JPWO2013153968A1 - Ultrasonic diagnostic equipment - Google Patents

Abstract

Provided is an ultrasonic diagnostic apparatus capable of identifying the position of a measurement object and detecting a mechanical response by ultrasonic transmission / reception. Difference in acoustic impedance between the ultrasonic probe that transmits and receives echo signals from within the object, the changeover switch that switches between transmitting and receiving each element of the ultrasonic probe, and the first ultrasonic wave transmission and reception within the object A first ultrasonic transmission / reception unit for detecting a wave, a displacement generation unit for radiating a displacement-generating focused beam into the object to displace the tissue, and a second ultrasonic transmission / reception to receive an echo signal from the object. , A displacement detector that detects the shear wave displacement caused by the focused beam for generating the displacement at a plurality of positions, a central controller that controls the displacement generator and the displacement detector, and an ultrasonic tomographic image showing the difference in acoustic impedance A shear wave displacement map indicating the shear wave displacement is superimposed and displayed, and has a display unit, and muscles, tendons, ligaments, and the like are highlighted in a line on the ultrasonic tomographic image.

Description

  The present invention relates to an ultrasonic diagnostic apparatus that highlights muscles, ligaments, and tendons by ultrasonic transmission / reception.

  As a method for diagnosing breast cancer, liver cirrhosis, vascular disorder, etc., there is a method (elastography technique) for diagnosing the hardness inside a subject from ultrasonic echo signals instead of a doctor's palpation. In the hardness diagnosis by the elastography technique, the worker presses the probe against the surface of the subject and presses it to cause displacement in the tissue inside the measurement object such as a living body. The displacement in the compression direction is estimated from the echo signals before and after the compression of the living tissue by the compression, and the distortion which is the spatial differential amount of the displacement is obtained. Further, a value related to hardness, for example, Young's modulus is calculated from strain and stress. In this method, there is a problem that the imaging target is limited to an organ that exists where compression from the body surface is easy. For example, since a slip surface exists as an intervening layer between the body surface and the liver, it is difficult to perform compression that causes sufficient displacement.

  Therefore, there is a technique for diagnosing hardness by applying a radiation pressure inside a subject using an ultrasonic focused beam and displacing the target tissue while suppressing the influence of the intervening layer. For example, there is ARFI (Acoustic Radiation Force Impulse) Imaging described in Patent Document 1. In this technique, the amount of tissue displacement that occurs in the direction of travel of the focused beam for generating displacement is imaged, or shear waves that are generated in a direction perpendicular to the direction of travel of the focused beam for generating displacement as the tissue is displaced at the focal point. An elastic modulus such as a shear elastic modulus and a Young's modulus is calculated from an estimation of the propagation velocity of (= Shear Wave, hereinafter referred to as a shear wave). If this technique is used, in addition to the effect of reducing the influence of the intervening layer such as the above-mentioned sliding surface, the tissue is displaced by ultrasonic waves, so that diagnosis with less technique dependence is expected.

  On the other hand, in recent years, diagnosis using ultrasound in the orthopedic field has begun to attract attention. Usually, X-ray and MRI have been mainly used for diagnosis in orthopedics. Ultrasound diagnostic devices are superior in real time and portability, although their spatial resolution is inferior to them. It also has the merit of observing the movement of muscles, tendons, ligaments, etc. while moving the joint part. Based on the above, prevention of orthopedic diseases using an ultrasound diagnostic apparatus and follow-up after surgery are expected.

  At present, some orthopedic surgeons try to display the tomographic images of ligaments and tendons (hereinafter referred to as B-mode images) using an ultrasound diagnostic device and observe the joint state of the ligaments and tendons. ing. Here, the B-mode image is obtained by transmitting an ultrasonic wave to a living tissue, receiving a reflected wave from a boundary between two media having different acoustic impedances, and displaying a luminance value in gray scale.

US2004068184

  The orthopedic surgeon reads from the B-mode image and identifies the positions of muscles, tendons, ligaments, and the like. Therefore, whether or not muscles, tendons, ligaments, etc. can be specified depends on the image resolution of the B-mode image. Muscles, tendons, ligaments, etc. have a layer structure, and the thickness of each layer is less than the time resolution (several hundred μm) determined by the frequency (up to 20 MHz) used in a normal ultrasonic diagnostic apparatus (several tens of μm) Several μm). Therefore, B-mode images of muscles, tendons, ligaments, etc. are blurred. In addition, because muscles, tendons, ligaments, etc. have a spatially complex structure, it seems that the B-mode two-dimensional tomographic image is torn even though the muscles, tendons, ligaments, etc. are joined. It may be displayed.

  As described above, whether or not an operator can specify the position of muscles, tendons, ligaments, etc. depends on the image resolution of the ultrasonic tomogram in the ultrasonic diagnosis in the orthopedic region. The number of surgeons that can be used is limited. Further, in a two-dimensional tomographic image, there are cases in which connections such as muscles, tendons, and ligaments are not displayed.

  Therefore, it is desirable to display these positions on the ultrasonic tomographic image so that the positions of muscles, tendons, ligaments, etc. can be specified without depending on the operator's technique and the image quality of the ultrasonic tomographic image. Even when a two-dimensional tomographic image is used, it is desirable to display so that the structure of muscles, tendons, ligaments, etc. can be grasped.

  An object of the present invention is to provide an ultrasonic diagnostic apparatus capable of identifying a position of a measurement object and grasping a structure by ultrasonic transmission / reception.

The ultrasonic diagnostic apparatus of the present invention is
An ultrasonic probe that transmits and receives echo signals from within the object; a changeover switch that switches between transmission and reception of each element of the ultrasonic probe; and acoustic impedance that performs first ultrasonic transmission and reception within the object. A first ultrasonic transmission / reception unit that detects a difference between the first ultrasonic transmission / reception unit, a displacement generation unit that radiates a displacement-generating focused beam into the object to displace the tissue, and a second ultrasonic transmission / reception echo signal from the target A displacement detection unit that detects shear wave displacement generated by the displacement generating focused beam at a plurality of positions, a central control unit that controls the displacement generation unit and the displacement detection unit, An ultrasonic tomographic image showing the difference and a display unit for displaying the shear wave displacement map showing the shear wave displacement superimposed, and muscles, tendons, ligaments, etc. are highlighted in a line on the ultrasonic tomographic image. The

  According to the present invention, shear waves propagating along muscles, tendons, and ligaments are detected, and the positions of the muscles, tendons, ligaments, etc. are highlighted in a line on the ultrasonic tomographic image. Regardless of the image quality of the acoustic tomogram, the operator can specify the position and observe the shape. Furthermore, the ultrasonic diagnostic apparatus proposed in the present invention makes it possible to prevent a disease related to a specified site, diagnose the disease, and monitor the postoperative course of the disease.

1 is a system configuration diagram of an ultrasonic diagnostic apparatus in Examples 1 and 2. FIG. It is a figure which shows the propagation direction of the shear wave produced by radiation pressure in each Example. It is a figure explaining the beam forming of an ultrasonic wave based on each Example. It is a figure which shows the sequence of the ultrasonic beam transmission / reception based on Example 1. FIG. It is a figure which shows the processing flow which displays a muscle, a ligament, and a tendon based on Example 1. FIG. It is a figure which shows the concept of the function measurement of the tendon using the radiation pressure based on Example 1. FIG. FIG. 6 is a diagram illustrating an example of an image displayed on the display unit 7 according to the first embodiment. It is a figure explaining the reconfiguration | reconstruction display of a muscle, a ligament, and a tendon based on Example 1. FIG. It is a figure explaining the setting of several ROI based on Example 2. FIG. It is a figure explaining the example of observation of a muscle, a ligament, and a tendon based on Example 1 and 2. FIG. FIG. 10 is a system configuration diagram of an ultrasonic diagnostic apparatus according to a third embodiment. It is a figure explaining the histogram of the shear wave velocity based on Example 3. FIG. It is a figure explaining the tear measurement of the tendon using reflection of the shear wave based on Example 3. FIG. It is a figure explaining the display of the speed of a shear wave, and a spatial differential value based on Example 3. FIG. It is a figure explaining the tear measurement of the tendon using the time waveform of the shear wave based on Example 3. FIG. It is a figure explaining the tear measurement of the tendon using the frequency spectrum of the shear wave displacement based on Example 3. FIG. It is a figure explaining the measurement of the standing wave of the tendon based on Example 3. FIG. It is a figure explaining the tension | tensile_strength measurement based on Example 3. FIG. It is a figure explaining the Lamb wave measurement of the tendon based on Example 3. FIG. It is a figure explaining the excitation method of the shear wave which uses the direct-acting motor based on Examples 1-3. It is a figure explaining the excitation method of the shear wave which uses the eccentric motor based on Examples 1-3. It is a figure explaining the excitation method of the shear wave which uses the multi-degree-of-freedom rotary motor based on Examples 1-3. According to the first to third embodiments, (a) a probe attachment position when one ultrasonic probe is used, and (b) a probe when two ultrasonic probes are used. It is a figure explaining the attachment position. It is a figure explaining the ring array ultrasonic probe 8 based on Examples 1-3.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 shows the overall configuration of the apparatus according to the first and second embodiments. In the figure, an ultrasonic probe that transmits and receives an ultrasonic beam toward a subject (not shown), a displacement generator 10 that causes a displacement in the subject, and a difference in acoustic impedance in the subject are detected. One ultrasonic transmission / reception unit 20, a second ultrasonic transmission / reception unit 30 that detects a displacement generated in the subject, and a displacement generation unit 10, the first ultrasonic transmission / reception unit 20, and the second ultrasonic transmission / reception unit 30 are controlled. It is the structure which consists of the central control part 3 for this. The ultrasonic probe 1 is connected to the displacement-generating transmission beam generating unit 13, the first ultrasonic transmitting / receiving unit 20, and the second ultrasonic transmitting / receiving unit 30 via a transmission / reception switching switch 2 that functions as a transmission / reception switching unit. ing. The central control unit 3 also controls the transmission / reception changeover switch 2 that functions as a transmission / reception switching unit directly or indirectly.

  The first ultrasonic transmission / reception unit 20 gives a delay time and a weight to the transmission signal of the element of the ultrasonic probe 1 using the waveform generated by the transmission waveform generation unit for the B mode image (not shown). The central control unit 3 controls the ultrasonic beam for detecting displacement to be focused on a desired position of the subject (not shown). The echo signal reflected in the subject and returned to the probe is converted into an electrical signal by the ultrasonic probe 1 and sent to the first ultrasonic transmission / reception unit 20. The first ultrasonic transmission / reception unit 20 includes a signal processing circuit that performs phasing addition of echo signals and performs envelope detection, log compression, bandpass filter, gain control, and the like. An output signal from the first ultrasonic transmission / reception unit 20 is input to a monochrome DSC (digital scan converter) 5. In the monochrome DSC 5, tomographic image (B-mode image) information representing the luminance composed of monochrome is formed. As described above, the B-mode image displays the difference in acoustic impedance of the living tissue.

  The displacement generation unit 10 will be described. The displacement generation transmission beam generation unit 13 gives a delay time and a weight to the transmission signal for each element of the ultrasonic probe 1 using the waveform generated by the displacement generation transmission waveform generation unit 11. Control is performed by the central control unit 3 so that the ultrasonic beam is focused at the position set by the focal position setting unit 12. The electrical signal from the displacement-generating transmission beam generating unit 13 is converted into an ultrasonic signal by the ultrasonic probe 1 and irradiated with a displacement-generating ultrasonic beam toward a subject (not shown).

  The second ultrasonic transmission / reception unit 30 gives a delay time and a weight to the transmission signal of the element of the ultrasonic probe 1 using a waveform generated by a transmission waveform generation unit for displacement detection (not shown), not shown. Control is performed by the central control unit 3 so that the ultrasonic beam for displacement detection is focused on a desired position of the subject.

  The echo signal reflected in the subject and returned to the probe is converted into an electrical signal by the ultrasonic probe 1 and sent to the second ultrasonic transmission / reception unit 30. The second ultrasonic transmission / reception unit 30 includes a signal processing circuit that performs phasing addition of echo signals and performs envelope detection, log compression, bandpass filter, gain control, and the like. The output signal from the second ultrasonic transmission / reception unit 30 is input to the shear wave displacement calculation unit 32.

  In addition, the shear wave displacement calculation unit 32 calculates the displacement of each part by correlation calculation. Further, the displacement information output from the shear wave displacement calculation unit 32 is input to the color DSC 4 and is subjected to hue modulation according to the value of the shear wave displacement by the color DSC 4. Information that is hue-modulated by the color DSC 4 (hereinafter referred to as a distorted color image) is transmitted to the synthesizing unit 6 and displayed on the display unit 7 so as to be superimposed on the B-mode image. Information on the shear wave displacement calculated by the shear wave displacement calculation unit 32 is transmitted to the color scale setting unit 50 via the central control unit 3. The color scale setting unit 50 creates a color scale corresponding to the shear wave displacement color image based on the maximum value and the minimum value of the shear wave displacement. The color scale is displayed on the display unit 7 adjacent to the B-mode image and the distorted color image.

  The displacement information output from the shear wave displacement calculation unit 32 is output to the focal position setting unit 12. The displacement information output from the shear wave displacement calculator 32 is used when determining the next focal position from the initial focal position. Details regarding this are described in Example 2. The focal position setting unit 12 sets a focal point read from an information recording medium (not shown), and determines a focal position based on displacement information.

  The central control unit 3, the shear wave displacement calculation unit 32, and the like, which are a part of the blocks shown in the figure, can be realized by executing a program in a central processing unit (CPU) that functions as a processing unit. .

  In this embodiment, as shown in FIG. 2, the linear array type ultrasonic probe 1 is brought into contact with the body surface of the subject, and the displacement generating ultrasonic beam is focused on the target tomographic plane in the body. explain. Here, a case will be described in which the propagation direction of the ultrasonic wave for generating displacement is a direction perpendicular to the body surface within a desired tomographic plane.

  As shown in the upper and lower stages of FIG. 3, ultrasonic beam forming is performed by obtaining the distance between each focal point and the position of each element 100 of the ultrasonic probe 1 and calculating the distance difference between the elements. This is realized by transmitting a delay time calculated for each element by dividing by the sound speed of the signal. When an ultrasonic focused beam for generating displacement is applied to the focal point, radiation pressure is generated according to absorption and scattering of the ultrasonic wave accompanying propagation. Normally, the radiation pressure becomes maximum at the focal point, and displacement occurs in the living tissue in the focal region. Further, when the irradiation of the ultrasonic focused beam is stopped, the amount of displacement is reduced. In FIG. 2, as schematically shown, the generation of the radiation pressure generates a shear wave in the horizontal direction from the subject surface starting from the focal point.

  Next, a method for transmitting and receiving an ultrasonic beam for detecting a shear wave displacement by the ultrasonic probe 1 will be described with reference to FIG. FIG. 4 shows an irradiation sequence of a displacement generation transmission beam, a displacement detection transmission beam, and a displacement detection reception beam. A displacement detection transmission beam and a displacement detection reception beam are turned on in this order to obtain a reference signal used for calculation for detecting the displacement of the shear wave. ON / OFF is controlled by the amplitude value of the voltage, for example, and ON is 1 and OFF is 0. In the future, unless otherwise specified, ON means 1 and OFF means 0. The transmitted beam is irradiated when turned on. Note that when the received beam is turned ON, the second ultrasonic transmission / reception unit 30 and the ultrasonic probe 1 are connected in the transmission / reception wave changeover switch 2, and the second ultrasonic transmission / reception unit 30 performs the shear wave displacement calculation. For performing ultrasonic transmission / reception.

  First, after the reference signal for the shear wave displacement calculation is obtained by the second ultrasonic transmission / reception unit 30, the displacement generation transmission beam generation unit 13 irradiates the focal point F with the displacement generation transmission beam, and the shear wave is generated. Is generated. At this time, the repetition frequency PRFp of the displacement-generating transmission beam is set by the displacement-generating transmission waveform generation unit 11 and irradiated at the repetition frequency PRFp a plurality of times. By increasing the carrier frequency, the beam width is narrow, and imaging can be performed with high spatial resolution. In FIG. 4, as an example, the number of times of irradiation with the displacement-generating transmission beam is three, but the number is not limited to this. When the number of times of irradiation is greater, the displacement detection beam is detected after the displacement generation beam is irradiated, so that the displacement detection transmission beam and the displacement detection reception beam are sequentially turned on. The displacement of the shear wave is calculated using the previously obtained reference signal and the signal obtained by the displacement detecting transmission / reception beam. For the calculation of the displacement, correlation calculation, phase difference detection, etc., which are well-known techniques, are used, and the displacement detection calculation shear wave displacement calculation unit 32 performs the displacement detection. The displacement detection beam is repeatedly turned ON at the repetition frequency PRFd, and the time waveform of the shear wave displacement is detected. PRFd is set to a sampling interval that can be sufficiently measured with respect to the period T of the shear wave, for example, 1 / 10T. PRFd is set by the second ultrasonic transmission / reception unit 30.

  Next, a processing flow for highlighting muscles, ligaments, and tendons will be described using the flowchart of FIG. As described above, the processing flow for highlighting muscles, ligaments, and tendons can be realized by the program processing of the CPU. First, in step S00, processing for highlighting muscles, ligaments, and tendons is started. Next, in step S02, a tomographic image is displayed. The tomographic image to be displayed is, for example, a B mode image. In step S04, a position F1 or a range (ROI: Region of Interest) in which muscles, ligaments, and tendons are to be highlighted is set. For example, the position F1 is set to a part of the ligament as shown in FIG. Reference numeral 1 denotes an ultrasonic probe.

  The width of the shear wave propagation direction x of the ROI to be measured is determined from the effective propagation distance of the shear wave. Further, the width of the ROI in the direction y perpendicular to the shear wave propagation direction x is determined from the focal depth of the focused beam for generating displacement. In FIG. 6, y is perpendicular to the surface of the living body and is the depth direction in the body.

  Here, the effective propagation distance will be described. Since shear waves propagate with attenuation, exceeding a certain propagation distance exceeds the displacement detection limit value of the ultrasonic diagnostic apparatus. The distance that becomes the displacement detection limit is called the effective propagation distance. However, the displacement detection limit value is determined by parameters such as the dynamic range of the ultrasonic diagnostic apparatus and the frequency of the ultrasonic beam for displacement detection. The effective propagation distance of the shear wave is the acoustic intensity of the focused beam for generating the displacement, the F value of the focused beam for generating the displacement (= focal length / aperture diameter), the frequency of the focused beam for generating the displacement, It can be determined from parameters such as the width of the beam in the direction in which the focused beam propagates (= depth of focus), the irradiation time of the focused beam for generating the displacement, and the maximum displacement of the generated shear wave.

  The ROI position may be determined through an input device such as a keyboard, a trackball, or a mouse (not shown) by looking at the tomographic image displayed on the display unit 5 by the operator in step S02. Alternatively, the position of the ROI may be set by the central control unit 3 as a standard position corresponding to the measurement site such as the knee, ankle, waist, shoulder, etc. from a storage device (memory) not shown. When the operator looks at the tomographic image displayed on the display unit 5 in step S02 and sets the position and ROI, the position of the ligament, tendon, and muscle may not be determined from the tomographic image. In this case, the position assumed by the surgeon and the ROI are set.

  Next, in step S06, the displacement of the shear wave is measured. When the excitation position of the shear wave is F1 in FIG. 6, the measurement position is the same y coordinate as F1 and one or more coordinates P1, P2, P3 of the shear wave propagation direction x. In this case, the number of coordinates is 3, but is not limited to 3. Here, the x direction is a direction perpendicular to the propagation direction y of the focused beam for generating displacement. As shown in FIG. 2, in the case where the measurement region is a homogeneous medium, the shear wave propagates in a direction perpendicular to the focused beam for generating displacement, so that it is parallel to the direction along the ligament assumed to be the x axis. Ideally.

  In FIG. 6, the direction along the ligament and the x-axis are parallel. However, if the object to be measured is a rod or plate like muscle, ligament, or tendon, the shear wave propagates along the muscle, ligament, or tendon, so the direction along the ligament assumed to be the x axis When the focused beam for generating parallel displacement is irradiated to the ligament, the shear wave propagates along the ligament, so that the x-axis and the direction along the ligament are not necessarily required to be parallel.

  In each measurement coordinate P1, P2, P3 of FIG. 6, the displacement of the shear wave becomes large at the y coordinate where the ligament exists. That is, the displacement of the shear wave becomes large at the positions Q1, Q2, and Q3 in FIG. By connecting a plurality of positions Q1, Q2 and Q3 where the displacement of the shear wave becomes large with straight lines and displaying the linear shear wave displacement superimposed on the B-mode image, the ligament can be highlighted. The line may not be a straight line but may be displayed with smoothing.

  FIG. 6 is a diagram in the case of highlighting by irradiating a focused beam for generating displacement to the ligament, but the same applies to muscles and tendons in addition to the ligament. Subsequently, in S10, a color map of the measured shear wave displacement is superimposed on the tomographic image and displayed on the screen of the display unit 7 (FIG. 7). The tomographic image is the same as the tomographic image displayed in S02, or a tomographic image captured at the time after S04 before or after the shear wave displacement measurement. In addition, a color map based on the amount of displacement of the shear wave is displayed on the display unit 7. In addition to the color map, only the displacement amount larger than a certain threshold value may be displayed in a single color.

  The threshold value may be automatically read from a memory (not shown) based on irradiation conditions such as a measurement site and a frequency of a focused beam for generating displacement and a focal length. Alternatively, the operator may select a color with a color bar on the screen using an input device (not shown) while viewing the color map, or may input a displacement amount to determine the threshold value.

  When a signal to be ended is input via an input device (not shown) in step S12 of FIG. 5, the process of highlighting muscles, ligaments, and tendons is ended in step S14. If it is desired to measure again within the position or ROI set in S04, or if it is desired to set the ROI to another position and perform measurement, the process returns to step S04 or step S06, and the displacement of the shear wave is continuously measured. .

  In the processing flow for highlighting muscles, ligaments, and tendons described above, the width of the ROI in the direction y in FIG. 6 is not limited to the focal depth of the focused beam for generating displacement. Values that can be used instead of the depth of focus include the assumed muscle, ligament, and tendon thicknesses, values determined for each measurement site read from memory (not shown), and values input by the operator using an input device. Also good. The thickness may be measured by the surgeon by looking at the B-mode image, or may be calculated by well-known image processing using the brightness value of the B-mode image. At this time, the image processing is performed by an image processing unit (not shown) or the like. Alternatively, the thickness is a value determined for each measurement site read from a memory (not shown).

  The angle of the ROI can be freely set with respect to the body surface. The ROI may be other geometric structures such as a circle in addition to a rectangle. Further, the propagation direction of the displacement generating ultrasonic beam may be an oblique direction in addition to a direction perpendicular to the body surface. However, control is performed so that the direction of the shear wave displacement detection ultrasonic beam output from the second ultrasound transmission / reception unit 30 is not parallel to the direction in which the shear wave travels, and as much as possible. Since the shear wave propagation direction is a displacement direction, that is, a direction orthogonal to the direction of the displacement generating focused beam, if the propagation direction of the received beam and the shear wave propagation direction are parallel, detection sensitivity to the displacement is detected. Because you will lose. Therefore, the propagation direction of the displacement generating ultrasonic beam is preferably set to be perpendicular to the body surface.

  If the depth of focus of the focused beam for generating displacement is larger than the thickness of muscles, ligaments, tendons, etc., shear waves are also displaced in surrounding tissues such as muscles, ligaments, tendons. In this case, in order to detect only the shear wave velocity of the assumed muscle, ligament, tendon, etc., only the shear wave component of the muscle, ligament, tendon, etc. is extracted using a known moving filter or time window. You can do it.

  In the present embodiment, muscles, ligaments, and tendons are superimposed and highlighted on the B-mode image, but only muscles, ligaments, and tendons may be displayed.

  A method for highlighting another muscle, ligament, and tendon in this embodiment will be described with reference to FIG. Another method for highlighting muscles, ligaments, and tendons is a method for highlighting muscles, ligaments, and tendons by performing reconstruction processing from the three-dimensional shear wave displacement distribution. Specifically, the reconstruction is performed from the distribution of the displacement amount of the two-dimensional (space) +1 dimension (time) = three-dimensional shear wave, and muscles, ligaments, and tendons are highlighted. A simple method is a method of performing peak hold processing using displacement amount distributions of a plurality of shear waves having different two-dimensional (space) measurement times in the time direction.

As a complicated method, as shown in FIG. 8, for example, a single image is created by synthesizing the displacement distribution of shear waves in the ROI at times t (1), t (2), and t (3). In the synthesized image, the displacement amounts of the shear waves of ROI1, ROI2, and ROI3 that have large displacements at t (1), t (2), and t (3) are synthesized. Peak hold processing and image composition processing are performed by the composition unit 6.

  Since it is possible to control the repetition frequency at which the focused beam for displacement generation is irradiated, only the frequency components synchronized with the repeated frequency of the focused beam for displacement extraction are extracted from the received beam for shear wave detection. Lock-in detection may be performed. Specifically, first, the repetition frequency PRFp of irradiation of the displacement generation transmission beam set by the displacement generation transmission waveform generation unit 11 is transmitted to the second ultrasonic transmission / reception unit 30 via the central control unit 3.

  Next, lock-in detection is performed on the signal received by the second ultrasonic transmission / reception unit 30 at the repetition frequency PRFp, and the detected signal is output to the shear wave displacement calculation unit 32. Since the amount of displacement of a specific frequency component of the shear wave can be detected by performing lock-in detection, the shear wave can be detected with high accuracy even when the shear wave waveform has frequency dispersion. Further, by setting the frequency used for the lock-in detection to a frequency different from the frequency component due to the heartbeat or the surgeon's hand shake, it is possible to remove the noise signal due to the heartbeat or the handshake of the surgeon.

  Waves generated by irradiation of a focused beam for generating displacement include shear waves, surface waves, traveling waves, standing waves, and the like. After irradiating the focused beam for generating displacement, the displacement amount / velocity of the surface wave, traveling wave, etc., the spatial differential value of the displacement, etc. may be detected and highlighted. Here, the speeds of the shear wave, surface wave, and traveling wave are determined, for example, at positions along the propagation direction of the shear wave, surface wave, and traveling wave, and the time at which each wave arrives at each position. Estimated from the relationship. Further, after irradiating the focused beam for generating displacement, the displacement amount of the standing wave, the spatial differential value of the displacement, etc. may be detected and highlighted. This is performed by the spatial differential value shear wave displacement calculation unit 32 of velocity and displacement.

  By using a focused beam when vibrating muscles, ligaments, and tendons as in this embodiment, it is possible to generate vibrations at any location within the subject in a region corresponding to the focal shape of the focused beam.

  The difference between the present invention and ARFI Imaging will be described. ARFI Imaging detects an average velocity or spatial velocity distribution in the ROI for a single transmission beam for generating displacement. In ARFI Imaging, in order to measure the average shear wave velocity and Young's modulus in a wide area such as the mammary gland and liver, the F value of the focused beam for generating displacement is set as large as possible. When the F value is increased, the shear wave waveform approaches the plane wave waveform, and the shear wave propagates over a long distance.

  On the other hand, in the present invention, a focused beam for generating displacement is irradiated to local positions such as muscles, ligaments, and tendons, and measurement is performed using shear waves that propagate along the muscles, ligaments, and tendons. In other words, measurements are made using the vibrations of the muscles, ligaments, tendons, etc. themselves. Therefore, the F value should be equal to or less than the thickness of muscles, ligaments, and tendons (several tens to several μm). Even if the F value is small, by using the vibration mode of muscles, ligaments, and tendons themselves, the ultrasonic energy is confined in the muscles, ligaments, and tendons and propagates over a long distance.

  For example, when ARFI Imaging is applied to the liver, the frequency is 2 to 4 MHz and the F value is 1 to 2.5. In this case, the focal depth is 12 to 14 mm. In addition, when ARFI Imaging is applied to the mammary gland, the frequency is 5 to 7 MHz and the F value is 1 to 2.5. In this case, the depth of focus is 1 to 7 mm. On the other hand, in the present invention, the frequency is 15 to 30 MHz and the F value is 0.5 to 0.8. In this case, the depth of focus is 0.04 to 0.1 mm. Further, if a focused beam of high frequency, for example, 100 MHz, is used, inspection can be performed with a resolution of 10 μm. However, when the frequency becomes high, the penetration of the ultrasonic wave becomes small, and it becomes difficult to diagnose a deep place.

  Because muscles, ligaments, and tendons have bones nearby, and bones have a higher absorption coefficient of ultrasound than soft tissues and increase in temperature, ensure safety by reducing the F value. Can do. That is, it can be said that it is desirable from the viewpoint of safety that there is no bone within the depth of focus of the focused beam for generating displacement.

  The difference from the further ARFI Imaging is that, while ARFI Imaging normally measures the average velocity in space, it follows the muscles, ligaments, and tendons for a single transmission beam for generating displacement. This is a point for detecting a linear (linear) speed.

  The difference between the present invention and the Doppler method will be described. The Doppler method is a method of measuring and visualizing blood flow. In the Doppler method, the repetition frequency of ultrasonic beam irradiation is controlled within the range of the assumed blood flow velocity. On the other hand, in the present invention, the speed of shear waves generated in muscles, ligaments, and tendons can be controlled by controlling the repetition frequency PRFp of the focused beam for generating displacement. It differs from the Doppler method in that the velocity of the muscle, ligament, and tendon is measured using both the repetition frequency PRFp of the focused beam for generating the displacement and the repetition frequency PRFd of the displacement detection beam.

  Normally, in the continuous wave Doppler method, the F value for Doppler detection is set as large as possible in the ROI. The present invention is different in that the F value is set small as described above. Further, in the pulse Doppler method, there is one point to be detected with respect to one transmitted blood beam for blood flow measurement. On the other hand, in this embodiment, a linear (linear) velocity along the muscle, ligament, and tendon is detected for a single focused beam for generating displacement.

  Example 2 will be described. In Example 1, only one ROI was set in S04 of FIG. However, as described above, the effective propagation distance of the ROI width shear wave is limited. As shown in FIGS. 9A and 9B, when it is desired to highlight a tendon or the like in a range wider than the effective propagation distance of the shear wave, it is necessary to provide a plurality of ROIs. At this time, the tendon or the like is not always parallel to the body surface, and may have an angle with respect to the body surface.

  In that case, from the xy coordinate of the focal position F1 of the focused beam for generating displacement first irradiated in the ROI 1 and the xy coordinate of the position where the displacement amount of the shear wave measured after that becomes large, By estimating the focal position F2 irradiated with the ROI2, it becomes possible to continuously highlight tendons and the like. Specifically, the next focal point F2 is estimated from the slope K of the straight line connecting F1 in FIG. 9A and the position Q1 where the displacement of the shear wave increases. That is, F2 is estimated so that the slopes of F1 and F2 are K. Specifically, the position in the x direction of the focal position F2 is set to a position in the + x direction from ROI1, and the y coordinate of F2 is determined from the coordinates of F1, the inclination K, and the x coordinate of the focal position F2.

  At this time, the center position of ROI2 in the y direction is translated by the same distance as the distance between the focus F1 and the focus F2 in the y direction. FIG. 9A shows an example of measuring up to ROI4. The calculation of estimating the position where the next focused beam for generating displacement is irradiated from the focal position and the position where the displacement of the shear wave becomes large is performed by setting the displacement of the shear wave and the value of the observation position as the focal position from the shear wave displacement calculation unit 32. This is output to the unit 12 and performed by the focal position setting unit 12. In the processing flow of FIG. 5, after S06 or S10, the process returns to S04 and the process is repeated. Although the method for setting the next focal position based on one measurement position in each ROI has been described, the next focal position may be determined using a plurality of positions where the displacement of the shear wave becomes large.

  By setting the width of each ROI in the x direction to be small, it is possible to estimate the irradiation position of the next focused beam for generating displacement more accurately. In addition, if the width of the ROI in the x direction is set to be large, the positioning accuracy for estimating the irradiation position of the next focused beam for generating displacement is lowered, but the total number of times of irradiation of the focused beam for generating displacement is reduced. Measurement can be safely performed on the subject.

  Another method is shown in FIG. 9B. It is assumed that displacement generation is performed at the left end in ROI1. At this time, in the x coordinate P1 measured at the right end of ROI1, the focus F2 is set so that the y coordinate of the position Q1 where the displacement of the shear wave is the largest becomes the y coordinate of the next focus F2. However, the x coordinate of the focal point F2 is located at the left end in the ROI2. In this case, it is not necessary to calculate the slope of the straight line connecting F1 and the measurement position P1 as in the method of FIG. 9A, and the next focal position is determined in a shorter time than the method of FIG. can do. You may set so that the right end of ROI1 and the left end of ROI2 may overlap so that a muscle, a ligament, and a tendon may be highlighted continuously.

  Further, Q1 and F2 may be at the same position. On the other hand, in the method of FIG. 9A, the next focal position can be estimated before the shear wave reaches the end of each ROI. Therefore, it is possible to irradiate the next focused beam for generating displacement immediately after the shear wave reaches the end of the ROI, which is superior to FIG. 9B in real time. Further, in FIG. 9B, it is easier to set the focus on the positions of muscles, ligaments, and tendons.

  In Example 1 and Example 2, by highlighting muscles, ligaments, and tendons, for example, observation as shown in FIG. 10 can be performed. As shown in (1) of FIG. 10, when a tendon is displayed in a B-mode image with two branches in the B-mode image, both are connected or only one is connected. It is unknown. When the displacement of the shear wave is measured by irradiating the tendon with a focused beam for generating displacement, the shear wave propagates to the connected tendon and the displacement is observed, and only the connected tendon is highlighted.

  In (2) of FIG. 10, in the B-mode image, when it is displayed that a part of the tendon is torn, it is impossible to distinguish whether it is really torn or deviated from the cross section of the tomographic image. When judging the presence or absence of tearing only from the B-mode image, the operator moves the ultrasonic probe 1 in the short axis direction of the ultrasonic probe to move the tomographic image in the short axis direction, and spatially The tendon structure must be examined. This method requires high skill of the surgeon and takes time. On the other hand, in the method of generating a shear wave and observing the displacement, it is possible to determine whether it is connected by the displacement of the shear wave. For example, when a left-side tendon in FIG. 10B is irradiated with a focused beam for generating displacement, a shear wave propagates along the tendon and reaches the end A. The shear wave reaching the end A is not displayed in the B-mode image, but if there is a spatially connected tendon, it further propagates the tendon and shears to the end B of the tendon on the right side of the B-mode image. A wave appears.

  If the tendon is torn, no shear wave displacement is observed at the end B. However, the F value, frequency, etc. of the focused beam for generating the displacement must be controlled so that the effective propagation distance of the shear wave is longer than the length of the tendon deviating from the assumed B-mode image. Further, as shown in FIG. 10 (3), it is conceivable that shear waves are generated only in a desired layer among a plurality of tendon layers. The thickness of the tendon may be measured by the operator by looking at the B-mode image, or the thickness may be calculated by well-known image processing using the brightness value of the B-mode image. Image processing is performed by an image processing unit (not shown). In this case, a waveform for irradiating the displacement generating focused beam is set by the displacement generating transmission waveform generating unit 11 so that the focal depth of the focused beam for generating the displacement is smaller than the thickness of each layer. Displacement of shear waves may be observed in multiple muscle, ligament, and tendon layers, and the displacement of each layer may be combined and displayed. As a result, the surgeon can grasp partial damage on the surface or inside of the muscle, ligament, or tendon. Although tendons have been described in FIG. 10, the same applies to ligaments and muscles.

  In this way, the entire B-mode image is irradiated with a focused beam for generating displacement, and muscles, ligaments, and tendons are highlighted with the minimum number of times of focused beam for generating displacement without propagating shear waves. It is possible. By reducing the number of irradiations, diagnosis can be performed in a short observation time, and fatigue of the operator and subject can be minimized. In addition, the temperature rise of the living tissue associated with the irradiation of the focused beam for generating the displacement is minimized, and a safe diagnosis is possible.

  In Example 3, functional measurement of muscles, ligaments, and tendons will be described with reference to FIGS. In this example, the functions of the muscles, ligaments, and tendons highlighted in Examples 1 and 2 are further measured, and the diseases related to the orthopedic region (tendon tears, sprains, etc.) are prevented, diagnosed, and postoperatively progressed. Observation becomes possible. FIG. 11 shows the overall configuration of the apparatus according to the third embodiment. A different configuration from the first and second embodiments is that a function measuring unit 34 is added. In Example 3, after highlighting muscles, ligaments, and tendons in Examples 1 and 2, the function measuring unit 34 calculates the shear wave velocity histogram, calculates the shear viscosity, and the position of the tear outside the ROI. Identification, vibration mode measurement, tension measurement, Lamb wave measurement, and the result is displayed on the display unit 7.

  A specific inspection method will be described below. For example, assume that the shear wave velocity along the tendon has already been detected. The tendon can be divided into several widths, and the shear wave spectrum along the tendon can be calculated and displayed using the average shear wave velocity at the divided position. FIG. 12 shows the statistics (histogram) of the shear wave velocity. Here, it is called a velocity spectrum. Number of peaks of velocity spectrum (= 2), amplitude values (A1, A2) of each spectrum, average velocity (M1, M2) of each spectrum, spectrum width (D1, D2) which is a half value of each spectrum, etc. Values and spectral distribution graphs can be displayed on the same screen, and the state of the stressed muscles, ligaments, and tendons can be observed.

  The shear viscosity can be estimated from the relationship between the frequency and the velocity by estimating the velocity from the displacement waveform of the shear wave and the observation position for each specific frequency component, for example, as is well known in the art. Shear viscosity is correlated with the frequency spectrum of shear wave velocity.

  With reference to FIGS. 13 to 19, description will be given of the method of measuring the position of the fracture outside the ROI, measuring the fracture depth in the ROI, measuring the vibration mode (standing wave), tension, and Lamb wave.

  FIG. 13 shows a method for examining whether a muscle, a ligament, or a tendon outside the ROI is torn from the reflected wave of the shear wave, and for identifying the position of the tearing point. As shown in FIG. 13A, it is assumed that there is a shear wave observation position in the ROI and the fracture is outside the ROI. The displacement waveform of the shear wave at the observation position is shown in FIG. First, at time t1, a shear wave arrives. This is the first wave of FIG.

  Next, the second wave arrives at time t2 later than t1. The second wave is a reflected wave from the breaking position. The distance between the observation position and the fracture position can be calculated from the shear wave velocity in the ROI and Δt = t2-t1, and the fracture position can be specified from this distance. It is also possible to display the tear position on the screen by superimposing it on the B-mode image or the emphasized muscle, ligament, or tendon.

  Also, as a tear inspection method when the tear is in the ROI, a spatial differential value or a temporal differential value (= shear wave velocity) of the shear wave displacement along the muscle, ligament, tendon, etc. may be detected. . In this method, for example, the fracture position is detected from the discontinuity of the spatial differential value of the shear wave with respect to the direction along the tendon as shown in FIG. In addition, the fracture position is detected from the shear wave velocity with respect to the direction along the tendon and the discontinuity of the shear wave velocity.

  According to the above method, the position can be specified without directly irradiating a focused beam for generating displacement to a tear or a flaw, so that safe measurement can be performed without imposing a burden on the subject.

  Furthermore, as shown in FIG. 15, when there is a tear or a flaw in the ROI, it is possible to investigate the state of the tear or the like from the waveform shape of the shear wave. In the displacement waveform of the shear wave in FIG. 15, when the waveforms of the normal part and the fractured part are compared, the width of the shear wave is wide at the fractured part, and a ripple appears. In this way, the shape and depth of the tear / scratch can be identified from the number of ripples in the time waveform of the shear wave and the width of the wave. Similarly, as shown in FIG. 16, the shape and depth of a tear or a flaw can be estimated from the width of the frequency spectrum of shear wave displacement. This method can be used to further examine the shape and depth of the fracture when it is determined that the fracture is found in the inspection example (2) in FIG.

  Further, as shown in FIG. 17, the state of the muscle, ligament, and tendon can be measured from the mode (standing wave) when the muscle, ligament, and tendon are vibrated. This method is similar to checking with a finger to check for loose guitar strings. The standing wave is excited according to the ON / OFF frequency of the focused beam that excites the shear wave, and the thickness, length, hardness, etc. of the muscle, ligament, and tendon, and the displacement wave of the shear wave is generated. If the thickness and length are known in advance, it is possible to examine the information on hardness and tension from the standing wave. The thickness and length may be read by the operator from the B-mode image, or may be extracted from the B-mode image by an image processing unit (not shown).

  FIG. 17A shows a case where the number of focal points is one, and FIG. 17B shows a case where the number of focal points is two. If there is a single focus, there will be one belly. At this time, since the frequency spectrum of the displacement waveform of the shear wave becomes wide, a plurality of modes (mode A, mode B, mode C, mode D) are excited. Therefore, mode control is difficult and the accuracy of hardness estimation is low. On the other hand, when the number of focal points is two, only a specific mode can be excited by controlling the positions of the two focal points. Since the mode can be controlled, it is possible to measure the hardness with high accuracy by using two focal points. By functional measurement using standing waves, for example, muscles, ligaments, and tendon slack due to aging can be regularly examined.

  FIG. 18 shows an example of muscle / ligament / tendon tension measurement. When the thickness and length of muscles, ligaments, and tendons are known, it is possible to examine differences in local muscles, ligaments, and tendons from the shear wave velocity.

  FIG. 19 shows a function measurement method using a Lamb wave symmetric mode. The wavelength of the horizontal component of the tissue around the tendon (connective tissue, fat, muscle, etc.) and the wavelength of the Lamb wave of the target tissue (muscle, ligament, tendon, etc.) can be expressed by [Equation 1].

λ _L is the wavelength of the horizontal component of the surrounding tissue, and λ w is the wavelength of a Lamb wave such as a tendon. θ is the angle of incidence on a tendon as shown in FIG. When the incident angle theta has become theta _L, and Lamb waves generated can be observed displacement of Lamb wave in the observation points of the tendon such as (Figure 19 (b)). Therefore, by examining the theta _L, it is possible to estimate the wavelength of the Lamb wave. The tendon state such as the surface wave velocity can be quantitatively examined from the wavelength of the Lamb wave. In addition to Lamb waves, surface waves, Love waves, bending vibration modes of bars, torsional vibration modes of bars, and the like may be used.

  The speed, viscosity, mode (standing wave), tension, and Lamb wave wavelength described above can be useful for prevention and postoperative treatment effect determination by periodically inspecting. The function measurement unit 34 performs the above function measurement, and the output of the calculation result of the function measurement is input to the display unit 7 via the synthesis unit 5 and displayed on the screen. Here, the calculation results are: shear wave velocity, viscosity, fracture position, fracture depth, standing wave mode, Lamb wave wavelength, surface wave velocity, Love wave wavelength, rod bending vibration mode, rod Torsional vibration mode and the like.

  As an application of the above function measurement, shear wave velocity, viscosity, tear depth, standing wave mode when cuff is wrapped around the subject's arm or leg and the force with which the cuff presses the subject is changed. , Lamb wave wavelength, surface wave velocity, Love wave wavelength, rod bending vibration mode, rod torsional vibration mode, and other changes are measured. May be observed. In addition to using cuffs, applications such as bending or stretching the arm or leg, applying or withdrawing force, or having a weight with a different weight are considered.

  The ultrasonic diagnostic apparatus described in all the above embodiments can be used, for example, for diagnosis / prevention of post-surgical follow-up of sports disorders such as fractures and sprains, and joint dysfunction associated with aging. It is also possible to use the fact that the living body has a symmetrical shape.

  Specifically, it is possible to compare normal images and measured values of tears and tensions by comparing functional images such as fractures and tension, and images of sites with disease and normal sites at symmetrical positions. it can. Since sports disorders and joint dysfunction require diagnosis over a long period of time, images of normal parts and function measurement values are stored in a memory (not shown) and read from the memory at the time of diagnosis. Both images and function measurement values may be displayed so that the surgeon can compare and diagnose.

  In addition, as each element of the ultrasonic probe 1 in all the above-described embodiments, a piezoelectric element such as ceramic, a polymer piezoelectric element, or a capacitive element can be used.

  Moreover, in order to excite a shear wave, although the example which uses an ultrasonic focused beam was shown in said Example, an electric pulse, a mechanical motor, a spring, etc. can be used. When a focused beam is used, the spatial resolution in the propagation direction of the focused beam is increased. The mechanical motor may be a direct-acting mechanical vibrator as shown in FIG. A shear wave propagates in a direction perpendicular to the direction of motion of the mechanical vibrator. Further, an eccentric motor having a rotation motor and an eccentric portion as shown in FIG. 21 can be considered. FIG. 21 shows a case where there is one eccentric part.

  By using a plurality of eccentric parts and changing the interval between the eccentric parts, it is possible to vibrate at a higher frequency than the rotational frequency of the rotary motor, and measurement with high spatial resolution becomes possible. In addition, as shown in FIG. 22, a multi-degree-of-freedom rotary motor combining a plurality of metal balls that can move in multiple degrees of freedom or a gear made of a rubber material that can rotate in one direction is used. A mechanism for generating shear waves by using it can be considered. FIG. 22 shows three examples of the number of metal balls and gears, but the number is not limited to this.

  Moreover, you may increase a metal ball and a gear further in parallel with the concentric form of a rotary motor. Combining rotations in two or more directions than a direct acting motor can excite shear waves more efficiently and generate large shear wave displacements. If the displacement increases, the image quality can be improved and the measurement accuracy of the function measurement can be improved. When using a mechanical motor or a spring, the spatial resolution is generally inferior to that of a focused beam, but since it can be vibrated at a single frequency of the focused beam, measurement of shear wave velocity for each frequency, viscosity, Measurement accuracy such as mode estimation is improved.

  In the case where an ultrasonic focused beam is used, in this embodiment, one ultrasonic probe 1 is used for both generation and detection of a shear wave. However, a mechanism for generating a shear wave and a mechanism for detecting the shear wave are used. The mechanism may be separate. For example, a shear wave may be generated using a piezoelectric transducer, and the ultrasonic probe 1 may be used only for detecting the displacement of the shear wave. In this case, the positioning accuracy of the ultrasonic probe 1 and the piezoelectric transducer can be improved as compared with the case where shear wave generation and displacement detection are performed only by the ultrasonic probe 1.

  Since the shear wave generation position and the observation position can be set to desired positions, the time until highlighting and the time required for function measurement can be shortened. However, another control device for moving the position to an arbitrary place is required, which increases the cost of the entire device and increases the size of the device itself. When a mechanical vibrator, an electric pulse, or a spring is used, the displacement generation transmission waveform generation unit 11, the focus position setting unit 12, and the displacement generation transmission beam generation unit 13 shown in FIGS. 1 and 11 are not necessary. . Instead of these components, a mechanical drive unit, an electric pulse drive unit, and a spring drive unit (not shown) are required. The ultrasonic probe 1 is used only for ultrasonic transmission / reception for detecting a shear wave and ultrasonic transmission / reception for generating a B-mode image. The transmission / reception changeover switch 2 controls ON / OFF of the mechanical drive unit, the electric pulse drive unit, and the spring drive unit in addition to the ultrasonic probe 1.

  A jig for placing the ultrasound probe 1 on the body surface is provided in accordance with the standard shape of the measurement position of muscles, ligaments, tendons, etc., and the position to be highlighted or the position to be measured is out of the tomographic image It is possible to prevent this. By attaching the jig, the diagnosis time can be shortened, and comparison between the left and right sides of the body is easy. Moreover, you may design so that the shape of the ultrasonic probe 1 may match with the site | part which wants to measure. In this case, since it is not necessary to attach a jig or the like, the diagnosis time can be further reduced. If the jig is provided, the device can be manufactured at a lower cost.

  In functional measurement, the ultrasonic probe 1 is installed or rotated 360 degrees in a direction perpendicular to the direction along the muscles, ligaments, tendons, etc., so that the muscles, ligaments, tendons Etc. can be examined.

  When the minimum depth of focus that can be set by the ultrasound probe 1 is larger than the distance from the body surface of a tendon or the like to be diagnosed, the acoustic impedance between the ultrasound probe 1 and the measured body surface There is a method of providing an acoustic matching layer close to the acoustic impedance of a living body so that the focal position can be set on a tendon or the like. When the acoustic matching layer is used to measure parts close to the body surface, such as the ligaments and tendons of the hand, it is possible to improve image quality and functional measurement accuracy.

  The acoustic matching layer may be formed by covering a gel, which is an acoustic matching medium, with a housing made of a resin of about 10 to 100 μm, which is sufficiently smaller than the wavelength of ultrasonic waves. It is desirable that the shape of the body surface contact surface of the acoustic matching layer be a shape along the shape of the body. In other words, it is desirable that the portion in contact with the ultrasound probe 1 has a flat shape, and the shape of the surface in contact with the body surface is not flat, but is curved to match the shape of the elbow, knee, ankle, etc. .

  Furthermore, it is desirable that the housing is made of a polymer material or a rubber material so that it can be freely bent for each diagnosis so as to match the shape of the body of the subject. By using an acoustic matching layer that matches the body of the subject, it is possible to prevent the position of the B-mode image from shifting in the screen during shear wave measurement due to camera shake or the like of the ultrasonic probe 1. .

  FIG. 23A shows the attachment position of the ultrasonic probe 1. Since bone has a larger absorption coefficient of ultrasonic waves than other living tissues, the amount of temperature rise also increases. As the temperature increases, the safety of living tissue decreases. Therefore, it is desirable to bring the ultrasonic probe 1 into contact with the body surface so that no bone exists in the propagation path of the focused beam for shear wave excitation. For example, an attachment method as shown in FIG.

  When mode measurement is performed using two focused beams as shown in FIG. 17B, two ultrasonic probes 1 are prepared, and the probes face each other in parallel in FIG. By mounting in such a manner, the position of the two focal points can be easily controlled. It is also conceivable to make a diagnosis by covering the hands and feet 360 degrees using the ring array ultrasonic probe 8 in which the ultrasonic transducers 110 are arranged in a ring array shape as shown in FIG. When the ring array ultrasonic probe 8 is used, the direction of the focused beam and the positions F1 and F2 for generating the shear wave can be controlled with high accuracy.

  In Examples 1 to 3, when high-speed imaging such as transmission aperture synthesis technology is applied, the shear wave displacement detection resolution is improved, so that the spatial resolution of muscles, ligaments, and tendons highlighted on the screen is improved and the accuracy of function measurement is improved. Is possible. In addition, when high-speed imaging is applied, it is possible to diagnose muscles, ligaments, and tendons with higher elastic modulus.

  Further, in the first to third embodiments, when the linear array ultrasonic probe 1 is used, the surgeon can set the ultrasonic probe 1 so that muscles, ligaments, tendons and the like are arranged in the plane of the tomographic image. It is necessary to perform face-to-face alignment by moving. By using a two-dimensional array probe instead of the linear array ultrasonic probe 1 to perform three-dimensional muscles, ligaments, tendons, etc., it is possible to save the labor of face-to-face alignment, It is possible to grasp the shape of a tendon or the like in more detail. Therefore, when a two-dimensional array probe is used, as will be described with reference to FIG. 10 (2), it is not necessary to confirm whether a tendon or the like is off the tomographic plane.

  Examples 1 to 3 can be used for other diagnoses in the orthopedic field, for example, diagnosis and prevention of blood species and the like. Also, it can be applied to other organs such as diagnosis of liver fibrosis. Also, it can be applied to non-destructive inspection of industrial materials such as semiconductor chips.

  INDUSTRIAL APPLICABILITY The present invention is useful as an ultrasonic diagnostic apparatus that detects muscles, ligaments, and tendons by ultrasonic transmission / reception and emphasizes the position and shape.

DESCRIPTION OF SYMBOLS 1 ... Ultrasonic probe, 2 ... Transmission / reception changeover switch, 3 ... Central control part, 4 ... Color DSC, 5 ... Monochrome DSC, 6 ... Composition part, 7 ... Display part, 8 ... Ring array ultrasonic probe, DESCRIPTION OF SYMBOLS 210 ... Displacement generation part, 11 ... Displacement generation transmission waveform generation part, 12 ... Focus position setting part, 13 ... Displacement generation transmission beam generation part, 20 ... First ultrasonic transmission / reception part, 30 ... Second ultrasonic wave Transmission / reception unit, 32 ... shear wave displacement calculation unit, 34 ... function measurement unit, 50 ... color scale setting unit, 100 ... each element of the ultrasonic probe 1, 110 ... each element of the ring array ultrasonic probe 8.

Claims (15)

An ultrasonic probe for transmitting and receiving echo signals from within the object;
A changeover switch for switching transmission / reception of each element of the ultrasonic probe;
A first ultrasonic transmission / reception unit for detecting a difference in acoustic impedance by performing first ultrasonic transmission / reception in the object;
A displacement generating section for radiating a focused beam for generating displacement into the object to displace the tissue;
A displacement detector for performing second ultrasonic transmission / reception, receiving an echo signal from the object, and detecting shear wave displacement generated by the displacement generating focused beam at a plurality of positions;
A central control unit for controlling the displacement generation unit and the displacement detection unit;
An ultrasonic tomogram showing the difference in acoustic impedance; and a display unit for displaying the shear wave displacement map showing the shear wave displacement in a superimposed manner, and the tissue is highlighted in a line on the ultrasonic tomogram. An ultrasonic diagnostic apparatus. The ultrasonic diagnostic apparatus according to claim 1, wherein the portion where the shear wave propagates is any one of a muscle, a ligament, and a tendon. The ultrasonic diagnostic apparatus according to claim 1, wherein the ultrasonic diagnostic apparatus has an input function capable of inputting the focal position at which the focused beam for generating displacement is viewed while viewing the tomographic image. The ultrasonic diagnostic apparatus according to claim 1, wherein the superimposed image displayed on the display unit indicates a joint state of the muscle, ligament, and tendon. 5. The ultrasonic diagnostic apparatus according to claim 1, further comprising a function measuring unit that performs function measurement of an object using the shear wave displacement. 6. The ultrasonic diagnostic apparatus according to claim 5, wherein tension is measured by the function measuring unit. The ultrasonic diagnostic apparatus according to claim 5, wherein the function measurement unit measures a reflected wave of the shear wave. The ultrasonic diagnostic apparatus according to claim 5, wherein the function measuring unit measures the number of ripples in the time waveform of the shear wave, the width of the waveform, or the standing wave mode. A focal position setting unit for setting a focal position for radiating the displacement generating focused beam, and using the first set focal position and the position where the displacement of the shear wave is maximized, The ultrasonic diagnostic apparatus according to claim 1, wherein the second focal position for radiating the focused beam for use is set. The ultrasonic diagnostic apparatus according to claim 9, wherein the superimposed image displayed on the display unit indicates a joint state of the muscle, ligament, and tendon. 11. The ultrasonic diagnostic apparatus according to claim 9, further comprising a function measuring unit that performs function measurement of an object using the shear wave displacement. The ultrasonic diagnostic apparatus according to claim 11, wherein a tension is measured by the function measuring unit. The ultrasonic diagnostic apparatus according to claim 11, wherein the function measurement unit measures a reflected wave of the shear wave. The ultrasonic diagnostic apparatus according to claim 11, wherein the function measurement unit measures the number of ripples in the time waveform of the shear wave, the width of the waveform, or the standing wave mode. The ultrasonic diagnostic apparatus according to claim 1, wherein the shear wave displacement or the function measurement utilizes left-right symmetry of an object.

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