JP3917929B2 - Ultrasonic diagnostic equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an ultrasonic diagnostic apparatus that scans an ultrasonic beam over a three-dimensional region of a living body and forms and displays a three-dimensional image of the region.
[0002]
[Prior art]
Currently, an apparatus that scans an ultrasonic beam with respect to a three-dimensional region in a living body to form and display a three-dimensional image of a tissue has been put into practical use. The three-dimensional image is obtained, for example, by processing the echo data of the ultrasonic beam by the volume rendering method, as described in JP-A-10-33538, JP-A-10-277030, and the like. It is possible to represent the tissue three-dimensionally. As other methods for imaging a three-dimensional region, a surface extraction method, an integration method, a projection method, and the like are known.
[0003]
In the ultrasonic diagnostic apparatus, an ultrasonic beam is scanned in a first direction, echo data from a scanning plane including a plurality of ultrasonic beams is captured, and at the same time, the scanning plane is scanned in a second direction. Echo data from a three-dimensional region including the scanning plane is acquired. By such an ultrasonic beam scanning method, echo data from a three-dimensional region can be obtained. All scanning of the three-dimensional region of the ultrasonic beam is performed at a predetermined frame rate (Hz). This frame rate is determined by the transmission / reception depth and number of ultrasonic beams.
[0004]
In the volume rendering method, pixel data for one pixel of a three-dimensional image is calculated by performing arithmetic processing on echo data of one ultrasonic beam. Therefore, pixel data for one line is calculated by computing echo data from one scanning plane, and pixel data for one frame is computed by processing echo data from a three-dimensional region including a plurality of scanning planes. Will be calculated. Since the ultrasonic diagnostic apparatus repeatedly performs scanning of the ultrasonic beam at the above frame rate and performs arithmetic processing on the obtained echo data, the three-dimensional image is repeatedly calculated at the above frame rate.
[0005]
Further, in the ultrasonic diagnostic apparatus according to the related art, when displaying the 3D image calculated as described above on the screen of the monitor, one of the following two display modes is used as a method for updating the screen display. Is used.
[0006]
The first display mode is a method called a line unit display mode. As shown in FIG. 3A, each time the pixel data for one line is calculated by scanning an ultrasonic beam on each scanning plane. In this method, one line is rewritten. In this line unit display mode, the three-dimensional image 14 is rewritten for each line, and there is an advantage that the follow-up performance of the screen display with respect to the movement of the probe is improved. There are disadvantages that are annoying to the user.
[0007]
The second display mode is a method called a frame unit display mode. As shown in FIG. 3B, an ultrasonic beam is scanned over a three-dimensional area to calculate one frame of image data. This is a method of displaying one frame of a three-dimensional image every time. In this frame unit display mode, since there is no transition 12 of the screen display as described above, the screen display is easy to see, but since the display of the three-dimensional image is after the entire scanning of the ultrasonic beam is completed, the new tertiary The cycle until the original image is displayed becomes long, the follow-up performance of the screen display with respect to the movement of the probe is poor, and the user operability is deteriorated.
[0008]
[Patent Document 1]
JP-A-10-33538 [Patent Document 2]
JP-A-10-277030 [0009]
[Problems to be solved by the invention]
In addition, in order to adjust the real-time property of the screen display, the ultrasonic diagnostic apparatus of the prior art has a function of changing the interval of ultrasonic beams to be scanned to adjust the data density and changing the frame rate. Yes.
[0010]
In the normal case of obtaining echo data with a high data density, since the ultrasonic beams are transmitted and received at a narrow interval, it takes time to transmit and receive all the ultrasonic beams, and the frame rate is small. When the frame unit display mode is used in such a situation, there is a problem that the followability of the screen display is remarkably deteriorated and the user cannot know the real-time situation in the living body.
[0011]
In addition, if the frame rate is increased by increasing the interval between ultrasonic beams in order to improve the real-time performance of image display, using the line-by-line display mode speeds up the movement of the image on the screen. There is a problem that it becomes noticeable.
[0012]
As mentioned above, the situation where a problem occurs in the display of 3D images due to the size of the frame rate is given as an example, but if the above problem is generalized, the optimal display method for screen display will change depending on the situation It is.
[0013]
In order to solve the above-described problems, an object of the present invention is to provide an ultrasonic diagnostic apparatus in which a display mode is automatically optimized.
[0014]
[Means for Solving the Problems]
In order to achieve the above object, an ultrasonic diagnostic apparatus according to the present invention includes a transmission / reception unit that captures a plurality of echo data by scanning an ultrasonic beam over a three-dimensional region of a living body, and the plurality of echoes. Based on the data, an image forming unit that forms a three-dimensional image in which one frame is composed of a plurality of lines, and in the line unit display mode, the lines are sequentially displayed each time one line is formed by the image forming unit. A line unit display processing means for displaying a 3D image, and a frame unit display for displaying a 3D image each time a 3D image is formed by the 3D image forming unit in the frame unit display mode. Select the line unit display mode or the frame unit display mode based on processing means and reference information for mode selection Display mode selecting means that is those with.
[0015]
In the present invention, by selecting a display mode based on such reference information, it is possible to always display a three-dimensional image on the screen in a display mode optimal for the situation. Further, since the display mode is automatically selected, the user does not need to change the display mode and the operability of the ultrasonic diagnostic apparatus is improved.
[0016]
The reference information for mode selection includes, for example, operating conditions of the ultrasonic diagnostic apparatus, diagnostic part, diagnostic subject, patient name, diagnostician name, and the like. As the operating conditions of the ultrasonic diagnostic apparatus, ultrasonic transmission / reception conditions such as the transmission / reception depth of ultrasonic waves, the number of beams, or a frame rate related to formation of a three-dimensional region determined by these values can be considered.
[0017]
When the reference information is a frame rate of the 3D image, the display mode selection unit selects the line unit display processing unit when the frame rate is smaller than a predetermined threshold, and the frame rate is If it is larger than the predetermined threshold value, the frame unit display processing means may be selected. As a result, a three-dimensional image is displayed for each frame when the frame rate is high, so there is no change in screen display, and the image is easy for the user to see, and when the frame rate is low, a three-dimensional image is displayed for each line. Since the image is displayed, the image has good followability to the movement of the ultrasonic probe.
[0018]
Moreover, in one aspect of the present invention, each line is formed for each scanning plane of the ultrasonic beam. The three-dimensional image is formed based on a volume rendering method.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing the overall configuration of the ultrasonic diagnostic apparatus according to the present embodiment.
[0020]
The ultrasonic probe 22 includes a linear array type ultrasonic transducer disposed toward a three-dimensional region of a living body when in use, and electronically controls ultrasonic waves from the ultrasonic transducer. Thus, the ultrasonic beam is scanned in the X direction. The ultrasonic probe 22 includes a drive unit 24 having a motor, and the ultrasonic beam is mechanically scanned in the Z direction by the drive unit 24. By scanning the ultrasonic beam in the X direction, echo data from the scanning plane 10 spreading in the XY direction can be obtained. Further, echo data from a plurality of scanning planes 10 stacked in the Z direction can be obtained by scanning the ultrasonic beam in the Z direction. All scanning of the ultrasonic beam to the three-dimensional region is repeated at a predetermined cycle. This period is called a volume rate (Hz).
[0021]
The echo data acquired for each ultrasonic beam is sequentially output from the ultrasonic probe 22 to the transmission / reception unit 30. The rotary encoder 26 detects the coordinate in the Z direction of the ultrasonic probe 22 and outputs it to a digital scan converter (DSC) in the display control unit 28 described later. In this embodiment, the scanning of the ultrasonic beam in the Z direction is performed mechanically, but even if the ultrasonic beam is scanned electronically using a two-dimensional array type ultrasonic transducer. Good.
[0022]
The transmission / reception unit 30 supplies a transmission signal to the ultrasonic probe 22 and processes a reception signal output from the ultrasonic probe 22. The transmitter / receiver 30 outputs the echo data every time echo data of each ultrasonic beam is obtained. The echo data output from the transmission / reception unit 30 is first amplified by the amplifier 32, then logarithmically amplified by the LOG amplifier 34, converted into a digital signal by the A / D converter 36, and then sent to the image processing unit 38. Sent.
[0023]
The image processing unit 38 performs arithmetic processing on the echo data based on the volume rendering method to form a stereoscopic projection image of a three-dimensional area. That is, every time echo data of one ultrasonic beam is input, the image processing unit 38 performs an operation on the echo data by the volume rendering method, and calculates the operation data for each point on the ultrasonic beam. calculate. Based on these calculation data, pixel data of a three-dimensional image obtained by projecting the echo data of the ultrasonic beam in the Y direction is calculated. By performing such processing on the echo data of the ultrasonic beam included in one scanning plane, pixel data of a plurality of pixels constituting one line of the three-dimensional image is calculated, and by performing the processing on all the ultrasonic beams, the third order Pixel data of a plurality of pixels constituting one frame of the original image is calculated. This three-dimensional image is calculated at the above-described volume rate, that is, the frame rate (Hz) for obtaining a one-dimensional three-dimensional image. The calculated pixel data is output to the display control unit 28. In the present embodiment, calculation processing by the volume rendering method is performed, but calculation processing by an integration method, a projection method, or the like may be performed. In this embodiment, the projection is performed for each ultrasonic beam, that is, the projection is performed in the Y direction, but the projection may be performed in the X direction and the Z direction.
[0024]
The display control unit 28 includes a DSC including a display memory capable of storing a one-dimensional three-dimensional image, a line unit display processing unit that performs line unit display mode display, and a frame unit display that performs display control in the frame unit display mode. A processing unit is provided. When the pixel data of the three-dimensional image is input from the image processing unit 38, the display control unit 28 writes the pixel data into the display memory. At this time, pixel data of each pixel is specified by the X address and Z address of the ultrasonic beam, and these are written in association with the X and Z addresses on the display memory.
[0025]
One of the line unit display processing unit and the frame unit display processing unit is selected by the processing described later. When the line unit display processing unit is selected, the pixel data is received from the image processing unit 38. Every time it is input, that is, every line, it is written into the display memory. When the frame unit display processing unit is selected, the pixel data is written into the display memory every time one frame of pixel data is input. The three-dimensional image stored in the display memory is read at a cycle in which the display 42 updates the display, is converted back to an analog signal by the D / A converter 40, is sent to the display 42, and is displayed on the screen. Is displayed.
[0026]
In addition, the ultrasonic diagnostic apparatus is provided with a data density adjuster 44 for adjusting the data density of the echo data. The data density adjuster 44 includes a changeover switch and a rotary knob for adjusting the data density. When the data density is adjusted by the user, the data density value signal is transmitted to the transmission / reception unit 30, the drive unit 24, and the display. The data is output to the mode selection unit 46. The transmission / reception unit 30 adjusts the interval in the X direction of the ultrasonic beam transmitted from the linear array transducer based on the input data density value. Further, the drive unit 24 adjusts the interval in the Z direction of the ultrasonic beam based on the input data density value.
[0027]
The display mode selection unit 46 performs the following processing shown in FIG. First, the display mode selection unit 46 calculates the frame rate based on the transmission / reception depth of the ultrasonic waves inside the living body and the number of beams scanned by the ultrasonic waves (S201). Next, this frame rate is compared with a predetermined threshold value n (Hz) (S202). If the frame rate is smaller than the predetermined threshold value n, a selection signal for selecting the line unit display mode is output to the display control unit 28 (S203). If the frame rate is larger than the predetermined threshold value, the frame unit display is performed. A selection signal for selecting a mode is output to the display control unit 28 (S204). The display control unit 28 selects one of the two display control units according to the input selection signal, and performs a process of writing pixel data to the display memory.
[0028]
The selection of the display mode of the three-dimensional image is a characteristic process in this embodiment. With this, when the frame rate is high, the frame unit display mode is selected, and an image without a change in display is displayed on the screen. The image displayed on the screen can be easily viewed by the user. On the other hand, when the frame rate is slow, the line-by-line display mode is selected, and the screen display is sequentially displayed for each line. Therefore, an image with good followability to the movement of the ultrasound probe 22 is displayed on the screen. be able to. In this embodiment, since the display mode is automatically selected, the user does not need to change the setting and can make a diagnosis smoothly.
[0029]
In the above-described embodiment, the reference information for mode selection is the frame rate of the 3D image, and the display method of the screen display is changed based on this. However, the reference information is not limited to this. Other reference information includes, for example, operating conditions of the ultrasonic diagnostic apparatus, diagnostic site, diagnostic subject, patient name, diagnostician name, and the like. The operating conditions of the ultrasonic diagnostic apparatus include, for example, ultrasonic transmission / reception depth, the number of beams, and the like. In the above embodiment, the frame rate is calculated based on the ultrasonic transmission / reception depth and the number of beams. However, in other embodiments, the frame rate is measured based on the operation of the ultrasonic diagnostic apparatus. Is also possible. Further, the ultrasonic diagnostic apparatus may be configured such that the user can arbitrarily set the predetermined threshold value n, or the ultrasonic diagnostic apparatus may be configured so that the predetermined threshold value n is automatically changed according to the situation. Each of the above embodiments can be configured by hardware, but can also be configured by software.
[0030]
【The invention's effect】
In the present invention, a line unit display mode or a frame unit display mode is selected based on reference information for mode selection, and a 3D image is displayed in a display mode suitable for the situation. It can be.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an overall configuration of an ultrasonic diagnostic apparatus according to the present embodiment.
FIG. 2 is a flowchart showing processing performed by the ultrasonic diagnostic apparatus according to the present embodiment.
FIG. 3 is a diagram for explaining a line unit display mode and a frame unit display mode;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Scanning plane, 22 Ultrasonic probe, 24 Drive part, 26 Rotary encoder, 28 Display control part, 30 Transmission / reception part, 32 Amplifier, 34 LOG amplifier, 36 A / D converter, 38 Image processing part, 40 D / A converter, 42 display, 44 data density adjuster, 46 display mode selection section.

Claims (4)

A wave transmitting / receiving means for capturing a plurality of echo data by scanning an ultrasonic beam over a three-dimensional region of a living body;
A three-dimensional image forming unit that forms a three- dimensional image in which one frame is constituted by a plurality of lines based on the plurality of echo data;
In line unit display mode, a line unit display processing means for displaying a three-dimensional image by sequentially displaying the line every time one line is formed by the three-dimensional image forming unit;
In a frame unit display mode, frame unit display processing means for displaying a 3D image each time a 3D image of one frame is formed by the 3D image forming unit;
Display mode selection means for selecting the line unit display mode or the frame unit display mode based on reference information for mode selection;
Equipped with a,
The ultrasonic diagnostic apparatus according to claim 1, wherein the reference information for mode selection is a frame rate related to formation of the three-dimensional region . The ultrasonic diagnostic apparatus according to claim 1,
The display mode selection unit selects the line unit display processing unit when the frame rate is smaller than a predetermined threshold, and selects the frame unit display processing unit when the frame rate is larger than the predetermined threshold. An ultrasonic diagnostic apparatus. The ultrasonic diagnostic apparatus according to claim 1, wherein:
The ultrasonic diagnostic apparatus, wherein each line is formed for each scanning plane of the ultrasonic beam. The ultrasonic diagnostic apparatus according to any one of claims 1 to 3,
The ultrasonic diagnostic apparatus, wherein the three-dimensional image is formed based on a volume rendering method.

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