JP2010051553A - Ultrasonic diagnostic system and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To display the malignance state of a lesion part in an ultrasonic diagnostic system. <P>SOLUTION: In a two-wave transmission circuit 4, two signals of frequencies f1 and f2 are incident on a living body from an ultrasonic probe 2 and, when the reflected ultrasonic waves from the living body are received by the ultrasonic probe 2, they are respectively filtered by filter parts 8 and 16, and a B-mode image is formed as before from a signal of a fundamental wave (frequency f1) by a detection circuit 10 and a white/black B-mode image part 11. On the other hand, an intensity change rate operating part 17 compares the intensity of the micro-section (between adjacent pixels) in the depth direction of the living body with each other in the respective receiving signals of f1 and f2 to respectively calculate the rates of change of the intensity showing the magnitude of ultrasonic absorption and a color phase data forming part 18 estimates the states of biotissue at the respective points on a tomographic image from their ratio and forms the corresponding color phase data to superpose them on the B-mode image by an addition circuit 19. Accordingly, the color phase data become an index reflecting tissue properties (the malignancy state of the lesion part) and a diagnostician can easily judge the malignancy state of the lesion part. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an ultrasonic diagnostic apparatus and method for obtaining a tomographic image of a diagnostic part of a living body using ultrasonic waves.

  A conventional general ultrasonic diagnostic apparatus uses ultrasonic transmission / reception means for transmitting and receiving ultrasonic waves to a living body, and reflected ultrasonic signals from the ultrasonic transmission / reception means, tomographic image data in the living body at a predetermined cycle. It has image processing means obtained repeatedly and display means for displaying time-series tomographic image data obtained by this image processing means, and displays the tissue structure inside the living body as a B-mode image, an M-mode image or the like. It was. As a method for increasing the resolution of these images and making them easy to understand, an edge enhancement process such as a kernel kernel method is typically employed.

However, Patent Document 1 further discloses that the ultrasonic wave reception signal reflected from the living body is transmitted to the living body by frequency separation, and the relative relationships of the intensity of the obtained frequency components are different from each other. An ultrasonic diagnostic apparatus is disclosed in which a soft tissue and a hard tissue are displayed so as to be able to be compared with each other by imaging the change in relative strength relationship obtained at the time.
JP 2005-125082 A

  The above-described prior art is an excellent device that can display the tissue structure inside the living body by synthesizing it well because there are some that appear in the living tissue for each frequency component. . However, even if there is a lesioned part, the shape appears clearer than before, but it is not known from the image whether it is normal or malignant. In general, it is said that 60 to 70% of high-resolution images are used for diagnosis, and the rest includes information such as (undefined) shape and hardness of the lesion. Experience and intuition are required.

  An object of the present invention is to provide an ultrasonic diagnostic apparatus and method capable of displaying a malignant state of a lesion.

  In the ultrasonic diagnostic apparatus of the present invention, an ultrasonic signal is incident on a living body from a transmitting means, an ultrasonic signal from the living body responding to the incident ultrasonic wave is received by a receiving means, and the image processing means is a monochrome tomographic image. In the ultrasonic diagnostic apparatus in which data is generated and displayed on the display means, the transmitting means sequentially enters the living body at a plurality of frequencies that are separated from each other within a predetermined frequency range. The receiving means sequentially receives an ultrasonic signal from the living body in response to the incident ultrasonic wave, and the image processing means creates the black and white tomographic image data from any one of the received signals, In each received signal, the intensity in a minute section (between adjacent pixels) determined in advance in the depth direction of the living body is compared, and the intensity change rate calculating means for calculating the intensity change rate and the intensity change rate calculating means Above Compare the intensity change rates of the numbers, estimate the state of the biological tissue at each point on the tomogram based on the ratio of the intensity change rates, and create hue information corresponding to the estimated state of the biological tissue Hue information generating means for adding, and adding means for superimposing the hue information generated by the hue information generating means on the black and white tomographic image data generated by the image processing means and outputting to the display means It is characterized by that.

  According to the ultrasonic diagnostic method of the present invention, an ultrasonic signal is incident on a living body, an ultrasonic signal from the living body responding to the incident ultrasonic wave is received, and black and white tomographic image data is created and displayed. In the ultrasonic diagnostic method, incident ultrasonic waves to the living body are sequentially incident on the living body at a plurality of frequencies separated from each other within a predetermined frequency range, and ultrasonic signals from the living body in response to the incident ultrasonic waves are obtained. A step of sequentially receiving, a step of comparing intensity in a minute section (between adjacent pixels) determined in advance in the depth direction of the living body in each of the plurality of received signals, and obtaining an intensity change rate, respectively, Comparing the intensity change rates of the two, and estimating the state of the biological tissue at each point on the tomographic image based on the ratio of the intensity change rates, and corresponding to the estimated state of the biological tissue Characterized by comprising phase and obtaining information, and the step of the color information obtained to the display output superimposed on the tomographic image data of the black and white.

  According to the above configuration, an ultrasonic signal is incident on the living body from the transmitting means, an ultrasonic signal from the living body responding to the incident ultrasonic wave is received by the receiving means, and the image processing means generates black and white tomographic image data. In the ultrasonic diagnostic apparatus and method created and displayed on the display means, the living body is a complex such as muscle and bone. When an ultrasonic signal is incident on the living tissue, generally, water, oil, muscle bone However, when an ultrasonic signal having multiple frequencies is incident on a living tissue, the attenuation is caused by a tissue specific coefficient * thickness * frequency and depends on the frequency. If the difference in attenuation due to the frequency is emphasized, it is useful for diagnosis support. Specifically, in the case of a normal cell, the received intensity should be approximately proportional to the frequency difference (a multiple). However, when a disease or blockage occurs, a singular point where attenuation does not continue due to the difference in attenuation at that site. Appears, finds it and images it.

  For this reason, the transmitting means sequentially enters the living body at a plurality of frequencies separated from each other in a predetermined frequency range by incident ultrasonic waves to the living body, and the receiving means receives the ultrasonic waves from the living body in response to the incident ultrasonic waves. Receive ultrasonic signals sequentially. The image processing means creates the black and white tomographic image data such as a B-mode image from any one received signal using the fundamental wave or the harmonics as usual, while the intensity change rate calculating means For each of the plurality of received signals in time series, the intensity change rate representing the magnitude of ultrasonic absorption of the living tissue at the diagnosis site is compared by comparing the intensity in a predetermined minute section (between adjacent pixels) in the depth direction of the living body. Each of the obtained intensity change rates is compared with the hue information creation means, and the state of the biological tissue at each point on the tomographic image is estimated based on the ratio of the intensity change rates. Hue information corresponding to the state of the living tissue is created, superimposed on the black and white tomographic image data by the adding means, and output to the display means.

  Therefore, as has been reported in the past, the lesion site or infarcted site generally has a larger attenuation coefficient than the normal site. For example, the normal site has a frequency raised to the 1.6th power, that is, the frequency is 1.5. When it doubles, it becomes 1 / 1.91 times, it is 1.3 power in the infarcted region, that is, 1 / 1.69 times, 1.2 power in dilated cardiomyopathy, that is 1.63 times, Since this power value appears in the intensity change rate, the monochrome tomographic image is colored based on the ratio. Thus, the hue information becomes an index reflecting the tissue property (malignancy state of the lesion), and thus the diagnostician can easily determine the malignancy state of the lesion.

  In the ultrasonic diagnostic apparatus of the present invention, the plurality of frequencies are two different frequencies that do not become an integral multiple or a fraction of an integer, and are fundamental waves for creating the black and white tomographic image data. When the first frequency is f1 and the second frequency used for creating the hue information is f2, the relationship is selected as f1 <f2 <2f1.

  According to the above configuration, when f2 = 2f1, the harmonics with respect to the fundamental wave coincide with the second frequency, and thus measures such as increasing the transmission interval are required.

  Therefore, by selecting the above relationship, such a special measure becomes unnecessary. At twice the frequency, the penetration depth into the living body is almost halved. Therefore, it is preferably about f2 = 1.5f1.

  Furthermore, in the ultrasonic diagnostic apparatus according to the present invention, the plurality of frequencies are selected from 1 MHz to 30 MHz, preferably from 3 MHz to 25 MHz, and particularly preferably selected from f1 = 12 MHz and f2 = 18 MHz. .

  According to the above configuration, 1 MHz to 30 MHz, preferably 3 MHz to 25 MHz is a frequency generally used for a living body, and f1 = 12 MHz and f2 = 18 MHz are high frequency basics that can provide high resolution. A wave can satisfy the relationship of f2 = 1.5f1, which is preferable.

  In the ultrasonic diagnostic apparatus of the present invention, the transmitting piezoelectric element is composed of an inorganic piezoelectric element, and the receiving piezoelectric element is composed of an organic piezoelectric element, which are stacked on each other with the organic piezoelectric element as a living body side. It is characterized by that.

  According to the above configuration, when obtaining the intensity change rate in the minute section (between adjacent pixels), the organic piezoelectric layer that can obtain high sensitivity is used for reception, and the inorganic piezoelectric layer that can transmit with increased sound pressure. By using it for transmission, the intensity change rate can be obtained with good S / N.

  In the ultrasonic diagnostic apparatus and method of the present invention, an ultrasonic signal is incident on a living body from a transmitting means, an ultrasonic signal from the living body responding to the incident ultrasonic wave is received by a receiving means, and the image processing means is monochrome. In the ultrasonic diagnostic apparatus and method for generating tomographic image data and displaying the tomographic image data on the display means, the transmitting means sequentially transmits the ultrasonic waves incident on the living body at a plurality of frequencies separated from each other within a predetermined frequency range. The light is incident on a living body, and the receiving means sequentially receives an ultrasonic signal from the living body in response to the incident ultrasonic wave, and the image processing means generates a fundamental wave or a harmonic from any one of the received signals as usual. The black and white tomographic image data such as a B-mode image is used to create a minute section (between adjacent pixels) predetermined in the depth direction of the living body in each of a plurality of time-series received signals by the intensity change rate calculation means. In The intensity change rate representing the magnitude of ultrasonic absorption of the living tissue at the diagnosis site is obtained, and the obtained intensity change rates are compared with each other by the hue information creating means. Based on the ratio between the rates, the state of the biological tissue at each point on the tomographic image is estimated, hue information corresponding to the estimated state of the biological tissue is created, and superimposed on the black and white tomographic image data by the adding means And output to the display means.

  Therefore, the hue information serves as an index reflecting the tissue properties (malignancy state of the lesion), and thus the diagnostician can easily determine the malignancy state of the lesion.

  FIG. 1 is a block diagram showing an electrical configuration of an ultrasonic diagnostic apparatus 1 according to an embodiment of the present invention. The ultrasonic diagnostic apparatus 1 includes an ultrasonic probe 2, a transmission circuit control unit 3, a transmission circuit 4, an amplification circuit 5, an analog / digital converter 6, a reception circuit control unit 7, a first filtering unit 8, and an amplification. In addition to the configuration of a normal ultrasonic diagnostic apparatus having a circuit 9, a detection circuit 10, a monochrome B-mode image unit 11, an image display unit 12, a central control unit 13, a storage unit 14 and an operation panel 15, the transmission circuit control The ultrasonic signal of two frequencies f1 and f2 that are separated from each other in a predetermined frequency range by the unit 3 and the transmission circuit 4 are sequentially incident on the living body, and the second filtering unit 16, the intensity change rate calculating unit 17, the hue information generation A unit 18 and an adder circuit 19 are provided.

  The ultrasound probe 2 obtains one tomographic image by electronically performing beam scanning to transmit and receive ultrasound to a living body. Inside the ultrasound probe 2, as will be described later, an ultrasound generation source is provided. In addition, ultrasonic transducers 2a and 2b for receiving reflected ultrasonic waves are incorporated. The two-wave transmission circuit 4 generates a transmission pulse for driving the ultrasonic probe 2 to generate an ultrasonic wave, and also converges the transmitted ultrasonic wave by a built-in transmission phasing and adding circuit. A point is set to one or more depths.

  In the present embodiment, as the transmission pulse, in addition to the fundamental frequency (first frequency) f1 for creating the black and white tomographic image data, another frequency f2 (second frequency) is also used. It transmits sequentially. These relationships are two different frequencies that do not become an integral multiple or a fraction of an integer, and are first selected as a relationship of f1 <f2 <2f1. This is because, when f2 = 2f1, the harmonics with respect to the fundamental wave coincide with the second frequency f2, so it is necessary to take measures such as increasing the transmission interval. , Such special measures are not necessary. Further, at twice the frequency, the penetration depth of the pulse of the second frequency f2 into the living body is almost halved with respect to the fundamental wave. Therefore, it is preferably selected to be about f2 = 1.5f1. . Specifically, the first and second frequencies f1 and f2 are selected from 1 MHz to 30 MHz, particularly 3 MHz to 25 MHz, which is preferably used for a living body. This is because when the frequency is lower than 3 MHz, the resolution is lowered, and the image is difficult to be clear. When the frequency is 25 MHz or higher, the absorption of ultrasonic waves in the living body is increased, and reception in a deep living body part is performed. This is because it becomes difficult to obtain sufficient sensitivity. If the received signal is sufficiently amplified, it is possible to widen the frequency band from 25 MHz to 100 MHz, but this increases costs and increases the scale of the equipment. Considering the frequency, the above range is preferable. Particularly preferably, f1 = 12 MHz and f2 = 18 MHz are selected. This is because a high-frequency fundamental wave capable of obtaining high resolution satisfies the relationship f2 = 1.5f1.

Here, the ultrasonic diagnostic apparatus is based on obtaining a tomographic image by utilizing the fact that the absorption attenuation of ultrasonic waves varies depending on the state of the tissue in the living body, but the attenuation is larger at higher frequencies. For example, Takao Kamataki et al .: Measurement of ultrasonic attenuation characteristics of living body in 5 to 40 MHz band-Prototype of measurement system and measurement of human myocardial specimen-(Science Technical Report, MBE96-114, pp.65-90 (1996)) In the ultrasonic echo signal from the subject, the high frequency component is greatly attenuated according to the depth of the test, so that the center frequency of the frequency spectrum is lower than the center frequency of the ultrasonic transmission pulse. The attenuation coefficient of living tissue is said to be proportional to the first power of the frequency f (attenuation coefficient ∝f ¹ ).

  Therefore, in the present embodiment, as described above, the transmission circuit control unit 3 causes the two-wave transmission circuit 4 to sequentially transmit the transmission pulses of the two frequencies f1 and f2 from the ultrasonic transducer 2a, thereby ultrasonic vibration. The signal sequentially received by the child 2b is amplified by the amplifier circuit 5, converted into a digital signal by the analog / digital converter 6, and then the reception circuit controller 7 sets one or more convergence points of the received ultrasonic waves. Phased and added by a received wave phasing and adding circuit set to the depth, and filtered by the first and second filtering units 8 and 16 of the corresponding frequencies f1 and f2.

  FIG. 2 is a graph showing how the ultrasonic signals of two frequencies f1 and f2 having a relationship of f1 <f2 are attenuated in the living body, the vertical axis represents the reception intensity (sound pressure level), and the horizontal axis Represents the distance (depth) into the living body. Both are echo signals reflected from a certain point A. Even at the same distance (depth), the signal of the second frequency f2 having a higher frequency has a higher attenuation as described above. Both of them proceed from the point A to the points a and b with attenuation according to the respective frequencies f1 and f2 and the living tissue, but the contour line L1 between the points a and b and the points c and d. When passing through a small lesion sandwiched between L2 and L2, even if the same distance ΔL progresses, Δl1 (point c to point a) attenuates at frequency f1, whereas larger Δl2 (point b to point d) at frequency f2. ) Will only attenuate. Δf1 and Δf2 are the passage times of the minute lesions, which are reciprocals of the speeds. Since it is the same as the original living tissue after passing through this minute lesion, it is parallel to the original attenuation line (from A point to a point) and (from A point to b point), from c point to f point And it attenuates and progresses from d point to e point.

  Accordingly, after the signals of the first and second frequencies f1 and f2 are filtered by the first and second filtering units 8 and 16, respectively, the intensity change rate calculating unit 17 performs a predetermined minute in the depth direction of the living body. When the intensity in the section is compared, the intensity change rates α1 and α2 can be obtained respectively. When the intensity change rates α1 and α2 are compared with each other, the ratio is the ratio by the original attenuation line (from point A to point a). And (from point A to point b) and (from point c to point f) and (from point d to point e) and the ratio of the attenuation line of the lesion (from point a to point c) And (from point b to point d) do not match. For example, when the distance ΔL is infinitely close to zero (0), the minute interval becomes an interval between adjacent pixels.

  Therefore, from the ratio between the intensity change rates α1 and α2, the state of the living tissue (malignancy, specifically hardness) at each point on the tomographic image can be estimated, and the estimated living body Corresponding to the state of the tissue, for example, the higher the malignancy level (α1 <α2), the hue information is changed from yellow to red, and when the malignancy level is low (α1 ≧ α2), By creating, an image representing the malignancy can be created.

  On the other hand, the reception signal of any one of the signals of the first and second frequencies f1 and f2 (in this embodiment, the first frequency f1 of the fundamental wave) is amplified (gain correction) by the amplifier circuit 9. After that, the signal is input to the detection circuit 10 and subjected to signal processing such as log compression, detection, contour enhancement, filter processing, and the like, and is input to the monochrome B-mode image unit 11. The black-and-white B-mode image unit 11 obtains in-vivo tomographic image data from the output of the detection circuit 10 at an ultrasonic wave transmission period and outputs it to the image display unit 12 in synchronization with the television. In the present embodiment, the hue information created by the hue information creation unit 18 is added to the monochrome tomographic image data created by the detection circuit 10 and the monochrome B-mode image unit 11 serving as image processing means by the addition circuit 19. Superimpose and output to the image display unit 12. In addition, in response to an operation from the operation panel 15, only the monochrome B-mode image or only the hue information may be displayed as appropriate.

  FIG. 3 is a cross-sectional view showing an example of the structure of the single piezoelectric element 21 in the ultrasonic transducers 2 a and 2 b of the ultrasonic probe 2. The ultrasonic transducers 2a and 2b are ultrasonic transducers configured using a piezoelectric material, and are configured to include a large number of the piezoelectric elements 21 arranged one-dimensionally or two-dimensionally on a substrate 22. The ultrasonic beam formed by this array transducer is electronically scanned. Each piezoelectric element 21 includes an acoustic lens 23, a first matching layer 24, an organic piezoelectric layer 25, a first backing (damper) layer 26, a second matching layer 27, an inorganic piezoelectric element, from above the element (biological side). It comprises a layer 28, a second backing (damper) layer 29, a heat conducting layer 30 and the substrate 22. A cooling layer 31 is formed on the substrate 22.

  The inorganic piezoelectric layer 28 is made of an inorganic ceramic element such as PZT, and the organic piezoelectric layer 25 can be made of a polymer material such as vinylidene fluoride / 3-fluorinated ethylene copolymer. A signal line 33 for transmission is drawn from the electrode 32 provided on the lower surface of the inorganic piezoelectric layer 28 through the second backing layer 29, and from the electrode 34 provided on the upper surface of the organic piezoelectric layer 25. A receiving signal line 35 is drawn out on one side surface of the piezoelectric element 21, and the electrode 36 provided on the upper surface of the inorganic piezoelectric layer 25 and the electrode 37 provided on the lower surface of the organic piezoelectric layer 25 are connected to the piezoelectric element 21. A common GND line 38 is drawn out on the other side surface.

  The piezoelectric element 21 shown in FIG. 3 includes an ultrasonic transducer 2a for transmission (inorganic piezoelectric layer 28 and electrodes 32 and 36) and an ultrasonic transducer 2b for reception (organic piezoelectric layer 25 and electrodes 34 and 37). Are formed individually and formed as an integral laminated structure, but a conventional piezoelectric element sharing them may be used. Further, the two layers of the ultrasonic transducers 2a and 2b may transmit and receive individually for each frequency, and the ultrasonic transducer 2a transmits and receives the first and second frequencies f1 and f2, and the first The functions of the two-layer ultrasonic transducers 2a and 2b are appropriately determined depending on the piezoelectric material used, such as the reception of the frequency f1 and the ultrasonic transducer 2b only receiving the second frequency f2. It may be determined. However, in order to receive weak harmonics, the signal level (gain) tends to be insufficient even with the amplification of the preamplifier or the main amplifier. Therefore, as described above, the intensity change rate α1,1 in the minute section (distance ΔL). In obtaining α2, the organic piezoelectric layer 25 capable of obtaining high sensitivity is used for reception, and the inorganic piezoelectric layer 28 that can transmit by increasing the sound pressure is used for transmission. The change rates α1 and α2 can be obtained.

  Here, the inventor of the present application measured attenuation characteristics of normal, infarcted, and dilated cardiomyopathy human myocardial specimens. As a result, it has been confirmed that the attenuation coefficient is generally larger in the infarcted region than in the normal site, and the attenuation coefficient is 1.6 times the frequency in the normal site. That is, when the frequency is 1.5 times, the frequency becomes 1 / 1.91 times, but the infarcted region is 1.3 power, that is, 1 / 1.69 times, dilated cardiomyopathy 1.2 power, that is, 1 power. The measurement result is proportional to /1.63 times, and the value of the power is close in the dilated cardiomyopathy and the myocardial infarction myocardium, whereas the value of the power is different in the normal myocardium. Since this power value appears in the intensity change rates α1 and α2, the hue information obtained from the ratio is an index reflecting the tissue properties (malignancy state of the lesion), which makes it easy for the diagnostician The malignancy state of the part can be determined. For example, in blood vessel diagnosis, whether the blood vessel is normal or atherosclerosis can be diagnosed on the image display.

  4 and 5 show the experimental results of the inventors of the present application. FIG. 4 shows a case where a circular lesion image is performed, in which (a) is an image of only the first frequency f1, which is a fundamental wave, and (b) is using two frequencies f1 and f2 (f2 = 1.5f1). An image is shown. FIG. 5 is an image of a minute calcified lesion. Similarly, (a) is an image of only the first frequency f1, which is a fundamental wave, and (b) is two frequencies f1, f2 (f2 = 1.5f1). An image using is shown.

  Both FIG. 4 and FIG. 5 use two frequencies to superimpose the ratio of the intensity change rates α1 and α2 representing the magnitude of ultrasonic absorption of the living tissue in a minute section (distance ΔL), so that a clear image can be obtained. It is understood that it is obtained. The circular lesion used in FIG. 4 is a circular lesion phantom confined in agarose, and the microcalcification lesion used in FIG. 5 contains calcium carbonate finely dispersed in 100 to 200 nm in the agarose block. A distributed phantom was used.

  By the way, as a method for determining the properties of living tissue, elastography technology that uses the hardness (elastic modulus) of a lesioned part as a diagnostic index of benign or malignant has recently been developed. According to this, a living tissue is compressed with an ultrasonic probe, and the reflected echo signals before and after the compression are used to calculate the displacement of the living tissue caused by the compression in real time and display an elasticity (hardness) image. (For example, JP 2007-282932 A). Therefore, it is true that hardness is another parameter that allows us to see the properties of living tissue, but there are problems with reproducibility, such as changes due to slight pressure application, and operator skill is required. It becomes. On the other hand, the method using the ratio of the intensity change rates α1 and α2 of the present invention is easy to operate with good reproducibility.

  The B-mode image unit 11 may create a tomographic image including harmonics such as a second harmonic, a third harmonic, or a fourth harmonic, instead of creating a tomographic image from only the fundamental wave. Further, by performing edge enhancement on the ratio obtained from the intensity change rates α1 and α2 by the aforementioned kernel kernel method or the like, the contour of the lesion can be further clarified.

1 is a block diagram showing an electrical configuration of an ultrasonic diagnostic apparatus according to an embodiment of the present invention. It is a graph which shows the mode of attenuation | damping in a biological body of the ultrasonic signal of two frequencies. It is sectional drawing which shows the structural example of the piezoelectric element of 1 element in the ultrasonic transducer | vibrator of an ultrasonic probe. It is a figure of the circular lesion image which shows the experimental result of this inventor. It is a figure of the minute calcification lesion image which shows the experimental result of this inventor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ultrasonic diagnostic apparatus 2 Ultrasonic probe 2a, 2b Ultrasonic transducer 3 Transmission circuit control part 4 2 wave transmission circuit 5 Amplification circuit 6 Analog / digital converter 7 Reception circuit control part 8 1st filter part 9 Amplification Circuit 10 Detection circuit 11 Monochrome B-mode image unit 12 Image display unit 13 Central control unit 14 Storage unit 15 Operation panel 16 Second filtering unit 17 Strength change rate calculation unit 18 Hue information creation unit 19 Addition circuit 21 Piezoelectric element 22 Substrate 23 Acoustic lens 24 First matching layer 25 Organic piezoelectric layer 26 First backing (damper) layer 27 Second matching layer 28 Inorganic piezoelectric layer 29 Second backing (damper) layer 30 Thermal conduction layer 31 Cooling layer

Claims (5)

An ultrasonic signal is incident on the living body from the transmitting means, and an ultrasonic signal from the living body responding to the incident ultrasonic wave is received by the receiving means, and the image processing means creates black and white tomographic image data and displays it on the display means In the ultrasonic diagnostic apparatus designed to
The transmitting means sequentially enters the living body at a plurality of frequencies separated from each other within a predetermined frequency range by incident ultrasonic waves on the living body,
The receiving means sequentially receives ultrasonic signals from the living body in response to the incident ultrasonic waves,
The image processing means creates the black and white tomographic image data from any one received signal,
In each of the plurality of received signals, intensity change rate calculating means for comparing the intensity in a predetermined minute section in the depth direction of the living body to obtain an intensity change rate,
The plurality of intensity change rates obtained by the intensity change rate calculating means are compared, and based on the ratio of the intensity change rates, the state of the biological tissue at each point on the tomographic image is estimated, and the estimated Hue information creation means for creating hue information corresponding to the state of the biological tissue;
And an addition unit that superimposes the hue information created by the hue information creation unit on the black and white tomographic image data created by the image processing unit and outputs the superimposed data to the display unit. Diagnostic device.   The plurality of frequencies are two different frequencies that are not an integral multiple or a fraction of an integer, and the first frequency that is a fundamental wave for creating the black and white tomographic image data is f1, and the hue information The ultrasonic diagnostic apparatus according to claim 1, wherein a relationship of f1 <f2 <2f1 is selected when f2 is a second frequency used for the creation of.   The ultrasonic diagnostic apparatus according to claim 2, wherein the plurality of frequencies are selected from 1 MHz to 30 MHz.   4. The transmitting piezoelectric element is composed of an inorganic piezoelectric element, and the receiving piezoelectric element is composed of an organic piezoelectric element, which are laminated on each other with the organic piezoelectric element as a living body side. The ultrasonic diagnostic apparatus of any one of Claims. In an ultrasonic diagnostic method in which an ultrasonic signal is incident on a living body, an ultrasonic signal from the living body responding to the incident ultrasonic wave is received, black and white tomographic image data is created and displayed,
Incidently entering the living body at a plurality of frequencies separated from each other in a predetermined frequency range by incident ultrasonic waves on the living body;
Sequentially receiving ultrasonic signals from the living body in response to the incident ultrasonic waves;
In each of the plurality of received signals, comparing the strength in a predetermined micro-section in the depth direction of the living body, and obtaining the intensity change rate, respectively,
Comparing the obtained intensity change rates with each other, and estimating the state of the biological tissue at each point on the tomogram based on the ratio of the intensity change rates;
Obtaining hue information corresponding to the estimated state of the biological tissue;
And a step of superimposing the obtained hue information on the black and white tomographic image data for display output.

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