JPH0316561A - Ultrasonic diagnostic apparatus - Google Patents

Abstract

PURPOSE:To obtain an A-mode waveform of high resolving power by converting at least the speed data of M-mode data to position data and displaying A-mode data interpolated corresponding to interlaced scanning as an image. CONSTITUTION:In order to obtain A-mode data, the M-mode data 12a, 12b of the first and second fields are read on the basis of the control signal 14c from an M-mode Doppler data memory control circuit 14 and converted to the position data 16a, 16b of the first and second fields according to an address indication signal 18a by a rightness/position data converter circuit 16 to be outputted. An A-mode interpolation circuit 24 selects the position data of adjacent scanning lines from the position data 16a, 16b of the first and second fields to perform interpolation processing and outputs an A-mode waveform 24a. This waveform 24a becomes the output wave form of the first and second field data interpolated by interlaced scanning and the A-mode waveform is displayed as image at an accurate position with high resolving power.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an ultrasonic diagnostic apparatus, particularly an ultrasonic diagnostic apparatus that transmits and receives ultrasonic waves to and scans a subject to obtain A mode, M mode, or Dobra mode information, respectively. The present invention relates to an ultrasonic diagnostic device that displays images.

[Prior art] In the medical field, A-mode, M-mode, or Doppler mode information obtained by transmitting and receiving ultrasound waves to and from a subject and performing various types of scanning such as linear, sector, and competitive scans is displayed as a diagnostic image of the affected area. Ultrasonic diagnostic equipment is widely used.

In this type of diagnostic equipment, the ultrasound diagnostic method includes:
There are various types of display, such as A mode and M mode display based on pulse reflection method, and Dobra mode display based on Dobra method, and each mode display has an extremely wide range of use and is used for diagnosing organs and parts of a subject.

In particular, in the pulse reflection method, which is a method of capturing reflected echoes from the interface between two materials with different acoustic impedances,
A-mode display is a method in which echoes generated on an ultrasound beam traveling in a straight line inside the subject are depicted as a one-dimensional waveform, with the vertical axis representing the time axis and the horizontal axis representing the waveform representing the size of the echo. The image is displayed. In this case, if the speed of sound is constant, the time axis indicates distance, and the position of the reflector can be measured in A mode.

In this A mode display, the size and shape of the reflector,
Although it is not possible to intuitively grasp 3D positional relationships, it has the characteristics of being inexpensive, easy to handle, and has a wide range of applications. It has become possible to obtain a lot of information such as the size of each part, their qualitative differences (echo intensity), and the movement status and speed of each tissue.

In other words, in this M mode display, the probe is moved over the subject, and the intensity of the reflected echo as well as the frequency shift due to the Dobra effect is expressed as the intensity of a bright spot on the image display, which is swept at a constant speed on the time axis. It can be regarded as a type of motion curve of each tissue within the subject.

Therefore, the echo distribution of one cross-section of the scanned test region is displayed as a two-dimensional image.

Also, one of the methods using the reflection method is the Dobra mode display, which also uses the Dobra effect, and measures the moving speed of the reflector from the difference in frequency.

Therefore, in this Dobra mode display, the velocity distribution of blood flow etc. is superimposed on one cross-sectional image and displayed in two dimensions, making it possible to observe the movement and movement of the examined part in the tomographic image.For example, the observation of cardiac valves, It is used for testing intravascular blood flow.

In recent years, in this type of ultrasonic diagnostic apparatus, each of the above A modes,
Taking advantage of the characteristics of M mode and Dobra mode display, a single device is used to display images individually or simultaneously depending on the region to be examined or the diagnostic situation.

[Problems to be Solved by the Invention] However, in the past, M mode, Dobra information memory and A
It is necessary to provide two memories independent of the mode information memory, which increases the memory capacity and is wasteful. Furthermore, in the control system, two memory control circuits corresponding to each memory are required, making the circuit complicated.

Therefore, in order to simplify the control system and reduce the memory capacity, the applicant proposed an ultrasonic diagnostic device that converts speed information of M mode information into position information and outputs A mode information. ing.

That is, this conventional ultrasonic diagnostic apparatus has a display memory that stores M-mode information detected from received echo components, and reads speed information of the M-mode information by an A-mode display circuit to display A-mode information. It converts it into positional information and outputs an A-mode waveform.

As a result, it has become possible to display images of M-mode information having speed information stored in the display memory and A-mode information at a predetermined time phase of the M-mode information individually or simultaneously in real time. .

However, in the conventional apparatus, it was not possible to obtain a high resolution of the A-mode waveform displayed on a television monitor or the like as shown in FIG.

That is, normally, when displaying the above-mentioned mode waveforms as images on a television monitor or the like, both the first field scan (odd number scan) and the second field scan (even number scan) are used as interlaced scanning, as shown in FIG. However, the A mode information only had information for one pixel in one scanning line as position information.

Therefore, for each field, or each scan line,
Only one pixel could be output and displayed, making it impossible to obtain sufficient resolution.

On the other hand, when displaying the M-mode waveform as an image, the echo distribution of a new surface of the scanned area as velocity information is 2
Since the image is visualized dimensionally, a certain degree of resolution has been obtained even with one field scan, but in the A-mode waveform of the position information mentioned above, information at a predetermined time phase of the M-mode waveform is converted into a one-dimensional waveform. Therefore, even if the first and second field scans were performed, an accurate A-mode waveform could not be obtained.

OBJECTS OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and its purpose is to convert at least speed information of M mode information into position information, and convert A mode information interpolated in correspondence with interlaced scanning. The objective is to provide a high-resolution A-mode waveform by displaying the image.

[Means for Solving the Problems] In order to achieve the above object, the ultrasonic diagnostic apparatus according to the present invention performs interlaced scanning to obtain velocity information for displaying at least M mode information as an image from a received echo. an interlaced scanning memory which is stored separately in first and second field scanning in correspondence with the first and second field scanning, and speed information is read from the interlaced scanning memory for each field scanning and converted into positional information as A mode information. A brightness/position information conversion circuit and the converted position information are used manually to select position information of adjacent scanning lines from the first field information and second field information and perform interpolation processing, resulting in interpolated A mode. It has an A-mode interpolation circuit that outputs information, and is characterized in that it obtains a high-resolution A-mode waveform by image processing the interpolated A-mode information.

[Operations] Since the above structure is adopted, according to the present invention, at least the M mode information of the echo component received from the subject is scanned in the first and second modes for image display in accordance with interlaced scanning. It is stored separately in field scans. Then, the stored speed information for each field is read out and converted to position information to obtain A mode information. Then, from this converted A mode information, an A mode interpolation circuit uses the first field information and the first field information. Interpolation processing is performed by selecting positional information of adjacent scanning lines from the two-field information.

As a result, by displaying the interpolated A-mode information as an image, a high-resolution A-mode waveform can be obtained.

[Embodiment] Hereinafter, a preferred embodiment of the present invention will be described based on the circuit block diagram of FIG. 1 and FIG. 2.

The characteristic feature of the present invention is that at least speed information for displaying M mode information is stored in correspondence with interlaced scanning, converted into position information, and interpolated from first and second field information. The objective is to display an image of an A-mode waveform by obtaining A-mode information.

In the circuit block diagram of FIG. 1, the circuit configuration will be explained below.

The A/D converter 10 is a converter for converting the Doppler frequency shift extracted from the received echo as speed information into a predetermined digital signal. This memory stores speed information for forming the M mode and Dobra mode output from the D converter 10, and this display memory 12 supports interlaced scanning for displaying images on a television monitor, etc. Speed information is stored separately for the first field scan and the second field scan.

The M-mode Dobra information memory control circuit 14 is a control circuit for controlling writing/reading of the digital signal output from the A/D converter 10 into the M-mode Dobra information display memory 12 in units of one pixel. That is, this memory control circuit 14 is for controlling the writing or reading of M mode and Doppler mode information in correspondence with the first and second fields of the television monitor. A write enable signal 14a is output to the write/read address of the display memory 12.

Further, a control signal 14c is outputted in order to convert speed information as M mode and Dobra mode information into position information and control it.

The brightness/position information conversion circuit 16 is for reading the speed information stored in the M-mode Doppler information display memory 12, converting it into position information, and outputting the A-mode information.

The conversion address generation circuit 18 is a circuit for comparing the brightness information of the M mode and Doppler mode information with the address in the horizontal scanning direction of the television image in the brightness/position information conversion circuit 16, specifying the position, and converting it into position information. It is.

The latch 20 is a circuit for storing input position information and converting it into position information delayed by one scanning line in the horizontal scanning direction of the television image.

The switching circuit 13 is a circuit that switches and outputs luminance information for interlaced scanning of a television image every first and second field scanning. Further, the switching circuit 22 is a circuit for selecting a pair of position information corresponding to the second field scan, or position information delayed by one line thereof, and position information corresponding to the first field scan.

The A-mode interpolation circuit 24 inputs the positional information of the first field and the positional information of the second field corresponding to the switching of the switching circuit 22 in order to display a television image with the A-mode waveform corresponding to interlaced scanning. , interpolate the position information,
A mode waveform is output.

The adder circuit 26 outputs the first or second output from the switching circuit 13.
M mode waveform which is velocity information for each field scan,
This is an arithmetic circuit that inputs the A-mode waveform output from the A-mode interpolation circuit 24 and performs addition processing.

The D/A converter 28 is a converter that converts the digital signal output from the adding circuit 26 into an analog signal in order to display an image.

The television monitor 30 is a display device that displays images of each A mode, M mode, and Dobra mode waveform.

Next, an example of the operation of the circuit shown in FIG. 1 will be explained with reference to FIGS. 2 and 3.

In Fig. 1, the received echoes that are M mode and Dobra mode information obtained from the subject by scanning ultrasound are A/
It is converted into a digital signal by the D converter 10, write-controlled by the M mode Dobra information memory control circuit 14, and stored in the M mode Dobra information display memory 12.

Here, in order to correspond to interlaced scanning for image display, M
Mode, Doppler information display memory 12 contains M mode,
The Dobra information is stored separately in a first field scan and a second field scan according to the write command of the write enable signal 14a.

For example, as shown in FIG.
．． 3, 4, . . . are manually entered into the display memory 12, 12a, 1.3, 5, .
12b, 2.4.6.8 for second field scanning
．． . . . are alternately stored via an inverter according to the write enable signal 14a.

For example, when obtaining the M mode waveform from the speed information stored in the display memory 12, the waveform is inputted to the addition circuit 26 via the switching circuit 13. That is, M mode information 1, 3,
5,... and 2. 4. When 6, .

As a result, an M-mode waveform 13g of one of the field information can be obtained, and based on this information, the M-mode waveform is finally displayed as an image on the television monitor 30 via the D/A converter 28.

On the other hand, in order to obtain A mode information, the display memory 1
It is necessary to read out two fields worth of M mode information stored in No. 2 and convert it into position information.

In other words, in the M mode, the control signal 14c output from the Doppler information memory control circuit 14 controls the M mode for two fields.
The mode information 12aS12b is read out simultaneously, and the brightness/
It is input to the position information conversion circuit 16. Then, the M mode information 12a, 12 for the input first and second fields is
b is specified by a command from the conversion address generation circuit 18.

This is compared with the address in the horizontal scanning direction of the television by the address designation signal 18a, converted into position information 15a and 16b of the first and second fields, and output.

Next, the characteristic operation of this embodiment for obtaining interpolated A-mode information will be explained using FIG.

FIG. 3 shows the A mode information before the position information is manually input to the A mode interpolation circuit 24 and after the position information is manually input and interpolated (16a, 16b, 24a).

In FIG. 3, the positional information 16a corresponding to the first and second field scans output from the luminance/positional information conversion circuit 16 are shown as ■, ■, ■. ...and 16b ■, ■, ■
,..., first, 1 corresponding to the first field
6a is directly input to the A-mode interpolation circuit 24, and then 1σb corresponding to the second field is input to the A-mode interpolation circuit 24 via the switching circuit 22, or the latch 20 and the switching circuit 22 are connected to each other. A mode interpolation circuit 24 via
is input. This is done by switching the switch position C or D of the switching circuit 22.

Here, when the switch position of the switching circuit 22 is C,
Information for the first field is interpolated.

As shown in FIG. 2, the outputs 16a and 16b from the brightness/position information conversion circuit 16 are simultaneously sent to the A-mode interception circuit 24 as ■■, ■■, ■■, . Entered in pairs.

As a result, the A mode interpolation circuit 24 has ■■ of 1'' and ■■
is 3゛, ■■ is 5゛, etc., and interpolation processing is performed to obtain the first field information as position information.

Next, when the switch position of the switching circuit 22 is D, the information for the second field is interpolated. In this case, as shown in FIG. 3, only the output 16b of the luminance/position information conversion circuit 16 is inputted to the A-mode interpolation circuit 24 via a latch.

That is, for example, when 16a and 16b are output simultaneously as ■■, the latch 20 is manually inputted by ■ of 16b, resulting in a delay of one scanning line. Therefore, first, only ■ is input to the human power of the A-mode interpolation circuit 24 (in this case, no interpolation is performed).

Then, at the next timing, ■■ are simultaneously output, but ■ of 16b is manually input to the latch 20, and there is a delay of one scanning line. Therefore, the pair of ■ becomes the aforementioned ■,
The pair ■■ is input to the A mode interpolation circuit 24.

In this way, the A-mode interpolation circuit 24 interpolates each pair of ■■, ■■, ■■, ... shown in FIG.
Interpolation is performed such that ■ is 2'', ■■ is 4'', ■■ is 6'', etc., and second field information can be obtained as position information.

Here, in the interpolation process of the A-mode interpolation circuit 24, interpolated position information is obtained by comparing the magnitude relationship between two pieces of input information. For example, at switch position C of the switching circuit 22 shown in FIG.
To obtain the information of ゛, interpolate the information of one pixel each of the line of ■ and the line of ), and as a result, all the pixels of the 1' line become illuminated as shown in FIG.

Similarly, as shown in FIG. 2, each pair of fields ■■, ■■, . . . and ■■, ■■, . . . is also interpolated.

As described above, the A-mode interpolation circuit 24 uses the position information of the first field (■■, ■■, . . . ) and the position information of the second field (■■, ■■, . . .・), the position information of adjacent scanning lines is selected and interpolation processing is performed, and the first field information is 1'3'', 5', 7'...
, the second field information is 2-4'', 6'...
A mode waveform 24a is output. This A mode waveform 24a has first and second field information 1', 2', 3', 4 interpolated by interlaced scanning as shown in FIG.
The output waveforms are '5', 6', and so on.

As a result, the A mode waveform 24a is inputted to the adding circuit 26 and subjected to addition processing with the aforementioned M mode information 13a.

The signal is then converted into an analog signal via the D/A converter 28, and the M mode waveform and A mode waveform are displayed as images on the television monitor 30.

Then, the state in which the A mode information is displayed as an image is displayed in the third
It is shown as an interpolated A-mode waveform 24a in the figure and FIG.

In the image display by the A-mode interpolation circuit 24 of this embodiment,
First and second field information is obtained as interpolated position information for all pixels for each scanning line, but conventionally,
As shown in FIG. 4, the first and second field information was obtained for only one pixel for each scanning line.

As a result, as is clear from a comparison between the human power information 16a and the output information 24a shown in FIG. Images can be displayed at high resolution. Therefore, the diagnostician can accurately grasp the A-mode waveform and can perform appropriate diagnosis.

[Effects of the Invention] As described above, according to the ultrasonic diagnostic apparatus according to the present invention, luminance information is stored in correspondence with interlaced scanning and divided into first and second field scanning (information), and each field is Each location is converted into position information, selected, and interpolated.

As a result, by displaying an image from the interpolated A-mode information, a high-resolution A-mode waveform can be obtained and faithfully reproduced. Therefore, the diagnostician can accurately grasp the position of the reflector, thereby making it possible to perform an appropriate diagnosis.

[Brief explanation of drawings]

FIG. 1 is a circuit block diagram showing an embodiment of the ultrasonic diagnostic apparatus according to the present invention. FIG. 2 is an explanatory diagram showing an example of interpolation processing in this embodiment. FIG. 4 is a diagram showing an image display state of an interpolated A-mode waveform. FIG. 4 is a diagram showing an image display state of a conventional A-mode waveform. 12... M mode, Doppler information display memory 13.2
2... Switching circuit 14... M mode, Dobra information memory control circuit 16
... Brightness/position information conversion circuit 24 ... A mode interpolation circuit.

Claims (1)

[Claims] (1) In an ultrasonic diagnostic apparatus that transmits and receives ultrasound waves to and from a subject and displays images of at least A-mode and M-mode information from the received echo components, to display at least M-mode information from the echo components as images. an interlaced scanning memory that stores the speed information of the field separately in first and second field scanning in correspondence with the interlaced scanning, and reads out the speed information for each field from the interlaced scanning memory and stores it as A mode information. A luminance/position information conversion circuit converts the converted position information into position information, and inputs the converted position information, selects position information of adjacent scanning lines from the first field information and the second field information, and performs interpolation processing. , an A-mode interpolation circuit that outputs interpolated A-mode information, and a high-resolution A-mode waveform is obtained by displaying the A-mode information interpolated by the A-mode interpolation circuit as an image. Features of ultrasonic diagnostic equipment.