JP3943653B2 - Ultrasonic diagnostic equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an ultrasonic diagnostic apparatus that scans the inside of a subject with ultrasonic waves and generates and displays an ultrasonic image based on an obtained echo signal.
[0002]
[Prior art]
There are various devices for medical applications of ultrasound, and the mainstream is an ultrasound diagnostic device for tomographic images of soft tissue 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. Compared to other diagnostic apparatuses such as an X-ray diagnostic apparatus, an X-ray CT apparatus, an MRI, and a nuclear medicine diagnostic apparatus, the ultrasonic diagnostic apparatus is real-time. It has unique features such as display capability, small size and low cost, high safety without exposure to X-rays, and blood flow imaging by ultrasonic Doppler method.
[0003]
For this reason, the application range is wide in the heart, abdomen, mammary gland, urology, and gynecology. In particular, a simple operation that simply assigns an ultrasound probe from the body surface provides a real-time display of heart beats and fetal movements, and because it is highly safe, it can be repeatedly examined and moved to the bedside. Therefore, it is easy to carry out inspections.
[0004]
As described above, ultrasonic diagnostics having various advantages are available, but in recent years, image quality parameters that can be freely changed on the operator side have become widespread, and their convenience has further increased.
[0005]
Typical image quality parameters include echo signal gain, luminance modulation input / output relationship, the number of rasters for inter-raster smoothing, the number of frames for inter-frame smoothing, and the like.
[0006]
The gain of the echo signal, the number of rasters for smoothing between rasters, and the number of frames for smoothing between frames change discretely by raising / lowering the stage with an up / down switch provided on the operation panel. ing.
[0007]
In addition, the operator can enter numerical values or display numerical values on the screen as to how the gain, raster number, and number of frames increase and decrease as the stage is moved up and down. By selecting from several specified values, it is possible to change within a certain limit range.
[0008]
In order to change the specifications as desired in this way, it is necessary to fully understand the meaning of the numerical values in advance, which is very unfriendly to the operator. In addition, the specification can be changed only by the greatest common divisor desired by the operator, and the degree of freedom is low. Furthermore, there is a problem that it is not possible to intuitively understand how the image quality changes with the changed specifications.
[0009]
[Problems to be solved by the invention]
An object of the present invention is to provide an ultrasonic diagnostic apparatus capable of easily changing the specification of image quality parameters.
[0010]
[Means for Solving the Problems]
The present invention relates to an ultrasonic diagnostic apparatus that scans the inside of a subject with ultrasonic waves and generates and displays the internal ultrasonic image based on the obtained echo signal . Sample curves are displayed in a list in the first area in the screen, and one sample curve selected from the plurality of sample curves is enlarged and displayed in the second area in the screen, and the sample curve displayed in the second area or A sample image that is changed according to an arbitrarily deformed sample curve is configured to be displayed in the third area in the screen .
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an ultrasonic diagnostic apparatus according to the present invention will be described with reference to the drawings according to preferred embodiments. FIG. 1 shows the configuration of an ultrasonic diagnostic apparatus according to this embodiment. This apparatus has 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 with the system controller 1 as a control center. A specification adjustment processor 9 is included.
[0012]
Here, for convenience of explanation, only the units 5 and 6 of the two types of examination modes of the B mode (tomographic image) and the color flow mapping (CFM) mode (blood flow image) are shown.
M mode that can display the movement of each part on one line of the heart over time and observe changes in the size of the heart, the speed of valve movement, etc.
Although there is no distance resolution, continuous wave Doppler mode that can measure the maximum blood flow velocity with high accuracy from a high-quality blood flow pattern,
A blood flow at one point on the slice may be selected, and each processing unit such as a pulse wave Doppler mode capable of observing the blood flow state at that point in detail may be appropriately combined and equipped. Since the configuration of these processing units may be a conventionally known one, description thereof will be omitted here.
[0013]
The ultrasonic probe 2 has a plurality of micro piezoelectric elements arranged at the tip portion in order to mediate between the side that handles electrical signals and the subject side that imparts internal information to the ultrasonic waves. The form of the probe 2 is arbitrarily selected from among sector correspondence, linear correspondence, convex correspondence, and the like.
[0014]
The transmission 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 pulsar 34. A clock pulse oscillated from the clock generator 31 is frequency-divided by the rate pulse generator 32 to generate a rate pulse for determining an ultrasonic transmission rate (number of transmissions per second). This rate pulse is distributed to, for example, 100 channels, and a delay time necessary for determining the directivity of transmission by the transmission delay circuit 33 is individually given for each channel. The pulser 34 individually amplifies the rate pulse for each channel and applies it to the piezoelectric element of the probe 2.
[0015]
The piezoelectric element of the probe 2 is excited by this signal pulse and generates an ultrasonic wave. This ultrasonic wave propagates in the living body, and is reflected one after another at a discontinuous surface of acoustic impedance in the middle. This reflection intensity mainly depends on the difference in acoustic impedance of the discontinuous surface. Ultrasonic waves are also reflected on the heart wall and blood cells and undergo a frequency shift according to the beam direction component of the velocity.
[0016]
The echo due to such reflection returns to the probe 2 and vibrates the piezoelectric element. Thereby, 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, given an appropriate delay time by the reception delay circuit 42, and added by the adder 43. As a result, reception directivity is given to the echo signal, and only the echo component from the 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.
[0017]
Note that the gain of the preamplifier 41 can be changed according to 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 the detection circuit 51, the amplitude signal is logarithmically amplified by the logarithmic amplifier 52, and converted into a digital signal by the analog / digital converter 53.
[0018]
The color flow mapping processing unit 6 includes a mixer 61, a low-pass filter 62, an analog / digital converter (A / D / C) 63, an MTI filter 64, an autocorrelator 65, and a calculation unit 66. The The mixer 61 and the low-pass filter 62 perform a quadrature phase detection of an echo signal using a reference signal that vibrates at the center frequency of the transmission ultrasonic wave, and receive a frequency shift from a moving body such as a blood cell or an organ wall. Take out (Doppler signal). This Doppler signal is sampled at a 0.5 mm interval, for example, with respect to one scanning line according to a predetermined sampling frequency by the analog / digital converter 63 and converted into a digital signal, and then sent to the MTI filter 64.
[0019]
The MTI filter 64 is a high-pass filter, removes low-frequency components (clutter components) related to a moving body having a relatively low moving speed such as a heart wall from a Doppler signal, and also uses high frequencies related to a moving body such as a blood cell having a relatively high moving speed. Only the component (blood flow component) is extracted. Then, the frequency of the blood flow component is obtained by the autocorrelator 65, and the calculation unit 66 calculates the average blood flow velocity, the dispersion of the blood flow velocity, and the power (Doppler signal) mainly reflecting the blood flow volume from the frequency. For each sample point.
[0020]
The display unit 7 includes a digital scan converter (D · S · C) 71, a look-up table (L · U · T) 72, a digital / analog converter (D · A · C) 73, And a color display 74.
[0021]
As shown in FIG. 2, the digital-analog converter 73 takes in the image signals from the B-mode processing unit 5 and the color flow mapping processing unit 6 into the spatial filter 712 via the input buffer 711, and here the number of adjacent pixels A high-frequency component is removed from a spatial pixel value change at the same depth for a raster of a book, spatial smoothing is performed, and this spatially smoothed image signal is transmitted through a frame memory 713. This time, it is sent to the temporal filter 714, where high frequency components are removed from temporal pixel value changes at the same position for several adjacent frames, and temporal smoothing (smoothing) is performed. The image signal smoothed in terms of time and time is output through an output buffer 715.
[0022]
The spatial filter 712 and the temporal filter 713 are composed of FIR type or IIR type digital filters, convolution of a series number into a pixel column to be filtered, add those values, and output, as is well known. By freely changing the series, the number of rasters to be spatially filtered and the cutoff frequency, the number of frames to be temporally filtered and the cutoff frequency can be arbitrarily changed.
[0023]
The image quality specification adjustment unit 9 is a characteristic part having a function related to the specification of the image quality parameter of the display image. The following are typical image quality parameters.
[0024]
POST PROCESS (Luminance Modulation); for example, a technique applied to gamma correction, by appropriately converting the output luminance value to the input luminance value using the conversion table of the look-up table 72, A certain range can be emphasized. By rewriting the conversion table of the look-up table 72, the luminance modulation characteristic can be arbitrarily changed.
[0025]
GAIN (gain); a parameter for adjusting the brightness of the entire image, and is realized by a gain operation 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 / decreasing the number of rasters to be processed by the spatial filter 712 in the digital scan converter 71. be able to.
[0026]
PERSISTENCE (temporal smoothing); a so-called inter-frame smoothing process, in which the temporal smoothness of a moving image is adjusted by changing the number of frames handled as a filter target by the time filter 714 in the digital scan converter 71. Can do.
[0027]
Among these, the values of the image quality parameters such as the gain, the number of rasters, and the number of frames can be changed stepwise (discretely) between 1 and 10, for example, and the up button 81 on the operation panel 8 is set to 1. Each time the pressure is applied, the parameter state (hereinafter referred to as “stage”) is increased by one step (step), and each time the lowering button 82 is pressed once, the parameter state is decreased by one step. In this embodiment, the horizontal axis is the stage and the vertical axis is the stage. This change is referred to as “image quality parameter specification”. A specification curve is created as the value of the image quality parameter, and the specification of the image quality parameter is provided to the operator in an easy-to-understand manner using this curve, and the specification can be easily changed by changing this curve (Fig. 4 (a), (c), (d)).
[0028]
In the case of a luminance modulation parameter, the luminance modulation characteristic (specification) can be changed by rewriting the conversion table as described above. In this embodiment, the horizontal axis represents input luminance (input signal) and the vertical axis represents output luminance. As the (output signal), the luminance modulation characteristic (specification) can be expressed as an input / output curve in an easy-to-understand manner, and the gain specification can be easily changed by changing the input / output curve (FIG. 4). (See (b)).
[0029]
FIG. 3 shows a configuration example of the image quality specification adjustment processor 9. The image quality specification adjustment processor 9 has a configuration in which an input / output (I / O) interface 92, a ROM 93, and an EEPROM 94 are connected to a processor 91.
[0030]
Various commands related 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 output signals related to the display of the image quality specification change screen configured by the processor 9 are as follows. It is sent to the digital scan converter 71 via the input / output interface 92.
[0031]
The ROM 93 is preinstalled with application programs related to image quality specification changes and character string data necessary for screen creation. An EEPROM 94 is provided to store the image quality specifications arbitrarily changed by the operator using this program and to reproduce them as necessary.
[0032]
Next, the image quality specification changing operation will be described. First, an operator activates an application program by operating an appropriate key on the operation panel 8, and selects the type of image quality whose specification is desired from luminance modulation, gain, spatial smoothing, and temporal smoothing. Then, first, an initial screen as shown in FIG. 5 is constituted by the processor 91 and displayed.
[0033]
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 on the apparatus side is displayed as a guide image, and this image quality is changed as needed according to the specification during the specification changing operation. Thus, the operator can gradually bring the specifications closer to the desired state while confirming the image quality with this guide image.
[0034]
In the area (B), the specification curve and the input / output curve prepared in advance in the ROM 93, and in addition to this, the specification curve and the input / output curve changed by the operator in the past and stored in the EEPROM 94 are used as sample curves. List in the form. Of the plurality of sample curves, the one designated by the operator is enlarged and displayed in the area (C). This area (C) is a work area, and the operator can freely transform the sample curve displayed in this area (C) using an input device such as a mouse on the operation panel 8 as shown in FIG. It can be done. For example, when an arbitrary point on the curve is appropriately raised or lowered, the processor 91 recreates a new curve by using an appropriate mathematical method such as curve approximation.
[0035]
The operator can freely change the curve and reach the desired specification while confirming the image quality of the guide image that is changed following the specification in real time. The specifications finally determined in this manner are registered in the EEPROM 94, and can be read and reproduced as appropriate from here.
[0036]
In this way, the specification of image quality is displayed in a visually easy-to-understand manner with a curve, and the specification can be changed by deforming this curve. Specification changes can be completed quickly and easily.
[0037]
FIG. 7 shows an example of an ultrasonic image generated in real time while actually scanning the subject with ultrasonic waves, and an example of a display screen of an ultrasonic image reproduced and displayed without scanning. As shown in this figure, the current specification curve can be displayed or hidden on the same screen as the ultrasonic image, so that the operator can check the current specification in a timely manner.
It goes without saying that the present invention is not limited to the above-described embodiments and can be implemented with various modifications.
[0038]
【The invention's effect】
In the present invention, since the specification of the image quality parameter is displayed in a graph, the operator can easily understand this specification visually. Moreover, by changing the graph, the specification of the image quality parameter can be freely changed, so that the specification change can be facilitated.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of an ultrasonic diagnostic apparatus according to an embodiment of the present invention.
FIG. 2 is a block diagram showing the configuration of the digital scan converter of FIG.
3 is a block diagram showing a configuration of an image quality unit in FIG. 1. FIG.
FIG. 4 is a diagram showing specification curves of gain, luminance gradation, inter-raster smoothing, and inter-frame smoothing.
5 is a diagram showing an example of a screen for changing the specification of image quality parameters displayed on the display of FIG. 1;
FIG. 6 is a supplementary diagram for explaining a method of deforming a specification curve.
7 is a diagram showing an example of a normal display screen of an ultrasonic image on the display shown in FIG.
[Explanation 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 ... Control panel,
9 ... Image quality specification adjustment unit,
31 ... clock generator,
32. Rate pulse generator,
33 ... transmission delay circuit,
34 ... Pulsa,
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-to-analog converter,
74 ... Color display,
91 ... Processor,
92 ... I / O interface,
93 ... ROM,
94… EEPROM,
711 ... an input buffer,
712 ... Spatial filter,
713: Frame memory,
714 Time filter,
715: Output buffer.

Claims (5)

In an ultrasound diagnostic apparatus that scans the inside of a subject with ultrasound and generates and displays an ultrasound image of the inside based on the obtained echo signal,
A plurality of sample curves related to image quality parameters of the ultrasonic image are displayed in a list in the first area in the screen, and one sample curve selected from the plurality of sample curves is enlarged and displayed in the second area in the screen, and An ultrasonic diagnostic apparatus configured to display a sample image displayed according to a sample curve displayed in the second region or a sample curve arbitrarily deformed in the third region in the screen. .   The super image quality parameter according to claim 1, wherein the image quality parameter is at least one of a gain of the echo signal, an input / output relationship of luminance modulation, a raster number of inter-raster smoothing, and a frame number of inter-frame smoothing. Ultrasonic diagnostic equipment.   The gain, the number of rasters, and the number of frames are discretely changed by raising / lowering the stage by an up / down switch operation. The specification of the number of rasters is represented by gain, the horizontal axis is represented by the stage, the vertical axis is represented by the number of rasters, the specification of the number of frames is represented by the horizontal axis is the stage, and the vertical axis is represented by the number of frames. The ultrasonic diagnostic apparatus according to claim 2, wherein the output-related specifications are represented by an input signal on the horizontal axis and an output signal on the vertical axis.   The ultrasonic diagnostic apparatus according to claim 1, wherein a sample image is displayed on the same screen as the graph, and an image quality of the sample image is changed in real time according to the changed specification.   The ultrasonic diagnostic apparatus according to claim 1, wherein the changed specification can be registered and reproduced.

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