time difference is large, there is a problem that a step is conspicuous on the image and hinders diagnosis.

  The present invention solves the above-described problem, and an object thereof is to provide an ultrasonic diagnostic apparatus capable of generating an image in which a step caused by a time interval (time difference) at which data is acquired is less noticeable. To do.

  The invention according to claim 1 is a plurality of cross sections substantially orthogonal to the main scanning direction arranged in the main scanning direction, and transmission / reception means for transmitting ultrasonic waves to the subject and receiving reflected waves from the subject. The scanning lines included in each of the scanning lines are grouped into one individual area along the main scanning direction, and the number of times of transmission / reception of ultrasonic waves is set to a predetermined number for each of the plurality of scanning lines included in the individual area. Until the transmission / reception means transmits / receives ultrasonic waves to the respective scanning lines once in order, and the number of times of transmission / reception with respect to the plurality of scanning lines reaches the predetermined number, it is substantially orthogonal to the main scanning direction. In another individual area in the sub-scanning direction, the transmission / reception unit transmits / receives ultrasonic waves one by one to each scanning line in order until the number of ultrasonic transmission / reception times reaches the predetermined number. , Multiple pieces Scan control means for causing the transmission / reception means to perform transmission / reception of ultrasonic waves for each region, and a color Doppler of at least one of the plurality of cross sections based on a reception signal acquired by transmission / reception of ultrasonic waves by the transmission / reception means. An ultrasonic diagnostic apparatus comprising: image generation means for generating image data; and display control means for displaying a color Doppler image based on the color Doppler image data on a display means.

  According to the present invention, the scanning lines included in each of the plurality of cross-sections arranged in the main scanning direction are grouped into one individual area along the main scanning direction, and ultrasonic waves are transmitted and received for each individual area. By generating the color Doppler image data of the cross section based on the reception signal acquired by transmission / reception, it becomes possible to make the time difference of the data acquired by each scanning line constant. As a result, it is possible to generate a color Doppler image in which the level difference caused by the time interval (time difference) at which data is acquired is less noticeable.

(Constitution)
An ultrasonic diagnostic apparatus according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a block diagram showing an ultrasonic diagnostic apparatus according to an embodiment of the present invention. FIG. 2 is a diagram for explaining an ultrasonic transmission / reception method according to the embodiment of the present invention.

  An ultrasonic diagnostic apparatus 1 according to an embodiment of the present invention includes an ultrasonic probe 2, a transmission / reception unit 3, a signal processing unit 4, an image storage unit 5, an image generation unit 6, a display control unit 7, a user interface (UI) 8, And a control unit 9.

  As the ultrasonic probe 2, a two-dimensional array probe in which a plurality of ultrasonic transducers are two-dimensionally arranged is used. The ultrasonic probe 2 transmits an ultrasonic wave to the subject and receives a reflected wave from the subject as an echo signal. A one-dimensional array probe that swings a plurality of ultrasonic transducers arranged in a line in a predetermined direction (scanning direction) in a direction (swinging direction) orthogonal to the scanning direction may be used.

  The transmission / reception unit 3 includes a transmission unit and a reception unit, supplies an electrical signal to the ultrasonic probe 2 to generate an ultrasonic wave, and receives an echo signal received by the ultrasonic probe 2.

  The transmission unit supplies an electrical signal to the ultrasonic probe 2 under the control of the scan control unit 91 to transmit an ultrasonic wave beam-formed (transmission beamform) to a predetermined focal point. A specific configuration of the transmission unit will be described. The transmission unit includes a clock generation circuit, a transmission delay circuit, and a pulsar circuit (not shown). The clock generation circuit is a circuit that generates a clock signal that determines the transmission timing and transmission frequency of the ultrasonic signal. The transmission delay circuit is a circuit that performs transmission focus with a delay when transmitting ultrasonic waves. The pulsar circuit incorporates pulsars corresponding to the number of individual paths (channels) corresponding to each ultrasonic transducer, generates a drive pulse at a delayed transmission timing, and each ultrasonic transducer of the ultrasonic probe 2 To supply.

  The reception unit receives the echo signal received by the ultrasonic probe 2 and performs delay processing on the echo signal, thereby phasing the analog reception signal (received beam-formed) digital reception data Convert to In other words, the receiving unit adds the echo signals received at different times in accordance with the distances from the target reflector to each ultrasonic transducer, with their phases (time) aligned, and is in focus. One piece of received data (image signal on one scanning line) is generated.

  A specific configuration of the receiving unit will be described. The reception unit includes a preamplifier circuit, an A / D conversion circuit, and a reception delay / addition circuit (not shown). The preamplifier circuit amplifies the echo signal output from each ultrasonic transducer of the ultrasonic probe 2 for each reception channel. The A / D converter circuit A / D converts the amplified echo signal. The reception delay / adder circuit gives a delay time necessary for determining the reception directivity to the echo signal after A / D conversion, and adds the delay time. By the addition, the reflection component from the direction according to the reception directivity is emphasized.

  Here, an ultrasonic transmission / reception method performed by the ultrasonic probe 2, the transmission / reception unit 3, and the scan control unit 91 will be described with reference to FIG. In the setting information storage unit 93 of the control unit 9, coordinate information indicating the three-dimensional imaging region S, coordinate information of each scanning line included in the imaging region S, and ultrasonic waves are transmitted to and received from each scanning line. Information indicating the order (order information) and the number of times of transmission / reception of ultrasonic waves for each scanning line are stored as transmission / reception conditions. The scan control unit 91 controls transmission / reception of ultrasonic waves by the transmission / reception unit 3 in accordance with transmission / reception conditions stored in the setting information storage unit 93.

  For example, a case where the three-dimensional imaging region S shown in FIG. 2 is scanned with ultrasonic waves will be described. In the example illustrated in FIG. 2, image data of the three-dimensional imaging region S is acquired by scanning four cross sections 100, 200, 300, and 400 with ultrasonic waves. The transmission / reception unit 3 scans the ultrasonic wave along the main scanning direction X under the control of the scan control unit 91, and further scans the ultrasonic wave along the sub-scanning direction Y orthogonal to the main scanning direction X, The entire imaging area S is scanned. In this embodiment, color Doppler image data in a cross section along the sub-scanning direction Y is generated using a cross section along the sub-scanning direction Y as an image generation plane. In other words, color Doppler image data in a cross section orthogonal to the main scanning direction X is generated.

  As an example, the number of scanning lines in one cross section of the image generation surface is 16, and the number of transmission / reception of ultrasonic waves for each scanning line is 6. Then, the four scanning lines are combined into one individual area. In this embodiment, four scanning lines along the main scanning direction X orthogonal to the image generation plane are combined into one individual area. That is, the scanning lines included in different cross sections along the main scanning direction X are combined into one individual region. For example, the scanning lines A, B, C, and D along the main scanning direction X are combined into one individual area S1. Scan line A belongs to cross section 100, scan line B belongs to cross section 200, scan line C belongs to cross section 300, and scan line D belongs to cross section 400. As described above, the four scanning lines A, B, C, and D included in the different cross-sections 100, 200, 300, and 400 along the main scanning direction X are combined into one individual region S1. Thereby, the number of times of transmission / reception of ultrasonic waves for each individual area is {number of scanning lines (4)} × {number of transmission / reception for one scanning line (6 times)} = 24 times. Note that the number of scanning lines included in one individual region may be referred to as the number of stages of alternating scanning (the number of alternating stages). In this embodiment, as an example, the number of stages of alternate scanning is four. The number of stages of the alternate scan is stored in the setting information storage unit 93 of the control unit 9 as a transmission / reception condition.

  Then, under the control of the scan control unit 91, the transmission / reception unit 3 performs transmission / reception of ultrasonic waves once in order with respect to the four scanning lines included in one individual region, and 6 for each scanning line. Send and receive ultrasound. At this time, the transmission / reception unit 3 transmits / receives ultrasonic waves to / from each scanning line according to a predetermined pulse repetition frequency (PRF). Then, after transmitting / receiving ultrasonic waves to / from one individual region 24 times, the transmission / reception unit 3 transmits ultrasonic waves to the adjacent individual region 24 times in the sub-scanning direction Y under the control of the scan control unit 91. Send and receive. Thus, the transmission / reception unit 3 transmits / receives ultrasonic waves 24 times for each individual area.

  For example, ultrasonic waves are transmitted and received one by one in order for the scanning lines A to D included in one individual region S1. Then, until the ultrasonic waves are transmitted and received six times for each scanning line from the scanning line A to the scanning line D, the ultrasonic waves are transmitted and received in order from the scanning line A to the scanning line D once. Specifically, the transmission / reception unit 3 transmits an ultrasonic wave to the scanning line A once under the control of the scan control unit 91 (corresponding to the order “1”), and next to the adjacent main scanning direction X. Ultrasonic waves are transmitted once to the scanning line B (corresponding to the order “2”), and then ultrasonic waves are transmitted once to the adjacent scanning line C in the main scanning direction X (corresponding to the order “3”). Next, the ultrasonic wave is transmitted once to the adjacent scanning line D in the main scanning direction X (corresponding to the order “4”). As described above, the transmission / reception unit 3 sequentially performs once for each of the four scanning lines A, B, C, and D included in the different cross sections 100, 200, 300, and 400 along the main scanning direction X. Send and receive ultrasound. After transmitting / receiving ultrasonic waves to / from the scanning line D, the transmitting / receiving unit 3 performs the second transmission / reception with respect to the scanning line A again under the control of the scan control unit 91 (corresponding to the order “5”).

  After transmitting and receiving ultrasonic waves 6 times each from the scanning line A to the scanning line D included in the individual area S1, the transmission / reception unit 3 controls the adjacent individual in the sub-scanning direction Y under the control of the scan control unit 91. For the scanning lines E to H included in the region S2, the ultrasonic waves are transmitted and received once in order until the ultrasonic waves are transmitted and received six times for each scanning line.

  After transmitting and receiving ultrasonic waves six times for each of the scanning lines E to H included in the individual region S2, the transmitting / receiving unit 3 moves to the adjacent individual region S3 in the sub-scanning direction under the control of the scan control unit 91. The ultrasonic waves are transmitted and received one by one with respect to the included scanning lines IL. And the transmission / reception part 3 transmits / receives an ultrasonic wave once in order with respect to four scanning lines contained in an individual area | region one after another under control of the scanning control part 91. FIG.

  Then, the transmission / reception unit 3 scans the individual regions S1, S2, S3, S4,... Along the sub-scanning direction Y with ultrasonic waves under the control of the scan control unit 91, so that the entire imaging region S is scanned. Scan. As will be described later, the image generation unit 6 generates color Doppler image data in a cross section (image generation plane) along the sub-scanning direction Y.

  The signal processing unit 4 includes a B mode processing unit 41 and a CFM processing unit 42. The data output from the transmission / reception unit 3 is subjected to predetermined processing in any of the processing units.

  The B-mode processing unit 41 visualizes echo amplitude information and generates B-mode ultrasonic raster data from the echo signal. Specifically, the B-mode processing unit 41 performs band-pass filter processing on the signal sent from the transmission / reception unit 3, then detects the envelope of the output signal, and performs logarithmic conversion on the detected data. Apply compression processing.

  The CFM processing unit 42 visualizes the moving blood flow information and generates color ultrasonic raster data. Blood flow information includes information such as speed, dispersion, and power, and blood flow information is obtained as binarized information. Specifically, the CFM processing unit 42 includes a phase detection circuit, an MTI filter, an autocorrelator, and a flow velocity / dispersion calculator. The CFM processing unit 42 performs a high-pass filter process (MTI filter process) for separating the tissue signal and the blood flow signal, and provides blood flow information such as blood flow velocity, dispersion, and power by autocorrelation processing. Ask for points. In addition, non-linear processing for reducing and reducing tissue signals may be performed.

  Further, the signal processor 4 may be provided with a Doppler processor. The Doppler processing unit extracts a Doppler shift frequency component by performing phase detection on the reception signal output from the transmission / reception unit 3, and further performs an FFT process to generate a Doppler frequency distribution representing the blood flow velocity.

  The ultrasonic raster data processed by the signal processing unit 4 is output to the image storage unit 5 and stored in the image storage unit 5.

  The image generation unit 6 generates image data based on the ultrasound raster data stored in the image storage unit 5 under the control of the image generation control unit 92. For example, the image generation unit 6 includes a DSC (Digital Scan Converter), and converts the ultrasonic raster data after signal processing represented by the scanning line signal sequence into image data represented by orthogonal coordinates. (Scan conversion process). For example, the image generation unit 6 generates B-mode image data representing the tissue shape of the subject by performing scan conversion processing on the B-mode ultrasound raster data subjected to signal processing by the B-mode processing unit 41. . The image generation unit 6 generates color Doppler image data (color flow mapping data) by performing scan conversion processing on the color ultrasonic raster data subjected to signal processing by the CFM processing unit 42.

  For example, when the volume data is acquired by scanning the imaging region S with ultrasonic waves, the image generation unit 6 performs two-dimensional B-mode image data (hereinafter referred to as “two-dimensional B”) on an arbitrary cross section based on the volume data. Mode image data) and two-dimensional color Doppler image data (hereinafter referred to as “two-dimensional color Doppler image data”) in an arbitrary cross section. In addition, the image generation unit 6 performs volume rendering on the volume data, thereby performing three-dimensional B-mode image data (hereinafter referred to as “three-dimensional B-mode image data”) or three-dimensional color Doppler image data (hereinafter referred to as “three-dimensional B-mode image data”). , Referred to as “three-dimensional color Doppler image data”).

  The display control unit 7 causes the display unit 81 to display an image based on the image data generated by the image generation unit 6. For example, the display control unit 7 causes the display unit 81 to display a two-dimensional B-mode image based on the two-dimensional B-mode image data and a two-dimensional color Doppler image based on the two-dimensional color Doppler image data. Further, the display control unit 7 may display the two-dimensional B-mode image and the two-dimensional color Doppler image on the display unit 81 in a superimposed manner. When the image generation unit 6 generates 3D B-mode image data or 3D color Doppler image data, the display control unit 7 displays the 3D B mode image or 3D color Doppler image on the display unit 81. Display.

  Here, an image generation method by the image generation unit 6 and the image generation control unit 92 will be described with reference to FIG. The setting information storage unit 93 of the control unit 9 stores cross-sectional coordinate information for generating two-dimensional color Doppler image data as an image generation condition. In this embodiment, coordinate information of a cross section orthogonal to the main scanning direction X is stored in the setting information storage unit 93 as an image generation condition. Specifically, coordinate information of the cross-sections 100, 200, 300, and 400 orthogonal to the main scanning direction X is stored in the setting information storage unit 93.

  The image generation control unit 92 outputs the cross-sectional coordinate information stored in the setting information storage unit 93 to the image generation unit 6. Upon receiving the cross-sectional coordinate information from the image generation control unit 92, the image generation unit 6 generates two-dimensional color Doppler image data in a cross section orthogonal to the main scanning direction. In the example illustrated in FIG. 2, the image generation unit 6 generates two-dimensional color Doppler image data in a cross section along the sub-scanning direction Y orthogonal to the main scanning direction X. For example, the image generation unit 6 generates two-dimensional color Doppler image data in the cross section 100 orthogonal to the main scanning direction X. Then, the display control unit 7 causes the display unit 81 to display the two-dimensional color Doppler image in the cross section 100.

  The operator can specify a desired cross section among the cross sections 100, 200, 300, and 400 orthogonal to the main scanning direction X by using the operation unit 82. The image generation unit 6 receives the coordinate information of the cross section specified by the operator via the image generation control unit 92, and generates two-dimensional color Doppler image data in the specified cross section. Then, the display control unit 7 causes the display unit 81 to display a two-dimensional color Doppler image of the specified cross section.

  The image generation unit 6 may generate two-dimensional color Doppler image data of one cross section, or may generate two-dimensional color Doppler image data for each of a plurality of cross sections. For example, when the operator specifies a plurality of cross sections using the operation unit 82, the image generation unit 6 generates two-dimensional color Doppler image data for each of the specified plurality of cross sections. The display control unit 7 displays each two-dimensional color Doppler image on the display unit 81.

  For example, the cross section 100 is configured by scanning lines included in different individual regions. Therefore, the two-dimensional color Doppler image data in the cross section 100 is generated based on data acquired by scanning lines included in different individual regions. The cross section 100 includes a scanning line A belonging to the individual area S1, a scanning line E belonging to the individual area S2, a scanning line I belonging to the individual area S3, a scanning line M belonging to the individual area S4,. The data acquired by the scanning line A and the data acquired by the scanning line E are data at adjacent positions in the same cross section 100. Further, the data acquired by the scanning line E and the data acquired by the scanning line I are data at adjacent positions in the same cross section 100. Furthermore, the data acquired by the scanning line I and the data acquired by the scanning line M are data at adjacent positions in the same cross section 100.

  In the scanning lines A, E, I, M,... In the cross section 100, the time interval (time difference) at which data is acquired is constant between adjacent scanning lines. For example, the time difference between the scanning line A and the scanning line E, the time difference between the scanning line E and the scanning line I, and the time difference between the scanning line I and the scanning line M are constant. .

  As described above, the time difference of the data acquired by each scanning line is constant in the cross section that becomes the image generation surface, so that the time difference is partially increased on the image generation surface unlike the conventional technique. There is no. As a result, on the two-dimensional color Doppler image, the level difference due to the time difference at which the data is acquired becomes less conspicuous, and it is possible to prevent the diagnosis from being hindered.

  Also, for the scanning lines B, F, J, N,... In the cross section 200, the time interval (time difference) at which data is acquired is constant between adjacent scanning lines. Therefore, even on the two-dimensional color Doppler image in the cross section 200, a step due to the time difference is less noticeable. Even in the two-dimensional color Doppler images in the cross-sections 300 and 400, the step due to the time difference is less noticeable.

  Furthermore, the time interval (time difference) at which data is acquired is constant between the cross sections. In addition, the time difference at which data is acquired is smaller between the cross sections than the time difference according to the prior art. For example, the time difference between the scanning line A included in the cross section 100 and the scanning line B included in the cross section 200 and the time difference between the scanning line B included in the cross section 200 and the scanning line C included in the cross section 300 are constant. Furthermore, the time difference is smaller than that of the prior art. Thus, according to this embodiment, it is possible to keep the time interval (time difference) at which data is acquired constant between cross sections (between image generation planes) and further reduce the time difference. As a result, even in a three-dimensional color Doppler image, it is possible to make the image level difference caused by the time difference less noticeable.

  Further, according to this embodiment, the sampling period on each scanning line is quadrupled. That is, since the first transmission to the scanning line A is in the order “1” and the second transmission is in the order “5”, the sampling period on the scanning line is 4T. In other words, it is possible to increase the sampling cycle without lowering the frame rate (volume rate) and to cope with the measurement of a low blood flow velocity.

  The user interface 8 includes a display unit 81 and an operation unit 82. The display unit 81 includes a monitor such as a CRT or a liquid crystal display, and displays a color Doppler image, a B-mode image, or the like on the screen. The operation unit 82 includes a pointing device such as a joystick or a trackball, a switch, various buttons, a keyboard, or a TCS (Touch Command Screen).

  The control unit 9 includes a scan control unit 91, an image generation control unit 92, and a setting information storage unit 93. The control unit 9 is connected to each part of the ultrasonic diagnostic apparatus 1 and controls the operation of each part of the ultrasonic diagnostic apparatus 1.

  The setting information storage unit 93 stores ultrasonic transmission / reception conditions (transmission / reception conditions) by the transmission / reception unit 3. Further, the setting information storage unit 93 stores conditions for generating an image (image generation conditions) by the image generation unit 6. As described above, the scan control unit 91 causes the transmission / reception unit 3 to transmit / receive ultrasonic waves according to the transmission / reception conditions stored in the setting information storage unit 93. Further, as described above, the image generation control unit 92 outputs the image generation conditions stored in the setting information storage unit 93 to the image generation unit 6 and controls the generation of image data by the image generation unit 6.

  The control unit 9 includes a CPU and a storage device such as a ROM and a RAM. The storage device stores a control program for executing the function of the control unit 9. The control program includes a scan control program for executing the function of the scan control unit 91 and an image generation control program for executing the function of the image generation control unit 92. The CPU controls the transmission / reception of ultrasonic waves by the transmission / reception unit 3 according to the transmission / reception conditions stored in the setting information storage unit 93 by executing the scan control program. Further, the CPU executes the image generation control program to output the image generation conditions stored in the setting information storage unit 93 to the image generation unit 6 and cause the image generation unit 6 to generate image data.

  Further, the image generation unit 6 includes a CPU and a storage device such as a ROM and a RAM. The storage device stores an image generation program for executing the functions of the image generation unit 6. The CPU generates image data by executing an image generation program. For example, the CPU generates two-dimensional color Doppler image data in a cross section orthogonal to the main scanning direction X by executing an image generation program.

  As described above, a plurality of scanning lines along the main scanning direction X are grouped into one individual area, ultrasonic waves are transmitted / received for each individual area, and further, based on a reception signal acquired by the transmission / reception, By generating two-dimensional color Doppler image data in a cross section (image generation plane) orthogonal to the main scanning direction X, it is possible to make the time difference between the data acquired by each scanning line constant on the image generation plane. . Thus, unlike the prior art, there is no part where the time difference is partially increased on the image generation surface, so that it is possible to prevent the occurrence of a large step due to the time difference in the two-dimensional color Doppler image data. . Since a large step does not occur, the step due to the time difference becomes inconspicuous on the two-dimensional color Doppler image, and it is possible to prevent the diagnosis from being hindered.

  In the above-described embodiment, a case has been described in which the number of cross sections (image generation planes) is equal to the number of scanning lines included in one individual region (the number of alternating stages). As an example, the case where the number of cross sections is 4 and the number of alternating stages is 4 has been described. Next, a case where the number of cross sections is larger than the number of alternating steps will be described. In this case, it is preferable to set the total number of cross sections to an integral multiple of the number of alternating stages and transmit / receive ultrasonic waves. That is, it is preferable that the total number of scanning lines (total number of cross sections) arranged along the main scanning direction is an integral multiple of the number of scanning lines included in one individual region (alternate number of stages). For example, as in the above-described embodiment, when the number of alternating stages is 4, the number of cross sections is preferably 4, 8, 12, 16,. The number of cross sections and the number of alternating stages are stored in the setting information storage unit 93 as transmission / reception conditions. The scan control unit 91 sets the number of cross sections to an integral multiple of the number of alternate stages according to the transmission / reception conditions, and causes the transmission / reception unit 3 to transmit / receive ultrasonic waves.

  For example, when the number of alternating stages is 4 and the number of cross sections is 8, the scan lines included in the fourth cross section from the scan lines included in the first cross section are included in one individual region and included in the fifth cross section. The scanning line included in the eighth cross section from the scanning line to be included is included in another individual area. In this way, the number of scanning lines included in each individual area (alternate number of stages) is set to 4, the cross section is divided into two individual areas, and four scanning lines are included in each individual area. The transmission / reception unit 3 transmits / receives ultrasonic waves for each individual region under the control of the scan control unit 91.

  As described above, by setting the number of cross sections to be an integral multiple of the number of alternating stages, it is possible to easily control transmission / reception of ultrasonic waves, and it is possible to efficiently scan the imaging region S.

  Note that there is a difference in the acquired time between the data acquired in the fourth section and the data acquired in the fifth section. In this case, a filtering process may be performed to make the step on the image based on the time difference less noticeable.

[Modification]
Next, a modified example of the ultrasonic diagnostic apparatus 1 according to the above-described embodiment will be described. In this modified example, the scan control unit 91 takes in an ECG signal from the outside, changes the individual area to be scanned at a predetermined timing according to the ECG signal, and causes the transmission / reception unit 3 to transmit / receive ultrasonic waves.

  In this modification, an ECG signal (electrocardiographic waveform) of the subject is acquired by an electrocardiograph, and the ECG signal is output to the scan control unit 91. The scan control unit 91 receives the ECG signal output from the electrocardiograph and measures the timing for switching the individual area to be scanned. For example, the scan control unit 91 detects an R wave from the ECG signal, and switches the individual area to be scanned each time the R wave is detected, and causes the transmission / reception unit 3 to scan another individual area. That is, the scan control unit 91 causes the transmission / reception unit 3 to scan the same individual area until the next R wave is detected. In other words, the scan control unit 91 causes the transmission / reception unit 3 to scan by changing the individual area for each heartbeat. In this way, the scan control unit 91 causes the transmission / reception unit 3 to scan by changing the individual area to be scanned, using the detection of the R wave as a trigger. The scan control unit 91 uses the detection of the R wave as a trigger, but the individual area may be changed using a waveform other than the R wave as a trigger.

  For example, the case where the imaging region S shown in FIG. 2 is scanned will be described. Similarly to the above-described embodiment, the transmission / reception unit 3 transmits / receives ultrasonic waves in turn to the scanning lines A, B, C, and D in order for the individual region S1 under the control of the scan control unit 91, Ultrasound is transmitted and received 6 times for each scanning line. When the scan control unit 91 detects an R wave from the ECG signal, the scan target is switched from the individual region S1 to the individual region S2, and the individual region S2 is scanned by the transmission / reception unit 3. As described above, each time the R control wave is detected from the ECG signal, the scan control unit 91 switches the scan target from the individual area S1 to the individual area S2, and further switches from the individual area S2 to the individual area S3. The area is scanned by the transmission / reception unit 3.

  As described above, each time an R wave is detected, the individual area to be scanned is changed and scanned, so that one individual area is scanned with ultrasonic waves in one heartbeat. Although the time at which data at the boundary of each individual region is acquired differs for each individual region, since one individual region is scanned with one heartbeat, the time phases during one heartbeat are almost the same.

  For example, the scanning line A shown in FIG. 2 is included in the individual area S1, and the scanning line E is included in the individual area S2. The data acquired on the scanning line A and the data acquired on the scanning line E are different in time acquired, but the time phases during one heartbeat are almost the same. In this way, even when the acquired times are different, the difference in time phase when the data at the boundary of each individual area is acquired becomes small. As a result, on the two-dimensional color Doppler image on the image generation surface such as the cross section 100, it is possible to prevent the occurrence of a large step between the individual regions.

1 is a block diagram showing an ultrasonic diagnostic apparatus according to an embodiment of the present invention. It is a figure for demonstrating the transmission / reception method of the ultrasonic wave which concerns on embodiment of this invention. It is a figure for demonstrating the transmission / reception method of the ultrasonic wave which concerns on a prior art. It is a figure for demonstrating the transmission / reception method of the ultrasonic wave which concerns on a prior art. It is a figure for demonstrating the time when the data on each scanning line were acquired in the transmission / reception method of the ultrasonic wave which concerns on a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ultrasonic diagnostic apparatus 2 Ultrasonic probe 3 Transmission / reception part 4 Signal processing part 5 Image memory | storage part 6 Image generation part 7 Display control part 8 User interface (UI)
DESCRIPTION OF SYMBOLS 9 Control part 41 B mode process part 42 CFM process part 81 Display part 82 Operation part 91 Scan control part 92 Image generation control part 93 Setting information storage part

Claims (3)

Transmitting / receiving means for transmitting ultrasonic waves to the subject and receiving reflected waves from the subject;
A plurality of scanning lines included in each of a plurality of cross sections substantially orthogonal to the main scanning direction arranged in the main scanning direction are grouped into one individual area along the main scanning direction and included in the individual area. Until the number of times of transmission / reception of ultrasonic waves to / from each scanning line reaches a predetermined number, the transmission / reception means transmits / receives ultrasonic waves one by one to each scanning line in order, When the number of transmissions / receptions reaches the predetermined number, the transmission / reception means is sent to the transmission / reception unit until the number of ultrasonic transmissions / receptions reaches the predetermined number for another individual region in the sub-scanning direction substantially orthogonal to the main scanning direction Scanning control means for transmitting and receiving ultrasonic waves one by one in order to each scanning line, and causing the transmitting and receiving means to transmit and receive ultrasonic waves for each of a plurality of individual regions;
Image generation means for generating color Doppler image data of at least one of the plurality of cross sections based on a reception signal acquired by transmission and reception of ultrasonic waves by the transmission and reception means;
Display control means for displaying a color Doppler image based on the color Doppler image data on a display means;
An ultrasonic diagnostic apparatus comprising:   The scan control unit causes the transmission / reception unit to transmit / receive an ultrasonic wave by setting the total number of the plurality of cross sections arranged in the main scanning direction to an integral multiple of the number of scanning lines included in the one individual region. The ultrasonic diagnostic apparatus according to claim 1.   The scan control unit causes the transmission / reception unit to transmit / receive an ultrasonic wave at the predetermined timing based on the ECG signal of the subject, with respect to the other individual region. The ultrasonic diagnostic apparatus in any one.

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