JP3095357B2 - Ultrasound diagnostic equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic diagnostic apparatus for generating an ultrasonic image of a subject using ultrasonic waves. In particular, the present invention relates to an ultrasonic diagnostic apparatus used for diagnosing a subject having a cavity therein and having a function of quantitatively detecting the shape of the subject.

[0002]

2. Description of the Related Art Conventionally, an ultrasonic diagnostic apparatus has been used to diagnose a subject inside a body. The ultrasonic diagnostic apparatus transmits and receives an ultrasonic wave to and from a subject, and generates an ultrasonic image from echo data obtained based on the received wave. As the ultrasonic image, for example, B representing a tomographic image of the subject
A mode image is obtained. By using the ultrasound image, it is determined whether the subject is normal or abnormal.

[Prior Art 1] It is preferable to judge whether a subject is normal or not objectively. In order to enable objective judgment, it is required to quantitatively detect the shape of the subject. To meet such demands,
The conventional device has the following measurement functions. FIG.
Is a B-mode image recording a subject having a cavity therein. Here, it is assumed that the tissue thickness of the subject in the figure is measured. The operator sets the still image mode using the operation means, and visually identifies the positions of the inner surface and the outer surface of the subject while viewing the still image. In addition, the operator
Caliper points are set on the inner surface and the outer surface, respectively, using the operating means (for example, points a and b in FIG. 7).
The ultrasonic diagnostic apparatus measures the distance between the two set caliper points and displays the measured distance on the screen.

[Prior Art 2] Japanese Patent Application Laid-Open No. 7-250834 discloses an ultrasonic diagnostic apparatus for visually expressing the motion state of a subject. This conventional apparatus compares a latest frame image with a past frame image and extracts a displacement image representing the displacement of the subject. Then, by sequentially combining the displacement images with time, a displacement history image representing the displacement history of the subject is formed as shown in FIG. The displacement history image clearly shows how the subject moves. Therefore, by using the displacement history image,
Visual grasp of the movement of the subject is facilitated. Further, the publication proposes detecting a displacement amount of a subject from a displacement image in order to quantify a motion state of the subject.

[0005]

[Problems to be solved by the invention]

(1) When measuring the tissue thickness of a subject using the conventional technique, there are the following problems. In the prior art 1, an operator identifies an inner surface and an outer surface of an object by visually observing an ultrasonic image. Therefore, human subjective judgment affects the measurement result. This is not preferable for making an objective diagnosis.

In the prior art 1, the operator sets the caliper points on the inner surface and the outer surface of the subject.
The deviation at the time of setting the caliper point causes a measurement error. Eliminates the need to set caliper points,
It is required to improve measurement accuracy. In addition, in order to simplify the operation of the operator and shorten the measurement time, it is necessary to eliminate the operation of setting the caliper point.

(2) When the subject is an organ that moves like the heart, it is necessary to detect the amount of change in the shape of the subject. An abnormal movement can be found by quantitatively evaluating the movement state of the subject based on the amount of change. However, in the prior art 1, the shape of the subject is measured in a state where the still image mode is set. Therefore, in order to measure the amount of deformation of the subject, it is necessary to perform the above-described measurement operation many times on many still images having different shapes of the subject. Such an operation is complicated and very time-consuming.

(3) In the device of the prior art 2, the displacement amount is obtained in order to quantify the motion state of the subject. In the case where the subject has a cavity, when measuring the deformation toward the cavity, it is common to measure the displacement of the inner surface. However, the displacement amount of the inner surface is an absolute movement amount, and this displacement amount includes not only the deformation amount of the subject itself but also the moving amount accompanying translational movement and torsion movement of the whole subject. For example, even when the movement of the subject itself is slow and the amount of deformation of the subject is small, if the entire subject is performing the translational movement, the displacement amount corresponding to the translational movement is detected.

On the other hand, it is required to detect only the amount of deformation of the subject itself toward the cavity. This is for more accurately determining whether the deformation motion of the subject is normal. Prior art 2 has room for improvement to meet such a demand.

[Object of the present invention] The present invention has been made to solve the above problems. The present invention is applied when the subject has a cavity inside. An object of the present invention is to provide an ultrasonic diagnostic apparatus capable of accurately and quantitatively grasping the shape of a subject in a short time. It is a further object of the present invention to provide an ultrasonic diagnostic apparatus that quantitatively detects the motion state of the subject, and that detects the deformation amount of the subject as the motion state.

[0011]

[Means for Solving the Problems]

(1) An ultrasonic diagnostic apparatus of the present invention includes a transmitting / receiving means for capturing an ultrasonic image of a subject having a cavity therein by transmitting / receiving ultrasonic waves, and a first means for distinguishing a subject tissue from the cavity. Image processing means for converting the ultrasonic image into a ternary value on the basis of a threshold value of the second threshold value and a second threshold value which is larger than the first threshold value and distinguishes the subject tissue from the outer surface of the subject. And a tissue thickness for identifying the inner surface of the subject and the outer surface of the subject based on the ternarized ultrasonic image, and measuring a tissue thickness that is a distance between the inner surface of the subject and the outer surface of the subject. Measuring means.

Here, the subject having a cavity therein is, for example, a heart. The subject includes a sample containing a liquid (for example, blood) in the cavity.

According to the present invention, (1) "the reflectance of ultrasonic waves in the cavity is low, and therefore, the pixel value (luminance value, etc.) of the subject tissue and the cavity in the ultrasonic image are significantly different," and (2). Attention is paid to the characteristic of the ultrasonic image that “the reflectance of the ultrasonic wave on the outer surface of the subject is high, and therefore, the pixel values of the subject tissue and the outer surface of the subject are significantly different”. The ultrasonic image is ternarized using this characteristic. In the ternarized image, the boundary between the region of the subject tissue and the region of the cavity is specified as the inner surface of the subject. By determining the distance between the inner surface of the subject and the outer surface of the subject, the tissue thickness of the subject is determined. For example, the measurement of the tissue thickness is performed along a measurement line set in the ultrasonic image.

According to the present invention, it is unnecessary for the operator to visually check the ultrasonic image and specify the inner surface of the subject and the outer surface of the subject. Further, it is unnecessary to set the caliper point by manual operation. Therefore, the measurement of the shape of the subject is accurately performed in a short time.

(3) An ultrasonic diagnostic apparatus according to one aspect of the present invention is a data generating means for generating data indicating a motion state of a subject based on the tissue thickness obtained from each of a plurality of frames of ultrasonic images. Having. In the ultrasonic diagnostic apparatus, an ultrasonic image for each frame is sequentially obtained as time passes. Therefore, by obtaining the tissue thickness from the image of each frame, a change in the tissue thickness over time can be obtained. The state of deformation of the subject is determined from the change in the tissue thickness. Here, for example, a graph is created in which the horizontal axis represents time and the vertical axis represents tissue thickness.

(4) The data indicating the exercise state of the subject is
For example, it is data indicating the relative motion of the inner surface of the subject with respect to the outer surface of the subject with reference to the outer surface of the subject.

Conventionally, when observing the deformation on the cavity side of the subject, the displacement of the inner surface has been detected. According to the present invention, the deformation of the cavity side of the subject is determined by measuring the thickness of the subject tissue from a viewpoint different from the related art. Specifically, as described above, the relative motion of the inner surface of the subject with respect to the outer surface of the subject is determined based on the tissue thickness. An organ such as a heart has the property that the amount of deformation toward the cavity is much larger than the amount of deformation toward the outside. Therefore, the manner in which the subject is deformed toward the cavity by the relative motion is accurately represented.

Here, as described above, the movement of the subject is
This includes the deformation motion of the subject itself and the translational motion and the torsional motion of the entire subject. In the above configuration, by determining the relative motion of the subject, the influence of the translational motion and the torsional motion is reduced, and the deformation motion of the subject itself is more accurately obtained.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An ultrasonic diagnostic apparatus according to a preferred embodiment of the present invention (hereinafter, referred to as an embodiment) will be described below.
This will be described with reference to the drawings. Here, the present invention is applied to a sector scanning type apparatus, and the subject is a heart. Note that the present invention is similarly applied to other scanning-type devices, and the subject is not limited to the heart.

FIG. 1 shows the configuration of an ultrasonic diagnostic apparatus according to the present embodiment. In FIG. 1, a wave transmitting / receiving unit 10 includes an ultrasonic probe 12, a wave transmitting / receiving circuit 14, and a digital scan converter (DSC) 15, and transmits / receives ultrasonic waves to / from a subject to form an ultrasonic image ( B-mode image). The data of the ultrasonic image is data indicating a luminance value of each pixel in the image. The transmission / reception means 10 is connected to the frame memory 16. The frame memory 16
This is a known memory that records an ultrasonic image for each frame, and is controlled by a frame memory control circuit 18. The frame memory 16 is connected to the monitor 100 and to the image ternarization unit 20.

The image ternarizing section 20 includes a noise removing section 22,
Binarization circuit A24, binarization circuit B26, noise elimination unit A
28, a noise removing unit B30, and a synthesizing circuit 32. The noise removing unit 22 performs a smoothing process on the ultrasonic image sent from the frame memory 16,
Remove noise from images. The binarization circuit A24 has a comparator and the like, and binarizes the ultrasonic image based on the first threshold. The binarization circuit B26 has a configuration similar to that of the binarization circuit A24, and binarizes the ultrasonic image based on the second threshold value.

Here, the setting of the first threshold value will be described. Since the ultrasonic reflectivity of blood is low, the brightness value of the region of the heart chamber is significantly lower than that of the surroundings. Therefore, the first threshold value is set higher than the luminance value of the region of the heart chamber and lower than the luminance value of the region other than the heart chamber. By the binarization based on the first threshold, the region of the heart chamber and the region other than the heart chamber (including the myocardium) are clearly distinguished. In the binarized ultrasound image (hereinafter, binarized image), the luminance value of the region of the heart cavity is set to “0”, and the luminance value of the region other than the heart cavity is set to “1”.

Next, the setting of the second threshold value will be described. Since the adventitia surface is the boundary between the organs around the heart and the heart muscle,
The ultrasonic reflectance is high on the epicardium surface, and the luminance value of the epicardium surface is significantly higher than that of the surroundings. Therefore, the second threshold value is set lower than the luminance value of the epicardial surface of the heart and higher than the luminance value of the region other than the epicardial surface. Therefore, the second threshold value is equal to the first threshold value.
It is set higher than the threshold. By the binarization based on the second threshold value, the epicardial surface and a region other than the epicardial surface (including the myocardium) are clearly distinguished. Here, the luminance value of the region other than the epicardium surface is set to “0”, and the luminance value of the epicardium surface is set to “1”.

A noise removing section A28, a noise removing section B30
Is a so-called median filter, which performs noise removal processing to make the boundaries of each region in an image accurate and clear.
The synthesizing circuit 32 synthesizes the binarized images generated by the binarizing circuit A24 and the binarizing circuit B26 to generate a ternarized ultrasonic image (hereinafter, a ternary image). .

The image ternarization unit 20 is connected to a composite image frame memory 34. Synthetic image frame memory 3
Reference numeral 4 denotes a known memory that records an ultrasonic image for each frame, and is controlled by a frame memory control circuit 36. The composite image frame memory 34 is
0 and to the readout circuit 38.

The read circuit 38 is also connected to a line setting section 40. In the line setting unit 40, a measurement line is set in the image according to an instruction of the operator.
The readout circuit 38 reads out image data of pixels on the measurement line from the ternary image. Thereby, one-dimensional image data along the measurement line is obtained. The line memory 42 is connected to the read circuit 38. The line memory 42 is a known memory that records one-dimensional image data, and is controlled by a line memory control circuit 44.

The line memory 42 includes a distance measuring circuit 46,
They are sequentially connected to a graphing unit 48. Distance measurement circuit 4
Reference numeral 6 denotes a circuit for measuring a distance between two points along one-dimensional image data. Specifically, the distance between the point at which the luminance value changes from 0 to 1 and the point at which the luminance value changes from 1 to 2 in the one-dimensional image data is measured. The former point is a point on the endocardial surface of the heart, the latter point is a point on the epicardial surface of the heart,
Therefore, the measurement result indicates the thickness of the myocardium. Distance measurement circuit 46
Performs distance measurement for each frame. Graphing section 48
Generates a graph showing the temporal change of the myocardial thickness based on the myocardial thickness obtained for each frame. Graphing section 48
Are connected to the monitor 100.

The monitor 100 appropriately displays the graph sent from the graphing section 48, the ultrasonic image sent from the frame memory 16, and the ternary image sent from the composite image frame memory 34. The monitor 100 displays a graph or an image simultaneously or separately according to an operator's instruction.

The graphing unit 48 includes a time axis setting unit 5
0 is connected. The time axis setting unit 50 sets a measurement time axis in a graph displayed on the monitor 100 in accordance with an instruction from the operator. The graphing unit 48 reads the data on the time axis for measurement from the graph and digitizes the data,
This numerical value is displayed on the monitor 100.

The configuration of the ultrasonic diagnostic apparatus according to the present embodiment has been described above. Next, the operation of this device will be described.

The transmitting and receiving circuit 14 of the transmitting and receiving means 10 generates an ultrasonic transmission signal and sends it to the ultrasonic probe 12. The ultrasonic transducer of the ultrasonic probe 12 is excited according to the ultrasonic transmission signal, transmits ultrasonic waves to the subject, and receives the ultrasonic waves reflected by the tissue of the subject. Transmitting and receiving circuit 14
Detects echo data by detecting the received ultrasonic wave,
The SC 15 scan-converts the echo data to generate an ultrasonic image. An ultrasonic image is generated for each frame and sequentially recorded in the frame memory 16. The ultrasound image is sent from the frame memory 16 to the monitor 100 as needed, and is displayed on the screen of the monitor 100.

The ultrasonic image is stored in the frame memory 16
Is output to the noise removal unit 22 of the image ternarization unit 20. The noise removing unit 22 performs a pre-processing of the image ternarization as
Perform noise removal processing by smoothing. In this process, an average of the luminance values of nine pixels (3 × 3) in the image is obtained, and the average value is assigned to each pixel. This process is performed on the entire image. The ultrasonic image from which noise has been removed is output to the binarization circuit A24 and the binarization circuit B26.

The binarizing circuit A24 binarizes the ultrasonic image by comparing the ultrasonic image with the first threshold value. That is, the binarization circuit A24 divides the luminance value into a region with a luminance value lower than the first threshold value and a region with a luminance value higher than the first threshold value, and sets the luminance value of the former region to “0” and the luminance value of the latter region to “1”. FIG.
This shows a state in which the ultrasonic image recording the left ventricle of the heart is binarized by the binarization circuit A24. Heart chamber area 11
The luminance value of 0 (the central part of the image) is “0”, and the luminance value of the region 120 other than the heart chamber is “1”.

The binarized image is output to the noise removing unit A28. The noise removing unit A28 is a so-called median filter, and removes noise by making a majority decision. Specifically, luminance values of three consecutive pixels in the image are detected. Since the ultrasonic image is binarized, the luminance value is 0 or 1. Then, it is detected whether or not the luminance value of the central pixel located at the center of the three pixels is different from the value that occupies the majority of the luminance values of the three pixels. If they are different, the pixel value of the central pixel is corrected to a luminance value that accounts for the majority. This correction increases the shape accuracy of the boundary of the heart chamber region. The above processing is performed on the entire image. The object of the majority decision may be, for example, 5 pixels or 9 pixels (3 × 3). The binarized image from which noise has been removed is output to the synthesis circuit 3.
2 is output.

On the other hand, the binarizing circuit B26 compares the ultrasonic image with the second threshold value to binarize the ultrasonic image. That is, the binarization circuit A26 divides the luminance value into a region having a luminance value lower than the second threshold value and a region having a luminance value higher than the second threshold value, and sets the luminance value of the former region to "0" and the luminance value of the latter region to "1". FIG.
2 shows a state where the same ultrasonic image as that of FIG. 2 is binarized by the binarization circuit B26. Area 130 on the epicardial surface of the heart
Is “1”, and the luminance value of the region 140 other than the outer membrane surface is “0”. The binarized image is generated by the noise removing unit B3
Output to 0. The noise removing unit B30 operates in the same manner as the noise removing unit A28 to remove noise. The binarized image from which noise has been removed is output to the synthesis circuit 32.

The combining circuit 32 adds the two inputted ultrasonic images (FIGS. 2 and 3) to generate a ternary image as shown in FIG. In the figure, the region 20 of the heart chamber
The luminance value of 0 is “0”, and the luminance value of the myocardial region 210 (outside the heart chamber) is “1”. Then, in the area 220 of the epicardium surface, as a result of the addition processing, the luminance value is “2”. Note that the luminance value of the region 230 outside the outer membrane surface is “1”. This area 230 is a part where the organs around the heart are recorded. The ternary image is sent to the composite image frame memory 34 and recorded for each frame.

On the other hand, the operator uses the operating means to
The ultrasonic image recorded in the frame memory 16 is displayed on the monitor 100, and the still image mode is set. Then, the operator decides which part is to be measured,
A line as shown in FIG. 4 is designated at the measurement location. This line is taken into the line setting unit 40 and is set as a measurement line. Note that a configuration may be adopted in which the operator specifies a measurement line by displaying a ternary image. In addition, the configuration may be such that the operator designates a measurement reference point instead of a measurement line. In this case, for example, the line setting unit 40 passes the measurement reference point and passes through the boundary line between the regions 200 and 210 (or the regions 210 and 220 in FIG. 4).
Is determined, and this normal is used as a measurement line.

The reading circuit 38 fetches a measurement line from the line setting section 40, and fetches a ternary image from the composite image frame memory 34. Then, the image data of the pixels on the measurement line is read from the data of the ternary image. The read data indicates one-dimensional image data along the measurement line, and brightness values 0, 1, and 2 are arranged in the one-dimensional image data. For example, in the one-dimensional image data along the measurement line A in FIG. 4, a luminance value 0 is arranged in a heart chamber portion, a luminance value 1 is arranged in a myocardial portion, and then a luminance value is arranged in an epicardial surface portion. The value 2 is arranged, and the luminance value 1 is arranged around the heart. The one-dimensional image data is recorded in the line memory 42.

The line memory 42 outputs one-dimensional image data to the distance measuring circuit 46. The distance measurement circuit 46 detects a point at which the luminance value changes from 0 to 1 and a point at which the luminance value changes from 1 to 2, and measures the distance between the two points. The former point is a point on the endocardial surface of the heart, and the latter point is a point on the epicardial surface of the heart. Thus, the distance measurement indicates the thickness of the myocardium. The distance measurement value is output to the graphing unit 48.

The graphing section 48 creates a graph as exemplified in FIG. 5 using the distance measurement values (ie, myocardial thickness measurement values). The horizontal axis in FIG. 5 is time, and the vertical axis is distance (ie, myocardial thickness). The graphing unit 48
The distance measurement values obtained for each frame are sequentially plotted. Here, plotting is performed for each frame at a point where the time point corresponding to each frame is the x coordinate and the distance measurement value is the y coordinate. Thus, the graph of FIG. 5 is created, and this graph is output to the monitor 100. The monitor 100 displays the input graph on a screen. The monitor 100 appropriately displays the ultrasound image sent from the frame memory 16 together with the graph.

The operator designates a line T as shown in FIG. 5 at an arbitrary position on the graph displayed on the monitor 100 by using the operation means. This line is taken into the time axis setting unit 50 and is used as the measurement time axis T. The measurement time axis T is read by the graphing unit 48, and the graphing unit 48 displays the measured value of the myocardial thickness on the measurement time axis T on the monitor 100.

In addition, the graphing section 48 also generates a graph as shown in FIG. Here, three measurement lines A, B, and C are set by the line setting unit 40.
Then, for each line, the amount of change in myocardial thickness is displayed in the form of a bar graph.

The preferred embodiment of the present invention has been described above. Conventionally, in order to detect abnormal movement of the myocardium, displacement of the intima surface has been detected. In contrast, the present embodiment focuses on the fact that abnormal movement of the myocardium can be detected also by measuring the thickness of the myocardium. This will be described below.

The temporal change in the thickness of the myocardium detected by the apparatus of the present embodiment (FIG. 5) is also the relative movement of the intima surface with respect to the epicardium surface. Here, the heart is deformed in both directions on the epicardial surface side and the intimal surface side with the heartbeat movement. However, myocardium has the property of being hard near the epicardial surface and soft near the intimal surface, and the heart is surrounded by other organs. Therefore, the epicardium surface is less susceptible to the heartbeat motion, and the deformation to the epicardial surface side can be ignored when compared to the deformation to the intimal surface side. From the above, it is shown that the myocardium expands and contracts toward the ventricle due to the relative movement of the intima surface relative to the epicardium surface.

Here, the heart performs a translational motion and a torsional motion together with the heartbeat motion. On the other hand, the relative motion in FIG. 5 shows the deformation of the myocardium exclusively due to the heartbeat motion, and the effects of the translational motion and the torsional motion are reduced. Therefore, by using the device of the present embodiment, it is possible to accurately grasp only the deformation of the myocardium.

Further, the operator using the apparatus of this embodiment only needs to perform the operation of designating the measurement line once. There is no need to visually identify the intima or epicardium surface of the heart or to specify the caliper points on the intima or adventitia surface. The ultrasound diagnostic apparatus automatically measures the thickness of the myocardium along the measurement line for each frame, and
Display a graph like As described above, according to the present embodiment, it is possible to easily and accurately measure the thickness of the myocardium in a short time, and in particular, it is possible to detect a temporal change in the thickness of the myocardium in a short time. .

In this embodiment, the measurement line is fixed, and this line is used for processing each frame. Here, the heart translates in the direction of the measurement line and in the direction perpendicular to this line. Therefore, the measurement of the myocardial thickness is performed for each frame at a myocardial site that differs in a direction perpendicular to the measurement line. However, even if the measurement site is different, a sufficient measurement result can be obtained when an image of the heart as shown in FIG. 4 is targeted. This is because the difference between the thickness of the myocardium in the direction perpendicular to the measurement line is not a problem. However, when the translational movement or the torsion movement of the subject is severe, it is preferable to change the setting of the measurement line for each frame as necessary.

[Brief description of the drawings]

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

FIG. 2 is an explanatory diagram showing an ultrasonic image binarized by a binarization circuit A of the apparatus of FIG. 1;

FIG. 3 is an explanatory diagram showing an ultrasonic image binarized by a binarization circuit B of the apparatus of FIG. 1;

FIG. 4 is an explanatory diagram showing an ultrasonic image ternarized by a synthesizing circuit of the apparatus of FIG. 1;

FIG. 5 is an explanatory diagram showing a graph created by a graphing unit of the apparatus of FIG. 1;

FIG. 6 is an explanatory diagram showing a graph created by a graphing unit of the apparatus of FIG. 1;

FIG. 7 is an explanatory diagram showing a method for measuring a tissue thickness of a subject using an ultrasonic image in Conventional Technique 1.

FIG. 8 is an explanatory diagram showing a displacement history image obtained by Conventional Technique 2.

[Explanation of symbols]

Reference Signs List 10 transmitting / receiving means, 12 ultrasonic probe, 14 transmitting / receiving circuit, 16 frame memory, 20 image ternarization section, 2
4 binarization circuit A, 26 binarization circuit B, 32 synthesis circuit, 34 synthesized image frame memory, 38 readout circuit, 40 line setting unit, 42 line memory, 46
Distance measurement circuit, 48 graphing unit, 100 monitors.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-8-103442 (JP, A) JP-A-8-89503 (JP, A) JP-A-8-627 (JP, A) JP-A-7- 194597 (JP, A) JP-A-5-317314 (JP, A) JP-A-4-279156 (JP, A) JP-A-4-128976 (JP, A) JP-A-4-52872 (JP, A) JP-A-57-182784 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) A61B 8/00-8/15

Claims (5)

(57) [Claims] 1. A transmitting / receiving means for capturing an ultrasonic image of a subject having a cavity therein by transmitting / receiving ultrasonic waves, a first threshold value for distinguishing a subject tissue from the cavity, Image processing means for converting the ultrasonic image into a ternary value based on a second threshold value which is larger than the first threshold value and distinguishes the subject tissue from the outer surface of the subject; Based on the ultrasonic image, a tissue thickness measuring unit that specifies a subject inner surface and a subject outer surface, and measures a tissue thickness that is a distance between the subject inner surface and the subject outer surface. An ultrasonic diagnostic apparatus characterized by the above-mentioned. 2. The apparatus according to claim 1, wherein the image processing unit includes: a first binarizing unit that creates a first binarized image based on the first threshold value; A second binarizing means for creating a second binarized image based on a second threshold value, and combining the first binarized image and the second binarized image to obtain a third binarized image; An ultrasonic diagnostic apparatus comprising: a synthesizing unit that generates a binarized image. 3. The apparatus according to claim 1, further comprising a measurement line setting unit that sets an arbitrary measurement line in the ultrasonic image, wherein the tissue is measured by the tissue thickness measurement unit. An ultrasonic diagnostic apparatus, wherein the thickness is measured along the measurement line. 4. The apparatus according to claim 1, wherein data representing a motion state of the subject is created based on the tissue thickness obtained from each of a plurality of ultrasound images. An ultrasonic diagnostic apparatus comprising: 5. The apparatus according to claim 4, wherein the data indicating the motion state of the subject is data indicating a relative motion of the inner surface of the subject with respect to the outer surface of the subject with respect to the outer surface of the subject. An ultrasonic diagnostic apparatus characterized by the above-mentioned.