JP3692278B2 - Ultrasonic diagnostic equipment - Google Patents

Description

[0001]
[Technical field to which the invention belongs]
The present invention relates to an ultrasonic diagnostic apparatus that obtains an in-vivo image by transmitting and receiving ultrasonic waves in the medical field.
[0002]
[Prior art]
Conventionally, an ultrasonic diagnostic apparatus described in Japanese Patent Laid-Open No. 11-76231 is known.
FIG. 4 shows a configuration of a conventional ultrasonic diagnostic apparatus. This apparatus includes a probe 1 that transmits and receives an ultrasonic signal into a living body. The switch circuit 2 selects several transducers that transmit and receive ultrasonic waves from a plurality of micro transducers of the probe 1. The TX beamformer 4 gives a delay time to the trigger pulse that triggers the driver 3 so that the ultrasonic wave to be transmitted can be deflected and converged, and the driver 3 responds to the trigger pulse from the TX beamformer 4 in response to the probe pulse. 1 is driven by a pulse signal.
[0003]
The echo signal from the living body received by the probe 1 is amplified by the preamplifier 5, and the amplified echo signal gives a delay time by the RX beam former 6 to deflect and converge the received beam. The fundamental wave component of the echo signal output from the beam former 6 is extracted by the fundamental wave filter 7, and the harmonic component of the echo signal output from the beam former 6 is extracted by the harmonic filter 9. The output of the fundamental filter 7 and the harmonic filter 9 can be switched by the switch 16. The AM detector 8 detects the amplitude of the echo signal selected by the switch 16, and the scan converter (digital scan converter, DSC) 12 writes the magnitude of the amplitude of the echo signal. Convert to image data. The image data is displayed on the display 13 as an image of the subject.
[0004]
The synchronization signal generation circuit 14 generates a synchronization signal in accordance with the generation timing of the ultrasonic pulse and the display method of the display 13, and this synchronization signal is input to the TX beamformer 4 and the display 13. The scanning line address generator 15 instructs the scanning beam address of the ultrasonic beam to the TX beam former 4, the RX beam former 6, and the DSC 12.
[0005]
In the configuration of FIG. 4, the driver 3 generates a pulse with respect to the scanning line address of the ultrasonic beam indicated by the scanning line address generation circuit 15, and the ultrasonic pulse is transmitted from the probe 1 to the subject. Although the ultrasonic pulse propagates in the subject and is reflected by the reflector, the ultrasonic wave propagating in the living body is distorted in the waveform of the ultrasonic pulse due to the influence of the nonlinear characteristic of the propagation medium. This distortion is included in the echo signal, and the harmonic component generated when the waveform is distorted can be extracted by removing the fundamental component with the harmonic filter 9. The harmonic component from which the distortion of the echo signal waveform is extracted is subjected to AM detection by the AM detector 8, converted into a geometric shape in accordance with the scanning shape of the ultrasonic beam by the DSC 12, and displayed on the display 13.
[0006]
Since the distortion of the echo signal increases as the ultrasonic signal becomes stronger, the distortion increases particularly near the center of the ultrasonic beam. Therefore, the diagnostic image obtained from the harmonic component extracted by the harmonic filter 9 can obtain an image with good azimuth resolution and clear contrast. However, since the harmonic component of the echo signal has a high frequency, the attenuation is large and the penetration is lower than the image obtained with the fundamental wave, so that a deep part cannot be observed. For this reason, the switch 16 is provided to switch the fundamental wave and the harmonic wave according to the diagnosis situation. Alternatively, an image obtained with the fundamental wave and an image obtained with the harmonic can be combined and displayed to compensate for a decrease in penetration.
[0007]
In addition, as a method for removing the fundamental component from the echo signal of the prior art different from this and extracting the distortion component, Japanese Patent Laid-Open No. 9-224939 discloses that transmission pulses having different excitation levels are transmitted a plurality of times. A method for extracting a distortion component by subtracting an echo signal obtained for each transmission is described.
[0008]
[Problems to be solved by the invention]
However, in the above-described conventional ultrasonic diagnostic apparatus, it is necessary for the examiner to switch the image of the fundamental wave component and the harmonic wave component according to the diagnosis situation. In addition, an image obtained by combining the fundamental wave component and the harmonic component has a problem that the effect of improving the contrast by the harmonic component is diminished.
The present invention has been made to solve such a problem, and ultrasonic diagnosis that visually relieves a decrease in contrast and a decrease in penetration by displaying a harmonic image and a fundamental wave image in different display colors. A device is provided.
[0009]
[Means for Solving the Problems]
The ultrasonic diagnostic apparatus of the present invention includes an ultrasonic probe that transmits and receives an ultrasonic signal into a living body, a first filter unit that extracts a distortion component from an echo signal received by the ultrasonic probe, Second filter means for extracting a fundamental wave component from an echo signal received by the ultrasonic probe; first and second AM detectors for detecting amplitudes from the first and second filter means; A lookup table for storing display color data, which is referred to by amplitude levels output from the first and second AM detectors, and a display; and the display includes the amplitude data and color data output by the lookup table. It has the structure which displays a diagnostic image.
With this configuration, it is possible to refer to the look-up table based on the AM detected signal with the fundamental wave component and the harmonic wave component, determine the display color corresponding to the signal, and display the image on the display.
[0010]
In the ultrasonic diagnostic apparatus of the present invention, the look-up table is color data so that the lookup table is referenced two-dimensionally by the output from the first AM detector and the output from the second AM detector. Is written.
With this configuration, the display color of the image based on the amplitude of the AM detection signal of the fundamental wave component and the display color of the image based on the amplitude of the AM detection signal of the harmonic component can be superimposed and displayed in different colors.
[0011]
Further, color data so that the look-up table is referenced two-dimensionally by the output from the first or second AM detector and the ratio of the outputs from the first and second AM detectors. Is written.
With this configuration, an image based on the ratio of the fundamental wave and the harmonic wave can be displayed on the image of the fundamental wave component or the harmonic wave component.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows an ultrasonic diagnostic apparatus according to the first embodiment of the present invention. The same components as those of the prior art shown in FIG. 4 are denoted by the same reference numerals.
In the first embodiment, two AM detectors, that is, an AM detector 8 corresponding to the fundamental filter 7 and an AM detector 10 corresponding to the harmonic filter 8 are provided. The amplitude signals F and H from the two AM detectors are both input to a look-up table (LUT) 11.
[0013]
The fundamental wave filter 7 extracts a fundamental wave component from the echo signal from the RX beam former 6. As for this fundamental wave component, the amplitude signal F is detected by the AM detector 8 and input to a look-up table (LUT) 11. The harmonic filter 9 extracts a harmonic component from the echo signal from the RX beam former 6. As for this harmonic component, the amplitude signal H is detected by the AM detector 10 and input to the LUT 11. The LUT 11 is a table that can be referenced from the levels of the amplitude signal F and the amplitude signal H, and R (red), G (green), and B (blue) of data in the table referenced by the amplitude signal F and the amplitude signal H. R, G, and B corresponding to the amplitude signal F and the amplitude signal H are output from the LUT 11 to the DSC 12 according to the value. The DSC 12 scan-converts the output from the LUT 11 and outputs it to the display 13 as image data. The display 13 displays an image of the subject for diagnosis.
[0014]
As described above, the ultrasonic diagnostic apparatus according to the first embodiment of the present invention refers to the LUT 11 with the two signals of the AM detected signal with the fundamental component and the AM detected signal with the harmonic component. Then, display colors corresponding to the two signals are determined, and an image is displayed with the two display colors. Therefore, two images based on amplitude signals of the fundamental wave component and the harmonic component can be displayed simultaneously. Images with harmonic components have improved contrast but lack of image penetration. In the present invention, since the image by the harmonic component and the image by the fundamental wave are displayed in different display colors, it is not necessary to switch between the two images depending on the diagnosis situation, and the two images have different display colors. Therefore, it is possible to visually compensate for the decrease in contrast.
[0015]
In the first embodiment, as a method for extracting a waveform distortion component (harmonic component) from an echo signal, a method for extracting a harmonic component by the harmonic filter 9 has been described. It is also possible to carry out by the method described in JP-A-9-224939.
[0016]
FIG. 2 explains the input amplitude signal H and amplitude signal F and the display color outputs C1 and C2 output from the data written in the LUT 11 in the first embodiment of the present invention. .
FIG. 2A shows the relationship between the amplitude signal F obtained by AM detection of the fundamental wave component and the display output C1. C1 is one color in which R, G, and B are mixed at an arbitrary ratio, or one color of R, G, and B, and is written in the lookup table with an arbitrary function. Also. FIG. 2B shows the relationship between the amplitude signal H obtained by AM detection of the harmonic component and the display output C2. C2 is one color in which R, G, and B are mixed at an arbitrary ratio different from C1, or one color of R, G, and B different from C1, and is written in the lookup table by an arbitrary function. The R, G, and B outputs of the LUT 11 are added to the R, G, and B outputs of the C1 and C2 outputs and output. The display colors and functions of C1 and C2 are arbitrary. For example, when C1 is set to blue and C2 is set to white, two display images are displayed in two colors so as to overlap each other. When observing an image with harmonic components displayed in white, the penetration of the long-distance portion is insufficient, but since the fundamental image displayed in blue can be referred to, there is no extra effort on the examiner. Diagnosis can be advanced efficiently.
[0017]
FIG. 3 illustrates the amplitude signal H or amplitude signal F that is input to the data written in the LUT 11 and the display color outputs C1 and C2 that are output therefrom in the second embodiment of the present invention. is there. The second embodiment shown in FIG. 3 is different from the first embodiment shown in FIG. 2 in that one of the inputs of the LUT 11 has a ratio of the amplitude signals F and H.
FIG. 3A shows the relationship between the amplitude signal F or H and the display output C1. F can be used as the amplitude signal, or H can be used as the amplitude signal. C1 is one color in which R, G, and B are mixed at an arbitrary ratio, or one color of R, G, and B, and is written in the lookup table with an arbitrary function. FIG. 5B shows the relationship between the ratio between the amplitude signal H and the amplitude signal F and the display output C2. H / F can be used as the ratio, or F / H can be used as the ratio. C2 is one color in which R, G, and B are mixed at an arbitrary ratio different from C1, or one color of R, G, and B different from C1, and is written in the lookup table by an arbitrary function.
[0018]
It is not necessary to separately provide a configuration for obtaining the ratio between the amplitude signals H and F, and the H / F value obtained by calculation from the amplitude signals H and F input to the LUT 11 in the same configuration as in FIG. This is a format in which the contents of the lookup table can be referred to by the value of F / H, and this value is stored in the LUT 11. The R, G, and B outputs of the LUT 11 are added to the R, G, and B outputs of the C1 and C2 outputs and output.
Thus, by making one of the LUTs 11 a ratio of the amplitude signals H and F, it becomes possible to express the difference in acoustic nonlinear characteristics in the ultrasonic propagation medium by the difference in display color on the diagnostic image, Differences in characteristics of living tissue that could not be expressed only by the amplitude signals F and H can be displayed on an image and provided for diagnosis.
[0019]
【The invention's effect】
As described above, according to the ultrasonic diagnostic apparatus of the present invention, an ultrasonic probe that transmits and receives an ultrasonic signal into a living body, and a distortion component is extracted from an echo signal received by the ultrasonic probe. First filter means; second filter means for extracting a fundamental wave component from an echo signal received by the ultrasonic probe; and first and second means for detecting amplitudes from the first and second filter means. A second AM detector; a look-up table for storing a display color referred to by the amplitude level output from the first and second AM detectors; and an amplitude output by the look-up table. By displaying the diagnostic image on the display with the color and color, there is no need to switch between the two images depending on the diagnosis situation, and both images are displayed in different display colors. It has the effect that compensate for a reduction in the contrast.
[0020]
In addition, by making one of the look-up tables a ratio of the amplitude signals H and F, it is possible to express a difference in acoustic nonlinear characteristics in the ultrasonic propagation medium by a difference in display color on the diagnostic image. The characteristic difference of the living tissue, which could not be expressed only by the amplitude signals F and H, can be displayed on the image and provided for diagnosis.
[Brief description of the drawings]
FIG. 1 is a block diagram of an ultrasonic diagnostic apparatus according to an embodiment of the present invention. FIG. 2A is a diagram showing a relationship between an amplitude signal F and a display output C1 according to the first embodiment of the present invention. FIG. 3B is a diagram showing the relationship between the amplitude signal H and the display output C2 in the first embodiment of the present invention. FIG. 3A is a diagram showing the amplitude signal F in the second embodiment of the present invention. FIG. 4B is a diagram showing the relationship between H and the display output C1, and FIG. 4B is a diagram showing the relationship between the ratio of the amplitude signals F and H and the display output C2 in the second embodiment of the present invention. Block diagram of ultrasonic diagnostic equipment [Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Probe 2 Switch circuit 3 Driver 4 TX beam former 5 Preamplifier 6 RX beam former 7 Fundamental wave filter 8 AM detector 9 Harmonic filter 10 AM detector 11 LUT
12 DSC
13 Display 14 Synchronization Signal Generation Circuit 15 Scan Line Address Generation Circuit

Claims (3)

An ultrasonic probe that transmits and receives an ultrasonic signal into a living body, first filter means for extracting a distortion component from an echo signal received by the ultrasonic probe, and an echo received by the ultrasonic probe Second filter means for extracting a fundamental wave component from the signal; first and second AM detectors for detecting amplitudes from the first and second filter means; and the first and second AM detectors. And a display which stores display color data which is referred to by the amplitude levels of the fundamental wave and the harmonics output from the device, and a display, and the diagnostic image is displayed on the display with the amplitude data and the color data output from the lookup table. An ultrasonic diagnostic apparatus characterized by displaying.   2. The super table according to claim 1, wherein the look-up table is written with color data so as to be referenced two-dimensionally by an output from the first AM detector and an output from the second AM detector. Ultrasonic diagnostic equipment.   In the look-up table, color data is written so as to be referenced two-dimensionally by the output from the first or second AM detector and the ratio of the output from the first and second AM detectors. The ultrasonic diagnostic apparatus according to claim 1.

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