JP6212160B1 - Ultrasonic diagnostic equipment - Google Patents

Abstract

An improved technique for measurement using elasticity information of a tissue and display of an elasticity image is provided. An elasticity information generation unit generates an elasticity information frame including a plurality of elasticity values representing a distribution of elasticity information of a tissue, using a displacement measured by a displacement measurement unit. The region-of-interest setting unit 22 sets a fat ROI (fat region of interest) for fat and sets a tumor ROI (tumor region of interest) for a tumor (or tumor). The mask processing unit 60 performs mask processing on each elasticity value determined to be an abnormal value at least in the region of interest in the elasticity information frame. The elasticity calculation unit 70 calculates, for example, an average elasticity value based on a plurality of elasticity values that are not masked in the region of interest. The elasticity calculator 70 calculates a diagnostic value such as FLR based on the average elasticity value of the tumor ROI and the average elasticity value of the fat ROI. [Selection] Figure 1

Description

  The present invention relates to an ultrasonic diagnostic apparatus, and more particularly to a technique for obtaining elasticity information of a tissue.

  A technique for obtaining elasticity information of a tissue in an ultrasonic diagnostic apparatus is known. For example, elastography is known that obtains tissue elasticity information by compressing tissue in a subject from the body surface of the subject and measuring the strain of the tissue caused by the compression with ultrasound.

  For example, Patent Document 1 describes a technique for setting a region of interest for each of a lesioned part and a fat layer in an ultrasonic image in an ultrasonic diagnostic apparatus that obtains elasticity information of a living tissue by elastography. . The ultrasonic diagnostic apparatus of Patent Document 1 is suitable for diagnosis related to elasticity information while reducing the burden of user operation by specifying a tissue boundary or the like based on a luminance value of a pixel in an ultrasonic image or the like. It is possible to set various areas of interest. Then, diagnosis information on a lesion such as a tumor can be obtained from the elasticity information in the set region of interest.

  Patent Document 2 discloses an elastic image in which an area of image information in which an elastic value having no display value is obtained is identified as noise in an elastic image representing a distribution of elastic values in a tissue, and the identification result is reflected. Techniques for forming are described. Thereby, for example, area rejection in which color display of elasticity values in an image area having no display value is not performed, or frame rejection in which color display of elasticity values in a frame without display value is not performed is realized.

International Publication No. 2013/183432 Japanese Patent No. 4455003

  The invention according to Patent Document 1 is an epoch-making invention that enables setting of a region of interest suitable for diagnosis related to elasticity information while reducing the burden of user operation. The invention according to Patent Document 2 is an epoch-making invention capable of obtaining an elastic image having high image quality and high reliability. The inventors of the present application have conducted research and development on further improvements of these ground-breaking inventions.

  An object of the present invention is to provide an improved technique in measurement and elasticity image display using tissue elasticity information.

  An ultrasonic diagnostic apparatus suitable for the above object comprises an elastic information generating unit that generates an elastic information frame composed of a plurality of calculation values representing a distribution of elastic information of a tissue in a living body, and the elastic information frame. By expressing a plurality of calculated values as relative values, an elastic image forming unit that forms a display frame for an elastic image, and whether or not each calculated value is an abnormal value in at least a region of interest in the elastic information frame. A determination processing unit for determining, and an elasticity calculation unit for obtaining a representative calculation value representing the region of interest based on a plurality of calculation values excluding each calculation value determined as an abnormal value in the region of interest. Features.

  In the above configuration, the elasticity information frame is composed of a plurality of calculated values representing the distribution of tissue elasticity information (information related to tissue hardness). A preferable specific example of each calculated value is an elastic value such as a strain amount and an elastic modulus of the tissue. When the distribution of elasticity information is displayed as an elasticity image, the size of each calculated value is expressed using a limited image expression such as a change in color tone or a change in gradation. Therefore, when generating the elastic image display frame, a plurality of calculation values representing the distribution of elasticity information are expressed as relative values. By using the relative value expression, for example, only the range from the maximum value to the minimum value included in the plurality of calculation values constituting the elasticity information frame is displayed, and the size of each calculation value contained in the range is set. It may be expressed by a change in color tone or a change in gradation. Therefore, for example, it is possible to display the distribution of elasticity information by making maximum use of limited image expression such as a change in color tone or a change in gradation. When generating the elastic image display frame, the plurality of calculation values may include an abnormal value (an abnormal value in the measurement described later). This is because the influence of the abnormal value on the image is reduced by the relative value expression. Thereby, the legibility of the elastic image realized conventionally can be maintained.

  On the other hand, in the measurement using elasticity information, each of the initial calculated values before the relative value is expressed, for example, each calculated value expressed by an absolute value is respected. Then, it is determined whether or not each calculated value is an abnormal value for a plurality of initial calculated values in at least the region of interest in the elasticity information frame. Each calculation value determined to be an abnormal value is subjected to mask processing, for example, and a representative calculation value representing the region of interest is obtained based on a plurality of calculation values not subjected to mask processing. For example, an average elasticity value relating to a plurality of elasticity values (such as a tissue strain amount and an elastic modulus) which are a plurality of computation values not subjected to mask processing is calculated as a representative computation value. Note that when calculating the representative calculation value, it is determined whether each calculation value is an abnormal value, and the representative calculation value is calculated based on a plurality of calculation values excluding each calculation value determined to be an abnormal value. Good. Thus, in the measurement using elasticity information, the elasticity information with reduced influence of the abnormal value, preferably without the influence of the abnormal value, is preferably respected while respecting the plurality of initial calculation values before the relative value expression. Can be obtained.

  As described above, according to the ultrasonic diagnostic apparatus having the above-described configuration, priority is given to the visibility by maintaining or improving the image quality in the display of the elastic image, and each initial calculation value is respected in the measurement using the elastic information. However, highly accurate measurement is realized in which the influence of abnormal values is reduced or eliminated.

  In a desirable specific example, the determination processing unit determines that each calculation value whose sign is inverted is an abnormal value in at least a region of interest in the elasticity information frame.

  In a desirable specific example, the determination processing unit determines whether or not each calculated value is an abnormal value by threshold processing in at least a region of interest in the elasticity information frame.

  In a preferred embodiment, the determination processing unit performs a mask process on each calculation value determined to be an abnormal value in at least the region of interest in the elasticity information frame, and the elasticity calculation unit performs mask processing in the region of interest. A representative calculation value representing the region of interest is obtained based on a plurality of calculation values that have not been processed.

  In a preferred embodiment, the ultrasonic diagnostic apparatus further includes a region-of-interest setting unit that sets a normal tissue region of interest for a normal tissue in a living body, and sets a lesion tissue region of interest for a lesion tissue in the living body. And the determination processing unit determines whether or not each calculation value is an abnormal value in the normal tissue region of interest and the lesion tissue region of interest, and the elasticity calculation unit is an abnormality in the normal tissue region of interest Calculating a representative calculation value of the normal tissue region of interest based on a plurality of calculation values to be calculated excluding each calculation value determined as a value, and calculating each of the calculation values determined as an abnormal value in the lesion tissue region of interest A representative calculation value of the region of interest of the lesion tissue is calculated based on a plurality of calculation values to be calculated except for.

  In a desirable specific example, the elasticity calculation unit calculates an average elasticity value regarding a plurality of elasticity values that are a plurality of calculation values of the calculation target in the normal tissue region of interest as a representative calculation value of the normal tissue region of interest, An average elasticity value regarding a plurality of elasticity values that are a plurality of computation values of the computation target in the lesion tissue region of interest is calculated as a representative computation value of the lesion tissue region of interest, and the average elasticity value of the normal tissue region of interest and the A ratio of the average elasticity value of the lesion tissue region of interest is calculated.

  In a preferred embodiment, the ultrasonic diagnostic apparatus calculates the ratio of the number of calculation values of the calculation target to the total number of calculation values in the normal tissue region of interest and the calculation of the calculation target to the total number of calculation values in the lesion tissue region of interest. The ratio of the number of values is displayed.

  In a preferred embodiment, the ultrasonic diagnostic apparatus determines the presence / absence of a display value for each calculation value of a plurality of calculation values constituting the elasticity information frame, and the elasticity image forming unit configures the elasticity information frame. The display frame is generated by performing a rejection process on each calculated value determined to have no display value among the plurality of calculated values. For example, it is desirable that the determination processing unit determine whether or not the calculated value is an abnormal value for each calculated value determined to have display value. Further, the elasticity calculation unit obtains a representative calculation value based on a plurality of calculation values excluding each calculation value determined to have no display value and each calculation value determined to be an abnormal value in the region of interest. It is desirable to calculate.

  In a preferred embodiment, the ultrasonic diagnostic apparatus performs a mask process on each calculation value determined to be an abnormal value in the elasticity information frame, and displays an area composed of a plurality of calculation values subjected to the mask process. The mask image is formed.

  In a preferred embodiment, the ultrasonic diagnostic apparatus forms a display image in which the elastic image and the mask image are displayed side by side.

  According to the present invention, an improved technique for measurement using elasticity information of a tissue and display of an elasticity image is provided. For example, according to a preferred aspect of the present invention, in the display of the elastic image, priority is given to the visibility by maintaining or improving the image quality, and in the measurement using the elasticity information, the abnormal value is respected while respecting each initial calculation value. High-precision measurement with reduced or eliminated influence of is realized.

1 is an overall configuration diagram of an ultrasonic diagnostic apparatus suitable for implementing the present invention. It is a figure which shows the specific example of a display frame and a measurement frame. It is a figure which shows the specific example of the elasticity measurement using the ultrasonic diagnosing device of FIG. It is a figure which shows the specific example of the display image which arranged the elasticity image and the mask image.

  FIG. 1 is an overall configuration diagram of an ultrasonic diagnostic apparatus suitable for implementing the present invention. The probe 10 is an ultrasonic probe that transmits and receives ultrasonic waves to and from a subject (living body) including, for example, a tissue to be diagnosed. The probe 10 includes a plurality of vibration elements that transmit and receive ultrasonic waves, and transmission of the plurality of vibration elements is controlled by the transmission / reception unit 12 to form a transmission beam. Further, the plurality of vibration elements receive ultrasonic waves from within the region including the diagnosis target, and a signal obtained thereby is output to the transmission / reception unit 12, and the transmission / reception unit 12 forms a reception beam along the reception beam. Received signals (echo data) are collected. In this way, an ultrasonic beam (transmission beam and reception beam) is scanned in the scanning plane including the diagnosis target, and an ultrasonic reception signal is obtained. It should be noted that techniques such as transmission aperture synthesis may be used in transmission / reception of ultrasonic waves.

  The tomographic image forming unit 20 forms image data of a tomographic image based on the reception signal obtained from the transmission / reception unit 12. The tomographic image forming unit 20 performs signal processing such as gain correction, log compression, detection, contour emphasis, and filter processing on the received signal as necessary, so that the B corresponding to the scan plane including the diagnosis target is obtained. Image data (tomographic image data) of the mode image is formed. For example, the tomographic image forming unit 20 forms tomographic image data of a plurality of frames (a plurality of time phases).

  The displacement measuring unit 30 measures the displacement of the tissue to be diagnosed in the subject based on the received signal obtained from the transmitting / receiving unit 12. For example, the displacement measuring unit 30 corresponds to different time phases among frame data (data corresponding to tomographic images) of a plurality of frames (a plurality of time phases) formed over a plurality of time phases based on the received signal. A displacement vector indicating the displacement of the tissue at each measurement point in each frame (in each frame data), that is, each measurement point in the scanning plane, by performing two-dimensional correlation calculation processing on the two frame data, That is, a two-dimensional displacement vector relating to the direction and size of the displacement is derived, and thereby the distribution of the displacement vector at a plurality of measurement points in the tomographic image is obtained. For deriving the displacement vector, various known methods can be used. For example, a block matching method or a phase gradient method is preferable.

  In the block matching method, each frame, that is, the tomographic image, is divided into a plurality of blocks by blocks each consisting of several pixels in the vertical direction and several pixels in the horizontal direction, and each block has a block in one frame. The block most similar to is searched in the other frame. Thereby, the displacement between time phases is calculated for each measurement point (each block) in each frame, and, for example, a two-dimensional displacement vector is obtained. Note that a displacement vector at each measurement point may be obtained by referring to search results of a plurality of blocks and performing a process such as predictive encoding, that is, a process of determining a sample value based on a difference.

  Also, in the phase gradient method, the phase information of the wave of the received signal is obtained from the received signal constituting each frame, and the amount of movement of the wave of the received signal is calculated from the change in the phase information between the time phases. For example, a one-dimensional or two-dimensional displacement vector in the reception beam direction may be obtained by deriving the displacement of each measurement point.

  The elasticity information generation unit 40 uses the displacement measured by the displacement measurement unit 30 to derive the elasticity information of the tissue within the diagnosis target (for example, an elastic value such as strain or elastic modulus). For example, based on the displacement vector at each measurement point measured between two pieces of frame data corresponding to different time phases, the elasticity information generation unit 40 is configured to detect tissue strain and elasticity at each measurement point for a plurality of measurement points. Calculate elasticity such as modulus. The elasticity information generation unit 40 calculates an elasticity value for each measurement point for a plurality of measurement points in each frame for each time phase (each frame) over a plurality of time phases. As a result, elastic information frames composed of a plurality of elasticity values are generated one after another over a plurality of time phases.

  When obtaining elasticity information (for example, elasticity values such as strain and elastic modulus) of the tissue in the elasticity information generation unit 40, for example, the probe 10 is pressed against the subject, and the tissue in the subject is measured from the body surface of the subject. And the displacement of the tissue due to the compression is measured. At that time, for example, a pressure sensor (not shown) detects the pressure between the transmission / reception surface of the probe 10 and the body surface of the subject, and a stress measurement unit (not shown) is based on the pressure detected by the pressure sensor. The stress at each measurement point inside the subject may be measured. In addition, even if a user such as a doctor or a laboratory technician simply holds the probe 10 in his / her hand and touches the probe 10 against the body surface of the subject, the displacement of the tissue can be measured by minute vibration (tremor) of the user's hand. .

  The elasticity information generation unit 40 calculates the elastic modulus of the tissue at each measurement point with reference to the stress measured by the stress measurement unit. The strain data is calculated by spatially differentiating the amount of tissue movement, for example, displacement. The elastic modulus data is calculated by dividing the change in stress by the change in strain.

  The elasticity image forming unit 50 forms image data of an elasticity image that visually indicates the distribution of elasticity information of the tissue based on the elasticity information frame obtained from the elasticity information generating unit 40. Elastic images can be formed by known techniques. The elastic image forming unit 50, for example, based on the elastic value (strain or elastic modulus) of each measurement point within the display target area of the elastic information frame corresponding to each time phase or the entire elastic information frame. The display frame is formed. The display frame is provided with hue information corresponding to the elasticity value at each measurement point, that is, hue information of red (R), green (G), and blue (B) that are the three primary colors of light. Is done. For example, a relatively hard (hard) elastic value is associated with a color based on blue, and a relatively soft (soft) elastic value is associated with a color based on red. The elasticity value is associated with a color based on green.

  The region-of-interest setting unit 22 sets a region of interest in a measurement target part in an ultrasonic image (tomographic image or elastic image). The region-of-interest setting unit 22 sets, for example, a fat ROI (fat region of interest) for fat and a tumor ROI (tumor region of interest) for a tumor (or tumor) in an ultrasound image.

  The mask processing unit 60 functions as a determination processing unit that determines whether or not each calculated value is an abnormal value at least in the region of interest in the elasticity information frame. Further, the mask processing unit 60 performs a mask process on each elastic value (each calculated value) determined to be an abnormal value. The elasticity information frame is obtained from the elasticity information generation unit 40, and the region of interest (fat ROI and tumor ROI) is set by the region of interest setting unit 22.

  The elasticity calculation unit 70 obtains a representative calculation value that represents the region of interest based on a plurality of calculation values that have not been subjected to mask processing within the region of interest. The elasticity calculation unit 70 calculates, for example, an average elasticity value related to a plurality of elasticity values (such as a tissue strain amount and an elasticity modulus), which are a plurality of calculation values not subjected to mask processing, as a representative calculation value. Further, the elasticity calculation unit 70 calculates a diagnostic value such as FLR (Fat Lesion Ratio) based on elasticity information in the region of interest, for example, an average elasticity value.

  The display processing unit 80 forms a display image related to the diagnosis of elasticity information based on the tomographic image data obtained from the tomographic image forming unit 20 and the elasticity image data (display frame) obtained from the elasticity image forming unit 50. . For example, the display processing unit 80 forms a display image showing a B-mode image and an elastic image based on the tomographic image data. In addition, the display processing unit 80 forms a display image indicating the representative calculation value and the diagnostic value obtained from the elasticity calculation unit 70. The display image formed in the display processing unit 80 is displayed on the display unit 82.

  The control unit 100 generally controls the inside of the ultrasonic diagnostic apparatus shown in FIG. The overall control by the control unit 100 also reflects an instruction received from a user such as a doctor or a laboratory technician via the operation device 90.

  Among the configurations shown in FIG. 1 (respectively marked parts), the transmission / reception unit 12, the tomographic image forming unit 20, the region of interest setting unit 22, the displacement measuring unit 30, the elastic information generating unit 40, the elastic image forming unit 50, the mask Each unit of the processing unit 60, the elasticity calculation unit 70, and the display processing unit 80 can be realized using, for example, hardware such as an electric / electronic circuit or a processor. It may be used. In addition, all or a part of the functions corresponding to the above-described units may be realized by cooperation of hardware such as a CPU, a processor, or a memory, and software (program) that defines the operation of the CPU or the processor.

  A preferred specific example of the display unit 82 is a liquid crystal display or the like, and the operation device 90 can be realized by at least one of a mouse, a keyboard, a trackball, a touch panel, and other switches, for example. And the control part 100 is realizable by cooperation with hardwares, such as CPU, a processor, a memory, and the software (program) which prescribes | regulates operation | movement of CPU, a processor, for example.

  The overall configuration of the ultrasonic diagnostic apparatus in FIG. 1 is as described above. Next, specific examples of functions realized by the ultrasonic diagnostic apparatus of FIG. 1 will be described in detail. In addition, about the structure (each part to which the code | symbol was attached | subjected) shown in FIG. 1, the code | symbol of FIG. 1 is utilized in the following description.

  FIG. 2 is a diagram illustrating specific examples of the display frame and the measurement frame. FIG. 2 shows a display frame including a tumor to be diagnosed and a measurement frame.

  The display frame is formed by the elastic image forming unit 50 based on the elastic information frame obtained from the elastic information generating unit 40. The elastic image forming unit 50 forms an elastic image display frame by expressing each elastic value (for example, 16-bit data) of a plurality of elastic values constituting the elastic information frame as a relative value expression (for example, 8-bit data). . For example, the average value of a plurality of elasticity values in the display target area of the elasticity information frame or the entire elasticity information frame is set as the median value of the relative value expression, and within a range from the minimum value to the maximum value possible as the relative value expression (for example, Each elasticity value is converted into a relative value within the range of 8-bit data. Thereby, in the display frame, for example, intermediate hardness (average value of a plurality of elastic values) is associated with green, maximum hardness is associated with blue, and minimum hardness (softest) Is associated with red, and the hardness in the display frame is relatively represented by the hue.

  The measurement frame is formed by the mask processing unit 60 based on the elasticity information frame obtained from the elasticity information generation unit 40. The mask processing unit 60 performs mask processing on each elasticity value determined as an abnormal value among a plurality of elasticity values constituting the elasticity information frame. Each elasticity value (for example, 16-bit data) constituting the elasticity information frame is derived by the elasticity information generation unit 40 using the displacement measured by the displacement measurement unit 30.

  Displacement of the tissue in the subject when the probe 10 applied to the body surface of the subject is compressed toward the body direction of the subject (the deep side in the depth direction) and when the compression is released The direction of changes. For example, assuming that the in-vivo direction (the deep side in the depth direction) of the subject is the positive direction, the displacement of the tissue is generally positive when the probe 10 is compressed, and the compression of the probe 10 is released. The tissue displacement is generally negative.

  However, in a region where there are many hard tumors or blood vessels, for example, tumors or blood vessels may adversely affect pattern matching (block matching), and the displacement of the original tissue may not be accurately measured. Therefore, for example, when the probe 10 is compressed and the displacement of the tissue is positive in the whole but the displacement reversed in the negative direction is measured, or the pressure of the probe 10 is released and the tissue is released. In some cases, the displacement that is reversed in the positive direction is measured even though the displacement of the first is negative. If the sign of the displacement is reversed, the sign (positive / negative) of the elasticity value (calculated value) obtained based on the displacement is also reversed.

  Therefore, the mask processing unit 60 determines that each elasticity value (each calculated value) whose sign is inverted among a plurality of elasticity values constituting the elasticity information frame is an abnormal value, and masks each elasticity value. Apply processing. Each elasticity value subjected to the mask process is excluded from the measurement target by the elasticity calculation unit 70. Note that the mask processing unit 60 may determine whether or not each elastic value is an abnormal value by threshold processing. For example, each elastic value exceeding the upper threshold may be determined as an abnormal value, and each elastic value lower than the lower threshold may be determined as an abnormal value. The upper threshold and the lower threshold are appropriately set according to, for example, the type of tissue to be determined and the accuracy of displacement measurement (pattern matching, etc.). A configuration in which the upper threshold and the lower threshold can be appropriately changed (adjusted) may be employed.

  The mask processing unit 60 may perform mask processing for the entire elastic information frame, or may perform mask processing only for the region of interest (tumor ROI and fat ROI).

  FIG. 2 also shows a specific example of the region of interest (tumor ROI and fat ROI). The region of interest is set by the region of interest setting unit 22. The region-of-interest setting unit 22 sets a region of interest (ROI) for a region of interest to be measured in, for example, tomographic image data. The ultrasonic diagnostic apparatus of FIG. 1 can obtain elasticity information of various tissues and the like, and in particular, has a function of calculating a FLR (Fat Lesion Ratio) which is a suitable diagnostic value in diagnosis of a mammary gland or the like. Yes. FLR is the ratio of the elasticity value of fat and tumor (tumor) (the elasticity value of fat / the elasticity value of tumor). The region-of-interest setting unit 22 sets, for example, a region of interest (tumor ROI) related to a tumor that is a diagnosis target in FLR and a region of interest (fat ROI) related to fat to be compared. FIG. 2 shows a specific example of the region of interest (tumor ROI and fat ROI) in the display frame and the measurement frame corresponding to the same cross section as the tomographic image data.

  The tumor ROI is set, for example, in a tumor region in the tomographic image data corresponding to each time phase. The region-of-interest setting unit 22 sets a circular tumor ROI in a tomographic image data corresponding to each time phase, for example, by a well-known method detailed in Patent Document 1. Specifically, based on the designated point set for the tumor by a user such as a doctor, for example, the largest possible tumor ROI is set inside the tumor around the designated point. For example, the boundary between the tumor and the other tissue is specified based on the luminance value of the pixel in the tomographic image data, and is as large as possible on the tumor side of the boundary between the tumor and the other tissue, and preferably touches the boundary inside the tumor. A circular tumor ROI is set.

  For example, the region-of-interest setting unit 22 maintains the position of the designated point over a plurality of time phases based on designated points designated by a user such as a doctor or a laboratory technician. The tumor ROI is set as large as possible, preferably inscribed inside the tumor. Note that the region-of-interest setting unit 22 does not use the user's designated point as the center of the tumor ROI as it is, but, for example, in the vicinity of the designated point, a circular tumor that is maximally large by a known method described in detail in Patent Document 1. The center point of the tumor ROI may be searched so that the ROI is set. Thus, a circular tumor ROI is set by the region-of-interest setting unit 22. Of course, the user may instruct the center position and size of the circular tumor ROI, and the region-of-interest setting unit 22 may set the tumor ROI according to the instruction.

  For the fat ROI, for example, a user such as a doctor visually confirms an ultrasonic tomographic image displayed on the display unit 82 and adjusts the center position and radius size of the fat ROI in the tomographic image. Is set by Note that the fat ROI may be set by a known method described in detail in Patent Document 1 by omitting a user operation on fat. For example, by specifying the boundary of the tissue based on the luminance value or the like of the pixel in the tomographic image data, it is possible to reduce the burden of the user operation, and preferably the fat ROI is set without requiring the user operation. Also good.

  Further, for example, when a user such as a doctor designates a designated point for a tumor in the tomographic image data of a desired time phase, the region of interest setting unit 22 performs tumor ROI for each time phase over a plurality of time phases. It is desirable to set the fat ROI. That is, it is desirable that the tumor ROI and the fat ROI are set for each time phase over a plurality of time phases only by the user specifying one designated point for the tumor in the desired time phase. Note that the tumor ROI and the fat ROI may be set only in the time phase to be measured in the elasticity calculation unit 70.

  The tumor ROI and the fat ROI are used when the elasticity calculation unit 70 obtains diagnostic information. Based on the measurement frame obtained from the mask processing unit 60, the elasticity calculation unit 70 obtains diagnostic information such as a tumor to be diagnosed. A preferred specific example of diagnostic information regarding a tumor is FLR. The elasticity calculator 70 calculates the FLR based on the elasticity information in the measurement frame. FLR is the ratio of the elastic value of fat and tumor (tumor) (elastic value of fat / elastic value of tumor).

  The elasticity calculation unit 70 obtains the elasticity value of the tumor based on a plurality of elasticity values (calculation values) that are not subjected to mask processing in the tumor ROI in the measurement frame. For example, an average value of strain in the tumor ROI obtained based on a plurality of elasticity values not subjected to masking processing is set as the elasticity value (average elasticity value) of the tumor. The elasticity calculation unit 70 obtains the elasticity value of fat based on a plurality of elasticity values (calculation values) that are not subjected to mask processing in the fat ROI in the measurement frame. For example, an average value of strain in the fat ROI obtained based on a plurality of elasticity values not subjected to mask processing is set as a fat elasticity value (average elasticity value).

  According to the specific example described with reference to FIG. 2, the abnormal value is masked in the tumor ROI and the fat ROI, so that the influence of the abnormal value is reduced, and preferably the elasticity information without the influence of the abnormal value. (Average elasticity value) can be obtained.

  Note that the ratio of the number of calculation values not subjected to mask processing (the number of effective calculation values) to the total number of calculation values in the tumor ROI and the number of calculation values not subjected to the mask processing for the total number of calculation values in the fat ROI (valid The ratio of (the number of calculated values) may be displayed on the display unit 82 by a numerical value, for example. Thereby, users such as doctors and laboratory technicians can evaluate the reliability and validity of elasticity information (average elasticity value) obtained by using the tumor ROI and the fat ROI. Of course, the ratio of the number of computation values (number of invalid computation values) subjected to mask processing to the total number of computation values in the tumor ROI, and the number of computation values (invalid computation values) subjected to mask processing for the total number of computation values in fat ROI. Number) may be displayed on the display unit 82.

  In addition, in setting the tumor ROI and fat ROI, it is not necessary to consider the presence of abnormal values, so there is a burden for setting, in particular, a user operation burden when the user sets the tumor ROI and fat ROI. Can be reduced. In addition, for example, while observing the shape (circular shape) of the region of interest that has been frequently used in the diagnosis of FLR, a precise strict shape of a suitable measurement region can be adaptively set by mask processing within the region of interest. .

  In forming an elastic image, it is desirable that the elastic image forming unit 50 performs the rejection described in detail in, for example, Patent Document 2. That is, the presence / absence of display value is determined for each calculation value of the plurality of calculation values constituting the elasticity information frame, and the elasticity image forming unit 50 has no display value among the plurality of calculation values constituting the elasticity information frame. It is desirable to generate a display frame by subjecting each of the calculated values determined to the rejection processing detailed in Patent Document 2.

  In Patent Document 2, statistical processing using a plurality of element data constituting measurement result frame data (see FIG. 3 of Patent Document 2) relating to elasticity information as a population is performed, and the statistical feature amount (for example, average or standard deviation) ) Is measured quality frame data (see FIG. 4 of Patent Document 2), and the magnitude relation with the threshold is determined for a plurality of element data constituting the measured quality frame data. The determination result frame data (see FIG. 6 of Patent Document 2) having the presence / absence of the image data is formed, and elastic hue frame data (FIGS. 9 to 12 of Patent Document 2) is generated according to the determination result indicated by the determination result frame data A specific example is described. Thereby, for example, area rejection in which color display of elasticity values in an image area having no display value is not performed, or frame rejection in which color display of elasticity values in a frame without display value is not performed is realized.

  When the rejection process detailed in Patent Document 2 is used, the elastic image forming unit 50 performs, for example, a statistical process using a plurality of calculation values constituting an elastic information frame as a population, and the statistical feature amount thereof. Measurement quality frame data (FIG. 3 of Patent Document 2) having element data (for example, average or standard deviation) is configured, and determination result frame data (FIG. 6 of Patent Document 2) is configured based on the measurement quality frame data. The display frame (elastic hue frame data) may be generated according to the determination result indicated by the determination result frame data. Thereby, for example, area rejection in which color display of elasticity values in an image area having no display value is not performed, or frame rejection in which color display of elasticity values in a frame without display value is not performed is realized. It should be noted that the elasticity value corresponding to the image area or frame that is the object of rejection is preferably excluded from the computation object in the elasticity computing unit 70. Furthermore, it is desirable for the mask processing unit 60 to determine whether or not an elasticity value corresponding to an image region or frame that is not the object of rejection is an abnormal value.

  FIG. 3 is a diagram showing a specific example of elasticity measurement using the ultrasonic diagnostic apparatus of FIG. FIG. 3 shows a flowchart of FLR measurement, which is a preferred specific example of elasticity measurement.

  First, a tomographic image in a subject (living body) to be measured is displayed, and a user such as a doctor or laboratory technician diagnoses, for example, a tumor while viewing the tomographic image in the subject displayed on the display unit 82. The position of the object is confirmed (S301). In the confirmation, a tomographic image is formed over a plurality of time phases while the posture (position and direction) of the probe 10 is appropriately adjusted, and a suitable cross section is searched for in diagnosis.

  When a cross section that suitably captures a diagnostic object such as a tumor is found, for example, when the user operates the operation device 90, the elastic image mode is started (S302). Then, for example, the probe 10 is pressed against the subject, the tissue in the subject is compressed from the body surface of the subject, and elasticity measurement is performed based on the displacement of the tissue due to the compression (S303). It is also possible for a user such as a doctor or a laboratory technician to perform elasticity measurement by minute vibration (shake) of the user's hand simply by holding the probe 10 in his / her hand and placing the probe 10 on the body surface of the subject. .

  When the user determines that the elasticity measurement has been performed satisfactorily, the user performs a freeze operation using the operation device 90, for example, and ends the measurement (S304). As a result, a time phase corresponding to the time point of the freeze operation and a plurality of time phase elasticity information frames corresponding to several seconds immediately before the freeze operation are stored in the memory or the like. Then, elasticity images corresponding to the elasticity information frames of the plurality of time phases are displayed on the display unit 82, and the user can view the elasticity information of the plurality of time phases stored in the memory while viewing the elasticity image displayed on the display unit 82. A diagnostic frame is selected from the frames (S305).

  When the diagnostic frame is selected, the region-of-interest setting unit 22 selects the region of interest (tumor ROI) related to the tumor to be diagnosed in the FLR and the region of interest (fat ROI related to fat to be compared) with respect to the diagnostic frame. ) Is set (S306).

  Then, mask processing is performed by the mask processing unit 60 on the diagnostic frame in which the region of interest is set (S307), and using the diagnostic frame (measurement frame) obtained from the mask processing unit 60, The elasticity calculator 70 calculates FLR, which is the ratio of the elasticity value of fat and tumor (tumor) (the elasticity value of fat / the elasticity value of tumor) (S308). The calculated FLR is displayed on the display unit 82 by, for example, a numerical value or a graph.

  A mask image may be displayed on the display unit 82. For example, the mask processing unit 60 performs a mask process on each calculation value determined to be an abnormal value in the elasticity information frame, and displays a mask image representing a mask region composed of a plurality of calculation values subjected to the mask process. Form. Then, the display processing unit 80 forms a display image in which the elastic image obtained from the elastic image forming unit 50 and the mask image obtained from the mask processing unit 60 are displayed side by side.

  FIG. 4 is a diagram illustrating a specific example of a display image in which an elastic image and a mask image are arranged. The elastic image is formed by the elastic image forming unit 50. The elastic image forming unit 50 forms an elastic image in which the elastic value (hardness) of each part in the display frame (FIG. 2) is expressed in color. In FIG. 4, for convenience of illustration, color display in the elastic image is omitted (simplified by hatching).

  The mask image is formed by the mask processing unit 60. For example, the mask processing unit 60 forms a mask image representing a mask region composed of a plurality of calculation values subjected to mask processing in the measurement frame (FIG. 2). For example, a tomographic image (B-mode image) corresponding to the same cross section as the elastic image is displayed in the background of the mask area. Of course, an elastic image may be displayed on the background of the mask area.

  For example, the display processing unit 80 forms a display image in which an elastic image and a mask image are arranged side by side as in the specific example shown in FIG. 4, and the display image is displayed on the display unit 82. Note that a display image in which an elastic image and a mask image are arranged vertically may be formed, or a display image that displays only the mask image may be formed.

  As mentioned above, although preferred embodiment of this invention was described, embodiment mentioned above is only a mere illustration in all the points, and does not limit the scope of the present invention. The present invention includes various modifications without departing from the essence thereof.

  DESCRIPTION OF SYMBOLS 10 Probe, 12 Transmission / reception part, 20 Tomographic image formation part, 22 Region of interest setting part, 30 Displacement measurement part, 40 Elastic information generation part, 50 Elastic image formation part, 60 Mask processing part, 70 Elasticity calculation part, 80 Display processing part , 82 Display unit, 90 operation device, 100 control unit.

Claims (10)

An elasticity information generation unit that generates an elasticity information frame composed of a plurality of calculated values representing the distribution of elasticity information of the tissue in the living body;
An elastic image forming unit for forming a frame for displaying an elastic image by expressing a plurality of calculation values constituting the elastic information frame as relative values;
A determination processing unit that determines whether or not each calculated value is an abnormal value in at least a region of interest in the elasticity information frame;
An elasticity calculator that obtains a representative calculated value representing the region of interest based on a plurality of calculated values excluding each calculated value determined as an abnormal value in the region of interest;
I have a,
The determination processing unit determines that each calculated value whose sign is inverted is an abnormal value in at least a region of interest in the elasticity information frame.
An ultrasonic diagnostic apparatus. The ultrasonic diagnostic apparatus according to claim 1 ,
The determination processing unit performs a mask process on each calculated value determined as an abnormal value in at least a region of interest in the elasticity information frame,
The elasticity calculation unit obtains a representative calculation value representing the region of interest based on a plurality of calculation values not subjected to mask processing in the region of interest.
An ultrasonic diagnostic apparatus. An elasticity information generation unit that generates an elasticity information frame composed of a plurality of calculated values representing the distribution of elasticity information of the tissue in the living body;
An elastic image forming unit for forming a frame for displaying an elastic image by expressing a plurality of calculation values constituting the elastic information frame as relative values;
A determination processing unit that determines whether or not each calculated value is an abnormal value in at least a region of interest in the elasticity information frame;
An elasticity calculator that obtains a representative calculated value representing the region of interest based on a plurality of calculated values excluding each calculated value determined as an abnormal value in the region of interest;
A region-of-interest setting unit that sets a normal tissue region of interest for a normal tissue in a living body, and sets a lesion tissue region of interest for a lesion tissue in the living body;
Have
The determination processing unit determines whether each calculation value is an abnormal value in the normal tissue region of interest and the lesion tissue region of interest,
The elasticity calculation unit calculates a representative calculation value of the normal tissue region of interest based on a plurality of calculation values to be calculated excluding each calculation value determined as an abnormal value in the normal tissue region of interest, and the lesion Calculating a representative calculated value of the lesioned tissue region of interest based on a plurality of calculation values of the calculation target excluding each calculated value determined as an abnormal value in the tissue region of interest ;
Displaying the ratio of the number of calculation values of the calculation target to the total number of calculation values in the normal tissue region of interest and the ratio of the number of calculation values of the calculation target to the total number of calculation values in the lesion tissue region of interest.
An ultrasonic diagnostic apparatus. The ultrasonic diagnostic apparatus according to claim 3 .
The determination processing unit determines that each calculated value whose sign is inverted is an abnormal value in at least a region of interest in the elasticity information frame.
An ultrasonic diagnostic apparatus. The ultrasonic diagnostic apparatus according to claim 3 .
The determination processing unit determines whether or not each calculated value is an abnormal value by threshold processing in at least a region of interest in the elasticity information frame.
An ultrasonic diagnostic apparatus. The ultrasonic diagnostic apparatus according to any one of claims 3 to 5 ,
The determination processing unit performs a mask process on each calculated value determined as an abnormal value in at least a region of interest in the elasticity information frame,
The elasticity calculation unit obtains a representative calculation value representing the region of interest based on a plurality of calculation values not subjected to mask processing in the region of interest.
An ultrasonic diagnostic apparatus. The ultrasonic diagnostic apparatus according to any one of claims 3 to 6 ,
The elasticity calculation unit calculates an average elasticity value related to a plurality of elasticity values that are a plurality of calculation values of the calculation target in the normal tissue region of interest as a representative calculation value of the normal tissue region of interest, and the lesion tissue region of interest An average elasticity value for a plurality of elasticity values that are a plurality of computation values of the computation target in the region is calculated as a representative computation value of the lesion tissue region of interest, and an average elasticity value of the normal tissue region of interest and the lesion tissue region of interest Calculate the ratio of average elasticity value,
An ultrasonic diagnostic apparatus. The ultrasonic diagnostic apparatus according to any one of claims 1 to 7,
Determining the presence or absence of display value for each of the plurality of calculation values constituting the elasticity information frame;
The elastic image forming unit generates a display frame by performing a rejection process on each calculated value determined to have no display value among a plurality of calculated values constituting the elastic information frame.
An ultrasonic diagnostic apparatus. The ultrasonic diagnostic apparatus according to any one of claims 1 to 8,
Masking each calculation value determined to be an abnormal value in the elasticity information frame, and forming a mask image representing an area composed of a plurality of calculation values subjected to mask processing;
An ultrasonic diagnostic apparatus. The ultrasonic diagnostic apparatus according to claim 9,
Forming a display image in which the elastic image and the mask image are displayed side by side;
An ultrasonic diagnostic apparatus.

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