JP2015008942A - Ultrasonic diagnostic apparatus, image visualization method and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a visualization performance of a microstructure such as a microcalcification part in an analyte more than before.SOLUTION: A B mode image generation section 22 generates a plurality of B mode images corresponding to each of a plurality of directions on the basis of each of a plurality of reception signals generated in accordance with each transmission of an ultrasonic wave sequentially transmitted toward mutually different directions. An extraction section 24 reads out a pixel value of each pixel corresponding to the same reflection point from each of the plurality of B mode images and extracts a specific pixel by performing comparative analysis in the plurality of B mode images of the read pixel value. The specific pixel extracted by the extraction section 24 is displayed on a monitor 30.

Description

  The present invention relates to an ultrasonic diagnostic apparatus, an image rendering method, and a program that generate a tomographic image of a subject by transmitting and receiving ultrasonic waves.

  2. Description of the Related Art An ultrasonic diagnostic apparatus that transmits ultrasonic waves from an ultrasonic probe to a subject and generates a tomographic image of the subject based on a reflected wave from the inside of the subject is known. In such an ultrasonic diagnostic apparatus, a technique is known in which ultrasonic waves are transmitted in a plurality of directions different from each other and one tomographic image is generated based on a reception signal obtained by each transmission.

  For example, Patent Document 1 discloses a first scan in which ultrasonic transmission is performed in a direction perpendicular to the azimuth direction on a subject into which a puncture needle is inserted, and a plurality of directions different from the directions at the time of the first scan. It is described that the second scan for performing ultrasonic transmission is performed. In the apparatus described in Patent Document 1, the first ultrasonic image is generated using the reflected wave received by the ultrasonic probe by the first scan, and the ultrasonic probe 1 is received by the second scan. A second ultrasonic image group that is an ultrasonic image for each of a plurality of directions is generated using the reflected wave. Then, an image that matches a predetermined condition is selected as a third ultrasound image from the second ultrasound image group, a puncture needle region is extracted from the third ultrasound image, and the extracted puncture needle A needle image is generated based on the region, and a composite image of the first ultrasonic image and the needle image is generated.

JP 2012-213606 A

  At present, it is considered that the mammography apparatus using X-rays is superior to the ultrasonic diagnostic apparatus in the rendering performance for the microcalcification portion generated in the breast. This is because in the ultrasound image, both the mammary gland structure and the microcalcification portion are depicted as reflection points with relatively high brightness, and the image of the microcalcification portion is buried in the image of the mammary gland structure.

  In the ultrasonic diagnosis, there is no risk of exposure unlike the mammography apparatus using X-rays, and therefore it is desired to improve the rendering performance of the microcalcification part in the ultrasonic diagnosis apparatus. At present, various studies have been made to improve the rendering performance of the microcalcification portion, but it is not sufficient.

  The present invention has been made in view of the above points, and an ultrasonic diagnostic apparatus, an image rendering method, and an image rendering method capable of improving the rendering performance of a microstructure such as a microcalcification portion in a subject as compared with the conventional one. The purpose is to provide a program.

  According to the first aspect of the present invention, image generation means for generating a plurality of images corresponding to each of the plurality of directions based on the reflected waves of the ultrasonic waves reflected in different directions from the reflection point; Extraction means for performing a comparative analysis of pixel values of pixels corresponding to the same reflection point in the plurality of images generated by the image generation means to extract specific pixels that approximate pixel values; and Display means for displaying the specific pixel extracted by the means.

  According to a second aspect of the present invention, the extraction unit is configured to obtain a pixel value between the plurality of images among the pixels corresponding to the same reflection point in the plurality of images generated by the image generation unit. There is provided an ultrasonic diagnostic apparatus according to a first aspect of extracting, as the specific pixel, a pixel whose difference value or index value indicating the magnitude of variation is a predetermined threshold value or less.

  According to a third aspect of the present invention, the extraction unit is configured to obtain a pixel value between the plurality of images among the pixels corresponding to the same reflection point in the plurality of images generated by the image generation unit. There is provided an ultrasonic diagnostic apparatus according to a first aspect that extracts a pixel having a correlation value equal to or greater than a predetermined threshold as the specific pixel.

  According to a fourth aspect of the present invention, the extraction unit extracts, as the specific pixel, a pixel having a pixel value equal to or greater than a predetermined threshold in each of the plurality of images generated by the image generation unit. An ultrasonic diagnostic apparatus according to the second or third aspect is provided.

  According to a fifth aspect of the present invention, the extracting means is the smallest pixel between the plurality of images among the pixels corresponding to the same reflection point in the plurality of images generated by the image generating means. An ultrasonic diagnostic apparatus according to a first aspect for extracting pixels having a value equal to or greater than a predetermined threshold is provided.

  According to a sixth aspect of the present invention, there is provided the ultrasonic diagnostic apparatus according to any one of the first to fifth aspects, wherein the display means displays only the pixels extracted by the extraction means.

  According to a seventh aspect of the present invention, the display means displays the pixels extracted by the extraction means on any image generated by the image generation means so as to be visible. An ultrasonic diagnostic apparatus according to any aspect is provided.

  According to an eighth aspect of the present invention, the extraction means includes a minimum pixel value between the plurality of images among the pixels corresponding to the same reflection point in the plurality of images generated by the image generation means. The ultrasonic diagnostic apparatus according to the first aspect of the present invention is provided, wherein the display means displays an image composed of the pixels extracted by the extraction means.

  According to a ninth aspect of the present invention, the image generation means is based on each of a plurality of reception signals generated in response to each transmission of ultrasonic waves sequentially transmitted in a plurality of different directions. An ultrasonic diagnostic apparatus according to any one of the first to eighth aspects for generating a plurality of images corresponding to each of the plurality of directions is provided.

  According to the tenth aspect of the present invention, each of the plurality of directions is subjected to phasing addition processing along each of a plurality of different directions with respect to the reception signal generated in response to transmission of the ultrasonic wave. Further comprising a phasing addition means for generating a plurality of phasing addition signals corresponding to the plurality of phasing addition signals based on each of the plurality of phasing addition signals generated by the phasing addition means. An ultrasonic diagnostic apparatus according to any one of the first to eighth aspects for generating a plurality of images corresponding to each of the directions is provided.

  According to an eleventh aspect of the present invention, the image generating means corresponds to at least one transmission of ultrasonic waves transmitted in one direction and another direction inclined by 90 ° with respect to the one direction. An ultrasonic diagnostic apparatus according to a ninth aspect for generating two images is provided.

  According to a twelfth aspect of the present invention, the phasing / adding means may be configured such that the received signal generated in response to the transmission of the ultrasonic wave is inclined in one direction and 90 ° to the one direction. An ultrasonic diagnostic apparatus according to a tenth aspect is provided that performs phasing addition processing along each of the directions to generate at least two phasing addition signals corresponding to each of the one direction and the other direction. The

  According to a thirteenth aspect of the present invention, an image generation step of generating a plurality of images corresponding to each of the plurality of directions based on reflected waves of ultrasonic waves reflected in different directions from the reflection point; An extraction step of performing comparison analysis of pixel values of pixels corresponding to the same reflection point in the plurality of images generated in the image generation step to extract specific pixels that approximate pixel values; and the extraction A display step for displaying the particular pixel extracted in the step.

  According to the fourteenth aspect of the present invention, an image for generating a plurality of images corresponding to each of the plurality of directions on the basis of reflected waves of ultrasonic waves reflected in different directions from the reflection point. Generating means, and extracting means for performing comparison analysis of pixel values of pixels corresponding to the same reflection point in the plurality of images generated by the image generating means to extract specific pixels that approximate pixel values; There is provided a program for functioning as display means for displaying the specific pixel extracted by the extraction means.

  According to the ultrasonic diagnostic apparatus, the image rendering method, and the program according to the present invention, it is possible to improve the rendering performance of a microstructure such as a microcalcification portion in a subject.

1 is a block diagram showing a configuration of an ultrasonic diagnostic apparatus according to an embodiment of the present invention. 1 is a block diagram showing a configuration of a computer included in an ultrasonic diagnostic apparatus according to an embodiment of the present invention. It is a flowchart which shows the flow in the transmission / reception processing program performed in the ultrasound diagnosing device which concerns on embodiment of this invention. FIG. 4A and FIG. 4B are diagrams showing incident waves and reflected waves of ultrasonic waves transmitted in different directions. It is a flowchart which shows the flow of a process in the drawing process program which concerns on embodiment of this invention. It is a figure which shows the area | region where the same reflective point is formed when an ultrasonic wave is transmitted in a mutually different direction. It is a flowchart which shows the flow of a process in the drawing process program which concerns on other embodiment of this invention. It is a flowchart which shows the flow of a process in the drawing process program which concerns on other embodiment of this invention. It is a flowchart which shows the flow of a process in the drawing process program which concerns on other embodiment of this invention. It is a flowchart which shows the flow of a process in the drawing process program which concerns on other embodiment of this invention. It is a flowchart which shows the flow of a process in the drawing process program which concerns on other embodiment of this invention. It is a figure which shows the aspect of the reception focus process in the ultrasonic diagnosing processing apparatus which concerns on embodiment of this invention. It is a flowchart which shows the flow of the rendering process in the rendering process program which concerns on other embodiment of this invention.

Hereinafter, an ultrasonic diagnostic apparatus according to an embodiment of the present invention will be described with reference to the drawings.
[First embodiment]
FIG. 1 is a block diagram showing a configuration of an ultrasonic diagnostic apparatus 1 according to an embodiment of the present invention. The ultrasonic probe 10 transmits an ultrasonic wave toward a diagnosis site of the subject, and receives a reflected wave (echo) of the ultrasonic wave reflected inside the subject to generate a reception signal. The ultrasonic probe 10 includes, for example, a plurality of piezoelectric elements 10a arranged linearly. Each of the piezoelectric elements 10 a generates an ultrasonic wave according to the drive pulse signal supplied from the transmission processing unit 14. Each of the piezoelectric elements 10 a receives a reflected wave of an ultrasonic wave reflected in the subject, generates a reception signal that is an electric signal, and supplies the reception signal to the reception processing unit 16. The ultrasonic probe 10 may have any scanning method such as a linear type, a convex type, and a sector type.

  The transmission processing unit 14 is connected to each of the piezoelectric elements 10a via signal wiring. The transmission processing unit 14 generates a driving pulse signal for driving each piezoelectric element 10a, and supplies the driving pulse signal to each piezoelectric element 10a through a signal wiring. The transmission processing unit 14 controls the transmission direction of ultrasonic waves by giving a relative time difference to each of the drive pulse signals supplied to each piezoelectric element 10a.

  The reception processing unit 16 includes an amplifier and an A / D converter (not shown) provided corresponding to each of the piezoelectric elements 10a. The reception processing unit 16 amplifies the reception signal generated in each of the piezoelectric elements 10a in an amplifier and converts it into a digital signal in an A / D converter. The reception processing unit 16 includes a reception signal memory 16a that stores a reception signal for each piezoelectric element 10a (each channel) converted into a digital signal.

  The phasing addition processing unit 18 provides a relative time difference to the reception signal for each piezoelectric element 10a supplied from the reception processing unit 16 to align the time phases of the reception signals for each piezoelectric element 10a, and then the piezoelectric element 10a. A phasing addition process (reception focus process) for adding each received signal is performed. The timing at which the ultrasonic waves reflected by a certain reflection point in the subject enter each piezoelectric element 10a does not match. This is because the propagation distance of the reflected wave from a certain reflection point to each piezoelectric element 10a is different for each piezoelectric element. The phasing addition processing unit 18 gives a relatively long delay time to the reception signal generated by the piezoelectric element arranged at a position where the distance from the reflection point is relatively short. On the other hand, a relatively short delay time is given to the reception signal generated by the piezoelectric element arranged at a position where the distance from the reflection point is relatively long. As described above, the phasing addition processing unit 18 gives a relative time difference to the reception signals of the respective channels generated for each piezoelectric element 10a to align these time phases, and integrates the reception signals of the phasing channels. Thus, a phasing addition signal is generated.

  The extraction unit 24 reads out the pixel value of each pixel corresponding to the same reflection point in the plurality of B-mode images from each of the plurality of B-mode images generated in the B-mode image generation unit 22, and reads out the pixel values A comparison analysis between a plurality of B-mode images is performed to extract a specific pixel whose pixel value approximates.

  The B-mode image generation unit 22 performs known filtering processing, log compression processing, envelope detection processing, STC (Sensitivity Time Control) processing, interpolation processing, and the like for the phasing addition signal supplied from the phasing addition processing portion 16. A B-mode image in which the signal intensity of the phasing addition signal is converted into luminance is generated by performing scan conversion processing or the like. At this time, the B-mode image generation unit 22 generates an image signal of the B-mode image so that the position of the specific pixel extracted by the extraction unit 24 can be visually recognized on the B-mode image. For example, the B-mode image generation unit 22 generates an image signal so that the luminance of a specific pixel extracted by the extraction unit 24 is sufficiently higher than the luminance of other pixels. Alternatively, the B-mode image generation unit 22 may generate an image signal by assigning a color different from other pixels to the pixel extracted by the extraction unit 24.

  The input unit 12 receives various types of operation inputs by the user, and includes, for example, a pointing device such as a mouse or a trackball, or an input unit such as a keyboard. By operating the input unit 12, the user can perform, for example, start and end of transmission / reception of ultrasonic waves, switching of a display image displayed on the monitor 30, designation of a region of interest inside the subject, and the like.

  The monitor 30 has a display screen that displays a B-mode image based on the image signal supplied from the B-mode image generation unit 22. When a specific pixel is extracted by the extraction unit 24, the position of the specific pixel is displayed on the monitor 22 in a manner that can be visually recognized on the B-mode image.

  In the ultrasonic diagnostic apparatus 1 according to the present embodiment, the transmission processing unit 14, the reception processing unit 16, the phasing addition processing unit 18, the B-mode image generation unit 22, and the extraction unit 24 are as shown in FIG. CPU 200, ROM 201 (Read Only Memory) that stores various programs executed by CPU 200, RAM (Random Access Memory) 202 that temporarily stores data used for arithmetic processing in CPU 200, and generated image data And a computer including an HDD (Hard Disk Drive) 203 for storing and the like.

  Below, the effect | action of the ultrasound diagnosing device 1 which concerns on embodiment of this invention is demonstrated. First, a transmission / reception process in which the ultrasonic diagnostic apparatus 1 transmits / receives an ultrasonic wave to generate a reception signal will be described.

  FIG. 3 is a flowchart showing the flow of processing in the transmission / reception processing program executed by the CPU 200 of the ultrasonic diagnostic apparatus 1. This transmission / reception processing program is stored in advance in the ROM 201, and is executed, for example, when the user inputs a predetermined operation to the input unit 12.

  In step S <b> 1, the transmission processing unit 14 generates a drive pulse signal and supplies it to the ultrasonic probe 10. At this time, the transmission processing unit 14 gives a relative time difference to the drive pulse signal supplied for each piezoelectric element 10a so that the transmission direction of the ultrasonic wave is a predetermined direction.

  Thereby, the ultrasonic probe 10 transmits an ultrasonic wave toward the predetermined direction in the subject. An echo by reflection of the ultrasonic beam transmitted from the ultrasonic probe 10 is received by each of the piezoelectric elements 10a. Each of the piezoelectric elements 10 a converts the reflected echo into a reception signal that is an electric signal and supplies the reception signal to the reception processing unit 16.

  In step S2, the reception processing unit 16 waits for input of the reception signal, and when receiving the reception signal from the ultrasonic probe 10, in step S3, the signal including amplification and A / D conversion for the reception signal of each channel. The received signal subjected to the processing is stored in the received signal memory 16a.

  In step S4, the transmission processing unit 14 determines whether or not a predetermined number of ultrasonic transmissions have been completed. If the transmission processing unit 14 determines that the transmission of the predetermined number of ultrasonic waves is not completed, the process proceeds to step S5.

  In step S5, the transmission processing unit 14 changes the setting of the ultrasonic wave transmission direction and returns the process to step S1. Thereafter, the processing from step S1 to step S5 is repeatedly executed until the transmission of the predetermined number of ultrasonic waves is completed. Thereby, ultrasonic waves are transmitted in a plurality of directions different from each other, and a plurality of reception signals generated according to each transmission are stored in the reception signal memory 16a.

  As described above, the ultrasonic diagnostic apparatus 1 according to the present embodiment sequentially transmits ultrasonic waves in a plurality of mutually different directions, and receives each of the reception signals generated according to each transmission of the ultrasonic waves as a reception signal memory. 16a. Note that, among the transmissions of ultrasonic waves that are performed a plurality of times, those that are performed so that the transmission direction of the ultrasonic waves is substantially perpendicular to the transmission / reception surface of the ultrasonic probe 10 may be included. In addition, ultrasonic waves may be transmitted in at least two different directions, but ultrasonic waves may be transmitted in three or more different directions.

  4A and 4B schematically show an incident wave (solid line) and a reflected wave (broken line) of an ultrasonic wave transmitted from the ultrasonic probe 10 toward different directions in the subject P. FIG. FIG. As shown in FIGS. 4A and 4B, the subject P includes a mammary gland structure M extending in a direction substantially parallel to the transmission / reception surface 10S of the ultrasonic probe 10 and a breast tissue calcified. It is assumed that the microcalcification part C formed by doing, for example, the diameter of 1 mm or less is included.

FIG. 4A shows a case where ultrasonic waves are transmitted in a direction substantially perpendicular to the transmission / reception surface 10 </ b> S of the ultrasonic probe 10. Here, the reflection at the surface of large mammary gland M of relatively surface area next to the specular reflection (specular reflection), the traveling direction of the reflected wave R _M caused by reflection on the surface of the mammary gland structure M is, ultrasound angle of incidence Depending on the direction. Accordingly, as shown in FIG. 4 (a), when the ultrasonic wave in a direction substantially perpendicular to the mammary gland M enters the traveling direction of the reflected wave R _M is a reception surface 10S of the ultrasonic probe 10 The direction is substantially perpendicular to the direction. That is, in this case, almost all of the reflected wave R _M is to be received by the ultrasonic probe 10. On the other hand, the reflection on the surface of the microcalcification portion C having a relatively small surface area is diffuse reflection. Therefore, the reflected wave _RC generated by the reflection on the surface of the microcalcification portion C is scattered in various directions and received by the ultrasonic probe 10.

On the other hand, FIG. 4B shows a case where ultrasonic waves are transmitted in an oblique direction with respect to the transmission / reception surface 10 </ b> S of the ultrasonic probe 10. In this case, the ultrasonic wave transmitted from the ultrasonic probe 10 enters the breast structure M from an oblique direction. Thus, the oblique direction with respect to the transmission and reception surface 10S of the traveling direction the ultrasonic probe 10 of the reflected wave R _M caused by reflection on the surface of the mammary gland M. As a result, it becomes impossible to receive the reflected wave R _M ultrasonic probe 10. On the other hand, even when an ultrasonic wave is transmitted in an oblique direction with respect to the transmission / reception surface 10S of the ultrasonic probe 10, the reflected wave _{RC of the} ultrasonic wave reflected from the surface of the microcalcification part C is scattered in various directions. Therefore, the reflected wave _RC can be received by the ultrasonic probe 10 as in the case shown in FIG.

Thus, if the ultrasonic wave is transmitted to a plurality of different directions, the reflected wave R _M caused by reflection on the surface of the mammary gland M, received at all if also be received by the ultrasonic probe It may not be done. That is, the mammary gland structure M may or may not be rendered in a plurality of B-mode images generated corresponding to transmissions of ultrasonic waves transmitted in a plurality of different directions.

On the other hand, the ultrasonic reflected wave _RC reflected on the surface of the microcalcification part C is received by the ultrasonic probe 10 regardless of the transmission direction of the ultrasonic wave. That is, the micro calcification part C is drawn in any of a plurality of B mode images generated corresponding to each transmission of ultrasonic waves transmitted in a plurality of different directions.

  In the ultrasonic diagnostic apparatus 1 according to the present embodiment, a tissue having a relatively large surface area such as the mammary gland structure M exhibits specular reflectivity with respect to the ultrasonic wave, while a microstructure such as the microcalcification portion C is provided. A microstructure such as the microcalcification portion C is drawn using the fact that it exhibits diffuse reflectivity with respect to ultrasonic waves.

  Next, a description will be given of a rendering process for rendering a microstructure such as the microcalcification portion C based on the reception signal corresponding to each transmission direction acquired by the ultrasound diagnostic apparatus 1 performing the above transmission / reception process. To do.

  FIG. 5 is a flowchart showing the flow of processing in the rendering processing program executed by the CPU 200 of the ultrasonic diagnostic apparatus 1. This rendering processing program is stored in advance in the ROM 201, and is executed, for example, when the user inputs a predetermined operation to the input unit 12. Before the rendering processing program is executed, the above transmission / reception processing program (see FIG. 3) is executed, and a plurality of reception signals corresponding to the respective transmission directions are already stored in the reception signal memory 16a. To do. Here, it is assumed that in the previous transmission / reception process, ultrasonic waves are transmitted in two different directions, and two reception signals corresponding to the transmissions in the two directions are stored in the reception signal memory 16a.

  In step S11, the phasing addition processing unit 18 reads out two reception signals corresponding to the two transmission directions acquired by executing the transmission / reception process from the reception signal memory 16a.

  In step S12, the phasing addition processing unit 18 performs phasing addition processing on each of the two reception signals read from the reception signal memory 16a.

  In step S13, the B-mode image generation unit 22 performs a known filtering process, a log compression process, and an envelope detection process for each phasing addition signal corresponding to each transmission direction supplied from the phasing addition processing unit 18. , STC (Sensitivity Time Control) processing, interpolation processing, scan conversion processing, and the like are performed to generate image signals of two B-mode images corresponding to two transmission directions.

  In step S <b> 14, the extraction unit 24 reads out the pixel value of each pixel corresponding to the same reflection point in the two B-mode images from each of the two B-mode images generated in the B-mode image generation unit 22. Here, FIG. 6 illustrates a case where ultrasonic waves are transmitted in the vertical direction and a case where ultrasonic waves are transmitted in an oblique direction with respect to the transmission / reception surface 10 </ b> S of the ultrasonic probe 10. In this case, the extraction unit 24 calculates the pixel value of each pixel corresponding to the same (common) reflection point in the area A indicated by hatching in FIG. 6 from each of the two B-mode images corresponding to each transmission direction. read out.

  In step S15, the extraction unit 24 derives, for each pixel corresponding to the same reflection point, the difference value D between the plurality of B-mode images of the pixel value of each pixel corresponding to the read same reflection point. That is, the extraction unit 24 performs a process of deriving a pixel value difference value D between two B-mode images corresponding to each transmission direction for each pixel corresponding to the same reflection point.

For example, as shown in FIG. 4A, when ultrasonic waves are transmitted in a direction perpendicular to the transmission / reception surface 10S of the ultrasonic probe 10, the ultrasonic waves reflected from the surface of the mammary gland structure M are transmitted. Since the reflected wave _RM is received by the ultrasonic probe 10, the pixel value of each pixel corresponding to each reflection point on the mammary gland structure M is compared in the B-mode image generated in response to the transmission in the vertical direction. Large value. On the other hand, as shown in FIG. 4B, when ultrasonic waves are transmitted obliquely to the transmission / reception surface 10S of the ultrasonic probe 10, the ultrasonic waves reflected from the surface of the mammary gland structure M are transmitted. Since the reflected wave _RM is hardly received by the ultrasonic probe 10, the pixel value of each pixel corresponding to each reflection point on the mammary gland structure M in the B-mode image generated in response to the transmission in the oblique direction is approximately. It becomes zero. Therefore, the difference value D derived for the pixel value of each pixel corresponding to each reflection point on the mammary gland structure M is a relatively large value. On the other hand, the reflected wave R _C of the ultrasonic wave reflected by the micro-calcifications C is received by the ultrasonic probe 10 regardless of the transmission direction of the ultrasound. Therefore, the difference value D derived for the pixel value of each pixel corresponding to each reflection point on the microcalcification portion C is a relatively small value.

  In step S16, the extraction unit 24 extracts pixels whose difference value D derived in step S15 is equal to or less than a predetermined threshold value. That is, the extraction unit 24 extracts pixels having a relatively small change in pixel value between two B-mode images corresponding to each transmission when ultrasonic waves are transmitted in two different directions. That is, by this process, pixels corresponding to each reflection point on the mammary gland structure M are excluded, while pixels corresponding to each reflection point on the microcalcification portion C are extracted.

  In step S <b> 17, the B mode image generation unit 22 extracts, for example, the pixels extracted by the extraction unit 24 on the B mode image corresponding to the transmission direction specified by the user from the B mode images generated in step S <b> 13. Reconstruct the B-mode image as specified. For example, the B-mode image generation unit 22 generates an image signal of the B-mode image so that the luminance of the pixels extracted by the extraction unit 24 is sufficiently higher than that of other pixels. Alternatively, the B-mode image generation unit 22 may generate an image signal by assigning a color different from other pixels to the pixel extracted by the extraction unit 24. The B mode image generation unit 22 supplies the generated image signal to the monitor 30. As a result, a B-mode image in which the position, size, and range of the microcalcification unit 30 are clearly displayed is displayed on the monitor 30.

  As described above, in the ultrasonic diagnostic apparatus 1 according to the embodiment of the present invention, a tissue having a relatively large area such as the mammary gland structure M exhibits specular reflection, while a microstructure such as the microcalcification portion C is used. The microstructure is drawn using the fact that the body shows diffuse reflectivity. Specifically, the ultrasonic diagnostic apparatus 1 transmits ultrasonic waves in a plurality of directions different from each other in the subject, and generates a plurality of B-mode images based on reception signals acquired according to each transmission. Then, a difference value D between a plurality of B-mode images of a pixel value of each pixel corresponding to the same reflection point in each B-mode image is derived, and pixels whose derived difference value D is equal to or less than a predetermined threshold are extracted. . By performing pixel extraction in this way, pixels corresponding to each reflection point on the mammary gland structure M are excluded, while pixels corresponding to each reflection point on the microcalcification part C are extracted. Therefore, according to the ultrasonic diagnostic apparatus 1 according to the embodiment of the present invention, it is possible to improve the visualization performance of a microstructure such as a microcalcification part in a subject.

  In the above example, a case where a specific pixel is extracted by comparing and analyzing a pixel value of a single pixel between a plurality of B-mode images is illustrated, but the present invention is not limited to this. For example, a specific pixel group may be extracted by comparing and analyzing pixel values representing a pixel group composed of a plurality of adjacent pixels between a plurality of B-mode images. In this case, for example, the extraction unit 24 may derive a difference value D for the average value of the pixel values of a plurality of adjacent pixels, and extract a pixel group in which the difference value D is equal to or less than a predetermined value.

[Second Embodiment]
FIG. 7 is a flowchart showing the flow of processing in the rendering processing program according to the second embodiment of the present invention. The program is obtained by replacing step S14 in the rendering processing program according to the first embodiment shown in FIG. 5 with step S14a. Hereinafter, parts different from the rendering processing program according to the first embodiment will be described.

  In step S14a, the extraction unit 24 selects each pixel corresponding to the same reflection point in the plurality of B-mode images from each of the plurality of B-mode images corresponding to each transmission direction generated in the B-mode image generation unit 22. Among these pixel values, a pixel value greater than or equal to a predetermined value is read. In step S15, the extraction unit 24 derives a difference value D between the plurality of B-mode images of the pixel value read out in this way for each pixel corresponding to the same reflection point. Thus, in the diagnostic processing according to the second embodiment, the condition is that the pixel value from which the difference value D is derived is equal to or greater than a predetermined value.

  Since the microcalcification part C is harder than a breast tissue, the pixel value corresponding to the microcalcification part C becomes a comparatively large value. That is, the pixel corresponding to the minute lime C has a relatively high luminance on the B-mode image. Therefore, in the rendering processing program according to the present embodiment, by setting a lower limit value for the pixel value of the pixel extracted by the extraction unit 24, it is possible to prevent pixels with relatively low luminance from being extracted. Thereby, it becomes possible to aim at the further improvement of the drawing precision of the micro calcification part C. FIG.

[Third Embodiment]
FIG. 8 is a flowchart showing the flow of processing in the rendering processing program according to the third embodiment of the present invention. The rendering processing program according to the first and second embodiments described above transmits ultrasound in two different directions, and renders a microstructure based on two B-mode images corresponding to each transmission. there were. On the other hand, the rendering processing program according to the third embodiment transmits ultrasonic waves in three or more directions different from each other, and converts the microstructures based on three or more B-mode images corresponding to the respective transmissions. It can be applied when rendering.

  The rendering program according to the third embodiment is obtained by replacing steps S15 and S16 in the rendering processing program according to the first embodiment shown in FIG. 5 with steps S15b and S16b, respectively. Hereinafter, parts different from the rendering processing program according to the first embodiment will be described.

  In step S15b, the extraction unit 24 reads the pixel values of each pixel corresponding to the same reflection point, read from each of the plurality of B mode images corresponding to each of the plurality of transmission directions, among the plurality of B mode images. An index value Z indicating the magnitude of is derived for each pixel corresponding to the same reflection point. As the index value Z indicating the magnitude of variation in pixel values, for example, a variance value, a standard deviation, a difference value between the maximum value and the minimum value, or the like can be applied.

  In step S16b, the extraction unit 24 extracts pixels whose index value Z derived for each pixel corresponding to the same reflection point is equal to or less than a predetermined threshold value. That is, the extraction unit 24 extracts pixels with relatively small variations in pixel values between a plurality of B-mode images corresponding to each transmission when ultrasonic waves are transmitted in a plurality of different directions. That is, by this process, pixels corresponding to each reflection point on the mammary gland structure M are excluded, while pixels corresponding to each reflection point on the microcalcification portion C are extracted. Therefore, according to the rendering processing program according to the third embodiment, it is possible to improve the rendering accuracy of the microcalcification portion C as in the first embodiment.

  In the above example, a case where a specific pixel is extracted by comparing and analyzing a pixel value of a single pixel between a plurality of B-mode images is illustrated, but the present invention is not limited to this. For example, a specific pixel group may be extracted by comparing and analyzing pixel values representing a pixel group composed of a plurality of adjacent pixels between a plurality of B-mode images. In this case, for example, the extraction unit 24 may derive a variation index value Z for the average value of each pixel value of a plurality of adjacent pixels, and extract a pixel group in which the index value Z is equal to or less than a predetermined value. . In addition, the process in step S14 in the rendering process program according to the present embodiment can be replaced with the process in step S14a in the rendering process program according to the second embodiment shown in FIG.

[Fourth Embodiment]
FIG. 9 is a flowchart showing the flow of processing in the rendering processing program according to the fourth embodiment of the present invention.

  The rendering program according to the fourth embodiment is obtained by replacing steps S14 to S17 in the rendering processing program according to the first embodiment shown in FIG. 5 with steps S14c to S17c, respectively. Hereinafter, parts different from the rendering processing program according to the first embodiment will be described.

  In step S <b> 14 c, the extraction unit 24 is adjacent to the same reflection point in the plurality of B-mode images from each of the plurality of B-mode images corresponding to the transmission directions generated in the B-mode image generation unit 22. The pixel value is read out for each of the pixel groups composed of a plurality of pixels.

  In step S15c, the extraction unit 24 derives, for each pixel group corresponding to the same reflection point, a correlation value A between a plurality of B-mode images of the pixel values of the read pixel group.

  Here, since the mammary gland structure M has specular reflection, the mammary gland structure M is depicted in a plurality of B-mode images generated corresponding to each transmission of ultrasonic waves transmitted in a plurality of different directions. It may or may not be rendered. Accordingly, when the correlation value A is derived among a plurality of B-mode images corresponding to each transmission direction for the pixel values of the pixel group corresponding to each reflection point on the mammary gland structure M, the value becomes a relatively small value. On the other hand, since the micro calcification part C has diffuse reflectance, the micro calcification part is included in any of the plurality of B-mode images generated corresponding to the respective transmissions of ultrasonic waves transmitted in a plurality of different directions. There is a high possibility that C is drawn. Therefore, when the correlation value A is derived among a plurality of B-mode images corresponding to each transmission direction with respect to the pixel value of the pixel group corresponding to each reflection point on the microcalcification part C, the value is a relatively large value. It becomes.

  In step S16c, the extraction unit 24 extracts a pixel group in which the correlation value A derived for each pixel group in step S15c is greater than or equal to a predetermined threshold value. That is, the extraction unit 24 uses a pixel group (that is, each pixel value) having a relatively large correlation value A between a plurality of B-mode images corresponding to each transmission when ultrasonic waves are transmitted in a plurality of different directions. Are extracted). Thereby, the pixel group corresponding to each reflection point on the micro calcification part C is extracted. That is, by this process, the pixel group corresponding to each reflection point on the mammary gland structure M is excluded, while the pixel group corresponding to each reflection point on the microcalcification part C is extracted.

  In step S <b> 17 c, the B-mode image generation unit 22 specifies the pixel group extracted by the extraction unit 24 on the B-mode image corresponding to the transmission direction specified by the user, for example, among the B-mode images generated in step S <b> 13. The B-mode image is reconstructed as follows. For example, the B-mode image generation unit 22 may generate an image signal so that the luminance of the pixel group extracted by the extraction unit 24 is sufficiently higher than other pixels. Alternatively, the B-mode image generation unit 22 may generate an image signal by assigning a color different from other pixels to the pixel group extracted by the extraction unit 24. The B mode image generation unit 22 supplies the image signal of the reconstructed B mode image to the monitor 30. As a result, a B-mode image in which the position, size, and range of the microcalcification unit 30 are clearly displayed is displayed on the monitor 30. Therefore, according to the rendering processing program according to the fourth embodiment, it is possible to improve the rendering accuracy of the microcalcification portion C.

  In step S14c in the rendering processing program according to the present embodiment, the extraction unit 24 extracts the plurality of B modes from each of the plurality of B mode images corresponding to the transmission directions generated by the B mode image generation unit 22. When reading each pixel value of a pixel group composed of a plurality of adjacent pixels corresponding to the same reflection point in the image, only the pixel value equal to or greater than a predetermined threshold value may be read. As described above, it is possible to improve the rendering accuracy of the micro calcification portion C by providing that the pixel value that is the target for deriving the correlation value A is a predetermined value or more.

[Fifth Embodiment]
FIG. 10 is a flowchart showing the flow of processing in the rendering processing program according to the fifth embodiment of the present invention.

  The rendering program according to the fifth embodiment is obtained by replacing steps S15 and S16 in the rendering processing program according to the first embodiment shown in FIG. 5 with steps S15d and S16d, respectively. Hereinafter, parts different from the rendering processing program according to the first embodiment will be described.

In step S15d, the extraction unit 24 derives the minimum pixel value B _min between a plurality of B-mode images for each pixel corresponding to the same reflection point.

In step S16d, the extraction unit 24 extracts pixels whose minimum pixel value B _min between the B-mode images derived for each pixel corresponding to the same reflection point is equal to or greater than a predetermined threshold value.

As described above, since the mammary gland structure M has specular reflection, the mammary gland structure M is included in a plurality of B-mode images generated in response to transmissions of ultrasonic waves transmitted in a plurality of different directions. It may or may not be rendered. When the mammary gland structure M is not drawn, the pixel value corresponding to each reflection point on the mammary gland structure M is substantially zero. On the other hand, since the micro calcification part C has diffuse reflectance, the micro calcification part is included in any of the plurality of B-mode images generated corresponding to the respective transmissions of ultrasonic waves transmitted in a plurality of different directions. There is a high possibility that C is drawn. Therefore, the minimum pixel value _Bmin between the plurality of B-mode images of the pixels corresponding to the respective reflection points on the mammary gland structure M is likely to be substantially zero. On the other hand, there is a high possibility that the minimum pixel value B _min between the plurality of B-mode images of the pixels corresponding to each reflection point on the micro calcification portion C is a value larger than zero.

Therefore, according to the rendering processing program according to the fifth embodiment, pixels whose minimum pixel value B _min between B-mode images derived for each pixel corresponding to the same reflection point is greater than or equal to a predetermined threshold are extracted. Therefore, it is possible to exclude pixels corresponding to each reflection point on the mammary gland structure M and to extract pixels corresponding to each reflection point on the microcalcification portion C. Thereby, it becomes possible to improve the drawing accuracy of the microcalcification part C.

  Note that the processing in step S14 in the rendering processing program according to the present embodiment can be replaced with the processing in step S14a in the rendering processing program according to the second embodiment shown in FIG. In the first to fifth embodiments, the pixel or the pixel group extracted by the extraction unit 24 is illustrated as being superimposed on the B-mode image displayed on the monitor 30, but the extraction unit 24 is illustrated. Only the pixel or pixel group extracted by the above may be displayed on the monitor 30 so as to clearly indicate these positions.

[Sixth Embodiment]
FIG. 11 is a flowchart showing the flow of processing in the rendering processing program according to the sixth embodiment of the present invention. The rendering program according to the sixth embodiment is obtained by replacing steps S15 to S17 in the rendering processing program according to the first embodiment shown in FIG. 5 with steps S15e and S16e. Hereinafter, parts different from the rendering processing program according to the first embodiment will be described.

  In step S15e, the extraction unit 24 extracts, for each pixel corresponding to the same reflection point, a pixel having a minimum pixel value between a plurality of B-mode images.

  In step S16e, the B-mode image generation 24 reconstructs the B-mode image using the pixel having the minimum pixel value extracted by the extraction unit 24 in step S15e, and monitors the image signal of the reconstructed B-mode image. 30.

  As described above, since the mammary gland structure M has specular reflection, the mammary gland structure M is included in a plurality of B-mode images generated in response to transmissions of ultrasonic waves transmitted in a plurality of different directions. It may or may not be rendered. When the mammary gland structure M is not drawn, the pixel value corresponding to each reflection point on the mammary gland structure M is substantially zero. On the other hand, since the micro calcification part C has diffuse reflectance, the micro calcification part is included in any of the plurality of B-mode images generated corresponding to the respective transmissions of ultrasonic waves transmitted in a plurality of different directions. There is a high possibility that C is drawn. Therefore, in the ultrasonic diagnostic apparatus according to the present embodiment, a pixel having the smallest pixel value (lowest luminance) is extracted between a plurality of B-mode images generated in response to each transmission of ultrasonic waves, and the extracted pixel To reconstruct the B-mode image. Thereby, a pixel value zero is assigned to the pixel corresponding to each reflection point on the mammary gland structure M, while a pixel value greater than zero is assigned to the pixel corresponding to each reflection point on the microcalcification part C. As a result, only the minute calcification portion C can be depicted on the monitor 30. Therefore, according to the rendering processing program according to the sixth embodiment, it is possible to improve the rendering accuracy of the microcalcification portion C.

  In addition, when transmitting ultrasonic waves in a plurality of different directions, it is preferable that at least two transmission directions are included such that an angle between a certain transmission direction and another transmission direction is 90 °. Thereby, in the rendering process according to the first to sixth embodiments, pixels corresponding to the respective reflection points on the mammary gland structure M can be efficiently excluded, and as a result, the microcalcification portion C is rendered. The accuracy can be improved.

[Seventh Embodiment]
The ultrasonic diagnostic apparatus according to the first to sixth embodiments transmits ultrasonic waves in two or more directions different from each other, and a microstructure based on a plurality of B-mode images generated according to each transmission It was to depict. On the other hand, the ultrasonic diagnostic apparatus according to the seventh embodiment has a plurality of directions different from each other with respect to one reception signal generated in response to transmission of an ultrasonic wave transmitted in any one direction. A phasing addition process (reception focus process) is performed along each to generate a plurality of B-mode images corresponding to each of the plurality of reception focus directions, and a microstructure is formed based on the plurality of B-mode images. Draw.

FIGS. 12A and 12B show a mode in which the phasing addition processing is performed on the received signal along different reception focus directions. FIG. 12A shows a case where the reception focus direction is set in a direction perpendicular to the transmission / reception surface of the ultrasonic probe 10. The timing at which the reflected wave generated at the reflection point R shown in FIG. 12A is received by each piezoelectric element 10a is shown in each plot in the figure. Thus, the reception timing of the reflected wave generated at the reflection point R differs for each piezoelectric element 10a. The phasing addition processing unit 18 generates, as a phasing addition signal, a sum of signal values on each plot corresponding to the reflection points R in the reception signals a _{1 to} a ₁₁ generated by the piezoelectric elements 10a. When the reception focus direction is a direction perpendicular to the transmission / reception surface of the ultrasonic probe 10, the reflection point R is moved in the direction perpendicular to the transmission / reception surface of the ultrasonic probe 10 to generate a phasing addition signal at each time. .

FIG. 12B shows a case where the reception focus direction is set obliquely with respect to the transmission / reception surface of the ultrasonic probe 10. The timing at which the reflected wave generated at the reflection point R shown in FIG. 12B is received by each piezoelectric element 10a is shown in each plot in the drawing. The phasing addition processing unit 18 generates, as a phasing addition signal, a sum of signal values on each plot corresponding to the reflection points R in the reception signals a _{1 to} a ₁₁ generated by the piezoelectric elements 10a. When the reception focus direction is an oblique direction with respect to the transmission / reception surface of the ultrasonic probe 10, the reflection point R is moved in an oblique direction with respect to the transmission / reception surface of the ultrasonic probe 10 to generate a phasing addition signal at each time. . As shown in FIGS. 11A and 11B, when the reception focus direction is different, the combination of signal values to be added on the reception signals a _{1 to} a ₁₁ changes. The phase addition signals are different.

Thus, a plurality of phasing addition signals generated by performing phasing addition processing along each of a plurality of different directions with respect to a single received signal are sequentially transmitted in a plurality of different directions. This is equivalent to a plurality of phasing addition signals generated by performing phasing addition processing on each of the plurality of reception signals generated in response to each transmission of the generated ultrasonic waves. In other words, setting the reception focus direction to a certain direction and performing the phasing addition processing corresponds to receiving a reflected wave of the ultrasonic wave reflected in that direction. Therefore, by performing the phasing addition process along each of the plurality of reception focus directions, the reflected wave of the ultrasonic wave reflected toward each of the plurality of directions can be captured. Therefore, in the ultrasonic diagnostic apparatus according to this embodiment, a plurality of B-mode images corresponding to each transmission by transmitting ultrasonic waves in a plurality of different directions in the rendering processing according to the first to sixth embodiments. Instead of the process of generating the signal, the ultrasonic wave is transmitted only in a single direction, and the received signal obtained thereby is subjected to phasing addition processing along a plurality of reception focus directions different from each other. A rendering process including a process of generating a plurality of B-mode images corresponding to the focus direction is executed. FIG. 13 is a flowchart showing a process flow in a rendering process program according to the seventh embodiment of the present invention. Before the rendering processing program is executed, at least one ultrasonic transmission / reception is performed, and a reception signal generated in response to the transmission / reception of the ultrasonic wave is already stored in the reception signal memory 16a. And

  In step S31, the phasing addition process part 18 reads a received signal from the received signal memory 16a.

  In step S32, the phasing addition processing unit 18 performs phasing addition processing along each of a plurality of predetermined reception focus directions on the reception signal read from the reception signal memory 16a, and receives each reception focus. A plurality of phasing addition signals corresponding to each of the directions are generated. Here, it is assumed that the phasing addition processing is performed along two different reception focus directions.

  In step S33, the B-mode image generation unit 22 performs known filtering processing, log compression processing, envelope detection on each of the phasing addition signals corresponding to the reception focus directions supplied from the phasing addition processing unit 18. Processing, STC (Sensitivity Time Control) processing, interpolation processing, scan conversion processing, and the like are performed to generate two B-mode image signals corresponding to each of the two reception focus directions.

  In step S34, the extraction unit 24 reads out the pixel value of each pixel corresponding to the same reflection point in the two B-mode images from each of the two B-mode images generated by the B-mode image generation unit 22.

  In step S35, the extraction unit 24 derives, for each pixel corresponding to the same reflection point, the difference value D between the two B-mode images of the pixel value of each pixel corresponding to the read same reflection point.

  In step S36, the extraction unit 24 extracts pixels whose difference value D derived in step S35 is equal to or less than a predetermined threshold value. In other words, the extraction unit 24 extracts pixels having a relatively small change in pixel value between two B-mode images corresponding to two different reception focus directions. By this process, pixels corresponding to each reflection point on the mammary gland structure M are excluded, while pixels corresponding to each reflection point on the microcalcification portion C are extracted.

  In step S37, the B-mode image generation unit 22 reconstructs the B-mode image so as to clearly indicate the pixels extracted by the extraction unit 24 on the B-mode image generated in the previous step S33. For example, the B-mode image generation unit 22 may generate an image signal so that the luminance of the pixels extracted by the extraction unit 24 is sufficiently higher than other pixels. Alternatively, the B-mode image generation unit 22 may generate an image signal by assigning a color different from other pixels to the pixel extracted by the extraction unit 24. The B mode image generation unit 22 supplies the generated image signal to the monitor 30. As a result, a B-mode image in which the position, size, and range of the microcalcification unit 30 are clearly displayed is displayed on the monitor 30.

  Note that step S34 in the rendering processing program according to the present embodiment may be replaced with step S14a in the rendering processing program according to the second embodiment. Further, Step S35 and Step S36 in the rendering processing program according to the present embodiment can be replaced with Step S35b and Step S36b in the rendering processing program according to the third embodiment, respectively. Further, steps S34 to S37 in the rendering processing program according to the present embodiment can be replaced with steps S14c to S17c in the rendering processing program according to the fourth embodiment, respectively. Further, Step S35 and Step S36 in the rendering processing program according to the present embodiment can be replaced with Step S15d and Step S16d in the rendering processing program according to the fifth embodiment, respectively. Further, Steps S35 to S37 in the rendering processing program according to the present embodiment can be replaced with Steps S15e and S16e according to the sixth embodiment.

  In the above description, the pixel extracted by the extraction unit 24 is illustrated as being superimposed on the B-mode image displayed on the monitor 30. However, only the pixel extracted by the extraction unit 24 is positioned at that position. May be displayed on the monitor 30 so as to be clearly indicated.

  In addition, when performing phasing addition processing along a plurality of reception focus directions different from each other on the received signal, at least two receptions such that an angle formed by a certain reception focus direction and another reception focus direction is 90 °. Preferably, the focus direction is included. This makes it possible to efficiently eliminate pixels corresponding to each reflection point on the mammary gland structure M, and as a result, it is possible to improve the rendering accuracy of the microcalcification part C.

  In each of the above-described embodiments, the case where the microcalcification portion generated in the breast is illustrated is illustrated. However, the present invention is also applicable to the case where the microcalcification portion generated in other parts such as the thyroid gland and the prostate is drawn. It is possible to apply. In addition, the present invention can be applied not only to the microcalcification part but also to drawing other microstructures such as microclips that show diffuse reflectivity with respect to ultrasonic waves.

  In each of the above embodiments, a known filtering process, a log compression process, and an envelope detection process are performed on the phasing addition signal generated by performing the phasing addition process corresponding to a plurality of different transmission directions or reception directions. In a B-mode image generated by performing STC processing, interpolation processing, scan conversion processing, etc., a pixel structure value of each pixel corresponding to the same reflection point is subjected to comparative analysis to extract a micro structure such as micro calcification Although the case is illustrated, it is not limited to the B-mode image, and corresponds to the signal intensity such as the maximum value, the minimum value, or the difference value thereof in the phasing addition signal and the reception signal of each phased channel before addition. An index value to be derived may be derived, and a comparative analysis of the index value may be performed to extract a microstructure such as microcalcification.

  In each of the above embodiments, when transmitting ultrasonic waves in a plurality of different directions, the reception direction and the transmission direction may be the same or different.

DESCRIPTION OF SYMBOLS 1 Ultrasonic diagnostic apparatus 10 Ultrasonic probe 10a Piezoelectric element 14 Transmission process part 16 Reception process part 18 Phased addition process part 22 B mode image generation part 24 Extraction part 30 Monitor

Claims (14)

Image generating means for generating a plurality of images corresponding to each of the plurality of directions based on reflected waves of ultrasonic waves reflected in different directions from the reflection point;
Extraction means for performing a comparative analysis of pixel values of each pixel corresponding to the same reflection point in the plurality of images generated by the image generation means, and extracting a specific pixel that approximates the pixel value;
Display means for displaying the specific pixels extracted by the extraction means;
An ultrasonic diagnostic apparatus including:   The extraction means is an index value indicating a difference value or a variation in pixel values between the plurality of images among the pixels corresponding to the same reflection point in the plurality of images generated by the image generation means. The ultrasonic diagnostic apparatus according to claim 1, wherein a pixel having a value equal to or less than a predetermined threshold is extracted as the specific pixel.   The extraction unit is configured to select pixels having a correlation value of pixel values between the plurality of images equal to or greater than a predetermined threshold among the pixels corresponding to the same reflection point in the plurality of images generated by the image generation unit. The ultrasonic diagnostic apparatus according to claim 1, wherein the ultrasonic diagnostic apparatus is extracted as the specific pixel.   The ultrasonic diagnosis according to claim 2, wherein the extraction unit extracts a pixel having a pixel value equal to or greater than a predetermined threshold as the specific pixel in each of the plurality of images generated by the image generation unit. apparatus.   The extraction unit extracts a pixel whose minimum pixel value between the plurality of images is equal to or greater than a predetermined threshold among the pixels corresponding to the same reflection point in the plurality of images generated by the image generation unit. The ultrasonic diagnostic apparatus according to claim 1.   The ultrasonic diagnostic apparatus according to claim 1, wherein the display unit displays only the pixels extracted by the extraction unit.   The ultrasonic diagnostic apparatus according to claim 1, wherein the display unit displays the pixels extracted by the extraction unit on any one of the images generated by the image generation unit so as to be visible. . The extraction unit extracts a pixel having a minimum pixel value between the plurality of images among the pixels corresponding to the same reflection point in the plurality of images generated by the image generation unit,
The ultrasonic diagnostic apparatus according to claim 1, wherein the display unit displays an image composed of pixels extracted by the extraction unit.   The image generation means is configured to generate a plurality of signals corresponding to each of the plurality of directions based on each of a plurality of reception signals generated in response to each transmission of ultrasonic waves sequentially transmitted in a plurality of directions different from each other. The ultrasonic diagnostic apparatus according to claim 1, which generates an image. Performs phasing addition processing along each of a plurality of different directions on the reception signal generated in response to the transmission of the ultrasonic wave, and generates a plurality of phasing addition signals corresponding to each of the plurality of directions. Further comprising phasing and adding means for
9. The image generation unit according to claim 1, wherein the image generation unit generates a plurality of images corresponding to each of the plurality of directions based on each of the plurality of phased addition signals generated by the phased addition unit. The ultrasonic diagnostic apparatus of Claim 1.   The said image generation means produces | generates at least 2 image corresponding to each transmission of the ultrasonic wave transmitted toward the direction of 1 and the other direction inclined 90 degrees with respect to the said 1 direction. Ultrasound diagnostic equipment.   The phasing addition means performs phasing addition processing along each of one direction with respect to a reception signal generated in response to transmission of ultrasonic waves and another direction inclined by 90 ° with respect to the one direction. The ultrasonic diagnostic apparatus according to claim 10, wherein the ultrasonic diagnostic apparatus performs at least two phasing addition signals corresponding to each of the one direction and the other direction. An image generation step of generating a plurality of images corresponding to each of the plurality of directions based on reflected waves of ultrasonic waves reflected in different directions from the reflection point;
An extraction step of performing a comparative analysis of the pixel values of each pixel corresponding to the same reflection point in the plurality of images generated in the image generation step to extract a specific pixel that approximates the pixel value;
A display step for displaying the specific pixel extracted in the extraction step;
Image rendering method including Computer
Image generating means for generating a plurality of images corresponding to each of the plurality of directions based on reflected waves of ultrasonic waves reflected in different directions from the reflection point;
Extraction means for performing a comparative analysis of pixel values of each pixel corresponding to the same reflection point in the plurality of images generated by the image generation means, and extracting a specific pixel that approximates the pixel value;
Display means for displaying the specific pixels extracted by the extraction means;
Program to function as.