JP2006288544A - Ultrasonic diagnostic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide ultrasonic diagnostic apparatus which can accurately estimate the motion speed of a tissue by tissue Doppler imaging even during contrast echo, then, can analyze/evaluate blood flow information and motion information simultaneously. <P>SOLUTION: The ultrasonic diagnostic apparatus is provided with: a transmission and reception means for transmitting ultrasonic waves to a subject and receiving an echo signal from the subject; a first generation means for generating a first image showing a tomogram of the subject based on the echo signal; an estimation means for estimating a motion speed at each place of the tissue of the subject based on the echo signal; a second generation means for generating a second image concerning the motion speed of the tissue; a calculation means for calculating a variance in the motion speed at each place of the tissue; a third generation means for generating a third image showing the the state of the variance in the motion speed at each place of the tissue; and a display means for displaying the first image, the second image and the third image. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an ultrasound diagnostic apparatus that visualizes blood flow information and tissue motion information using ultrasound.

For example, as a technique for diagnosing ischemic disease, contrast echo that visualizes blood flow information of a local tissue such as the heart and tissue Doppler imaging that estimates motion information of a local tissue such as the myocardium (for example, Patent Document 1) is known. Contrast echo is a technique in which a contrast medium bubble is administered to a subject and the blood flow in the tissue is imaged using the strong ultrasonic scattering characteristics of the contrast medium bubble. Tissue Doppler imaging is a type of color Doppler tomography, and is a technique for estimating the motion speed of a tissue from a change in the frequency of ultrasound due to the Doppler effect.
JP-A-6-114059

  Recently, there is a need to simultaneously analyze blood flow information in a tissue and motion information of the tissue. However, when a contrast medium is administered to a subject for contrast echo, a pseudo Doppler component is generated when a bubble in the contrast medium breaks, and the tissue motion speed cannot be accurately estimated by tissue Doppler imaging. There's a problem.

  In addition, immediately after a bubble is destroyed in a so-called replinish, there is a problem that the estimation of the motion speed of the tissue is greatly influenced by the echo signal of the bubble flowing in the thick blood vessel.

  That is, it is extremely difficult to obtain the tissue motion speed with high accuracy by simultaneously performing contrast echo and tissue Doppler imaging.

  The present invention has been made in view of the above circumstances, and the object of the present invention is to accurately estimate the tissue motion speed by tissue Doppler imaging even during contrast echo, and to obtain blood flow information and motion information. An object of the present invention is to provide an ultrasonic diagnostic apparatus capable of analyzing and evaluating at the same time.

  In order to solve the problems and achieve the object, the ultrasonic diagnostic apparatus of the present invention is configured as follows.

(1) In an ultrasonic diagnostic apparatus that obtains a diagnostic image of a tissue by scanning a subject to which a contrast medium bubble is administered with an ultrasonic wave, an ultrasonic wave is transmitted to the subject, and an echo from the subject Transmission / reception means for receiving a signal, first generation means for generating a first image showing a tomographic image of the subject based on an echo signal received by the transmission / reception means, and an echo signal received by the transmission / reception means And a second generation for generating a second image relating to the movement speed of the tissue based on a plurality of movement speeds estimated by the estimation means. Means, calculation means for calculating the spatial variation of the exercise speed estimated by the estimation means, and third generation means for generating a third image showing the spatial variation of the exercise speed calculated by the calculation means And said First image, and a display means for displaying the second image, and the third image.

(2) In the ultrasonic diagnostic apparatus described in (1), the second image is an image showing a strain distribution of the tissue.

(3) In the ultrasonic diagnostic apparatus described in (1), the display unit superimposes and displays at least two of the first image, the second image, and the third image.

(4) In the ultrasonic diagnostic apparatus described in (1), the calculation unit calculates the variance of the motion speed estimated by the estimation unit.

(5) In the ultrasonic diagnostic apparatus described in (1), the transmission condition of the ultrasonic wave to the subject is controlled so that the variance value of the motion speed is equal to or less than a predetermined value set in advance. And a control means.

(6) In an ultrasonic diagnostic apparatus that obtains a diagnostic image of a tissue by scanning a subject to which a contrast agent bubble has been administered with an ultrasonic wave, an ultrasonic wave is transmitted to the subject, and an echo from the subject Transmission / reception means for receiving a signal, first generation means for generating a first image showing a tomographic image of the subject based on an echo signal received by the transmission / reception means, and an echo signal received by the transmission / reception means And a second generation for generating a second image relating to the motion speed of the tissue based on a plurality of motion speeds estimated by the estimation means. Means, a first display means for displaying the first image and the second image, and a first image generated by the first generation means, in the region of interest of the first image. A meter that measures changes in luminance over time Comprising means, and second display means for displaying the time change of luminance the measuring means is measured in real time.

(7) In an ultrasonic diagnostic apparatus for acquiring a diagnostic image of a tissue by scanning a subject to which a contrast medium bubble has been administered with an ultrasonic wave, an ultrasonic wave is transmitted to the subject, and an echo from the subject Transmission / reception means for receiving a signal, first generation means for generating a first image showing a tomographic image of the subject based on an echo signal received by the transmission / reception means, and an echo signal received by the transmission / reception means And a second generation for generating a second image relating to the movement speed of the tissue based on a plurality of movement speeds estimated by the estimation means. Means, a measuring means for measuring a temporal change in luminance within the region of interest of the first image based on the first image generated by the first generating means, and a luminance time measured by the measuring means Based on change Calculation means for calculating a parameter relating to blood flow in each part of the tissue; and third generation means for generating a third image indicating the distribution of the parameter based on a plurality of parameters calculated by the calculation means; Display means for displaying the first image, the second image, and the third image.

(8) In the ultrasonic diagnostic apparatus described in (7), the display unit superimposes and displays at least two of the first image, the second image, and the third image. To do.

  According to the present invention, the motion speed of a tissue can be accurately estimated by tissue Doppler imaging even during contrast echo. In addition, blood flow information and exercise information can be analyzed and evaluated simultaneously.

  First, a first embodiment of the present invention will be described with reference to FIG. 1 and FIG.

  FIG. 1 is a schematic diagram showing the configuration of the ultrasonic diagnostic apparatus according to the first embodiment of the present invention.

  As shown in FIG. 1, the ultrasonic diagnostic apparatus includes an ultrasonic probe 1, a transmission / reception circuit 2, an AD converter 3, a contrast signal processing unit 4, a TDI signal processing unit 5, a digital scan converter (hereinafter referred to as “DSC”). .) 6, a monitor 7 and a console 8 are provided.

  Hereinafter, each element will be described.

  The ultrasonic probe 1 has an array type piezoelectric vibrator. In this array type piezoelectric vibrator, a plurality of piezoelectric elements are arranged in a straight line and the arrangement direction is set as a scanning direction, and each piezoelectric element forms each channel for transmission and reception.

  The transmission / reception circuit 2 supplies a driving pulse to each piezoelectric element of the ultrasonic probe 1 to emit an ultrasonic pulse. The ultrasonic pulse forms a transmission beam for scanning the subject with a set transmission delay time while propagating through the subject. A part of the transmission beam is reflected on the boundary surface with different acoustic impedance in the subject to become an echo signal, and is received by each piezoelectric element of the ultrasonic probe 1. Further, the transmission / reception circuit 2 converts the echo signal received by each piezoelectric element into an electric signal, and forms a reception beam having a focus point determined by a set reception delay time.

  The AD converter 3 converts the output of the transmission / reception circuit 2 into a digital signal.

  The contrast signal processing unit 4 creates B-mode tomographic image data based on the output of the AD converter 3.

  Based on the output of the AD converter 3, the TDI signal processing unit 5 estimates the tissue motion speed by tissue Doppler imaging (TDI: a type of color Doppler tomography), in this embodiment, the myocardial motion speed. Based on this, motion speed data indicating the motion speed distribution of the myocardium is created. Further, the TDI signal processing unit 5 creates strain data indicating a myocardial strain distribution based on the motion speed data. Further, the TDI signal processing unit 5 calculates the dispersion of the myocardial motion speed estimated by the tissue Doppler imaging for each minute region, and combines them to obtain dispersion data indicating the motion speed dispersion at various locations of the myocardium. create.

  Based on the outputs of the contrast signal processing unit 4 and the TDI signal processing unit 5, the DSC 6 generates a tomographic image showing the tomographic image of the subject in black and white, a distortion image showing the myocardial strain distribution in color, and a distribution of motion speed dispersion. A dispersed image or the like indicating the color in a color is generated. In addition, the DSC 6 generates a composite image for simultaneously displaying information acquired in a plurality of modes.

  The monitor 7 displays the tomographic image, TDI image, distributed image, and composite image created by the DSC 6.

  The console 8 is for adjusting the MI (mechanical index) value of the ultrasonic wave transmitted from the ultrasonic probe 1.

  Next, the operation of the ultrasonic diagnostic apparatus having the above configuration will be described.

  When the contrast agent bubble administered to the subject reaches the heart, transmission / reception of ultrasonic waves from the ultrasonic probe 1 is started. Thereby, imaging by ultrasonic waves is started. Note that transmission and reception of ultrasonic waves may be started before the contrast agent bubble reaches the heart.

  When imaging by ultrasound is started, a tomographic image indicating the intensity of the echo signal with black and white shading is created based on the echo signal received by the ultrasound probe 1. At the same time, motion speed data indicating the motion speed distribution of the myocardium is created by tissue Doppler imaging based on the echo signal received by the ultrasound probe 1.

  Once the motion velocity data is created, the variance of the myocardial motion velocity is calculated for each micro area based on this data, and by combining these, the variance of the motion velocity variance at each location of the myocardium is shown in color. An image is created. These tomographic images and dispersed images are superimposed and displayed on the monitor 7 as shown in FIG. A band-like portion 20 in FIG. 2 is a portion showing the distribution state of the distribution of the motion speed of the myocardium displayed in color.

  The operator determines whether or not the MI value of the ultrasonic wave transmitted from the ultrasonic probe 1 is appropriate while looking at the dispersion image displayed on the monitor 7. In other words, if the bubble in the myocardium collapses due to the transmission of ultrasound, the echo signal will change in frequency based on the collapse (disappearance) of the bubble, so the motion speed that cannot occur in the actual living body Spatial variation occurs. In other words, in an actual living body, the motion speed of tissues such as the myocardium should change smoothly. However, when bubbles are artificially collapsed by transmitting ultrasonic waves, spatial variations occur in the motion speed. End up. Therefore, in this embodiment, this spatial variation is expressed by variance, and it is determined whether the bubble in the myocardium is broken based on the variance value, that is, whether the ultrasonic MI value is not too large. I have to.

  If the operator sees the dispersed image and determines that the bubble is broken, the MI value of the ultrasonic wave is lowered. Then, when the MI value of the ultrasonic wave is lowered to such an extent that the bubbles are not broken, motion speed data is created again, and a strain image showing a myocardial strain distribution is created based on this data. These tomographic images and distortion images are superimposed and displayed on the monitor 7. The operator makes a diagnosis while simultaneously viewing the tomographic image and the distortion image superimposed on the monitor 7.

  According to the ultrasonic diagnostic apparatus according to the present embodiment, the variance of the motion speed at each location of the myocardium is calculated by tissue Doppler imaging, and the monitor 7 displays a dispersion image indicating the value of the motion speed variance in color.

  Therefore, it is possible to know whether or not the bubble in the myocardium is broken by looking at the dispersion image, and if the bubble is broken, the MI value of the ultrasound can be adjusted so that the bubble does not break. Thus, it becomes possible to remove the pseudo Doppler component generated by the bubble breaking.

  Thereby, even when contrast echo and tissue Doppler imaging are performed at the same time, the motion speed of the myocardium can be accurately estimated, so that the reliability of the strain image can be improved.

  In this embodiment, the operator adjusts the MI value by looking at the dispersion image. For example, the MI value is adjusted so that the value of the movement speed dispersion is less than or equal to a predetermined value set in the transmission / reception circuit 2. If a function as a control means for controlling transmission conditions such as values is provided, there is no need to display a dispersed image on the monitor 7, and the burden on the operator can be reduced.

  Next, a second embodiment of the present invention will be described with reference to FIGS. Here, the description of the same configuration and operation as in the above embodiment is omitted.

  In this embodiment, an example in which the myocardial motion speed is estimated by tissue Doppler imaging during the so-called replenishment will be described. Replenish is a method of observing the state of bubbles flowing into the scan plane with low MI values after destroying all the bubbles in the scan plane with high MI values. It is.

  In addition to the functions described in the first embodiment, the contrast signal processing unit 4 according to the present embodiment creates luminance change data indicating a temporal change in luminance for each minute region based on the output of the AD converter 3, and further A function of creating luminance data indicating luminance values at various locations of the myocardium by combining these is provided. In addition, the DSC 6 has a function of creating a luminance change graph indicating a temporal change in luminance in the region of interest R (shown in FIG. 3) based on the output of the contrast signal processing unit 4. The console 8 is also used to input timing for starting the creation of myocardial motion speed data to the TDI signal processing unit 5.

  Next, the operation of the ultrasonic diagnostic apparatus having the above configuration will be described.

  When the contrast agent bubble administered to the subject reaches the heart, transmission / reception of ultrasonic waves from the ultrasonic probe 1 is started. Thereby, imaging by ultrasonic waves is started. Note that transmission and reception of ultrasonic waves may be started before the contrast agent bubble reaches the heart.

  When imaging with ultrasound is started, a tomographic image indicating the intensity of the echo signal with black and white shading is generated based on the echo signal received by the ultrasound probe 1. At the same time, a luminance change graph showing the temporal change in luminance in the region of interest R is created. These tomographic images and the luminance change graph are simultaneously displayed on the monitor 7.

  FIG. 4 is a luminance change graph showing temporal changes in luminance in the region of interest R created during the reprint according to the embodiment.

  When an ultrasonic wave with a high MI value is transmitted, all the bubbles in the scan plane are destroyed, and the brightness value of the region of interest R becomes 0, as indicated by a part P1 in FIG. However, the destroyed bubble expands over time and repeats coalescence, and flows again from the coronary artery into the myocardial capillaries. As a result, the luminance in the region of interest R gradually increases, and after a predetermined time has elapsed, the capillaries in the myocardium are filled with bubbles, and the luminance of the region of interest R is indicated by a portion P2 in FIG. Stops rising.

  When the operator looks at the luminance change graph displayed on the monitor 7 and confirms that the capillaries in the region of interest R are filled with bubbles, that is, the increase in the luminance of the region of interest R stops, the tissue Doppler imaging is performed. Myocardial motion velocity data is created, and a strain image showing the myocardial strain distribution is generated based on this data. This distorted image is superimposed on the tomographic image.

  When the capillaries in the myocardium are filled with bubbles, the echo signals from the bubbles flowing in the capillaries out of the echo signals received by the ultrasound probe 1 become dominant, and the bubbles from the bubbles flowing in the thick blood vessels such as the coronary arteries. The echo signal is relatively lowered. In addition, since the blood flow velocity in the capillary is very slow and can be regarded as substantially zero, the velocity component of the bubble in the capillary is equal to the motion velocity of the myocardium. That is, the echo signal received by the ultrasonic probe 1 reflects the motion speed of the myocardium. As a result, if the increase in the brightness of the region of interest R stops, the influence of bubbles flowing in a thick blood vessel such as a coronary artery can be excluded from the estimation result of the myocardial motion speed. It is possible to estimate.

  According to the ultrasonic diagnostic apparatus according to the present embodiment, a luminance change graph showing the temporal change in luminance in the region of interest R is created, and it is confirmed that the capillaries in the myocardium are filled with bubbles based on this graph. Therefore, the motion velocity of the myocardium is estimated by tissue Doppler imaging.

  Therefore, for example, even when tissue Doppler imaging is performed while transmitting ultrasound with a high MI value, such as Replinish, the effects of bubbles flowing in thick blood vessels such as coronary arteries are estimated based on the estimation results of motion speed. Since it can be eliminated, it is possible to improve the estimation accuracy of the motion speed of the myocardium.

  Next, a third embodiment of the present invention will be described with reference to FIGS. In addition, the description is abbreviate | omitted about the structure and effect | action similar to 1st, 2nd embodiment here.

  In addition to the functions described in the first and second embodiments, the contrast signal processing unit 4 according to the present embodiment has a function of calculating parameters α and β (to be described later) relating to luminance temporal change based on luminance change data. It has. Further, the DSC 6 has a function of generating an α image indicating the parameter α in various locations of the myocardium in color and a β image indicating the parameter β in various locations of the myocardium in color based on the output of the contrast signal processing unit 4. Yes.

  Next, the operation of the ultrasonic diagnostic apparatus having the above configuration will be described.

  When the contrast agent bubble administered to the subject reaches the heart, transmission / reception of ultrasonic waves from the ultrasonic probe 1 is started. Thereby, imaging by ultrasonic waves is started. Note that transmission and reception of ultrasonic waves may be started before the contrast agent bubble reaches the heart.

  When imaging by ultrasound is started, a tomographic image in which the intensity of the echo signal is expressed by black and white shading is generated based on the echo signal received by the ultrasound probe 1. At the same time, motion speed data indicating the myocardial motion speed distribution is created by tissue Doppler imaging based on the echo signal received by the ultrasound probe 1, and a strain image indicating the myocardial strain distribution is created based on this data. The

  At the same time, luminance change data indicating temporal changes in luminance at various locations in the myocardium is created based on echo signals received by the ultrasound probe 1, and parameters relating to temporal changes in luminance at various locations in the myocardium are generated based on this data. α and β are calculated.

  The parameter α indicates the maximum amount of blood that can exist in the capillaries in the myocardium, and the parameter β indicates an index relating to the speed of blood flowing into the capillaries in the myocardium. That is, when the parameter α is large, a lot of blood can exist in the myocardium, and when the parameter β is large, a lot of blood can flow per unit time. In addition, the curves K1 and K2 shown in FIG. 4 show the case where the parameter β is large and the case where it is small, respectively.

  When the parameters α and β are calculated, an α image and a β image are generated that represent the values of the parameters α and β in various locations of the myocardium in color. The distorted image and the α image, and the distorted image and the β image are superimposed on each other as shown in FIGS.

  5A shows the distribution state of the parameter α displayed in color, and the belt-like portion 22 in FIG. 5B shows the distribution state of the parameter β displayed in color. Yes.

  The operator makes a diagnosis while simultaneously viewing the distorted image and the α image, and the distorted image and the β image. Since the parameter α indicates the maximum amount of blood that can exist in the capillaries in the myocardium as described above, if this value is small, it can be determined that the amount of retained blood has decreased. In addition, as described above, the parameter β is an index related to the velocity of blood flowing into the capillaries in the myocardium. Therefore, when this value is small, the inflow of blood into the capillaries in the myocardium is not smoothly performed. It can be judged. Thus, the operator can make a diagnosis by associating the myocardial strain state with the blood retention amount of the myocardium, or making a diagnosis by correlating the myocardial strain state with the difficulty of blood flow into the myocardium.

  According to the ultrasonic diagnostic apparatus having the above-described configuration, based on the luminance change data, the parameter α, which is the maximum blood volume that can be held by the capillaries in the myocardium, and the index related to the blood inflow rate into the capillaries in the myocardium. A certain parameter β is obtained, and an α image indicating the value of the parameter α at each location of the strain image and the myocardium, and a β image indicating the value of the parameter β at each location of the strain image and the myocardium are superimposed and displayed.

  As a result, the myocardial strain state at the same time and the blood retention amount of the myocardial capillaries, and the myocardial strain state and the blood flow velocity of the myocardial capillaries can be associated with each other. Diagnostic information can be obtained.

  The present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. Moreover, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, you may combine suitably the component covering different embodiment.

1 is a schematic diagram showing the configuration of an ultrasonic diagnostic apparatus according to a first embodiment of the present invention. The photograph which shows the tomographic image and dispersion | distribution image which were superimposed and displayed on the monitor which concerns on the same embodiment. The photograph which shows the region of interest of the heart concerning a 2nd embodiment of the present invention. The brightness | luminance change graph which shows the time change of the brightness | luminance in the region of interest produced during the reprint based on the embodiment. The photograph which shows the distortion image and alpha image superimposed on the monitor which concerns on 3rd Embodiment of this invention, and a distortion image and beta image.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Ultrasonic probe, 2 ... Transmission / reception circuit, 3 ... AD converter, 4 ... Contrast signal processing part, 5 ... TDI signal processing part, 6 ... Digital scan converter, 7 ... Monitor, 8 ... Console, 20 ... Band-shaped part, 21 ... strip-shaped portion, 22 ... strip-shaped portion, α ... parameter, β ... parameter, R ... region of interest.

Claims (8)

In an ultrasonic diagnostic apparatus for acquiring a diagnostic image of a tissue by scanning a subject to which a contrast agent bubble is administered with an ultrasonic wave,
Transmitting / receiving means for transmitting ultrasonic waves to the subject and receiving an echo signal from the subject;
First generation means for generating a first image indicating a tomographic image of the subject based on an echo signal received by the transmission / reception means;
Based on the echo signal received by the transmission / reception means, an estimation means for estimating a motion speed in various places of the tissue;
Second generation means for generating a second image relating to the movement speed of the tissue based on the plurality of movement speeds estimated by the estimation means;
Calculating means for calculating spatial variations in the exercise speed estimated by the estimating means;
Third generation means for generating a third image showing spatial variation in the exercise speed calculated by the calculation means;
Display means for displaying the first image, the second image, and the third image;
An ultrasonic diagnostic apparatus comprising:   The ultrasonic diagnostic apparatus according to claim 1, wherein the second image is an image showing a strain distribution of the tissue.   The ultrasonic diagnostic apparatus according to claim 1, wherein the display unit superimposes and displays at least two of the first image, the second image, and the third image.   The ultrasonic diagnostic apparatus according to claim 1, wherein the calculating unit calculates a variance of the motion speed estimated by the estimating unit.   2. The control device according to claim 1, further comprising a control unit that controls a transmission condition of ultrasonic waves to the subject so that a value of dispersion of the motion speed is equal to or less than a predetermined value set in advance. Ultrasound diagnostic equipment. In an ultrasonic diagnostic apparatus for acquiring a diagnostic image of a tissue by scanning a subject to which a contrast agent bubble is administered with an ultrasonic wave,
Transmitting / receiving means for transmitting ultrasonic waves to the subject and receiving an echo signal from the subject;
First generation means for generating a first image indicating a tomographic image of the subject based on an echo signal received by the transmission / reception means;
Based on the echo signal received by the transmission / reception means, an estimation means for estimating a motion speed in various places of the tissue;
Second generation means for generating a second image relating to the movement speed of the tissue based on the plurality of movement speeds estimated by the estimation means;
First display means for displaying the first image and the second image;
Measurement means for measuring a temporal change in luminance in a region of interest of the first image based on the first image generated by the first generation means;
Second display means for displaying in real time the luminance temporal change measured by the measurement means;
An ultrasonic diagnostic apparatus comprising: In an ultrasonic diagnostic apparatus for acquiring a diagnostic image of a tissue by scanning a subject to which a contrast agent bubble is administered with an ultrasonic wave,
Transmitting / receiving means for transmitting ultrasonic waves to the subject and receiving an echo signal from the subject;
First generation means for generating a first image indicating a tomographic image of the subject based on an echo signal received by the transmission / reception means;
Based on the echo signal received by the transmission / reception means, an estimation means for estimating a motion speed in various places of the tissue;
Second generation means for generating a second image relating to the movement speed of the tissue based on the plurality of movement speeds estimated by the estimation means;
Measurement means for measuring a temporal change in luminance in a region of interest of the first image based on the first image generated by the first generation means;
Calculation means for calculating a parameter relating to blood flow in various places of the tissue, based on a temporal change in luminance measured by the measurement means;
Based on a plurality of parameters calculated by the calculation means, a third generation means for generating a third image showing the distribution of the parameters;
Display means for displaying the first image, the second image, and the third image;
An ultrasonic diagnostic apparatus comprising:   The ultrasonic diagnostic apparatus according to claim 7, wherein the display unit superimposes and displays at least two of the first image, the second image, and the third image.

Images