JP2011200282A - Ultrasonic diagnostic apparatus and control program for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ultrasonic diagnostic apparatus which accurately extracts the contour of a region having different elasticity within a living tissue.SOLUTION: The ultrasonic diagnostic apparatus comprises a physical quantity data-forming unit which forms physical amount data of a living tissue on the basis of two temporary different echo signals on the same sound ray acquired by transmitting and receiving ultrasonic wave to the living tissue, a display unit which displays an elastic image EG on the basis of the physical amount data formed by the physical amount data-forming unit, and a contour extractor which calculates a threshold of the elastic data on the basis of change rate of the physical amount data between adjacent pixels and extracts the contour of a region C of a tumor by comparing the threshold with the elastic data of each pixel.

Description

  The present invention relates to an ultrasonic diagnostic apparatus that displays an elastic image representing the hardness or softness of a living tissue and a control program therefor.

  For example, Patent Literature 1 discloses an ultrasonic diagnostic apparatus that synthesizes and displays a normal B-mode image and an elastic image representing the hardness or softness of a living tissue. In this type of ultrasonic diagnostic apparatus, the elasticity image is created as follows. First, an ultrasonic probe is pressed against the body surface, and compression and relaxation thereof are repeated, and ultrasonic waves are transmitted and received while deforming a living tissue, thereby obtaining an echo signal. Based on the obtained echo signal, a physical quantity related to elasticity is calculated for each part of the living tissue, and the physical quantity is converted into hue information to create a color elastic image. Incidentally, as a physical quantity related to the elasticity of the living tissue, for example, a strain of the living tissue is calculated.

  Moreover, in the said patent document 1, the distortion calculated about each part of a biological tissue and a threshold value are compared, the area | region where elasticity differs is extracted, and the outline of the extracted area | region is superimposed and displayed on an elasticity image.

JP 2004-135929 A

  By the way, the amount of deformation of the living tissue changes depending on the strength of the compression force by the ultrasonic probe. Therefore, as in Patent Document 1, when comparing the strain calculated for each part of the biological tissue with the threshold and extracting a region having different elasticity, the threshold corresponding to the strength of the compression force on the biological tissue is set. It was necessary to set.

  The invention of the first aspect made to solve the above-mentioned problem is that the elasticity data of the living tissue is based on two temporally different echo signals on the same sound ray obtained by transmitting and receiving ultrasonic waves to the living tissue. The elasticity data creation unit for creating the elastic data, the display unit for displaying the elasticity image based on the elasticity data created by the elasticity data creation unit, and the elasticity data threshold value based on the rate of change of the elasticity data in the adjacent pixels. An ultrasonic diagnostic apparatus comprising: a contour extracting unit that compares the threshold value and elasticity data of each pixel and extracts a contour of a region having different elasticity in a living tissue.

  According to a second aspect of the invention, in the first aspect of the invention, the contour extraction unit sets a plurality of sampling lines in the elastic image, and a change rate of elastic data between adjacent pixels on each sampling line. Is an ultrasonic diagnostic apparatus that detects the maximum portion and calculates the threshold value based on elasticity data for any one of adjacent pixels in the maximum portion.

  According to a third aspect of the present invention, in the second aspect of the invention, the contour extraction unit may determine the elasticity data of pixels having elasticity closer to the elasticity of the region of interest among adjacent pixels in the maximum portion. An ultrasonic diagnostic apparatus characterized in that an average in a sampling line is calculated and the average is used as the threshold value.

  According to a fourth aspect of the invention, in the third aspect of the invention, the pixel having elasticity closer to the elasticity of the region of interest is a pixel corresponding to a harder biological tissue among adjacent pixels in the maximum portion. This is an ultrasonic diagnostic apparatus.

  According to a fifth aspect of the invention, in the invention according to any one of the second to fourth aspects, the contour extraction unit sets the sampling line within a predetermined region set in the elastic image. This is an ultrasonic diagnostic apparatus.

  The invention according to a sixth aspect is the invention according to any one of the first to fifth aspects, wherein the elasticity data is physical quantity data relating to elasticity of a biological tissue calculated based on the two echo signals. This is an ultrasonic diagnostic apparatus.

  The invention according to a seventh aspect is the invention according to any one of the first to fifth aspects, wherein the elasticity data is obtained by gradationizing physical quantity data relating to elasticity of a biological tissue calculated based on the two echo signals. An ultrasonic diagnostic apparatus characterized by the obtained elastic image data.

  The invention according to an eighth aspect is the invention according to any one of the first to seventh aspects, wherein the display setting unit is configured to display a display indicating a region surrounded by the contour extracted by the contour extraction unit on the elastic image. An ultrasonic diagnostic apparatus comprising:

  A ninth aspect of the invention is the invention of any one of the first to eighth aspects, further comprising a calculation unit that calculates an area or volume of a region surrounded by the contour extracted by the contour extraction unit. This is an ultrasonic diagnostic apparatus.

  The tenth aspect of the invention is an elasticity data creation function for creating elasticity data of a living tissue based on two echo signals different in time on the same sound line obtained by transmitting and receiving ultrasonic waves to the living tissue. And calculating a threshold value of elasticity data based on a rate of change of elasticity data in adjacent pixels, comparing the threshold value with the elasticity data of each pixel, and extracting a contour of a region having different elasticity in a living tissue A control program for an ultrasonic diagnostic apparatus, characterized by executing an extraction function.

  According to the invention of the above aspect, the threshold value set based on the change rate of the elasticity data in the adjacent pixels is compared with the elasticity data of each pixel, and the contour of the region having different elasticity in the living tissue is extracted. . As described above, the threshold value is calculated based on the rate of change of the elasticity data in adjacent pixels, so that even if the deformation amount of the living tissue is different, the contour of the region having different elasticity in the living tissue is accurately extracted. be able to.

It is a block diagram which shows an example of schematic structure of embodiment of the ultrasonic diagnosing device which concerns on this invention. It is explanatory drawing of creation of physical quantity data. It is a block diagram which shows the structure of the display control part in the ultrasonic diagnosing device shown in FIG. It is a figure which shows an example of the display of the display part in the ultrasonic diagnosing device shown in FIG. It is a figure which shows the flowchart at the time of displaying an outline on an elasticity image. It is a figure which shows the flowchart about calculation of the threshold value in the flowchart shown in FIG. It is a figure which shows the display part by which the predetermined area | region was set to the elasticity image. It is a figure explaining the setting of the sampling line in a predetermined area | region. It is a figure explaining the part where the change rate of distortion is the maximum between the adjacent pixels on a sampling line. It is a conceptual diagram which shows the pixel on a sampling line. It is a figure explaining the adjacent pixel in the sampling line of a diagonal direction. It is a figure explaining the extraction of the outline of the area | region of a tumor. It is a figure which shows the display part by which the outline was displayed on the elasticity image. It is a conceptual diagram which shows three cross sections orthogonal to each other. It is a figure which shows the display part in a 1st modification. It is a figure which shows the display part by which the two-dimensional area | region was set to the two-dimensional ultrasonic image. It is a figure explaining that the two-dimensional area | region was set about the predetermined cross section. It is a figure explaining the setting of a three-dimensional predetermined area | region. It is a block diagram which shows the structure of the display control part of a 2nd modification.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 includes an ultrasonic probe 2, a transmission / reception unit 3, a B-mode data creation unit 4, a physical quantity data creation unit 5, a display control unit 6, a display unit 7, a control unit 8, and an operation unit 9. Prepare.

  The ultrasonic probe 2 transmits an ultrasonic wave to a living tissue and receives an echo thereof. With the ultrasonic wave transmission / reception surface of the ultrasonic probe 2 in contact with the body surface, for example, based on an echo signal obtained by performing ultrasonic wave transmission / reception while repeating compression and relaxation, elasticity is obtained as described later. An image is created.

  The transmission / reception unit 3 drives the ultrasonic probe 2 under a predetermined scanning condition to perform ultrasonic scanning for each sound ray. The transmission / reception unit 3 performs signal processing such as phasing addition processing on the echo signal received by the ultrasonic probe 2. The echo signal signal-processed by the transmission / reception unit 3 is output to the B-mode data creation unit 4 and the physical quantity data creation unit 5.

  Incidentally, the transmission / reception unit 3 separately performs a B-mode image scan for creating a B-mode image and an elastic image scan for creating an elastic image. As elastic image scanning, at least two scans are performed on the same sound ray in a region (elastic image creation region) in which an elastic image is created in the subject.

  The B-mode data creation unit 4 performs B-mode processing such as logarithmic compression processing and envelope detection processing on the echo signal output from the transmission / reception unit 3 to create B-mode data.

  The physical quantity data creation unit 5 creates physical quantity data related to the elasticity of each part in the living tissue based on the echo signal output from the transmission / reception unit 3 (physical quantity data creation function). More specifically, the physical quantity data creation unit 5 calculates the strain St of each part in the living tissue caused by the compression and relaxation of the ultrasonic probe 2 as a physical quantity related to the elasticity of each part in the living tissue. Create physical quantity data. The physical quantity data creation unit 5 calculates a distortion St based on two echo signals on the same sound ray belonging to two temporally different frames (i) and (ii) as shown in FIG. Create physical quantity data consisting of data. The physical quantity data creation unit 5 is an example of an embodiment of an elasticity data creation unit in the present invention. The physical quantity data is an example of an embodiment of elasticity data in the present invention. Furthermore, the physical quantity data creation function is an example of an embodiment of the elasticity data creation function in the present invention.

  Specifically, the physical quantity data creation unit 5 sets a correlation window for the two echo signals, as described in, for example, Japanese Patent Application Laid-Open No. 2008-126079, and a complex correlation function between the correlation windows. The value obtained by performing the calculation of the imaginary part is taken as distortion St. In the Japanese Patent Application Laid-Open No. 2008-126079, the deviation of the waveform of the two echo signals is estimated as distortion.

  Incidentally, the correlation window corresponds to one pixel of the elastic image. Therefore, the distortion St data obtained for the pair of correlation windows set for the two echo signals is data for one pixel.

  The display control unit 6 is inputted with B mode data from the B mode data creation unit 4 and physical quantity data from the physical quantity data creation unit 5. As shown in FIG. 3, the display control unit 6 includes a B-mode image data creation unit 61, an elastic image data creation unit 62, a synthesis unit 63, a contour extraction unit 64, a contour extraction region setting unit 65, and a contour line setting unit. 66.

  The B-mode image data creation unit 61 and the elastic image data creation unit 62 have a scan converter. The B-mode image data creation unit 61 converts the B-mode data into B-mode image data having luminance information corresponding to the echo signal intensity. The elastic image data creation unit 62 converts the physical quantity data into color elastic image data having hue information corresponding to distortion (elastic image creation function).

  Incidentally, the luminance information in the B-mode image data and the hue information in the color elastic image data have predetermined gradations (for example, 256 gradations). That is, the B-mode image data is data obtained by gradation of the B-mode data, and the color elastic image data is data obtained by gradation of the physical quantity data.

  The B-mode data before being converted into B-mode image data and the physical quantity data before being converted into color elastic image data are referred to as raw data.

  The synthesizing unit 63 synthesizes the B-mode image data and the color elastic image data by adding them, and creates image data of a two-dimensional ultrasonic image displayed on the display unit 7. The image data is displayed on the display unit 7 as a two-dimensional ultrasonic image G in which a monochrome B-mode image BG and a color elastic image EG are combined as shown in FIG. In this example, the elastic image EG is displayed in the region of interest R in a translucent manner (with the background B-mode image transparent).

The contour extraction unit 64 sets a threshold value St _TH for the distortion St based on the rate of change of physical quantity data in adjacent pixels, that is, the rate of change of distortion St in adjacent pixels, and this threshold value St _TH and the physical quantity data of each pixel. The contour of the region having different elasticity in the living tissue is extracted by comparing (the value of strain St). The contour extracting unit 64 is an example of an embodiment of a contour extracting unit in the present invention.

  In this example, the contour extraction unit 64 extracts the contour of the region C of the tumor that is harder than normal tissue as a region having different elasticity in the living tissue. Details will be described later. The tumor region C is an example of an embodiment of a region of interest in the present invention.

The contour extraction region setting unit 65 sets a predetermined region r (see FIG. 7 described later) in the elastic image EG displayed in the region of interest R. The contour extraction region setting unit 64 sets the predetermined region r based on an input from the operation unit 9. The predetermined region r is set when the threshold value St _TH is calculated and the contour of the tumor region C is extracted. Details will be described later.

  The contour setting unit 66 displays a contour O indicating the contour of the tumor region C extracted by the contour extracting unit 64 on the elastic image EG. Details will be described later. The outline setting unit 66 is an example of an embodiment of a display setting unit in the present invention. Further, the contour line O is an example of an embodiment of a display showing a region surrounded by the contour extracted by the contour extracting unit in the present invention.

  The display unit 7 includes an LCD (Liquid Crystal Display), a CRT (Cathode Ray Tube), or the like. The display unit 7 is an example of an embodiment of a display unit in the present invention.

  The control unit 8 is constituted by a CPU (Central Processing Unit), reads a control program stored in a storage unit (not shown), and executes functions in each unit of the ultrasonic diagnostic apparatus 1. The operation unit 9 includes a keyboard and a pointing device (not shown) for the operator to input instructions and information.

  Now, the operation of the ultrasonic diagnostic apparatus 1 of this example will be described. First, the transmission / reception unit 3 transmits an ultrasonic wave from the ultrasonic probe 2 to a living tissue of a subject and acquires an echo signal thereof. At this time, the ultrasonic probe 2 transmits and receives ultrasonic waves while deforming the living tissue by repeatedly pressing and relaxing the subject, for example.

  When the echo signal is acquired, the B-mode data creation unit 4 creates B-mode data, and the physical quantity data creation unit 5 creates physical quantity data. Based on the B-mode data and physical quantity data, the B-mode image data creation unit 61 and the elastic image data creation unit 62 create B-mode image data and color elastic image data. An ultrasonic image G based on the combined image data is displayed on the display unit 7.

  When the ultrasonic image G is displayed, the contour line O is displayed on the elastic image EG in the ultrasonic image G after extracting the contour of the tumor region C. Specific processing will be described based on the flowchart of FIG.

First, in step S1, the contour extraction unit 64 calculates a distortion threshold St _TH used when performing contour extraction of a tumor region C. The contour extraction unit 64 sets a plurality of sampling lines SL (see FIG. 8 described later) in the elastic image EG, and on each sampling line SL, a portion where the rate of change of the distortion St between adjacent pixels is the maximum. To detect. Then, the threshold value St _TH is calculated based on the distortion St data for one of the adjacent pixels in the maximum portion. The calculation of the threshold value St _TH will be described in detail below based on the flowchart of FIG.

  In the flowchart of FIG. 6, first, in step S11, the contour extraction unit 64 sets a predetermined region r in the elastic image EG as shown in FIG. The predetermined region r is a quadrangle in this example, and the operator refers to the elastic image EG (or both the elastic image EG and the B-mode image BG) and is set to include a portion that seems to be a tumor. Is done. Further, the predetermined region r is set so that the center thereof is near the center of the portion considered to be a tumor.

  Incidentally, only the elastic image EG is shown in FIG. 7 for convenience of explanation (the same applies to FIGS. 8, 9, and 13).

  In step S12, the contour extraction unit 64 sets a sampling line SL in the predetermined region r as shown in FIG. However, this sampling line SL is not displayed on the elastic image EG, but is a virtual line.

  In this example, eight sampling lines SL1, SL2, SL3, SL4, SL5, SL6, SL7, and SL8 are set as the sampling line SL radially from the center of the predetermined region r. The sampling lines SL1, SL3, SL5, and SL7 are lines connecting the center of the predetermined region r and the midpoint of each side of the predetermined region r. The sampling lines SL2, SL4, SL6, and SL8 are lines that connect the center of the predetermined area and the apex of the predetermined area r.

  Next, in step S13, the contour extraction unit 64 detects a portion on the sampling lines SL1 to SL8 where the rate of change of the distortion St is maximum between adjacent pixels. Here, in the contour portion of the tumor region C, the rate of change of the distortion St between the adjacent pixels becomes large. Therefore, as shown in FIG. 9, the tumor region C on each of the sampling lines SL1 to SL8. In the contour portion, portions M1, M2, M3, M4, M5, M6, M7, and M8 where the change rate of the distortion St between adjacent pixels is the maximum are detected. Incidentally, the portions M1 to M8 are composed of adjacent pixels.

  Specifically, the pixels p1, p2, p3, p4,..., P (m−1), pm,..., P (n−1), pn on the sampling line SL1 as shown in FIG. A description will be given of the case where the symbols are lined up. The pixels p1 and pn are pixels corresponding to both ends of the sampling line SL, and the pixel p1 is a pixel on the center side of the predetermined region r.

  The contour extraction unit 64 is arranged between adjacent pixels p1 and p2, between pixels p2 and p3, between pixels p3 and p4,..., Between pixels p (m−1) and pm,. -1) The rate of change in strain between pn is calculated. The distortion change rate is a difference between distortion values calculated for adjacent pixels. Then, the contour extraction unit 64 detects a portion where the rate of change of the strain St is maximum. Here, for example, it is assumed that the distortion change rate between the pixels p (m−1) and pm is the maximum, and the portion where the distortion change rate is the maximum is the pixels p (m−1) and pm. In this case, these pixels p (m−1) and pm are pixels constituting the portion M1.

  Incidentally, adjacent pixels on the diagonal sampling lines S2, S4, S6, and S8 will be described with reference to FIG. FIG. 11 shows pixels p1 ′, p2 ′, p3 ′,..., P (n−1) ′, pn ′ on the sampling line S2. In the sampling line S2, a change in distortion between the adjacent pixels p1 'and p2', between the pixels p2 'and p3' on the sampling line S2, ..., and between the pixels p (n-1) 'and pn'. The rate is calculated, and the portion where the distortion change rate is maximum is detected.

Next, in step S14, the contour extraction unit 64 determines the center of the predetermined region r among the adjacent pixels constituting the portions M1 to M8 where the change rate of the distortion St is maximum in each sampling line SL1 to SL8. For the pixel side distortion St, an average value in the portions M1 to M8 is calculated, and this average value is set as the threshold value St _TH . For example, among the pixels p (m−1) and pm constituting the portion M1, the pixel on the center side of the predetermined region r is the pixel p (m−1). Therefore, for the portion M1, the value of the distortion St of the pixel p (m−1) is used when calculating the average value.

  Incidentally, among the adjacent pixels constituting the portions M1 to M8, the pixel on the center side of the predetermined region r is a pixel that is highly likely to be within the range of the tumor region C, and is a distortion of the tumor region C. It is a pixel that has an elasticity closer to that and a pixel that corresponds to a harder biological tissue.

However, in the calculation of the threshold value St _TH , the contour extraction unit 64 compares the distortion values St of adjacent pixels constituting the portions M1 to M8, and the value of the distortion St is high (the living tissue is hard). The average value of the pixel distortion St may be calculated.

When the distortion threshold value St _TH is calculated in step S1, the boundary between the tumor region C and the other region is extracted in step S2, and the contour of the tumor region C is extracted. Specifically, the comparing in a predetermined region r and strain St of each pixel and the threshold value St _TH, identifies the pixel below the pixel and the threshold value St _TH is equal to or greater than the threshold St _TH. Then, in a portion where pixels that are _{equal to} or greater than the threshold St _TH and pixels that are less than the threshold St _TH are adjacent to each other, the portion of the pixels that is less than the threshold St _TH is defined as the contour of the tumor region C. For example, as shown in FIG. 12, it is assumed that the pixels p15 and p18 are pixels that are _{equal to} or greater than the threshold St _TH , while the pixels p11, p12, p13, p14, p16, p17, and p19 are pixels that are less than the threshold. In this case, the pixels p11, p12, p13, p14, p16, p17, and p19 are defined as the contour of the tumor region C.

  Next, in step S3, as shown in FIG. 13, an outline O is displayed on the outline of the tumor region C.

According to the ultrasonic diagnostic apparatus 1 of the present example described above, the threshold value St _TH is set based on the rate of change of the distortion St in adjacent pixels. Therefore, even if the amount of deformation of the living tissue is different, the region C of the tumor can be accurately extracted.

  Further, since the contour line O is displayed at the contour portion of the tumor region C, the shape of the tumor can be accurately and easily grasped.

  Next, a modification of the above embodiment will be described. First, the first modification will be described. In the above-described embodiment, the two-dimensional elastic image EG has been described, but the same can be applied to a three-dimensional elastic image. Specifically, based on volume data obtained by transmitting / receiving ultrasonic waves in a three-dimensional region by the ultrasonic probe 2, as shown in FIG. 14, three cross sections XY, YZ, and ZX that are orthogonal to each other are shown. Regarding the cross section, as shown in FIG. 15, two-dimensional ultrasonic images G1, G2, and G3 are displayed on the display unit 7 and a three-dimensional elastic image EG4 is displayed. The ultrasonic image G1 is an image of the cross section XY, is an image obtained by combining a B-mode image BG1 and an elastic image EG1, and the ultrasonic image G2 is an image of the cross section YZ, and B This is a composite image of the mode image BG2 and the elastic image EG2. The ultrasonic image G3 is an image of the cross section ZX, and is an image obtained by combining the B-mode image BG3 and the elastic image EG3. Further, the three-dimensional elastic image EG4 is an elastic image created by volume rendering using a table whose opacity increases as the hardness of the living tissue increases (for example, Japanese Patent Application Laid-Open No. 2008-259605). . However, the three-dimensional elasticity image EG4 is shown as a cube in a simplified manner in FIG.

  In setting the predetermined region r in step S11, a two-dimensional region r ′ is specified in at least two of the cross sections XY, YZ, and ZX displayed on the display unit 7. The two-dimensional region r ′ is set so as to include the tumor region C. Thereby, a three-dimensional predetermined region r is set. More specifically, for example, as shown in FIG. 16, two-dimensional regions r1 ′ and r2 ′ are set in the ultrasonic image G1 and the ultrasonic image G2. As a result, as shown in FIG. 17, the region r1 ′ is set for the cross section XY, and the region r2 ′ is set for the cross section YZ. When the regions r1 ′ and r2 ′ are thus set, as shown in FIG. 18A, the two-dimensional region r1 ′ is a cross section, and the z direction (the surface direction of the cross section YZ) is the depth. As shown in FIG. 18 (B), a quadrangular prism region r2 ″ having a cross-section as a cross section and a depth in the x direction (plane direction of the cross section XY) as shown in FIG. The region where and overlap is the predetermined three-dimensional region r (not shown).

When the three-dimensional predetermined region r is set in this way, the contour extracting unit 64 sets the sampling line SL in the three-dimensional predetermined region r. Then, in the same manner as described above, after detecting a portion where the rate of change of the distortion St is maximum in adjacent pixels on the sampling line SL and calculating the distortion threshold St _TH , the contour of the tumor region C is extracted. . When the contour of the tumor region C is extracted, the contour line O of the tumor region C when viewed from a certain direction is displayed on the three-dimensional elastic image EG4, although not particularly illustrated.

  Next, a second modification will be described. In this example, the area and volume of the tumor region C may be calculated. When calculating the area, the display control unit 6, as shown in FIG. 19, displays the B-mode image data creation unit 61, the elastic image data creation unit 62, the synthesis unit 63, the contour extraction unit 64, and the contour. In addition to the extraction region setting unit 65 and the contour line setting unit 66, an area calculating unit 67 is provided. When calculating the volume, the display control unit 6 includes a volume calculation unit instead of the area calculation unit 67, although not particularly illustrated. The area calculation unit 67 and the volume calculation unit calculate the area and volume of the region surrounded by the contour of the tumor region C extracted by the contour extraction unit 64. The calculated area and volume may be displayed on the display unit 7.

As mentioned above, although this invention was demonstrated by each said embodiment, of course, this invention can be variously implemented in the range which does not change the main point. For example, the contour extraction unit 64 may calculate the threshold value St _TH using color elastic image data obtained by gradationing the physical quantity data instead of the physical quantity data (distortion St). That is, the contour extraction unit 64 may calculate the threshold value St _TH in the same manner as described above based on the rate of change of the color elastic image data in the adjacent pixels in the sampling line SL.

  In addition, the physical quantity data creation unit 5 may calculate a displacement due to deformation of the living tissue, an elastic modulus, etc. instead of strain as a physical quantity related to the elasticity of the living tissue.

  Further, instead of the outline O, as a display indicating the tumor region C, for example, a diagonal line may be displayed in the tumor region C.

1 Ultrasonic diagnostic device 5 Physical quantity data creation unit (elastic data creation unit)
62 Elastic image data creation unit (elastic data creation unit)
64 Contour extraction unit 66 Contour line setting unit (display setting unit)
67 Area calculation part (calculation part)
7 Display part O Contour line SL, SL1-SL8 Sampling line M1-M8 The part with the highest rate of change

Claims (10)

Based on two temporally different echo signals on the same sound line obtained by transmission / reception of ultrasonic waves to / from a living tissue, an elasticity data creating unit that creates elasticity data of the living tissue;
A display unit for displaying an elasticity image based on the elasticity data created by the elasticity data creation unit;
A contour extraction unit that calculates a threshold value of elasticity data based on a rate of change of elasticity data in adjacent pixels, compares the threshold value with the elasticity data of each pixel, and extracts a contour of a region having different elasticity in a living tissue. When,
An ultrasonic diagnostic apparatus comprising:   The contour extraction unit sets a plurality of sampling lines in the elastic image, detects a portion having the maximum rate of change in elasticity data between adjacent pixels on each sampling line, and detects adjacent pixels in the maximum portion. The ultrasonic diagnostic apparatus according to claim 1, wherein the threshold value is calculated based on elasticity data for any one of the pixels.   The contour extraction unit calculates an average of the sampling lines for the elasticity data of pixels having elasticity closer to that of the region of interest among adjacent pixels in the maximum portion, and uses the average as the threshold value. The ultrasonic diagnostic apparatus according to claim 2.   The ultrasonic diagnostic apparatus according to claim 3, wherein the pixel having elasticity closer to the elasticity of the region of interest is a pixel corresponding to a harder biological tissue among adjacent pixels in the maximum portion.   The ultrasonic diagnostic apparatus according to claim 2, wherein the contour extraction unit sets the sampling line in a predetermined region set in the elasticity image.   The ultrasonic diagnostic apparatus according to claim 1, wherein the elasticity data is physical quantity data relating to elasticity of a biological tissue calculated based on the two echo signals.   6. The elasticity image data according to claim 1, wherein the elasticity data is elasticity image data obtained by gradationizing physical quantity data relating to elasticity of a living tissue calculated based on the two echo signals. The ultrasonic diagnostic apparatus according to item.   The ultrasonic diagnosis according to claim 1, further comprising: a display setting unit configured to display a display indicating an area surrounded by the contour extracted by the contour extraction unit on the elastic image. apparatus.   The ultrasonic diagnostic apparatus according to claim 1, further comprising a calculation unit that calculates an area or volume of a region surrounded by the contour extracted by the contour extraction unit. On the computer,
Based on two echo signals that differ in time on the same sound line obtained by transmitting and receiving ultrasonic waves to and from the living tissue, an elasticity data creation function that creates elasticity data of the living tissue,
A contour extraction function that calculates a threshold value of elasticity data based on a rate of change of elasticity data in adjacent pixels, compares the threshold value with the elasticity data of each pixel, and extracts a contour of a region having different elasticity in a living tissue. When,
A control program for an ultrasonic diagnostic apparatus, characterized in that