JPH10328180A - Ultrasonic diagnostic system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To change the specification of a picture parameter easily to understand by displaying the specification of the picture parameter of an ultrasonic image by a graph and deforming the graph thereby changing the specification of the picture parameter. SOLUTION: A picture specification adjusting unit 9 is provided with a function concerning the specification of the picture parameter of a displayed image so that a gain, the number of rasters and the value of the picture parameter of the number of frames can be changed stepwise to raise the state (stage) of the parameter by one step at every time of pressing the raising button 81 of an operation panel 8 and to lower the state by one step each time of pressing a processing button 82. Then, a specification curve is prepared by setting a horizontal axis to be a stage and a vertical axis to be the value of the picture parameter to display on a display 74. In addition this curve is deformed by using an input device such as the mouse of the panel 8 to change a specification. Thereby, the operator visually easily understands the specification of the picture parameter.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic diagnostic apparatus which scans the inside of a subject with ultrasonic waves, and generates and displays an ultrasonic image based on the obtained echo signals.

[0002]

2. Description of the Related Art There are various medical applications of ultrasonic waves, and the mainstream is an ultrasonic diagnostic apparatus for tomographic images of soft tissues of a living body using an ultrasonic pulse reflection method. This ultrasonic diagnostic apparatus is a non-invasive examination method and displays a tomographic image of a tissue. It has unique features such as display capability, small and inexpensive device, high safety without exposure to X-rays, and blood flow imaging by ultrasonic Doppler method.

[0003] Therefore, it is widely used in the heart, abdomen, mammary gland, urology, obstetrics and gynecology, and the like. In particular, with the simple operation of simply assigning the ultrasound probe from the body surface, the state of the heart beat and the movement of the fetus can be obtained in real time display,
In addition, the safety is high, so that the inspection can be repeated, and the inspection while moving to the bedside can be easily performed.

As described above, various types of ultrasonic diagnostics have advantages, but in recent years, those in which the image quality parameter can be freely changed by the operator have become widespread, and the convenience thereof has been further enhanced. .

Typical image quality parameters include the gain of an echo signal, the input / output relationship of luminance modulation, the number of rasters in raster smoothing, the number of frames in interframe smoothing, and the like.

The gain of these echo signals, the number of rasters for smoothing between rasters, and the number of frames for smoothing between frames are discretely changed by raising and lowering the stage with an up / down switch provided on an operation panel. It has become.

Further, there is also a specification of how the gain, the number of raster lines, and the number of frames increase and decrease as the stage is moved up and down.
The operator can change the value within a certain limit by inputting a numerical value or selecting from several prescribed values displayed numerically on the screen.

In order to change the specifications as desired, it is necessary to fully understand the meaning of the numerical values in advance.
He was very unfriendly to the operator. Further, the specifications can be changed only in the greatest common denominator desired by the operator, and the degree of freedom is low. Further, there is a problem that it is not possible to intuitively understand how the image quality changes with the changed specification.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to provide an ultrasonic diagnostic apparatus capable of easily changing the specifications of image quality parameters.

[0010]

According to the present invention, there is provided an ultrasonic diagnostic apparatus which scans the inside of a subject with ultrasonic waves and generates and displays an ultrasonic image of the inside based on the obtained echo signals. The specification of the image quality parameter of the ultrasonic image is displayed in a graph, and the specification of the image quality parameter can be changed by deforming the graph. (Operation) In the present invention, since the specifications of the image quality parameters are displayed in a graph, the operator can easily understand the specifications visually. In addition, by changing the graph, the specifications of the image quality parameters can be freely changed, so that the specifications can be easily changed.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An ultrasonic diagnostic apparatus according to the present invention will be described below with reference to the drawings. FIG. 1 shows a configuration of an ultrasonic diagnostic apparatus according to the present embodiment. This apparatus has a system controller 1 as a control center, an ultrasonic probe 2, a transmission unit 3, a reception unit 4, a B-mode processing unit 5, a color flow mapping processing unit 6, a display unit 7, an operation panel 8, and an image quality. And a specification adjustment processor 9.

Here, for convenience of explanation, B-mode (tomographic image) and color flow mapping (CF)
Although only units 5 and 6 for two types of examination modes, M) mode (blood flow image), are shown,
M mode that displays the movement of each part on the line with the passage of time and observes changes in the size of the heart and the speed of valve movement, etc. There is no distance resolution, but maximum blood flow from high-quality blood flow patterns Appropriate processing units such as continuous wave Doppler mode, which can measure velocity, etc. with high accuracy, and pulse wave Doppler mode, which can select one point of blood flow on tomography and observe the state of blood flow at that point in detail You may equip it in combination. Since the configuration of these processing units may be a conventionally known one, the description is omitted here.

The ultrasonic probe 2 has a plurality of micro-piezoelectric elements arranged at its distal end to mediate between the side that handles electric signals and the side of the subject that applies internal information to the ultrasonic waves. ing. The form of the probe 2 is arbitrarily selected from among sectors, linear, convex, and the like.

The transmitting unit 3 for transmitting ultrasonic waves from the ultrasonic probe 2 includes a clock generator 31, a rate pulse generator 32, a transmission delay circuit 33, and a pulser 34. The clock oscillated from the clock generator 31 is frequency-divided by the rate pulse generator 32 to generate a rate pulse for determining the transmission rate of ultrasonic waves (the number of transmissions per second). The rate pulse is distributed to, for example, 100 channels, and a delay time required for the transmission delay circuit 33 to determine transmission directivity is individually given to each channel. The pulser 34 amplifies the rate pulse individually for each channel and applies it to the piezoelectric element of the probe 2.

The piezoelectric element of the probe 2 is excited by this signal pulse to generate an ultrasonic wave. The ultrasonic wave propagates in the living body, and is reflected one after another at a discontinuous surface of acoustic impedance in the middle of the ultrasonic wave. This reflection intensity mainly depends on the difference in acoustic impedance of the discontinuous surface. Ultrasonic waves are also reflected from the heart wall and blood cells, and undergo frequency shifts according to the beam direction component of the velocity.

The echo due to such reflection is caused by the probe 2
And vibrates the piezoelectric element. As a result, a weak echo signal is generated from the piezoelectric element. This echo signal is taken into the receiving unit 4, where it is first amplified individually for each channel by the preamplifier 41, and given an appropriate delay time by the receiving delay circuit 42, and
3 is added. Thereby, reception directivity is given to the echo signal, and only the echo component from a specific direction is emphasized. This echo signal is sent to the B-mode processing unit 5 and the color flow mapping processing unit 6, respectively.

The gain of the preamplifier 41 can be changed under the control of the system controller 1.
The B-mode processing unit 5 includes a detection circuit 51, a logarithmic amplifier 52, and an analog / digital converter (A / D).
C) 53. The echo signal is first detected (envelope detection) by a detection circuit 51, its amplitude signal is logarithmically amplified by a logarithmic amplifier 52, and is converted into a digital signal by an analog / digital converter 53.

The color flow mapping processing unit 6 includes a mixer 61, a low-pass filter 62, an analog / digital converter (A / D / C) 63, and an MTI
It comprises a filter 64, an autocorrelator 65, and a calculation unit 66. The mixer 61 and the low-pass filter 62
The echo signal is subjected to quadrature phase detection using a reference signal vibrating at the center frequency of the transmitted ultrasonic wave, and a shift component (Doppler signal) subjected to frequency shift is extracted from a moving body such as a blood cell or an organ wall. The Doppler signal is sampled for one scanning line at an interval of, for example, 0.5 mm in accordance with a predetermined sampling frequency by an analog / digital converter 63 and converted into a digital signal.
Send to 4.

The MTI filter 64 is a high-pass filter that removes low-frequency components (clutter components) related to a moving object having a relatively low moving speed, such as a heart wall, from a Doppler signal, and moves a blood cell or the like having a relatively high moving speed. Only high frequency components (blood flow components) related to the body are extracted. And
The frequency of this blood flow component is obtained by the autocorrelator 65, and the arithmetic unit 66 calculates the average speed of the blood flow, the dispersion of the blood flow speed, and the power (amplitude of the Doppler signal) mainly reflecting the blood flow from the frequency. Is calculated for each sample point.

The display unit 7 includes a digital scan converter (DSC) 71 and a look-up
A table (LUT) 72, a digital-analog converter (DAC) 73, and a color display 74 are provided.

Digital-to-analog converter 73
Captures image signals from the B-mode processing unit 5 and the color flow mapping processing unit 6 into a spatial filter 712 via an input buffer 711, as shown in FIG. A high-frequency component is removed from a spatial pixel value change at the same depth, spatial smoothing (smoothing) is performed, and the spatially smoothed image signal is converted to a temporal filter 714 via a frame memory 713. , Where high-frequency components are removed from temporal changes in pixel values at the same position with respect to several adjacent frames, and temporal smoothing (smoothing) is performed. This spatial and temporal smoothing is performed. The output image signal is output via the output buffer 715.

The spatial filter 712 and the time filter 713
Is composed of an FIR type or IIR type digital filter, convolves a series of pixels with a pixel row to be filtered, adds the values, and outputs the sum. As is well known, the series of rows is freely changed. This makes it possible to arbitrarily change the number of raster lines and cutoff frequency to be spatially filtered and the number of frames and cutoff frequency to be temporally filtered.

The image quality specification adjusting unit 9 is a characteristic part having a function relating to the specification of the image quality parameter of the display image. The following are typical image quality parameters.

POST PROCESS (brightness modulation): A technique applied to, for example, gamma correction, by appropriately converting an output luminance value to an input luminance value using a conversion table of a look-up table 72, A particular range of input luminance can be emphasized. Look Up Table 72
Can be arbitrarily changed by rewriting the conversion table.

GAIN (gain): a parameter for adjusting the brightness of the entire image, which is realized by operating the gain of the preamplifier 41 of the receiving unit 4. LATERAL SMOOTH (spatial smoothing): so-called inter-raster smoothing, which adjusts the spatial smoothness in an image by increasing or decreasing the number of rasters to be filtered by the spatial filter 712 in the digital scan converter 71. be able to.

PERSISTENCE (temporal smoothing): This is a so-called inter-frame smoothing process. The temporal smoothness of a moving image is changed by changing the number of frames to be filtered by the time filter 714 in the digital scan converter 71. Can be adjusted.

The values of the image quality parameters, such as the gain, the number of raster lines, and the number of frames, can be changed stepwise (discretely) from 1 to 10, for example. Each time the button 81 is pressed, the state of the parameter (hereinafter referred to as “stage”) increases by one step (step), and each time the down button 82 is pressed once,
It goes down step by step. The parameter value changes as the stage moves up and down.
In this embodiment, a specification curve is created with the horizontal axis as the stage and the vertical axis as the value of the image quality parameter, and the curve is used to provide the operator with the specifications of the image quality parameter visually easily, The specification can be easily changed by changing the curve (see FIGS. 4A, 4C, and 4D).

In the case of the parameters of the luminance modulation, the luminance modulation characteristics (specifications) can be changed by rewriting the conversion table as described above. In the present embodiment, the horizontal axis represents the input luminance (input signal) and the vertical axis represents the luminance. As an output luminance (output signal), the luminance modulation characteristic (specification) can be easily represented as an input / output curve, and the gain specification can be easily changed by changing the input / output curve. (See FIG. 4B).

FIG. 3 shows an example of the configuration of the image quality specification adjustment processor 9. The image quality specification adjustment processor 9 provides an input / output (I / O) interface 92 to the processor 91.
, A ROM 93 and an EEPROM 94 are connected.

Various commands relating to the change of the image quality specification input via the operation panel 8 are supplied to the processor 91 via the input / output interface 92, and are related to the display of the image quality specification change screen constituted by the processor 9. The output signal is sent to the digital scan converter 71 via the input / output interface 92.

An application program for changing the image quality specification and character string data necessary for screen creation are installed in the ROM 93 in advance. An EEPROM 94 is provided to store the image quality specification arbitrarily changed by the operator using this program and reproduce the image quality specification as necessary.

Next, the operation of changing the image quality specification will be described. First, an application program is started by an appropriate key operation on the operation panel 8 by an operator, and the type of image quality whose specification is desired to be changed is selected from among luminance modulation, gain, spatial smoothing, and temporal smoothing. Then, an initial screen as shown in FIG. 5 is formed by the processor 91 and displayed.

This screen is divided into three areas (A, B, C). In the area (A), an ultrasonic image actually collected from the subject or a sample image prepared in advance in the apparatus is displayed as a guide image, and this image quality is changed at any time according to the specification during the specification change work. With this guide image, the operator can, at any time, gradually bring the specifications closer to a desired state while checking the image quality.

In the area (B), the specification curve and the input / output curve prepared in advance in the ROM 93, and in addition, the specification curve and the input / output curve which are changed by the operator in the past and stored in the EEPROM 94 are sampled. As a list in the form of a graph. The one designated by the operator among the plurality of sample curves is enlarged and displayed in the area (C).
This area (C) is a working area, and the operator can freely deform the sample curve displayed in this area (C) as shown in FIG. I can do it. For example, if an arbitrary point on the curve is raised or lowered appropriately, the processor 91
Then, a new curve is created using an appropriate mathematical method such as curve approximation.

The operator can freely deform the curve and follow the specification in real time to reach the desired specification while checking the image quality of the changed guide image. The final specification is EEPRO
It is registered in M94 and can be read out and reproduced from here as appropriate.

As described above, the specifications of the image quality are displayed in a visually easy-to-understand manner with the curve, and the specification can be changed by deforming the curve. In addition, the image quality specification being changed can be checked at any time with the guide image. The specification change can be completed very simply and easily and quickly.

FIG. 7 shows an example of a display screen of an ultrasonic image generated in real time while actually scanning the subject with ultrasonic waves, or an ultrasonic image reproduced and displayed without scanning. As shown in this figure, the current specification curve can be displayed or not displayed on the same screen as the ultrasonic image, so that the operator can check the current specification as appropriate. I have. It is needless to say that the present invention is not limited to the above-described embodiment, and can be implemented with various modifications.

[0038]

According to the present invention, the specifications of the image quality parameters are displayed in a graph, so that the operator can easily understand the specifications visually. In addition, by changing the graph, the specifications of the image quality parameters can be freely changed, so that the specifications can be easily changed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an ultrasonic diagnostic apparatus according to one embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of the digital scan converter of FIG. 1;

FIG. 3 is a block diagram illustrating a configuration of an image quality unit in FIG. 1;

FIG. 4 is a diagram showing specification curves of gain, luminance gradation, inter-raster smoothing, and inter-frame smoothing.

FIG. 5 is a view showing an example of a screen for changing specifications of image quality parameters displayed on the display of FIG. 1;

FIG. 6 is an explanatory supplementary diagram of a method for deforming a specification curve.

FIG. 7 is a view showing an example of a normal display screen of an ultrasonic image on the display of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... System controller, 2 ... Ultrasonic probe, 3 ... Transmission unit, 4 ... Receiving unit, 5 ... B-mode processing unit, 6 ... Color flow mapping processing unit, 7 ... Display unit, 8 ... Operation panel, 9 ... Image quality specification adjustment unit, 31: clock generator, 32: rate pulse generator, 33: transmission delay circuit, 34: pulser, 41: preamplifier, 42: reception delay circuit, 43: adder, 51: detection circuit, 52 ... Logarithmic amplifier, 53 analog-digital converter, 61 mixer, 62 low-pass filter, 63 analog-digital converter, 64 MTI filter, 65 autocorrelator, 66 arithmetic unit, 71 digital scan Converter, 72 ... Look-up table, 73 ... Digital analog -Converter, 74: Color display, 91: Processor, 92: Input / output interface, 93: ROM, 94: EEPROM, 711: Input buffer, 712: Spatial filter, 713: Frame memory, 714: Time filter, 715: Output buffer .

Claims (5)

[Claims] 1. An ultrasonic diagnostic apparatus which scans the inside of a subject with an ultrasonic wave and generates and displays an ultrasonic image of the inside based on an obtained echo signal, wherein an image quality parameter of the ultrasonic image is specified. Is displayed as a graph, and the specification of the image quality parameter can be changed by deforming the graph. 2. The image quality parameter is at least one of a gain of the echo signal, an input / output relationship of luminance modulation, the number of rasters of inter-raster smoothing, and the number of frames of inter-frame smoothing. Item 7. An ultrasonic diagnostic apparatus according to Item 1. 3. The gain, the number of raster lines, and the number of frames are discretely changed by raising / lowering a stage by operating an up / down switch, and the specification of the gain is represented by a horizontal axis. The stage, the vertical axis is represented by gain, the specification of the number of rasters is the horizontal axis is the stage, the vertical axis is represented by the number of rasters, the specification of the number of frames is the horizontal axis is the stage, the vertical axis is the number of frames,
3. The ultrasonic diagnostic apparatus according to claim 2, wherein the input / output relation specification of the luminance modulation is represented by an input signal on a horizontal axis and an output signal on a vertical axis. 4. The ultrasonic diagnostic apparatus according to claim 1, wherein a sample image is displayed on the same screen as the graph, and the image quality of the sample image is changed in real time according to the changed specification. . 5. The ultrasonic diagnostic apparatus according to claim 1, wherein said changed specification is registered and can be reproduced.