JP2020018767A - Ultrasonic diagnosis system - Google Patents

Abstract

To provide an ultrasonic diagnosis system which can accurately area-divide an ultrasonic image of a breast being an area in which an individual difference between patients is large.SOLUTION: An ultrasonic diagnosis system having an ultrasonic diagnosis device for imaging an ultrasonic image of a breast comprises: a surface shape acquisition part for acquiring a surface shape of the breast; a storage part for storing a fat mass database indicating a relationship between magnitude of the breast and a thickness of fat; a model creation part for creating a breast volume model which is area-divided into tissues in the breast by using the surface shape and the fat amount database; a position detection part for detecting a position of an ultrasonic probe which is in imaging; a model deformation part for deforming the breast volume model on the basis of a position detected by the position detection part; and a display image creation part for creating a display image displayed at a display part on the basis of a reference image indicating each tissue of the deformed breast volume model at each area, and the ultrasonic image.SELECTED DRAWING: Figure 3

Description

  The present invention relates to image processing of an ultrasonic image picked up by an ultrasonic diagnostic apparatus, and particularly to a technique for dividing an ultrasonic image of a breast into regions.

  Ultrasound diagnostic apparatuses have attracted attention as a modality for breast cancer screening because they can observe a patient's body in a non-invasive and real-time manner and are less susceptible to dense breasts that are difficult to diagnose with X-ray mammography. On the other hand, in the imaging of the breast by the ultrasonic diagnostic apparatus, the range and the image quality to be imaged vary greatly depending on the manner in which the ultrasonic probe is brought into contact, so that the inspector is required to perform advanced procedures and interpret the ultrasonic image. Interpreters require vast knowledge and experience. Therefore, a technology for supporting an inspector and a radiogram interpreter is being developed.

  Patent Literature 1 discloses a method for improving the accuracy of detecting a lesion from an ultrasonic image based on a positional relationship between a lesion candidate and skin, fat, linear tissue, muscle, bone, and the like, which are anatomical objects. It is disclosed to verify the candidate. Patent Document 2 discloses an ultrasonic image captured at a position based on the position of the ultrasonic probe based on the position of the ultrasonic probe in order to improve the objectivity of ultrasonic diagnosis. Is disclosed.

JP 2015-154918 A JP 2018-775A

  However, Patent Literature 1 verifies whether a lesion candidate is a false positive by using the probability distribution information of a lesion candidate or a position where each tissue exists, and treats a breast, which is a site where individual differences are large between patients. Is not suitable. Breasts have large individual differences in the internal structure and are greatly deformed by contact with the ultrasound probe.Therefore, ultrasound images of each tissue and lesion in the breast vary greatly from patient to patient, and each tissue can be localized without considering individual differences. If divided, the accuracy will decrease.

  Therefore, an object of the present invention is to provide an ultrasonic diagnostic system capable of dividing an ultrasonic image of a breast, which is a site where individual differences between patients are large, with high accuracy.

  In order to achieve the above object, the present invention is an ultrasonic diagnostic system including an ultrasonic diagnostic apparatus that captures an ultrasonic image of the breast, a surface shape obtaining unit that obtains a surface shape of the breast, and a size of the breast. A storage unit that stores a fat mass database indicating a relationship with the thickness of fat, and a model generation unit that generates a breast volume model divided into regions in each tissue in the breast using the surface shape and the fat mass database, A position detection unit that detects the position of the ultrasound probe during imaging, and a model deformation unit that deforms the breast volume model based on the position detected by the position detection unit, and each of the deformed breast volume models in the breast volume model A display image generation unit configured to generate a display image to be displayed on the display unit based on the reference image indicating the tissue for each region and the ultrasonic image.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the ultrasonic diagnostic system which can divide an ultrasonic image of the breast which is a site | part with a large individual difference for every patient with high precision.

FIG. 3 is a hardware configuration diagram of the first embodiment. FIG. 2 is a configuration diagram of a main body 105 of the ultrasonic diagnostic apparatus 100 according to the first embodiment. FIG. 3 is a functional block diagram according to the first embodiment. FIG. 3 is a diagram showing an anatomical structure of the breast according to the first embodiment. FIG. 4 is a diagram illustrating a voxel model obtained by dividing a region according to the first embodiment. FIG. 5 is a diagram illustrating a procedure for dividing a voxel model into regions according to the first embodiment. FIG. 3 is a diagram illustrating an example of a fat mass database according to the first embodiment. FIG. 4 is a diagram illustrating an example of the structure of a PLY file according to the first embodiment. FIG. 4 is a diagram illustrating an example of a processing flow according to the first embodiment. FIG. 4 is a diagram illustrating an example of an imaging range in the breast volume model according to the first embodiment. FIG. 4 is a diagram illustrating an example of a reference image and a heat map of a mammary gland region according to the first embodiment. FIG. 14 is a functional block diagram according to a second embodiment. FIG. 11 is a diagram illustrating an example of a processing flow according to a second embodiment. FIG. 13 is a functional block diagram according to a third embodiment. FIG. 19 is a diagram illustrating an example of a processing flow according to a third embodiment.

  Hereinafter, preferred embodiments of an ultrasonic diagnostic system according to the present invention will be described with reference to the accompanying drawings. In the following description and the accompanying drawings, components having the same functional configuration will be denoted by the same reference numerals, and redundant description will be omitted.

  The hardware configuration of the present embodiment will be described with reference to FIG. This embodiment includes an ultrasonic diagnostic apparatus 100, a breast surface shape acquiring apparatus 101, and a probe position detecting apparatus 102. Hereinafter, each device will be described.

  The ultrasonic diagnostic apparatus 100 is an apparatus that acquires an ultrasonic image of a patient's breast, and includes an ultrasonic probe 103, a main body 105, a display device 106, and an input device 107. The ultrasonic probe 103 is brought into contact with the breast of the patient, emits an ultrasonic signal, and receives the ultrasonic signal reflected from the breast. The main body 105 generates an ultrasonic image based on the ultrasonic signal received by the ultrasonic probe 103. The main body 105 of the ultrasonic diagnostic apparatus 100 will be described later with reference to FIG. The display device 106 displays an ultrasonic image generated by the main body. The input device 107 is an operation device for the examiner to give an operation instruction to the ultrasonic diagnostic apparatus 100, and is specifically a keyboard, a touch panel, a mouse, or the like. The mouse may be another pointing device such as a trackpad or trackball.

  The breast surface shape acquisition device 101 is a device that acquires the surface shape of the patient's breast, and is, for example, a range image sensor or a stereo camera. In this embodiment, two distance image sensors are used to avoid occlusion.

  The probe position detection device 102 is a device that acquires the position and direction of the ultrasonic probe 103 in a three-dimensional space, and is, for example, a camera that detects an optical marker 104 installed on the ultrasonic probe 103. The probe position detecting device 102 is not limited to a camera that detects the optical marker 104, but may be a device that detects a magnetic marker installed on the ultrasonic probe 103, an acceleration sensor, or the like.

  The main body 105 of the ultrasonic diagnostic apparatus 100 will be described with reference to FIG. The main body 105 of the ultrasonic diagnostic apparatus 100 includes a CPU (Central Processing Unit) 201, a memory 202, a storage device 203, and an I / F (Inter Face) 204 connected by a system bus 205 so that signals can be transmitted and received. Here, “signal transmission / reception is possible” refers to a state in which signals can be transmitted / received to each other or from one side to the other, regardless of whether they are electrically or optically wired or wireless.

  The CPU 201 is a device that controls the operation of each component. The CPU 201 loads a program stored in the storage device 203 and data necessary for executing the program into the memory 202 and executes the program. The memory 202 stores programs to be executed by the CPU 201 and the progress of arithmetic processing. The storage device 203 is a device that stores programs executed by the CPU 201 and data necessary for executing the programs, and specifically includes a recording device such as a hard disk and an SSD (Solid State Drive), an IC card, an SD card, and a DVD. It is a device for reading and writing on a recording medium such as. The I / F 204 is a device that connects the main body 105 to the breast surface shape acquisition device 101, the probe position detection device 102, the ultrasonic probe 103, the display device 106, and the input device 107.

  The main part of this embodiment will be described with reference to FIG. Note that these main parts may be constituted by dedicated hardware or software operating on the CPU 201. In the following description, a case where the main part of the present embodiment is configured by software will be described. This embodiment includes a breast model generation unit 301, a model deformation unit 302, a B-mode image generation unit 303, and a display image generation unit 304. Hereinafter, each unit will be described.

  The breast model generation unit 301 generates a breast volume model using the surface shape of the breast acquired by the breast surface shape acquisition device 101 and the fat mass database stored in the storage device 203. The breast volume model is a volume model simulating the breast, and is generated as follows based on the surface shape of the breast.

  The breast surface shape acquisition device 101 acquires the breast surface shape as point cloud data PCD (Point Cloud Data). The PCD is a set of coordinate values of an infinite number of point groups existing on the patient's body surface. The breast model generation unit 301 removes noise from the PCD and discretizes it in a three-dimensional space to spread voxels, which are cubic elements, on the body surface of the patient. Further, the breast model generation unit 301 divides a breast region from a group of voxels spread on the body surface of the patient by a plane detection algorithm and threshold processing regarding curvature, and a space closed by the breast surface and the divided surface is divided into a plurality of voxels. Filling creates a voxel model of the breast. Since the breast is not composed of a single tissue but composed of a plurality of tissues, the breast model generation unit 301 divides the voxel model into regions for each tissue.

  FIG. 4 shows the anatomical structure of the breast in a sagittal section. Although there are individual differences in the size, density, etc. of the breast, there is no significant difference in the anatomical structure.The skin is arranged from the surface of the body in the order of skin, subcutaneous breast fat, mammary gland, postmammary fat, and pectoralis major. There are ribs and chest cavity below. The mammary gland is surrounded by subcutaneous mammary fat in contact with the skin and post mammary fat in contact with the pectoralis major and leads from the duct opening in the nipple to the duct sinus. In the mammary gland, lobules of the mammary gland are present in tufts, and extend radially from the ductal sinus to the end of the duct. Therefore, the breast model generation unit 301 divides the voxel model into a mammary gland region, a subcutaneous breast fat region, a duct duct sinus region, and a post-mammary fat region, as shown in FIG. FIG. 5 is a sectional view simulating the breast in the supine position.

A procedure for dividing the voxel model into regions will be described with reference to FIG. 6, like FIG. 5, a diagram simulating the breast when the supine position, cross-sectional view including a perpendicular line beat from the center A ₀ of the nipple of the breast to the pectoralis major muscle layer, for example, a sagittal cross section Ya It is an axial sectional view and the like. In addition, the end point of the breast in FIG. 6 is point B ₁ , point B ₂ , _one of the base points of the nipple is point A ₁ , and the leg of the perpendicular drawn from point A ₁ to line segment B ₁ B ₂ is point A ₂ , The length of the line segment A ₂ B ₁ is L. The positions of the points A ₁ , B ₁ , and B ₂ may be obtained by extracting inflection points obtained from PCD.

The boundary between the mammary gland region and the breast subcutaneous fat region will be described. The boundary between the mammary gland regions and the breast subcutaneous fat area, in the sectional view of FIG. 6, the line segment A ₁ A ₂ and the line segment A ₁ A ₂ point A 'and point on the body of the breast B' on the endpoint Is a set of points C ′ which internally divides a line segment A′B ′ orthogonal to the line at a fixed ratio. Here, _assuming that a point that internally divides the line segment A ₂ B ₁ is a point C and a length of the line segment B ₁ C is L _s , L _s is the maximum thickness of the breast subcutaneous fat region, and The position satisfies Equation 1.

The thickness of the mammary gland after fat region and L _t, the height of the Chichikanhora region and L _u. A point orthogonal to the line segment B ₁ B ₂ and passing through the point B ₁ intersects with the boundary between the pectoralis major muscle layer and the posterior mammary fat area as D ₁ , and similarly, an intersection of a line passing through the point B ₂ is indicated as D ₁ . and D _2.

Since the thickness of fat is correlated with the size of the breast, the thickness of fat may be determined based on the size of the breast calculated from the surface shape of the breast. For example, it may be determined thickness L _t of the maximum thickness L _s and mammary gland after fat region of the breast subcutaneous fat area from the height and volume of the breast. A fat mass database stored in the storage device 203 in advance is used to determine the fat thickness.

FIG. 7 shows an example of the fat mass database. 7 (a) is an example of a relationship between the height and volume of the maximum thickness L _s and breast breast subcutaneous fat area, FIG. 7 (b) and the height and volume of thickness L _t and breast mammary gland after fat region It is an example of the relationship. The fat mass database as shown in FIG. 7 is created based on medical images obtained by an MRI (Magnetic Resonance Imaging) device or the like. The fat mass database is not limited to the relationship between the size of the breast and the thickness of the fat, and may indicate the relationship between the BMI (Body Mass Index) index or the body fat percentage and the fat mass of the patient. In addition to the storage device 203, a fat mass database may be stored on a cloud, for example, and the fat mass database updated as needed may be downloaded as needed.

The breast model generation unit 301 obtains the thickness of the fat by comparing the size of the breast calculated from the surface shape of the breast with a fat mass database as shown in FIG. 7, and based on the obtained thickness of the fat. Divide the voxel model into regions. Note that the height L _u of Chichikanhora region, or determined as a percentage ratio of certain line segments A ₁ A ₂ and L _u, may be set to a predetermined value.

Above, the procedure of the region segmentation description, by being performed on a plurality of cross-sectional view including a perpendicular line beat from the center A ₀ of the nipple of the breast to the pectoralis major muscle layer, the voxel model of breast three-dimensionally The area is divided. Further, the breast model generation unit 301 generates a breast volume model composed of tetrahedral elements by connecting the centers of a plurality of voxels constituting the voxel model to adjacent voxels. A known algorithm such as a marching cube method may be applied to the generation of the breast volume model. The shape of the breast volume model is stored in a storage device 203 or the like in a known format such as a PLY (PoLYgon file format) file as shown in FIG. 8, and a different file indicates to which region each vertex or tetrahedral element belongs. Is stored.

  The model deforming unit 302 deforms the breast volume model generated by the breast model generating unit 301 based on the position of the ultrasound probe 103 during imaging detected by the probe position detecting device 102. Prior to the transformation of the breast volume model, the coordinate system of the probe position detecting device 102 is matched with the coordinate system of the breast surface shape acquiring device 101. Specifically, the ultrasonic probe 103 is stopped in a space where the measurement ranges of the breast surface shape acquisition device 101 and the probe position detection device 102 overlap, and the coordinates of the stationary point are determined by the coordinate system of the breast surface shape acquisition device 101 and the probe position. It is acquired in the coordinate system of the detection device 102. Then, the coordinate system of the probe position detecting device 102 is transformed homogeneously so that the stationary point of the coordinate system of the probe position detecting device 102 matches the stationary point of the coordinate system of the breast surface shape acquiring device 101.

  After the coordinate system is adjusted, the model deformation unit 302 sets the material model of the breast volume model to a Neo-Hookean model, which is a type of superelastic body, and performs deformation analysis by finite element analysis. The strain energy function W of the Neo-Hookean model is expressed by Equation 2.

Here, I ₁ is a first-order distortion invariant, and is obtained from Equation ₃ using the extension ratios λ ₁ , λ ₂ , and λ ₃ of the tetrahedral elements constituting the breast volume model as variables.

Moreover, C ₁₀ is a material constant that expresses the ease of deformation, is set for each element of the breast volume model. Specific numerical values of the material constants are appropriately set based on references from literatures, experimentally obtained values, and anatomical findings, for example, that the mammary gland is harder and less deformable than fat. By appropriately setting the material constants, highly reproducible deformation analysis becomes possible. For the deformation analysis, not only the Neo-Hookean model but also a Mooney-Rivlin model or an Ogden model may be used. Alternatively, the deformation analysis may be performed on the assumption of an elastic body such as a minute strain linear elastic body. Further, the deformation analysis may be performed using a mass spring model, a particle method elasticity analysis, or a combination thereof.

In the deformation analysis of the breast volume model, as a fixed condition, the boundary between the posterior mammary fat region and the pectoralis major muscle layer represented by the line segment D ₁ D ₂ in FIG. 6 is a fixed point at which the displacement is always 0. Displacements are given to a plurality of points on the surface where the breast volume model contacts the ultrasonic probe 103 by pressing the ultrasonic probe 103. The given displacement is calculated based on the position of the ultrasonic probe 103 detected by the probe position detecting device 102. The distortion of the tetrahedral element due to the applied displacement becomes a stress and spreads to the entire breast volume model.

  Since the Neo-Hookean model is a superelastic body, it vibrates due to an external force such as pressing of the ultrasonic probe 103. However, in the finite element analysis, the deformation is divided into minute times, and the deformation is converged by providing a stress attenuation term. Let it. The shape of the transformed breast volume model is stored in the storage device 203 or the like in the form of a PLY file as shown in FIG. 8 as the coordinates of each vertex.

  The B-mode image generating unit 303 generates an ultrasonic image called a so-called B-mode image based on the ultrasonic signal received by the ultrasonic probe 103. The generated ultrasonic image is used for diagnosis.

  The display image generation unit 304 generates a display image to be displayed on the display device 106 based on the breast volume model deformed by the model deformation unit 302 and the ultrasonic image generated by the B-mode image generation unit 303. The display image includes a reference image in which each tissue in the deformed breast volume model is divided into regions, and a captured ultrasonic image.

  An example of the flow of a process executed by the ultrasound diagnostic system including the above units will be described with reference to FIG. Hereinafter, each step will be described.

(S901)
The breast surface shape acquisition device 101 acquires the surface shape of the breast.

(S902)
The breast model generation unit 301 calculates the size of the breast from the surface shape of the breast acquired in S901, and compares the calculated size of the breast with the fat mass database stored in the storage device 203, thereby obtaining the amount of fat. Get the thickness of. The calculated breast size is, for example, the height and volume of the breast in the supine position, and the thickness of the obtained fat is, for example, the maximum thickness of the breast subcutaneous fat and the post-mammary fat in the supine position. Thickness.

(S903)
The breast model generation unit 301 generates a breast volume model based on the surface shape of the breast acquired in S901 and the thickness of the fat acquired in S902. A plurality of voxels are spread on the body surface of the patient based on the surface shape of the breast, and a voxel model is generated by filling the inside of the breast, which is a space closed by the spread voxel group, with the plurality of voxels. . The voxel model is divided into a mammary gland region, a subcutaneous breast fat region, a duct duct sinus region, and a post-mammary fat region based on the thickness of fat. Further, a breast volume model is generated by connecting the centers of voxels constituting the voxel model between adjacent voxels.

(S904)
The model deformation unit 302 positions the breast volume model and the ultrasonic probe 103. The alignment between the two is performed by matching the coordinate system of the breast surface shape acquiring device 101 with the coordinate system of the probe position detecting device 102.

(S905)
An ultrasonic signal is emitted from the ultrasonic probe 103 to the breast, and a scan is started.

(S906)
The B-mode image generation unit 303 generates a B-mode image based on the ultrasonic signal received by the ultrasonic probe 103, and causes the display device 106 to display the B-mode image.

(S907)
The probe position detecting device 102 acquires the position of the ultrasonic probe 103 during scanning by detecting the optical marker 104 installed on the ultrasonic probe 103.

(S908)
The model deformation unit 302 deforms the breast volume model based on the position of the ultrasound probe 103 acquired in S907. With the deformation of the breast volume model, the region indicating each tissue in the breast volume model also changes.

(S909)
The model deformation unit 302 generates a reference image based on the breast volume model after the deformation. The reference image is generated according to the imaging range of the B-mode image generated in S906. The imaging range of the B-mode image is a rectangular area as shown in FIG. 10 which is constituted by the long axis of the ultrasonic wave transmitting / receiving surface of the ultrasonic probe 103 and a line segment orthogonal to the ultrasonic wave transmitting / receiving surface. The horizontal length is the length of the major axis of the ultrasonic wave transmitting / receiving surface, and the vertical length is the imaging depth determined by the imaging conditions. Therefore, based on the position of the ultrasound probe 103 acquired in S907, the model deforming unit 302 sets a rectangular area indicating an imaging range in the deformed breast volume model, and extracts each area included in the rectangular area. To generate a reference image. Note that the breast volume model is composed of a subcutaneous breast fat region, a ductal sinus region, a mammary gland region, and a post-mammary fat region, and does not include the pectoralis major muscle layer or less, so that the imaging range of the B-mode image includes the pectoralis major muscle layer or less. In this case, in the reference image, the range is set to the pectoralis major muscle layer or lower. Since the skin exists between the ultrasonic probe 103 and the subcutaneous fat region of the breast, a predetermined range in the upper part of the reference image, for example, the upper 1.5 mm is set as the skin area.

  The generated reference image is stored in the storage device 203 or the like as a grayscale image having the same size as the B-mode image. Specifically, the skin region, the subcutaneous breast fat region, the ductal sinus region, the mammary gland region, the posterior mammary fat region, and six types of pixel values representing the pectoralis major and below are all pixels of the reference image as a label representing each region. Assigned to.

(S910)
The display image generation unit 304 generates a display image based on the ultrasonic image generated in S906 and the reference image generated in S909, and causes the display device 106 to display the display image. For example, based on the reference image, a heat map representing the probability that an area exists in the image is generated.

  A procedure for generating a heat map will be described with reference to FIG. 11 illustrating an example of a heat map of a mammary gland region generated based on a reference image and a reference image. First, a mammary gland region is extracted from the reference image. Next, only the extracted mammary gland region is subjected to a reduction process by a morphological operation, and is reduced in the vertical direction until the narrowest portion of the mammary gland region becomes one pixel. In the reduced area, the mammary gland existence probability score is set to 100. In addition, only the extracted mammary gland region is subjected to enlargement processing by a morphological operation, and is enlarged in the vertical direction until the mammary gland region contacts another region, for example, a subcutaneous breast fat region or a post-mammary fat region boundary. The existence probability score of the mammary gland is set to 0 outside the region after the enlargement. Lastly, a mammary gland existence probability score is calculated by linearly interpolating a region where the mammary gland existence probability score is neither 0 nor 100 based on the distance from the outside region. For example, at the center between the boundary of the region after reduction and the boundary of the region after enlargement, the existence probability score of the mammary gland is 50. Through the above procedure, the presence probability score of the mammary gland is obtained for the entire area of the reference image, and a heat map is generated.

  Further, a heat map is generated from the region divided image created using the B-mode image in the same procedure as in the case of the reference image, and the generated heat map and the heat map generated from the reference image are weighted and added. A new heat map may be generated. Equation 4 is used for weighted addition.

Here, P _j is the existence probability score of each pixel of the heat map after the weighted addition, j is the pixel number, w is a weight coefficient of 0 to 1, and Pe _j is the existence probability of each pixel of the heat map generated from the reference image. The score Pr _j is the existence probability score of each pixel of the heat map generated from the B-mode image. Note that in order to create a region-divided image from a B-mode image, pre-processing such as noise removal and known image processing such as pixel value threshold processing and region expansion processing are used.

  The display image generation unit 304 generates a display image by arranging the heat map generated from the reference image or the heat map after the weighted addition with the B-mode image or overlapping the B-mode image. When a heat map is superimposed on a B-mode image that is a grayscale image, it is preferable to use an RGB image as the heat map or add an alpha channel, for example, opacity to the heat map. Further, the boundary of the heat map may be superimposed on the B-mode image as an outline. Further, the display image may be generated by arranging the reference image with the B-mode image or overlapping the B-mode image, or the display image may be generated only by the reference image or the heat map.

  According to the flow of the processing described above, the ultrasonic image of the breast, which is a site where the individual difference between patients is large, can be divided into regions with high accuracy. That is, since the inside of the breast is divided into tissues based on the surface shape of the breast in which individual differences for each patient appear, deformation of the breast due to contact with the ultrasonic probe 103 is analyzed with high accuracy. Can be divided into regions with high accuracy.

  In the first embodiment, the case has been described in which the breast volume model is deformed based on the position of the ultrasonic probe 103 acquired by the probe position detection device 102, and the reference image is generated using the deformed breast volume model. If there is a gap between the ultrasonic wave transmitting / receiving surface of the ultrasonic probe 103 and the breast, noise is included in the generated B-mode image, which adversely affects the diagnosis. Therefore, in the present embodiment, based on the position of the ultrasonic probe 103 acquired by the probe position detection device 102, while determining whether the ultrasonic transmitting and receiving surface of the ultrasonic probe 103 is appropriately in contact with the breast, A description will be given of displaying a correction plan when inappropriate. Note that the overall configuration of this embodiment is the same as that of the first embodiment, and a description thereof will be omitted.

  The main part of this embodiment will be described with reference to FIG. Note that these main parts may be constituted by dedicated hardware or software operating on the CPU 201. In the following description, a case where the main part of the present embodiment is configured by software will be described. As in the first embodiment, this embodiment includes a breast model generation unit 301, a model deformation unit 302, a B-mode image generation unit 303, and a display image generation unit 304, and further includes a contact determination unit 1200 and a correction plan generation unit 1201. Prepare. Hereinafter, a description of the same configuration as in the first embodiment will be omitted, and the contact determination unit 1200 and the modification plan creation unit 1201 will be described.

  The contact determination unit 1200 determines whether or not the ultrasonic wave transmitting / receiving surface of the ultrasonic probe 103 is appropriately contacting the breast based on the position of the ultrasonic probe 103 during imaging detected by the probe position detection device 102. . The contact determination unit 1200 makes contact with the position of the ultrasonic probe 103 using either the surface shape of the breast acquired by the breast surface shape acquisition device 101 or any of the voxel model and the breast volume model generated by the breast model generation unit 301. Is determined. The contact determination unit 1200 not only determines the contact between the ultrasonic wave transmitting / receiving surface of the ultrasonic probe 103 and the breast, but also calculates the angle between the ultrasonic probe 103 and the surface of the breast, The movement locus may be recorded, and the result may be displayed on the display device 106.

  The modification plan creating unit 1201 creates a position where the ultrasonic probe 103 can appropriately contact the breast as a modification plan. For example, the shortest distance between each point on the ultrasonic wave transmitting / receiving surface of the ultrasonic probe 103 and each point on the surface of the breast, and a vector between the two points at the shortest distance are calculated, and the norm of the calculated vector is calculated. The largest one is created as a revision plan.

  The flow of the process according to the present embodiment will be described with reference to FIG. Steps S901 to S910 are the same as those in the first embodiment, and a description thereof will not be repeated, and only steps S1300 and S1301 will be described.

(S1300)
Contact determination section 1200 determines whether or not the ultrasonic wave transmitting / receiving surface of ultrasonic probe 103 is appropriately in contact with the breast. If appropriate, the process proceeds to S909, and if inappropriate, the process proceeds to S1301.

(S1301)
The correction plan creating unit 1201 creates a correction plan for the position of the ultrasonic probe 103 and causes the display device 106 to display the correction plan. After the display of the correction plan, the process proceeds to S905. Instead of displaying the correction plan on the display device 106, the correction plan may be presented to the operator by voice.

  According to the processing flow described above, it is determined whether or not the ultrasonic wave transmitting / receiving surface of the ultrasonic probe 103 is appropriately in contact with the breast, and if inappropriate, a correction plan for the position of the ultrasonic probe 103 is made. Since it is displayed, a B-mode image without noise can be obtained. Further, similarly to the first embodiment, it is possible to divide the ultrasonic image of the breast, which is a site where the individual difference between patients is large, with high accuracy. Furthermore, since a heat map is generated from a B-mode image without noise, the accuracy of region division can be further improved.

  In the second embodiment, a description will be given of determining whether the ultrasonic wave transmitting / receiving surface of the ultrasonic probe 103 is appropriately in contact with the breast based on the position of the ultrasonic probe 103 acquired by the probe position detecting device 102. did. When diagnosing the breast, it is desirable to take an image in a cross section orthogonal to the running direction of the milk duct. Therefore, in the present embodiment, based on the position of the ultrasonic probe 103 acquired by the probe position detection device 102, it is determined whether or not the imaging section is appropriately set, and a correction plan is displayed if inappropriate. Will be described. Note that the overall configuration of this embodiment is the same as that of the first embodiment, and a description thereof will be omitted.

  The main part of this embodiment will be described with reference to FIG. Note that these main parts may be constituted by dedicated hardware or software operating on the CPU 201. In the following description, a case where the main part of the present embodiment is configured by software will be described. As in the first embodiment, the present embodiment includes a breast model generation unit 301, a model deformation unit 302, a B-mode image generation unit 303, and a display image generation unit 304, and further includes an imaging section calculation unit 1400 and a modification plan generation unit 1201. Is provided. Hereinafter, a description of the same configuration as that of the first embodiment will be omitted, and the imaging section calculation unit 1400 and the modification plan creation unit 1201 will be described.

  The imaging section calculation unit 1400 calculates an imaging section based on the position of the ultrasonic probe 103 during imaging detected by the probe position detection device 102, and determines whether the imaging section is appropriate. Ultrasound is attenuated in a tubular tissue such as a milk duct included in a mammary gland area. Therefore, the milk duct is drawn as a low-luminance area in a B-mode image, particularly when the imaging cross section is parallel to the running direction of the milk duct. , It is difficult to distinguish from other organizations. Therefore, the imaging section calculation unit 1400 calculates the intersection angle between the traveling direction of the breast duct and the imaging section, and determines whether the imaging section is appropriate based on the calculated intersection angle.

  To calculate the intersection angle, a voxel model or a breast volume model generated by the breast model generation unit 301 is used together with the position of the ultrasonic probe 103. That is, the imaging section in the three-dimensional space is calculated based on the position of the ultrasonic probe 103, and the traveling direction of the breast duct is calculated based on the voxel model or the breast volume model. As shown in FIG. 4, in the sagittal section, the duct extends radially from the duct duct, and runs near the subcutaneous fat in parallel with the boundary with the subcutaneous fat. When the breast is viewed from the front, the ducts also run radially from the duct sinus. Therefore, the imaging cross-section calculation unit 1400 sets a spherical surface centered on the end of the mammary duct, and calculates the angle between the normal line of the set spherical surface and the imaging cross-section as the intersection angle.

  The determination of the imaging cross section is made based on whether the calculated intersection angle is larger than a predetermined threshold value, for example, 60 degrees. If the intersection angle is equal to or larger than the threshold value, it is determined that the intersection angle is appropriate. It is determined to be inappropriate. The threshold may be changed according to the purpose of diagnosis.

  The modification plan creating unit 1201 creates a position where the ultrasonic probe 103 forms an appropriate imaging section as a modification plan. For example, a position of the ultrasonic probe 103 at which the intersection angle calculated by the imaging section calculation unit 1400 exceeds a threshold value is created as a correction plan.

  The flow of the process of the present embodiment will be described with reference to FIG. Steps S901 to S910 are the same as those in the first embodiment, and a description thereof will not be repeated, and only steps S1500 and S1501 will be described.

(S1500)
The imaging section calculation unit 1400 calculates the imaging section and determines whether the calculated imaging section is appropriate. If it is appropriate, the process proceeds to S909, and if it is inappropriate, the process proceeds to S1501.

(S1501)
The correction plan creating unit 1201 creates a correction plan for the position of the ultrasonic probe 103 and causes the display device 106 to display the correction plan. After the display of the correction plan, the process proceeds to S905. Instead of displaying the correction plan on the display device 106, the correction plan may be presented to the operator by voice.

According to the flow of the processing described above, it is determined whether or not the imaging cross section is appropriately set, and if inappropriate, a correction plan of the position of the ultrasonic probe 103 is displayed. A suitable B-mode image can be obtained. Further, similarly to the first embodiment, it is possible to divide the ultrasonic image of the breast, which is a site where the individual difference between patients is large, with high accuracy. Further, since a heat map is generated from a B-mode image suitable for breast diagnosis, diagnosis accuracy can be improved.
The embodiments of the present invention have been described above. The present invention is not limited to these embodiments, and includes various modifications. For example, the above-described embodiments have been described in detail in order to explain the present invention in an easy-to-understand manner, and are not limited to those having all the configurations described above. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment. Furthermore, it is also possible to add the configuration of another embodiment to the configuration of one embodiment. Also, for a part of the configuration of each embodiment, it is possible to add, delete, or replace another configuration.

100: ultrasonic diagnostic apparatus, 101: breast surface shape acquisition apparatus, 102: probe position detecting apparatus, 103: ultrasonic probe, 104: optical marker, 105: main body, 106: display device, 107: input device, 201: CPU, 202: memory, 203: storage device, 204: I / F, 301: breast model generation unit, 302: model deformation unit, 303: B mode image generation unit, 304: display image generation unit, 1200: contact determination unit , 1201: amendment draft creating section, 1400: imaging section calculating section

Claims (8)

An ultrasound diagnostic system including an ultrasound diagnostic apparatus that captures an ultrasound image of the breast,
A surface shape acquisition unit that acquires the surface shape of the breast,
A storage unit that stores a fat mass database indicating a relationship between the size of the breast and the thickness of the fat,
A model generation unit that generates a breast volume model that is divided into tissues in the breast using the surface shape and the fat mass database,
A position detection unit that detects the position of the ultrasonic probe during imaging,
Based on the position detected by the position detection unit, a model deformation unit that deforms the breast volume model,
Ultrasound diagnosis, comprising: a display image generation unit that generates a display image to be displayed on a display unit based on a reference image indicating each tissue in the deformed breast volume model for each region and the ultrasonic image. system. The ultrasonic diagnostic system according to claim 1,
The model generating unit calculates the size of the breast from the surface shape, obtains the thickness of the fat by comparing the size of the breast with the fat mass database, and calculates the breast volume based on the thickness of the fat. An ultrasonic diagnostic system wherein the inside of a model is divided into regions for each tissue. The ultrasonic diagnostic system according to claim 1,
The model generation unit, in a cross section including a perpendicular line descended from the nipple of the breast to the pectoralis major, a reference line parallel to the perpendicular line and passing through the base of the nipple, a point on the reference line and an outer surface of the breast An ultrasonic wave characterized by setting a line segment perpendicular to the reference line as an end point and a set of points internally dividing the line segment at a fixed ratio as a boundary between a subcutaneous fat region and a mammary gland region. Diagnostic system. The ultrasonic diagnostic system according to claim 1,
The ultrasound diagnostic system according to claim 1, wherein the breast volume model is divided into a mammary gland region, a subcutaneous mammary fat region, a duct duct sinus region, and a post mammary fat region. The ultrasonic diagnostic system according to claim 1,
The model generation unit generates a voxel model in which the inside of the breast is filled with a plurality of voxels based on the surface shape, and generates the breast volume model by connecting the center of the voxel between adjacent voxels. An ultrasonic diagnostic system, characterized in that: The ultrasonic diagnostic system according to claim 1,
The fat mass database, as the size of the breast, including the height and volume of the breast in the supine position, as the thickness of the fat, including the thickness of the breast subcutaneous fat and the thickness of the post mammary fat in the supine position. Ultrasound diagnostic system featuring. The ultrasonic diagnostic system according to claim 1,
A contact determination unit that determines whether the ultrasonic probe is in contact with the breast based on the surface shape and the position of the ultrasonic probe,
When it is determined that there is no contact by the contact determination unit, a correction plan for the position of the ultrasonic probe is created so that the ultrasonic probe contacts the breast, and the correction plan is displayed on the display unit. An ultrasonic diagnostic system, further comprising a correction plan creating unit for causing the system to perform correction. The ultrasonic diagnostic system according to claim 1,
An imaging cross section is calculated based on the position of the ultrasonic probe, and an imaging cross section calculation unit that determines whether the imaging cross section is appropriate based on an intersection angle between the imaging cross section and the running direction of the milk duct,
When the imaging section is determined to be inappropriate by the imaging section calculation section, a correction plan for the position of the ultrasonic probe is created so that the imaging section has an appropriate angle, and the correction plan is An ultrasonic diagnostic system, further comprising a correction plan creating unit for displaying on a display unit.

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