JP6258286B2 - Ultrasonic diagnostic apparatus, image processing apparatus, and control program - Google Patents

Description

  Embodiments described herein relate generally to an ultrasonic diagnostic apparatus, an image processing apparatus, and a control program.

  2. Description of the Related Art Conventionally, an ultrasonic diagnostic apparatus has a smaller apparatus scale than other medical image diagnostic apparatuses such as an X-ray diagnostic apparatus, an X-ray CT (Computed Tomography) apparatus, and an MRI (Magnetic Resonance Imaging) apparatus. In addition, the ultrasonic diagnostic apparatus can display in real time the state of movement of the test object, such as the heart beat and the fetal movement, by a simple operation of simply touching the ultrasonic probe from the body surface. For these reasons, ultrasonic diagnostic apparatuses play an important role in today's medical care. In addition, ultrasonic diagnostic equipment that is not exposed to radiation has been developed to be small enough to be carried with one hand. Such ultrasonic diagnostic equipment can be easily used in medical settings such as obstetrics and home medical care. can do.

  Incidentally, in recent years, with the development of high-frequency probes and the development of image processing techniques, the resolution of ultrasonic images has been dramatically improved, and the use of ultrasonic diagnostic apparatuses has been rapidly increasing. For example, in the orthopedic field, a soft tissue with a layer structure in which minute fibers such as muscles and tendons are gathered in bundles is an object to be observed, but the ultrasonic diagnostic apparatus displays the layer structure on an ultrasound image. Can be represented. For this reason, an ultrasonic image is used as a clinically useful finding such that a doctor suspects an abnormality when the disappearance or tearing of a layer structure is observed on an ultrasonic image.

JP 2008-206779 A

Hiro et al, `` Detection of Fibrous Cap in Atherosclerotic Plaque by Intravascular Ultrasound by Use of Color Mapping of Angle-Dependent Echo-Intensity Variation '', Circulation JOURNAL OF THE AMERICAN HEART ASSOCIATION, March 6, 2001, P.1206-1211

  However, abnormalities observed on ultrasound images are difficult to detect for those unfamiliar, and clinically useful information itself is lost when smoothing is performed to facilitate observation of ultrasound images. There is also. Thus, conventionally, observation of an ultrasonic image depends on the ability of an observer, and therefore, it has been desired to quantitatively express information represented on the ultrasonic image.

The ultrasonic diagnostic apparatus according to the embodiment includes a generation unit and a display control unit. The generating unit generates a plurality of tomographic images having different ultrasonic transmission directions based on the echo data collected via the ultrasonic probe, and the plurality of tomographic images for each position in the region of interest in the subject. Among the images, a first tomographic image having a beam angle with the maximum luminance and two second tomographic images and a third tomographic image having a predetermined angle positioned before and after the beam angle are determined, and the determined first tomographic image is determined. Calculating an average value of the difference between the maximum luminance and the non-maximum luminance between the image, the second tomographic image, and the third tomographic image, and assigning a color corresponding to the average value to each position in the region of interest; A color mapping image representing the degree of tissue anisotropy at each position within the region of interest is generated. The display control unit displays at least one of the plurality of tomographic images or a superimposed image of the plurality of tomographic images side by side with the color mapping image on the display unit.

FIG. 1 is a block diagram illustrating the configuration of the ultrasonic diagnostic apparatus according to the first embodiment. FIG. 2 is a flowchart illustrating a processing procedure of ultrasonic image display in the first embodiment. FIG. 3A is a diagram for explaining the transmission direction of the ultrasonic beam in the first embodiment. FIG. 3B is a diagram for explaining the transmission direction of the ultrasonic beam in the first embodiment. FIG. 3C is a diagram for explaining the transmission direction of the ultrasonic beam in the first embodiment. FIG. 3D is a diagram for explaining the transmission direction of the ultrasonic beam in the first embodiment. FIG. 4 is a diagram for explaining storage of tomographic images in the first embodiment. FIG. 5 is a flowchart illustrating a processing procedure of tomographic image storage according to the first embodiment. FIG. 6A is a diagram illustrating a plurality of tomographic images generated for each direction of the ultrasonic beam in the first embodiment. FIG. 6B is a diagram illustrating a plurality of tomographic images generated for each direction of the ultrasonic beam in the first embodiment. FIG. 6C is a diagram illustrating a plurality of tomographic images generated for each direction of the ultrasonic beam in the first embodiment. FIG. 7 is a flowchart illustrating a processing procedure for analysis and analysis result display in the first embodiment. FIG. 8 is a diagram illustrating reception of ROI (Region Of Interest) designation in the first embodiment. FIG. 9 is a diagram illustrating an analysis result displayed in the first embodiment. FIG. 10 is a diagram illustrating another example of receiving ROI designation in the first embodiment. FIG. 11 is a diagram illustrating another example of the analysis result displayed in the first embodiment. FIG. 12A is a diagram illustrating an analysis result displayed in the second embodiment. FIG. 12B is a diagram illustrating an analysis result displayed in the second embodiment. FIG. 12C is a diagram illustrating an analysis result displayed in the second embodiment. FIG. 13A is a diagram illustrating another example of the analysis result displayed in the second embodiment. FIG. 13B is a diagram illustrating another example of the analysis result displayed in the second embodiment. FIG. 13C is a diagram illustrating another example of the analysis result displayed in the second embodiment. FIG. 14 is a diagram for explaining the analysis in the second embodiment. FIG. 15 is a diagram for explaining analysis and analysis result display in the third embodiment. FIG. 16 is a flowchart illustrating a processing procedure of ultrasonic image display in the third embodiment. FIG. 17 is a flowchart illustrating a processing procedure for analysis and analysis result display according to the third embodiment. FIG. 18 is a block diagram illustrating the configuration of the control unit according to the fourth embodiment. FIG. 19 is a diagram illustrating a B-mode image displayed in the fourth embodiment. FIG. 20 is a diagram illustrating another example of the B-mode image displayed in the fourth embodiment. FIG. 21 is a diagram for explaining a configuration example in another embodiment.

  Hereinafter, examples of the ultrasonic diagnostic apparatus, the image processing apparatus, and the analysis program according to the embodiment will be described.

  First, the configuration of the ultrasonic diagnostic apparatus 10 according to the first embodiment will be described. FIG. 1 is a block diagram illustrating a configuration of an ultrasonic diagnostic apparatus 10 according to the first embodiment. As illustrated in FIG. 1, the ultrasonic diagnostic apparatus 10 according to the first embodiment includes an apparatus main body 11, an ultrasonic probe 12, an input device 13, and a monitor 14.

  The ultrasonic probe 12 has a plurality of piezoelectric vibrators. The plurality of piezoelectric vibrators generate an ultrasonic wave based on a drive signal supplied from an ultrasonic transmission unit 21 included in the apparatus main body 11 to be described later, and receive a reflected wave from the subject P to generate an electric signal. Convert. The ultrasonic probe 12 includes a matching layer provided on the piezoelectric vibrator, a backing material that prevents propagation of ultrasonic waves from the piezoelectric vibrator to the rear, and the like.

  When ultrasonic waves are transmitted from the ultrasonic probe 12 to the subject P, the transmitted ultrasonic waves are successively reflected by the discontinuous surface of the acoustic impedance in the body tissue of the subject P, and the ultrasonic probe 12 is used as an echo signal. Are received by a plurality of piezoelectric vibrators. The amplitude of the received echo signal depends on the difference in acoustic impedance at the discontinuous surface where the ultrasonic waves are reflected. Note that the echo signal when the transmitted ultrasonic pulse is reflected by the moving blood flow or the surface of the heart wall, etc. depends on the velocity component in the ultrasonic transmission direction of the moving body due to the Doppler effect, Subject to frequency shift.

  The input device 13 includes a mouse, a keyboard, a button, a panel switch, a touch command screen, a foot switch, a trackball, and the like, and is connected to the device body 11. The input device 13 receives various instructions and setting requests from the operator of the ultrasonic diagnostic apparatus 10, and receives the received various instructions and setting requests (for example, a region of interest (ROI) setting request) in the apparatus main body 11. Forward.

  The monitor 14 displays a GUI (Graphical User Interface) for an operator of the ultrasonic diagnostic apparatus 10 to input various instructions and setting requests using the input device 13, or an ultrasonic image generated in the apparatus main body 11. And display analysis results.

  The apparatus main body 11 generates an ultrasonic image based on the reflected wave received by the ultrasonic probe 12. As illustrated in FIG. 1, the apparatus main body 11 includes an ultrasonic transmission unit 21, an ultrasonic reception unit 22, a B-mode processing unit 23, a Doppler processing unit 24, an image generation unit 25, and an image memory 26. An image composition unit 27, a control unit 28, a storage medium 29, and an interface 30.

  The ultrasonic transmission unit 21 includes a pulse generator 21 a, a transmission delay unit 21 b, and a pulsar 21 c, and supplies a drive signal to the ultrasonic probe 12. The pulse generator 21a repeatedly generates rate pulses for forming transmission ultrasonic waves at a predetermined rate frequency. Further, the transmission delay unit 21b is configured so that the pulse generator 21a determines the delay time for each piezoelectric vibrator necessary for focusing the ultrasonic waves generated from the ultrasonic probe 12 into a beam and determining the transmission directivity. For each rate pulse that occurs. The pulser 21c applies a drive signal (drive pulse) to the ultrasonic probe 12 at a timing based on the rate pulse. The transmission direction or the delay time for determining the transmission direction is stored in the storage medium 29, and the transmission delay unit 21 b gives the delay time with reference to the storage medium 29.

  In addition, by repeatedly scanning while changing the direction of the one-dimensional ultrasonic beam, information from a two-dimensional tomographic plane can be collected. However, there are not only one combination of beam directions for generating one tomographic image. There are various patterns.

  The ultrasonic reception unit 22 includes a preamplifier 22a, an A / D converter (not shown), a reception delay unit 22b, and an adder 22c, and performs various processes on the echo signal received by the ultrasonic probe 12. To generate echo data. The preamplifier 22a amplifies the echo signal and performs gain correction processing. The A / D converter performs A / D conversion on the gain-corrected echo signal. The reception delay unit 22b gives a delay time necessary for determining the reception directivity. The adder 22c performs an addition process of the echo signal processed by the reception delay unit 22b to generate echo data. By the addition process of the adder 22c, the reflection component from the direction corresponding to the reception directivity of the echo signal is emphasized, and a comprehensive beam for ultrasonic transmission / reception is formed by the reception directivity and the transmission directivity. Similar to transmission, the reception direction or the delay time for determining the reception direction is stored in the storage medium 29, and the reception delay unit 22 b gives the delay time with reference to the storage medium 29.

  The echo signal received by the ultrasonic probe 12 is mainly generated from the tissue boundary. When the acoustic impedances of the two media are different from each other, a phenomenon such as scattering (reflection) occurs. The physical constants that determine the acoustic impedance are the density and sound velocity of the media. That is, it can be said that the characteristics such as the hardness and softness of the tissue are reflected in the echo signal as they are.

  The B-mode processing unit 23 receives the echo data from the ultrasonic receiving unit 22, performs logarithmic amplification, envelope detection processing, and the like, and generates data (B-mode data) in which the signal intensity is expressed by brightness. .

  The Doppler processing unit 24 performs frequency analysis on velocity information from the echo data received from the ultrasonic receiving unit 22, extracts blood flow, tissue, and contrast agent echo components due to the Doppler effect, and moves moving objects such as average velocity, dispersion, and power. Data (Doppler data) obtained by extracting information from multiple points is generated.

  The image generation unit 25 generates an ultrasonic image from the B mode data generated by the B mode processing unit 23 and the Doppler data generated by the Doppler processing unit 24. Specifically, the image processing unit 25 generates a B-mode image from the B-mode data, and generates a Doppler image from the Doppler data. The image generation unit 25 converts (scan converts) the scanning line signal sequence of the ultrasonic scan into a scanning line signal sequence of a video format typified by a television or the like, and an ultrasonic image (B-mode image) as a display image. Or Doppler image).

  The image memory 26 is a memory that stores an ultrasonic image generated by the image generation unit 25 and an image generated by performing image processing on the ultrasonic image. For example, after diagnosis, the operator can call an image recorded during the examination, and can be reproduced as a still image or as a moving image using a plurality of images. The image memory 26 stores an image luminance signal after passing through the ultrasonic receiving unit 22, other raw data, image data acquired via a network, and the like as necessary.

  The control unit 28 controls the entire processing in the ultrasonic diagnostic apparatus 10. Specifically, the control unit 28, based on various instructions and setting requests input from the operator via the input device 13, various programs read from the storage medium 29, and various setting information, Control the processing of the sound wave receiving unit 22, the B-mode processing unit 23, the Doppler processing unit 24, and the image generation unit 25, or control the monitor 14 to display an ultrasonic image or the like stored in the image memory 26. To do.

  The storage medium 29 stores a device control program for performing ultrasonic transmission / reception, image processing and display processing, diagnostic information (for example, patient ID, doctor's findings, etc.), various data such as diagnostic protocol and various setting information, and the like. To do. In addition, the storage medium 29 stores an analysis program in which a procedure for executing processing similar to that of the analysis unit 28a described later and a procedure for executing processing similar to that of the analysis result display control unit 28b described later are described. The storage medium 29 is also used for storing images stored in the image memory 26 as necessary. Note that the data stored in the storage medium 29 can be transferred to an external peripheral device via the interface 30.

  The interface 30 is an interface related to the input device 13, the network, and a new external storage device (not shown). Data such as ultrasound images and analysis results obtained by the ultrasound diagnostic apparatus 10 can be transferred by the interface 30 to other apparatuses via a network.

  Note that the ultrasonic transmission unit 21 and the ultrasonic reception unit 22 incorporated in the apparatus main body 11 may be configured by hardware such as an integrated circuit, but may be a software modularized program. is there.

  The ultrasonic diagnostic apparatus 10 according to the first embodiment transmits ultrasonic beams in multiple directions via the ultrasonic probe 12 and receives echo signals in multiple directions via the ultrasonic probe 12.

  FIG. 2 is a flowchart illustrating a processing procedure of ultrasonic image display in the first embodiment, and FIGS. 3A to 3D are diagrams for explaining the transmission direction of the ultrasonic beam in the first embodiment. In the first embodiment, it is assumed that the ultrasonic diagnostic apparatus 10 transmits ultrasonic beams in three directions. However, the disclosed technique is not limited to this, and the number of transmission directions of ultrasonic beams is determined according to the operation. It can be arbitrarily changed according to the form and the like.

  As illustrated in FIG. 2, the ultrasound diagnostic apparatus 10 acquires the number of beam patterns when processing is started by receiving a start instruction from an operator (step S <b> 101). For example, the ultrasound diagnostic apparatus 10 acquires the number of beam patterns “3” stored in advance in the storage medium 29 by reading from the storage medium 29. Further, for example, the ultrasound diagnostic apparatus 10 obtains the beam pattern number “3” by receiving an instruction from the operator.

  Next, the ultrasonic diagnostic apparatus 10 transmits and receives ultrasonic waves in the i-th beam direction (step S102). Specifically, first, the transmission delay unit 21b and the reception delay unit 22b each calculate a delay time according to the number of beam patterns acquired in step S101. In the first embodiment, since the number of beam patterns is “3”, the transmission delay unit 21b and the reception delay unit 22b have a delay time that forms a predetermined beam direction for each of the three transmissions / receptions for each element. calculate. Then, the ultrasonic transmission unit 21 and the ultrasonic reception unit 22 perform transmission / reception of ultrasonic waves by using the delay time pattern calculated by the transmission delay unit 21b and the reception delay unit 22b.

  For example, the ultrasonic transmission unit 21 and the ultrasonic reception unit 22 are arranged so that the direction of the scanning line 42 is 90 degrees with respect to the piezoelectric transducer of the ultrasonic probe 12 as illustrated in FIG. 3A. Send and receive sound waves.

  Subsequently, the ultrasound diagnostic apparatus 10 generates a B-mode image (Step S103). Specifically, the B-mode processing unit 23 receives echo data from the ultrasonic reception unit 22, generates B-mode data from the received echo data, and sends the generated B-mode data to the image generation unit 25. Then, the image generation unit 25 generates a B mode image from the B mode data received from the B mode processing unit 23.

  Then, the ultrasonic diagnostic apparatus 10 determines whether or not the beam pattern has been completed up to the Nth (third in the first embodiment) beam pattern (step S104), and determines that the beam pattern has not ended (step S104). (No), the process returns to step S102. Thus, the ultrasonic diagnostic apparatus 10 according to the first embodiment generates three B-mode images corresponding to the number of beam patterns “3”.

  For example, the ultrasonic transmission unit 21 and the ultrasonic reception unit 22 are configured such that the direction of the scanning line 43 is smaller than 90 degrees with respect to the piezoelectric vibrator of the ultrasonic probe 12 as illustrated in FIG. 3B. Ultrasound is transmitted and received to generate a B-mode image. Further, for example, in the ultrasonic transmission unit 21 and the ultrasonic reception unit 22, as illustrated in FIG. 3C, the direction of the scanning line 44 is an angle larger than 90 degrees with respect to the piezoelectric vibrator of the ultrasonic probe 12. Thus, ultrasonic waves are transmitted and received to generate a B-mode image.

  If it is determined in step S104 that the processing has ended (Yes in step S104), the ultrasound diagnostic apparatus 10 generates a superimposed image (step S105), and displays the generated superimposed image on the monitor 14 (step S106). Specifically, the image generation unit 25 generates a superimposed image as a display image by superimposing three B-mode images generated corresponding to the number of beam patterns “3”, and the generated superimposed image is converted into an image composition unit. 27. Then, the image composition unit 27 displays the information on the monitor 14 by adding other information to the superimposed image sent from the image generation unit 25. Note that FIG. 3D shows a beam pattern after superposition when ultrasonic beams in three different directions are transmitted and received.

  The ultrasonic diagnostic apparatus 10 repeatedly executes the processing procedure of steps S102 to S106 described above until the processing is ended by receiving an end instruction from the operator or the like, and displays an ultrasonic image in real time. In the first embodiment, the image generation unit 25 has been described as generating a superimposed image from a B-mode image, but the disclosed technique is not limited to this. For example, the image generation unit 25 may generate a superimposed image directly from the B mode data.

  Here, as described above, the ultrasound diagnostic apparatus 10 according to the first embodiment performs processing for transmitting and receiving ultrasound beams in a plurality of directions and displaying a superimposed image in real time. A process of comparing and analyzing the echo signals corresponding to the spatial positions between the tomographic images is performed. In the following description, when described as “tomographic image for each direction”, the disclosed technique can be applied to either “B-mode data” or “B-mode image”. Will be described as a “B-mode image”.

  FIG. 4 is a diagram for explaining storage of tomographic images in the first embodiment. As illustrated in FIG. 4, the ultrasonic diagnostic apparatus 10 according to the first embodiment displays a superimposed image generated as a display image in real time on the monitor 14 and stores the generated superimposed image in the image memory 26. Do. In addition to the processing, the ultrasonic diagnostic apparatus 10 according to the first embodiment also stores a tomographic image for each direction in the image memory 26. This is for the purpose of comparison analysis processing.

  FIG. 5 is a flowchart illustrating a processing procedure of tomographic image storage according to the first embodiment. As illustrated in FIG. 5, for example, when the ultrasound diagnostic apparatus 10 according to the first embodiment receives a button press from the operator (Yes in Step S201), the B-mode image for each direction is stored in the image memory 26 (Step S201). S202). For example, the image generation unit 25 generates and generates three B-mode images (first tomographic image, second tomographic image, and third tomographic image) from the three B-mode data collected at the timing of pressing the button. Three B-mode images are stored in the image memory 26.

  6A to 6C are diagrams illustrating a plurality of tomographic images generated for each direction of the ultrasonic beam in the first embodiment. 6A corresponds to FIG. 3A, FIG. 6B corresponds to FIG. 3B, and FIG. 6C corresponds to FIG. 3C. The image generation unit 25 stores, for example, each of the three B-mode images illustrated in FIGS. 6A to 6C in the image memory 26.

  For example, as illustrated in FIGS. 6A to 6C, the subcutaneous tissue immediately below the ultrasonic probe 12 has a constant luminance between the B-mode images regardless of the direction of the ultrasonic beam. On the other hand, the “tendon” that runs laterally under the subcutaneous tissue immediately below the ultrasound probe 12 has the highest brightness (bright) in the B-mode image illustrated in FIG. 6A, but the B-mode illustrated in FIGS. 6B and 6C. In the image, the luminance is slightly reduced (darkened).

  The B-mode image illustrated in FIG. 6A is a tomographic image when the ultrasonic beam is incident on the “tendon” substantially perpendicularly as described with reference to FIG. 3A. In contrast, the B-mode image illustrated in FIGS. 6B and 6C is a tomographic image when the ultrasonic beam is incident on the “tendon” slightly obliquely.

  As described above, when the B-mode image for each direction is generated by changing the direction of the ultrasonic beam, the luminance looks different even in the same portion. This is due to the angle dependence (anisotropic effect) of the tissue. For example, a tissue having a fiber structure in which fibers are arranged in a specific direction, such as a muscle or a tendon, has a property that the intensity of an echo signal reflected differs depending on the direction of an incident ultrasonic beam. This is angle dependency.

  Returning to FIG. 1, the control unit 28 has an analysis unit 28a and an analysis result display control unit 28b. Each of these units performs a process of comparing and analyzing echo signals corresponding to spatial positions between tomographic images in each direction. The analysis unit 28a compares echo signals corresponding to spatial positions among a plurality of tomographic images generated for each direction of the ultrasonic beam, and analyzes the tissue properties of the subject depicted in the tomographic image. Specifically, the analysis unit 28a analyzes the tissue property by comparing the luminances assigned based on the intensity of the echo signal. A technique of directly comparing the intensity of the echo signal may be used. The analysis result display control unit 28b displays the analysis result analyzed by the analysis unit 28a on the monitor 14.

  FIG. 7 is a flowchart illustrating a processing procedure of analysis and analysis result display in the first embodiment, FIG. 8 is a diagram illustrating reception of ROI designation in the first embodiment, and FIG. 9 is a display in the first embodiment. It is a figure which illustrates the analysis result performed.

  As illustrated in FIG. 7, first, the analysis unit 28a determines whether or not an analysis instruction has been received from the operator (step S301). If it is determined that the analysis instruction has been received (Yes in step S301), the ROI designation image is displayed. It is displayed (step S302). For example, the analysis unit 28a displays an ROI designation image on the monitor 14 as illustrated in FIG.

  Next, the analysis unit 28a accepts the designation of the ROI on the image displayed in step S302, and if accepted (Yes in step S303), analyzes the luminance in the ROI (step S304).

  For example, as illustrated in FIG. 8, the analysis unit 28a accepts designation of “ROI1” and “ROI2” on the ROI designation image. Then, the analysis unit 28a analyzes the luminance in “ROI1” for each of the plurality of B-mode images generated for each direction of the ultrasonic beam, for example, obtains an average value of the luminance in “ROI1”, and so on. The echo signals corresponding to the spatial positions are compared between the B-mode images. Further, the analysis unit 28a analyzes the luminance in “ROI2” for each of the plurality of B-mode images generated for each direction of the ultrasonic beam, for example, obtains an average value of luminance in “ROI2”, and so on. The echo signals corresponding to the spatial positions are compared between the B-mode images.

  Then, the analysis result display control unit 28b displays the analysis result (step S305). For example, the analysis result display control unit 28b displays the analysis result illustrated in FIG. Note that the analysis result illustrated in FIG. 9 is merely an example, and the analysis result display control unit 28b may display the analysis result by numerical values, characters, other graphs, and the like.

  Now, the analysis results in Example 1 will be described with reference to FIG. For example, FIG. 9 shows the relationship between the beam angle and the brightness for each ROI. For example, it is assumed that the solid curve 51 corresponds to “ROI1” and the dotted curve 52 corresponds to “ROI2”. Then, while the analysis result of “ROI1” changes in luminance according to the angle of the ultrasonic beam, the analysis result of “ROI2” has little change in luminance according to the angle of the ultrasonic beam. I understand.

  Here, as described above, for example, a tissue having a fiber structure has an angle dependency that the intensity of the echo signal reflected differs depending on the direction of the incident ultrasonic beam. In other words, if the tissue having angle dependency is normal, when comparing echo signals corresponding to the spatial positions between the tomograms generated for each direction of the ultrasonic beam, it depends on the direction of the ultrasonic beam. The brightness is considered to change. On the other hand, if the echo signals corresponding to the spatial positions are compared between the tomographic images generated for each direction of the ultrasonic beam, and the luminance does not change according to the direction of the ultrasonic beam, the tissue is abnormal. it is conceivable that.

  That is, for example, in the example of FIG. 9, “ROI1” in which the luminance changes according to the angle of the ultrasonic beam is considered normal, but “ROI2” in which the luminance does not change according to the angle of the ultrasonic beam. Is considered abnormal. Thus, in the analysis result displayed by the analysis result display control unit 28b, information represented on the ultrasonic image is quantitatively expressed, and the operator views the analysis result displayed on the monitor 14. Thus, it is possible to quantitatively grasp information represented on the ultrasonic image.

  For convenience of explanation, it has been described that the tissue is “normal” or “abnormal” quantitatively, but the analysis result does not necessarily represent the normal abnormality of the tissue. For example, tissue properties are quantitatively expressed, such as whether the ultrasonic beam is easily reflected in various directions or whether it is easily reflected in only one direction.

  In the first embodiment, an example in which two ROI designations are received has been described. However, the disclosed technology is not limited to this. 10 is a diagram illustrating another example of acceptance of ROI designation in the first embodiment, and FIG. 11 is a diagram illustrating another example of the analysis result displayed in the first embodiment.

  For example, the analysis unit 28a accepts designations of “ROI1”, “ROI2”, “ROI3”, and “ROI4” on the ROI designation image as illustrated in FIG. Then, the analysis unit 28a analyzes the luminance in “ROI1,” “ROI2,” “ROI3,” and “ROI4” for each of a plurality of B-mode images generated for each direction of the ultrasonic beam, The echo signals corresponding to the spatial positions are compared between the images. And the analysis result display control part 28b displays an analysis result so that it may illustrate in FIG.

[Effect of Example 1]
As described above, in the ultrasound diagnostic apparatus 10 according to the first embodiment, the ultrasound transmission unit 21 and the ultrasound reception unit 22 transmit ultrasound beams in a plurality of directions via the ultrasound probe 12 and the ultrasound probe. 12 receives echo signals in a plurality of directions. In addition, the B-mode processing unit 23 and the image generation unit 25 generate a tomographic image for each direction of the ultrasonic beam using the echo signal received by the ultrasonic reception unit 22. Further, the analysis unit 28a compares echo signals corresponding to spatial positions among a plurality of tomographic images generated for each direction of the ultrasonic beam, and analyzes the tissue properties of the subject depicted in the tomographic image. . Further, the analysis result display control unit 28b displays the analysis result analyzed by the analysis unit 28a on the monitor 14. For this reason, according to the first embodiment, it is possible to quantitatively express information represented on the ultrasonic image. For example, the ultrasonic diagnostic apparatus 10 can quantitatively display the angle dependence. As a result, the operator can easily distinguish, for example, a tissue having a fiber structure in a specific direction from a tissue that does not.

  The analysis unit 28a analyzes the tissue properties by comparing the intensity of the echo signal or the luminance assigned based on the intensity. For this reason, according to the first embodiment, it is possible to effectively analyze the tissue properties of a tissue having angle dependency.

  In addition, the analysis unit 28a receives the designation of the region of interest and compares the echo signals in the designated region of interest. For this reason, according to the first embodiment, it is possible to perform an analysis process only for a region desired as an analysis target, and it is possible to perform an analysis efficiently.

  Next, the ultrasonic diagnostic apparatus 10 according to the second embodiment will be described. The ultrasonic diagnostic apparatus 10 according to the second embodiment displays a color mapping image as an analysis result.

  12A to 12C are diagrams illustrating analysis results displayed in the second embodiment. For example, the analysis unit 28a according to the second embodiment calculates the degree of angle dependency by obtaining the luminance change between pixels corresponding to the spatial positions between a plurality of B-mode images. For example, the analysis unit 28a selects two B-mode images from a plurality of B-mode images, and calculates a luminance difference between pixels corresponding to the spatial positions between the selected B-mode images. Then, the analysis unit 28a assigns a color according to the calculated luminance difference, and the analysis result display control unit 28b displays a color mapping image in which the image assigned the color by the analysis unit 28a and the original image are superimposed. . Note that the analysis result display control unit 28b may display only an image assigned a color as a color mapping image without necessarily superimposing the original image.

  For example, as illustrated in FIGS. 12A to 12C, the analysis unit 28a selects the B-mode image in FIG. 12A and the B-mode image in FIG. 12B, and the spatial position corresponds between the selected B-mode images. The luminance difference between pixels is calculated. The analysis unit 28a assigns a color according to the calculated luminance difference. For example, the color is assigned so that the red component becomes stronger when the luminance difference is large, and the yellow component becomes stronger when the luminance difference is small. Then, as illustrated in FIG. 12C, the analysis result display control unit 28b displays a color mapping image obtained by superimposing the color assigned image and the original image. For example, in the color mapping image illustrated in FIG. 12C, “tendon” that shows a strong angle dependency is clearly distinguished from other regions that have a weak angle dependency. In FIGS. 12A to 12C, for the sake of convenience of explanation, the difference in color is expressed by the difference in pattern.

  In the second embodiment, as in the first embodiment, it is possible to accept the designation of ROI. 13A to 13C are diagrams illustrating other examples of analysis results displayed in the second embodiment. For example, as illustrated in FIG. 13, the analysis unit 28a selects the B-mode image in FIG. 13A and the B-mode image in FIG. 13B, and within the area designated as the ROI among the selected B-mode images. Thus, the luminance difference between the pixels corresponding to the spatial positions is calculated. The analysis unit 28a assigns a color according to the calculated luminance difference. Then, as illustrated in FIG. 13C, the analysis result display control unit 28b displays a color mapping image obtained by superimposing the color assigned image and the original image. For example, in the color mapping image illustrated in FIG. 13C, only a part of the “tendon” showing strong angle dependency indicates that the angle dependency is weak. For example, a doctor can easily recognize that a part of a tendon has disappeared or torn by looking at the color mapping image.

  By the way, in the examples of FIGS. 12A to 12C and FIGS. 13A to 13C, since the tissue to be analyzed has a horizontal fiber structure, the expected effect can be obtained even by the method of comparing two B-mode images. Obtained. However, for example, when the tissue to be analyzed is not positioned parallel to the element surface of the ultrasonic probe 12, the above-described method may not provide the expected effect.

  Therefore, in general, it is desirable to employ a method of comparing three or more B-mode images. In this case, for example, the analysis unit 28a compares pixels corresponding to the spatial positions between three or more B-mode images, and obtains the angle of the ultrasonic beam with the highest luminance. Then, the analysis unit 28a calculates a luminance difference between the luminance at a predetermined angle positioned before and after the angle and the maximum luminance, and assigns a color.

For example, for point A in the B-mode image, the luminance at the beam angle x ° is I (x), and the beam angle at the maximum luminance is x _max . At this time, the brightness of the point A in the B-mode image obtained by transmitting and receiving a beam having a certain angle α away from the beam angle x _max is I (x _max + α), I (x _max −α). It is. Therefore, the luminance difference between these luminances and the maximum luminance is I (x _max ) −I (x _max + α), I (x _max ) −I (x _max −α). Therefore, the average value of I (x _max ) −I (x _max + α) and I (x _max ) −I (x _max −α) is defined as the degree of angle dependency.

  FIG. 14 is a diagram for explaining the analysis in the second embodiment. A certain point of the B-mode image indicated by the X mark illustrated in FIG. 14 shows the maximum luminance at the beam angle of reference numeral 62. On the other hand, a point in the B-mode image indicated by a circle indicates the maximum luminance at the beam angle of reference numeral 73. The degree of angle dependency at these two points is calculated using the luminance at the beam angles of reference numerals 61, 62, and 63 for the former point (the point marked with x). On the other hand, the latter point (marked with a circle) is calculated using the luminance at the beam angles of reference numerals 72, 73, and 74. Then, the analysis unit 28a assigns a color based on the obtained degree of angle dependency. In this way, the analysis unit 28a can quantitatively determine the degree of angle dependency regardless of whether the analysis target tissue is in the horizontal direction with respect to the ultrasonic probe 12.

  Next, an ultrasonic diagnostic apparatus 10 according to the third embodiment will be described. In the first embodiment and the second embodiment, the example has been described in which the ultrasonic diagnostic apparatus 10 performs the analysis of the tissue property after the fact. However, the disclosed technique is not limited thereto. That is, the ultrasonic diagnostic apparatus 10 according to the third embodiment displays an ultrasonic image in real time, performs analysis of tissue properties in real time, and displays an analysis result in real time.

  FIG. 15 is a diagram for explaining analysis and analysis result display in the third embodiment. As illustrated in FIG. 15, the ultrasonic diagnostic apparatus 10 according to the third embodiment displays a superimposed image generated as a display image on the monitor 14 in real time, and also stores a tomographic image for each direction in the image memory 26 in real time. To do. The ultrasonic diagnostic apparatus 10 according to the third embodiment analyzes the tomographic image for each direction stored in the image memory 26 in real time, and displays the color mapping image as the analysis result on the monitor 14 in real time. Note that the method described in the second embodiment can be used as a color mapping image generation method. 15 shows a monitor (monitor 1) that displays a superimposed image generated as a display image and a monitor (monitor 2) that displays a color mapping image. It may be displayed on the same monitor or may be displayed on another monitor.

  FIG. 16 is a flowchart showing a processing procedure of ultrasonic image display in the third embodiment, and FIG. 17 is a flowchart showing a processing procedure of analysis and analysis result display in the third embodiment. As can be seen by comparing the processing procedure illustrated in FIG. 16 with the processing procedure illustrated in FIG. 2, the ultrasonic diagnostic apparatus 10 according to the third embodiment differs from the processing in step S <b> 403 in step S <b> 403.

  In the case of the ultrasonic diagnostic apparatus 10 according to the first embodiment, the B-mode image generated in step S103 is temporarily stored in the image memory 26 until a superimposed image is generated in step S105. It was not necessary to be preserved after being used. This is because it is not an image to be analyzed. For this reason, the storage of the B-mode image is not explicitly shown in the flowchart illustrated in FIG. 2, and the storage of the B-mode image is specified in the flowchart illustrated in FIG.

  In this regard, in the case of the ultrasonic diagnostic apparatus 10 according to the third embodiment, the tissue property analysis is performed in real time and the analysis result is displayed in real time. Therefore, the B-mode image generated in step S403 is the analysis target image. To be stored in the image memory 26.

  Then, as illustrated in FIG. 17, when the B mode images corresponding to the number of beam patterns (N sheets) are stored in the image memory 26 (Yes in step S501), the analysis unit 28a calculates the luminance difference in real time. (Step S502). Then, the analysis unit 28a performs color mapping in real time according to the luminance difference (step S503), and the analysis result display control unit 28b displays the color mapping image in real time (step S504). For example, the analysis result display control unit 28b displays a color mapping image in real time side by side with a normal ultrasonic image (superimposed image). Note that the processing from step S501 to S504 is repeated until an end instruction is received from the operator, for example.

  It should be noted that the disclosed technique may be implemented in various different forms other than the above-described embodiments.

[Display of B-mode images by direction]
FIG. 18 is a block diagram illustrating the configuration of the control unit 28 according to the fourth embodiment. FIG. 19 illustrates a B-mode image displayed in the fourth embodiment. FIG. It is a figure which illustrates the other example of the B mode image displayed.

  As illustrated in FIG. 18, the control unit 28 according to the fourth embodiment further includes a direction-specific B-mode image display control unit 28 c. The direction-specific B-mode image display control unit 28c displays a plurality of B-mode images generated for each direction of the ultrasonic beam side by side on the monitor 14, or switches and displays each B-mode image. As a result, the operator can easily compare a plurality of B-mode images generated for each direction.

  For example, as illustrated in FIG. 19, the direction-specific B-mode image display control unit 28 c displays a plurality of B-mode images generated for each direction of the ultrasonic beam side by side on the monitor 14. Further, for example, the direction-specific B-mode image display control unit 28c switches and displays each B-mode image generated for each direction of the ultrasonic beam as illustrated in FIG. For example, when the operator operates the trackball (see the arrow in FIG. 20), the B-mode image generated for each direction of the ultrasonic beam is switched and displayed like frame advance.

[Control unit]
In the above embodiment, the transmission delay unit 21b and the reception delay unit 22b calculate the delay time, and transmit and receive ultrasonic waves using the calculated delay time pattern. It is not limited to. For example, the control unit 28 may perform control such as calculation of the delay time.

[Correction during analysis]
In the above embodiment, the analysis unit 28a did not perform any particular correction when analyzing the B-mode image. However, the disclosed technique is not limited to this, and the B-mode image is corrected and corrected. You may analyze. For example, when transmitting and receiving an ultrasonic beam in a direction shifted from the normal direction of the element surface of the ultrasonic probe 12, the echo signal is weaker than when transmitting and receiving in the normal direction with a change in the sound field. Tend to be. Therefore, the analysis unit 28a may perform the analysis after correcting in advance the change in luminance due to this influence. For example, the analysis unit 28a stores in advance the change in luminance acquired as experimental data or the like for each direction of the ultrasonic beam. The analysis unit 28a refers to the storage unit using the direction of the corresponding ultrasonic beam, and acquires the change in luminance to be corrected. Then, the analysis unit 28a performs analysis after correcting the luminance of the B-mode image using the obtained change. The correction timing may be corrected when the analysis is performed, or may be corrected when the B-mode image is generated.

[Analysis program]
Further, the analysis method described in the above embodiment may be executed by specifically realizing information processing by the analysis program using a computer. The computer has, for example, a CPU (Central Processing Unit), a system memory, a hard disk drive interface, a disk drive interface, a serial port interface, a video adapter, and a network interface. Connected. The system memory includes a ROM (Read Only Memory) and a RAM (Random Access Memory). The ROM stores a boot program such as BIOS (Basic Input Output System). The hard disk drive interface is connected to the hard disk drive. The disk drive interface is connected to the disk drive. For example, a removable storage medium such as a magnetic disk or an optical disk is inserted into the disk drive. The serial port interface is connected to, for example, a mouse and a keyboard. The video adapter is connected to a display, for example.

  Here, the hard disk drive stores, for example, an OS (Operating System), application programs, program modules, and program data. In other words, the analysis program according to the disclosed technique is stored in, for example, a hard disk as a program module in which a command to be executed by a computer is described. Specifically, a program module in which a procedure for executing the same process as the analysis unit 28a described in the above embodiment and a procedure for executing the same process as the analysis result display control unit 28b is stored in the hard disk. Is done.

  Note that the program module and program data related to the analysis program are not limited to being stored in the hard disk, but may be stored in, for example, a removable storage medium and read out by the CPU via a disk drive or the like. Alternatively, the program module and program data relating to the analysis program are stored in another computer connected via a network (LAN (Local Area Network), WAN (Wide Area Network), etc.), and are executed by the CPU via the network interface. It may be read out.

[Image processing device]
In the above-described embodiment, the ultrasonic diagnostic apparatus 10 includes the analysis unit 28a and the analysis result display control unit 28b. Alternatively, the ultrasonic diagnosis apparatus 10 includes the analysis unit 28a, the analysis result display control unit 28b, and Although the example provided with the direction-specific B-mode image display control unit 28c has been described, the embodiment is not limited thereto.

  For example, the image processing device 50 different from the ultrasound diagnostic device 10 may analyze the echo signal received by the ultrasound diagnostic device 10 and display the analysis result.

  FIG. 21 is a diagram for explaining a configuration example in another embodiment. As shown in FIG. 21, in other embodiments, the ultrasonic diagnostic apparatus 10 transmits ultrasonic beams in a plurality of directions via the ultrasonic probe 12 and via the ultrasonic probe 12 as in the first embodiment. Receive echo signals in multiple directions. Further, as in the first embodiment, the ultrasound diagnostic apparatus 10 generates a tomographic image for each direction of the ultrasound beam using the received echo signal. This tomographic image is sent to the image processing apparatus 50 via a network or the like. Note that an echo signal may be sent to the image processing apparatus 50 and a tomographic image may be generated for each direction of the ultrasonic beam on the image processing apparatus 50 side.

  On the other hand, the image processing apparatus 50 includes an interface 51, a control unit 52, and a monitor 53, as shown in FIG. The interface 51 is an interface related to a network or the like, like the interface 30 of the ultrasonic diagnostic apparatus 10. The control unit 52 is a processor that controls the entire processing in the image processing apparatus 50, as with the control unit 28 of the ultrasonic diagnostic apparatus 10. In addition, the monitor 53 displays the analysis result as in the monitor 14 of the ultrasonic diagnostic apparatus 10.

  Further, as shown in FIG. 21, the control unit 52 includes an analysis unit 52a, an analysis result display control unit 52b, and a direction-specific B-mode image display control unit 52c. In addition, embodiment is not restricted to this, The control part 52 does not need to be provided with the B-mode image display control part 52c according to direction, for example.

  The analysis unit 52a compares the echo signals corresponding to the spatial positions among a plurality of tomographic images generated for each direction of the ultrasonic beam, and analyzes the tissue properties of the subject depicted in the tomographic image. The analysis result display control unit 52 b displays the analysis result analyzed by the analysis unit 52 a on the monitor 53. The direction-specific B-mode image display control unit 52c displays a plurality of B-mode images generated for each direction of the ultrasonic beam side by side on the monitor 53, or switches and displays each B-mode image.

  According to the ultrasonic diagnostic apparatus, the image processing apparatus, and the analysis program of at least one embodiment described above, information represented on the ultrasonic image can be expressed quantitatively.

[Others]
Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 10 Ultrasonic diagnostic apparatus 28 Control part 28a Analysis part 28b Analysis result display control part

Claims (7)

Based on the echo data collected through the ultrasound probe, generate a plurality of tomographic images having different ultrasonic transmission directions, and for each position in the region of interest in the subject , among the plurality of tomographic images , The first tomographic image having the beam angle with the maximum luminance and the two second tomographic images and the third tomographic image having a predetermined angle positioned before and after the beam angle are determined, and the determined first tomographic image, second An average value of the difference between the maximum luminance and the non-maximum luminance between the tomographic image and the third tomographic image is calculated, and a color corresponding to the average value is assigned to each position in the region of interest. A generation unit that generates a color mapping image representing the degree of tissue anisotropy at each of the positions;
A display control unit that displays at least one of the plurality of tomographic images or a superimposed image of the plurality of tomographic images on the display unit side by side with the color mapping image;
An ultrasonic diagnostic apparatus comprising: Before Symbol display control unit, the plurality of tomographic images of the color mapping image to be displayed side by side on the display unit, the ultrasonic diagnostic apparatus according to claim 1. Prior Symbol display control unit, the plurality of one said color mapping image of the tomographic image, is displayed side by side on the display unit, the ultrasonic diagnostic apparatus according to claim 1. The ultrasonic diagnostic apparatus according to claim 3 , further comprising an input unit that receives an input for switching the tomographic image displayed on the display unit to another tomographic image. The ultrasound according to claim 1, wherein the generation unit determines tomographic images corresponding to two transmission directions with reference to the transmission direction of the first tomographic image as the second tomographic image and the third tomographic image. Diagnostic device. Based on the echo data collected through the ultrasound probe, generate a plurality of tomographic images having different ultrasonic transmission directions, and for each position in the region of interest in the subject , among the plurality of tomographic images , The first tomographic image having the beam angle with the maximum luminance and the two second tomographic images and the third tomographic image having a predetermined angle positioned before and after the beam angle are determined, and the determined first tomographic image, second An average value of the difference between the maximum luminance and the non-maximum luminance between the tomographic image and the third tomographic image is calculated, and a color corresponding to the average value is assigned to each position in the region of interest. A generation unit that generates a color mapping image representing the degree of tissue anisotropy at each of the positions;
A display control unit that displays at least one of the plurality of tomographic images or a superimposed image of the plurality of tomographic images on the display unit side by side with the color mapping image;
An image processing apparatus. Based on the echo data collected through the ultrasound probe, generate a plurality of tomographic images having different ultrasonic transmission directions, and for each position in the region of interest in the subject , among the plurality of tomographic images , The first tomographic image having the beam angle with the maximum luminance and the two second tomographic images and the third tomographic image having a predetermined angle positioned before and after the beam angle are determined, and the determined first tomographic image, second An average value of the difference between the maximum luminance and the non-maximum luminance between the tomographic image and the third tomographic image is calculated, and a color corresponding to the average value is assigned to each position in the region of interest. A color mapping image representing the degree of tissue anisotropy at each position of
Displaying at least one of the plurality of tomographic images or a superimposed image of the plurality of tomographic images on the display unit side by side with the color mapping image;
A control program that causes a computer to execute processing.