JP5691720B2 - Ultrasonic diagnostic equipment - Google Patents

Description

  The present invention relates to an ultrasonic diagnostic apparatus that transmits ultrasonic waves into a subject, receives ultrasonic waves reflected due to tissue differences, converts the received signals into images, and displays the images.

  An ultrasonic diagnostic apparatus is an apparatus that transmits an ultrasonic signal into a subject and diagnoses a lesion from a reflected wave. Unlike CT and X-rays, radiation is not used, so there is no risk of exposure and diagnosis can be performed, and it is used for early detection of cardiovascular diseases and cancer.

  FIG. 3 shows the configuration of a conventional ultrasonic diagnostic apparatus. The ultrasonic diagnostic apparatus includes a vibration element 100, a transmission beam control unit 110, a transmission beam forming unit 111, a reception beam forming unit 120, a display control unit 121, and a display unit 122.

  The transmission beam control unit 110 transmits a control signal for controlling the time direction for determining the shape of a transmission wave such as a pulse wave or a continuous wave, and for controlling the spatial direction for focusing the transmission wave at an arbitrary position. Output to the forming unit 111. Next, the transmission beam forming unit 111 calculates a drive timing amount for performing control in the time direction and a transmission delay amount for performing control in the spatial direction with respect to the input control signal, and calculates the drive timing amount and the transmission delay amount. And the drive signal is output to the vibration element 100. Next, a voltage is applied to the vibration element 100 by a drive signal input in the vibration element 100, thereby converting the voltage into vibration and transmitting an ultrasonic wave into the subject. Next, the ultrasonic wave transmitted into the subject in the vibration element 100 is reflected by the difference in acoustic impedance between tissues, converted into a sound ray signal by the vibration element 100, and input to the reception beam forming unit 120. Next, a reception delay meter is calculated for the sound ray signal input in the reception beam forming unit 120, addition processing is performed based on the reception delay amount, and an addition signal is output to the display control unit 121. Next, the addition signal input in the display control unit 121 is converted into a luminance signal and output to the display unit 122. The display unit 122 provides an ultrasonic signal generated by reflection in the subject to the operator as a luminance signal.

  In order to provide a high-quality ultrasonic image, it is necessary to set an appropriate delay amount for each vibration element. However, in a conventional ultrasonic diagnostic apparatus, the propagation speed of ultrasonic waves within a subject is about 1540 m / s. The amount of delay was set assuming a uniform structure. However, the living body is composed of various tissues such as fat, muscle, and soft tissue, and the sound speed of each tissue is 1400-1600 m / s due to the difference in density and elastic modulus. This is a cause of errors in the physical position shape between the ultrasonic image and the living body. In view of this, a technique has been devised in which the transmission / reception focus shift and physical position / shape error are reduced using a map (hereinafter referred to as a sound speed map) for determining the tissue boundary of the region of interest and displaying the sound speed distribution.

  For example, in Patent Document 1, a sound speed map is created, and a positional shift that occurs in an ultrasonic image is corrected in the B-mode image signal using the sound speed map. Here, there is a method of using changes in sound speed at a plurality of positions in the subject while shifting the position of the focal point while utilizing the fact that the sound speed is substantially the same in the region where the density is the same. In this way, ultrasonic waves are transmitted / received to / from the focal points at a plurality of positions, the sound speed at each focal position is calculated, and the sound speed calculated at a certain depth is compared with the sound speed calculated at another depth. . When these sound speeds change by a predetermined ratio or more, it is determined that there are different tissue boundaries between the two depths. In Patent Document 2, the thickness of the fat layer is calculated. In order to detect the boundary between the fat region and the living body region (here, the liver), the maximum value of the luminance of the ultrasonic diagnostic image is set as a threshold, and a signal received earlier than the time when the maximum value is received is assumed to be a fat region. The fat thickness is calculated.

JP 2009-56140 A JP-A-9-187456

  However, in Patent Document 1, an ultrasonic wave is transmitted to an arbitrary focal position in a subject by calculating a transmission delay amount using a preset sound velocity and creating a transmission focus. For this reason, the delay amount is calculated using a sound velocity different from that of the actual tissue, and the tissue boundary including the sound velocity error is determined.

  Moreover, in patent document 2, the thickness of a fat layer is calculated using the luminance signal after performing addition processing with respect to the signal obtained by each vibration element as a received signal. Similar to Patent Document 1, the transmission / reception delay amount is calculated using a preset sound speed, and the luminance signal is calculated using a sound speed different from the actual sound speed. For this reason, the detection of the boundary between fat and the living body includes an error in the difference in sound speed. Further, since it is necessary to perform addition processing for each drawing point, there is a problem that the calculation amount increases and the processing time becomes long.

  Further, the conventional configuration has a problem that the tissue boundary including the sonic deviation is determined because the signal after the delay addition process is used.

  The present invention solves the above-described conventional problems, and uses the sound ray signal before performing the delay addition process so as not to be affected by the deviation of the sound speed. However, there is a problem of S / N degradation of the sound ray signal due to a decrease in signal intensity due to not performing the delay addition process. Therefore, a tissue boundary detector is created using parameters relating to the thickness of the subject tissue and sound ray signals reflected and received within the subject. To provide an ultrasonic diagnostic apparatus using the tissue boundary detector to detect at least a boundary between a first tissue located under the skin of a subject and a second tissue located deeper. With the goal.

  According to the ultrasonic diagnostic apparatus of the present invention, there is no sound speed error generated in the delay amount calculation by using the signal before the delay addition, and the generation of the sound speed region realizing the determination of the tissue boundary with high accuracy and suppressing the calculation amount is achieved. Is possible. As a result, it is possible to provide an ultrasonic diagnostic apparatus capable of realizing high-quality tissue boundary determination with high noise robustness such as artifacts and less physical position error.

1 is a block diagram of an ultrasonic diagnostic apparatus according to Embodiment 1 of the present invention. Block diagram of ultrasonic diagnostic apparatus according to Embodiment 2 of the present invention Block diagram of conventional ultrasonic diagnostic equipment The figure which shows the operation | movement of the structure | tissue boundary detection part in Embodiment 1. Figure showing an example of attenuation (boundary between fat and muscle) Diagram showing an example of tissue boundary detection processing The figure which shows the example of the sound speed correction using the sound speed area

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

(Embodiment 1)
1. Description of Configuration FIG. 1 is a block diagram of an ultrasonic diagnostic apparatus including a tissue boundary detection unit according to Embodiment 1 of the present invention. The ultrasonic diagnostic apparatus includes a vibration element 100, a transmission beam control unit 110, a transmission beam forming unit 111, a reception beam forming unit 120, a display control unit 121, a display unit 122, a tissue information storage unit 130, and a tissue. A boundary detection unit 131 is provided. A dotted line surrounding the tissue information storage unit 130 and the tissue boundary detection unit 131 is used as a characteristic unit representing a difference from the conventional ultrasonic diagnostic apparatus, and the other configuration may not be the configuration illustrated in FIG.

2. Description of Operation (Function) Next, the operation of tissue boundary detection in the ultrasonic diagnostic apparatus will be described with reference to FIG.

  First, the transmission beam control unit 110 outputs a control signal in which the transmission wave shape is a pulse wave and the focus position is set to infinity, to the transmission beam forming unit 111 and the tissue boundary detection unit 131. Next, the transmission beam forming unit 111 calculates a drive timing amount for performing control in the time direction and a transmission delay amount for performing control in the spatial direction with respect to the input control signal, and calculates the drive timing amount and the transmission delay amount. And the drive signal is output to the vibration element 100. Here, the transmission delay amount is set to 0 because the focus position is set to infinity. Next, the vibration element 100 transmits a planar ultrasonic wave into the subject by applying a voltage to the vibration element 100 according to the input drive signal and converting the voltage into vibration. Next, a driving signal is input to the vibration element 100 and planar ultrasonic waves are transmitted into the subject. Next, the planar ultrasonic wave reflected by the difference in acoustic impedance in the subject is received by the vibration element 100 and outputs a sound ray signal to the tissue boundary detection unit 131. Similar to the sound ray signal, the tissue information storage unit 130 outputs the tissue information data in the region of interest to the tissue boundary detection unit 131. Next, at least a boundary between the first tissue located under the skin of the subject and the second tissue located deeper in the tissue boundary detection unit 131 is input with the control signal, the sound ray signal, and the tissue information data. Detect and output the tissue boundary distribution to the display unit 122. Next, the tissue boundary distribution is presented to the operator on the display unit 122.

[Description of Organization Information Storage Unit 130]
The operation of the organization information storage unit 130 will be described. The tissue information data has at least fat and muscle tissue information, and in addition, tissue information corresponding to the diagnosis site may be added. In the tissue information storage unit 130, the number of constituent tissues, the positional relationship of the tissues, the thickness of the tissues, the sound velocity of the tissues, the density of the tissues, and the ultrasonic attenuation amount of the tissues are stored in advance as the tissue information data. The operator can read the information from the memory by designating the organization information data based on the diagnosis area. For example, assuming that the diagnosis region is the abdomen, the tissue information data is composed of fat, muscle, and soft tissue. Further, there may be a manual mode in which the operator can set the tissue information data in consideration of the nature of the subject.

  Note that a personal tissue information calculation unit that calculates fat and muscle thickness in the diagnostic region may be created by setting the gender, weight, and body fat percentage of the subject, and may be input to the tissue information storage unit 130. In this case, the fat and muscle thickness calculated by the personal tissue information calculation unit may be output to the tissue boundary detection unit 131 instead of the fat and muscle thickness stored in the tissue information storage unit 130.

  Note that a temperature measurement unit that measures the temperature distribution of the subject surface may be created in the vibration element 100, and the sound velocity of the tissue stored in the tissue information storage unit 130 may be changed from the temperature distribution. When the temperature measured by the temperature measurement unit is higher than the standard temperature, the sound velocity is set faster than the standard sound velocity, and when the temperature measured by the temperature measurement unit is lower than the standard temperature, the sound velocity is set earlier than the standard sound velocity.

[Description of Tissue Boundary Detection Unit 131]
The operation of the tissue boundary detection unit 131 will be described with reference to FIG. FIG. 4 is a flowchart showing the tissue boundary detection process in the tissue boundary detection unit 131.

In step S101, the reception time range is set by receiving the organization information data. First, the reception time tr where the tissue boundary exists is calculated from the tissue information data using the thickness information d and the sound velocity v of each tissue, and is narrowed down to the reception time ranges tr ₁ and tr ₂ .

From Equation 1, the reception time range is set as tr ₁ <tr <tr ₂ .

  For example, in the fat region, the thickness of fat in the abdomen is 10 to 40 mm and the sound speed is 1460 m / s, so the reception time is in the range of 14 μs to 55 μs.

  Next, in step S102, the signal intensity range is set by inputting the tissue information data and the control signal. First, acoustic impedance is calculated in order to obtain the reflectance Rx and transmittance Tx of ultrasonic waves between tissues. The acoustic impedance Z is calculated using Equation 2 from the sound velocity v and density ρ of each tissue.

The reflectivity Rx / transmittance Tx of the ultrasonic wave is calculated using Equations 3 and 4 from the difference Z ₁ and Z _{2 in the} acoustic impedance between tissues.

  For example, since the acoustic impedance of fat is 1.32 MRayls and the acoustic impedance of muscle is 1.64 MRayls, the reflectance at the tissue boundary is 10.5%, and the transmittance is 89.5%.

Next, the attenuation rate of the ultrasonic wave in the tissue is set from the tissue information data. The attenuation rate is a specific value depending on the medium, and is proportional to the frequency and the distance. That is, the attenuation rate increases as the frequency increases and the distance propagated in the medium increases. Furthermore, it is necessary to consider the attenuation for the round trip. Attenuation amount a is calculated using the result number 5 as a function of time t with the transmission frequency f _c and damping factor dr and sonic v tissues.

  FIG. 5 shows the amount of attenuation at the boundary between fat and muscle. The attenuation amount indicates the ratio between the transmission wave and the sound ray signal, which are input / output of ultrasonic waves into the subject.

  Next, the signal intensity S is calculated using the reflectance Rx, the transmittance Tx, and the attenuation amount a. When the signal intensity S is calculated, the reflectance / transmittance is converted to decibels and calculated from Equation 6.

Then, to create a virtual input signal V _in the control signal as an input. The virtual input signal V _in from the vibration element 100 when the ultrasonic wave is transmitted, a signal applied to the vibrating element 100. At this time, since the absolute value of the amplitude varies depending on the position of the vibration element 100, it is necessary to multiply the control signal by a weighting coefficient. The control signal corresponding to each vibration element 100 is normalized using the Hamming window with the sound ray signal received by the central vibration element as the maximum value. Note that the normalization is not limited to the Hamming window. The signal subjected to detection processing for the weighted control signal to the virtual input signal V _in. Calculating a boundary strength function A is a time function having 7 from the signal strength S and the virtual input signal V _in.

The signal strength A ₁ is calculated using the first tissue boundary located under the skin of the subject, the signal strength A ₂ is calculated using the signal strength of the second tissue boundary. This is because, since the tissue positional relationship of the subject remains unchanged, a constraint condition that the amplitude is larger than the signal reflected at the tissue boundary existing at the next deep position can be set. For the sound ray signal AS received by each vibration element 100, the boundary intensity function A can be derived from the condition of A ₂ <AS <A ₁ .

  Next, in step S103, a boundary signal indicating a tissue boundary is detected from the sound ray signal AS. Here, tissue boundary detection will be described with reference to FIG. First, detection processing is performed on the sound ray signal AS. By performing quadrature detection on the sound ray signal AS, the reflection component generated at the boundary between the carrier wave component and the tissue can be separated by removing the phase change. As a result, it can be expected that the S / N can be improved. Although quadrature detection is performed here, of course, the detection method is not limited to quadrature detection. When the sound ray signal subjected to the detection process satisfies the conditions of the reception range tr and the signal intensity range A, a binarization process is performed with the maximum amplitude of the sound ray signal AS being 1, and a boundary signal is created. When a plurality of maximum amplitudes are detected, the adjacent boundary signal is compared with the reception time when the maximum amplitude is detected. Then, the boundary signal is created with the smaller difference from the reception time at the adjacent maximum amplitude as the maximum amplitude.

  Next, if the condition is not satisfied in step S104, the tissue thickness or the boundary strength function parameter is changed and the binarization process is performed again. The binarization process is performed on all the vibration elements to calculate a boundary signal. The boundary signal does not have to be calculated by all the vibration elements, and the boundary signal may be calculated by reducing the number of sound ray signals so as to satisfy a desired frame rate. In addition, it is considered that no thickness change exceeding the fracture resistance of the tissue occurs during ultrasonic diagnosis. Therefore, the reception time is calculated from the change in thickness that causes tissue destruction and the sound speed, and when there is a change greater than the reception time when adjacent boundary signals are compared, it is determined as an exceptional value.

  In step S105, the boundary signal is arranged two-dimensionally to create a tissue boundary. In this case, when the exceptional value processing is performed, the spline interpolation processing is performed in the vibration element direction so that the tissue boundary can be configured with a smooth curve. The interpolation method is not limited to spline interpolation.

  Next, the second tissue boundary is detected in the same procedure as the first tissue boundary. At that time, the reception time range setting S101 and the signal intensity range setting S102 in the second tissue boundary detection are detected by using the thickness information of the first tissue boundary. In this way, the tissue boundary is sequentially determined from the tissue on the subject surface layer. For example, when creating a boundary distribution composed of fat, muscle, and soft tissue, the tissue boundary between fat and muscle can be detected first in the weaving boundary detection process. In order to detect the boundary between muscle and soft tissue which is a deeper position, the thickness information of the fat region from the tissue boundary is reflected in the reception time range setting S101 and the signal intensity range setting S102. In the reception time range setting S101, the reception time range is set on the assumption that there is a boundary between muscle and soft tissue within a range of 10-20 mm from the boundary between fat and muscle. In the signal intensity range setting S102, the signal intensity range between the muscle and the soft tissue is set based on the attenuation in fat and the transmittance between the fat and muscle tissue. In this way, in consideration of the influence of fat, tissue boundary detection between muscle and soft tissue, which is the next tissue boundary, is performed. When the organization boundary based on the number of region constituent tissues set in the organization information storage unit can be determined, the creation of the organization boundary distribution is terminated.

[Description of Display Unit 122]
The operation of the display unit 122 will be described. The tissue boundary distribution output from the tissue boundary detection unit 131 is presented to the operator on the display unit 122. The presentation method has a method of outputting only the tissue boundary distribution, a method of outputting the tissue boundary distribution and the ultrasonic image separately on the same screen, and a function of outputting the superposition of the tissue region distribution on the ultrasonic image. Furthermore, the tissue boundary distribution is clarified by giving a difference in the color displayed for each region.

3. As described above, the ultrasonic diagnostic apparatus includes the tissue information storage unit 130 and the tissue boundary detection unit 131, thereby enabling tissue boundary detection without using a signal after delay addition. Become. Due to this effect, it is possible to provide a highly robust and highly accurate tissue boundary detection compared to a tissue boundary detection created from a signal after delay addition.

(Embodiment 2)
1. 2. Description of Configuration FIG. 2 shows a block diagram of an ultrasonic diagnostic apparatus having sound velocity correction according to Embodiment 2 of the present invention. The ultrasonic diagnostic apparatus includes a vibration element 100, a transmission beam control unit 110, a transmission beam forming unit 111, a reception beam forming unit 120, a display control unit 121, a display unit 122, a tissue information storage unit 130, and a tissue. In addition to the boundary detection unit 131, a sound speed distribution creation unit 210 and a sound speed correction unit 211 are provided.

2. Description of Operation (Function) Next, the operation of tissue boundary detection in the ultrasonic diagnostic apparatus will be described with reference to FIG.

  First, the transmission beam control unit 110 outputs a control signal in which the transmission wave shape is a pulse wave and the focus position is set to infinity, to the transmission beam forming unit 111 and the tissue boundary detection unit 131. Next, the transmission beam forming unit calculates a drive timing amount for performing control in the time direction and a transmission delay amount for performing control in the spatial direction with respect to the input control signal, and calculates the drive timing amount and the transmission delay amount. The drive signal is output to the vibration element 100 as a drive signal. Here, the transmission delay amount is set to 0 because the focus position is set to infinity. Next, the vibration element 100 transmits a planar ultrasonic wave into the subject by applying a voltage to the vibration element 100 according to the input drive signal and converting the voltage into vibration. Next, a driving signal is input to the vibration element 100 and planar ultrasonic waves are transmitted into the subject. Next, the planar ultrasonic wave reflected by the difference in acoustic impedance in the subject is received by the vibration element 100 and outputs a sound ray signal to the tissue boundary detection unit 131. Similar to the sound ray signal, the tissue information storage unit 130 outputs the tissue information data in the region of interest to the tissue boundary detection unit 131. Next, at least a boundary between the first tissue located under the skin of the subject and the second tissue located deeper in the tissue boundary detection unit 131 is input with the control signal, the sound ray signal, and the tissue information data. Detect and output the tissue boundary distribution to the sound velocity distribution creation unit 210. Next, the sound boundary distribution creation unit 210 receives the tissue boundary distribution and the tissue information, and the sound speed distribution is output to the sound speed correction unit 211 and the display unit 122. Next, the sound speed correction unit 211 receives the sound speed distribution and outputs the sound speed of each vibration element to the transmission delay amount calculation unit 12 and the reception delay amount calculation unit 22.

[Description of Sound Velocity Distribution Creation Unit 210]
The operation of the sound speed distribution creation unit 210 will be described. The sound velocity distribution is created by applying the sound velocity data to a region that is distinguished from the tissue information by the boundary created from the tissue information and the boundary created from the sound velocity data.

[Description of Sonic Correction Unit 211]
The operation of the sound speed correction unit 211 will be described with reference to FIG. Since the sound speed distribution is a sound speed distribution composed of the reception time and the tissue boundary, the sound speed distribution is converted with the reception time as the depth from the sound speed of each tissue. A straight line is assumed between the focus position and the vibration element from the difference between the arbitrary vibration element e and the distance L from the center of all vibration elements at the focus position of the depth D. The coordinates when the straight lines and the tissue boundaries B ₁ and B _{2 of the} sound velocity map are set to x ₁ , y ₁ , x ₂ and y _2, and the coordinates of the focus position D are set to x ₃ and y ₃ . The speed of sound at the vibration element e is calculated from Equation 8 from the ratio of the distance from the vibration element e to the tissue boundary B ₁ , the distance from the tissue boundary B ₁ to the tissue boundary B _2, and the straight line from the tissue boundary B ₂ to the focus position D. To do.

  The sound speed correction unit 211 performs sound speed correction by inputting the sound speed calculated in Equation 8 to the transmission beam forming unit 111 and the reception beam forming unit 120.

  In addition, the refractive index of an ultrasonic wave may be calculated from the sound speed difference between tissues using the sound speed distribution, and used for sound speed correction of the vibration element e. By performing the delay addition process in consideration of the refraction of the ultrasonic wave, it is possible to expect the effect of suppressing the generation of the virtual image and the artifact generated in the ultrasonic image.

3. 2. Description of Action and Effect In FIG. 2, the ultrasonic diagnostic apparatus configured as described above reduces a decrease in focus accuracy due to a deviation in sound speed during transmission / reception beamforming by using a sound speed correction method including a sound speed distribution creation unit 210 and a sound speed correction unit 211. It becomes possible. Due to this effect, the resolution of the ultrasonic image is improved, and a high-definition ultrasonic image can be provided.

(Other variations)
Although the present invention has been described based on the above embodiment, it is needless to say that the present invention is not limited to the above embodiment. The following cases are also included in the present invention.

  (1) Each of the above devices is specifically a computer system including a microprocessor, a ROM, a RAM, a hard disk unit, a display unit, a keyboard, a mouse, and the like. A computer program is stored in the RAM or hard disk unit. Each device achieves its functions by the microprocessor operating according to the computer program. Here, the computer program is configured by combining a plurality of instruction codes indicating instructions for the computer in order to achieve a predetermined function.

  (2) A part or all of the constituent elements constituting each of the above-described devices may be configured by one system LSI (Large Scale Integration). The system LSI is an ultra-multifunctional LSI manufactured by integrating a plurality of components on a single chip, and specifically, a computer system including a microprocessor, ROM, RAM, and the like. . A computer program is stored in the RAM. The system LSI achieves its functions by the microprocessor operating according to the computer program.

  (3) Part or all of the constituent elements constituting each of the above devices may be configured from an IC card that can be attached to and detached from each device or a single module. The IC card or the module is a computer system including a microprocessor, a ROM, a RAM, and the like. The IC card or the module may include the super multifunctional LSI described above. The IC card or the module achieves its function by the microprocessor operating according to the computer program. This IC card or this module may have tamper resistance.

  (4) The present invention may be the method described above. Further, the present invention may be a computer program that realizes these methods by a computer, or may be a digital signal composed of the computer program.

  The present invention also provides a computer-readable recording medium such as a flexible disk, hard disk, CD-ROM, MO, DVD, DVD-ROM, DVD-RAM, BD (Blu-ray Disc). ), Recorded in a semiconductor memory or the like. The digital signal may be recorded on these recording media.

  In the present invention, the computer program or the digital signal may be transmitted via an electric communication line, a wireless or wired communication line, a network represented by the Internet, a data broadcast, or the like.

  The present invention may be a computer system including a microprocessor and a memory, wherein the memory stores the computer program, and the microprocessor operates according to the computer program.

  In addition, the program or the digital signal is recorded on the recording medium and transferred, or the program or the digital signal is transferred via the network or the like, and executed by another independent computer system. It is good.

  (5) The above embodiment and the above modifications may be combined.

  The tissue boundary discriminating method in the ultrasonic diagnostic apparatus according to the present invention includes the tissue information storage unit 130, the tissue boundary detection unit 131, and the sound velocity distribution creation unit 210, and improves the performance of the conventional ultrasonic diagnostic apparatus, in particular. Adapting to sound speed correction is useful for improving image quality. Further, the present invention can be applied not only to an ultrasonic diagnostic apparatus but also to uses such as a nondestructive inspection apparatus using ultrasonic waves.

DESCRIPTION OF SYMBOLS 100 Vibration element 110 Transmission beam control part 111 Transmission beam formation part 120 Reception beam formation part 121 Display control part 122 Display part 130 Tissue information storage part 131 Tissue boundary detection part 210 Sonic distribution preparation part 211 Sonic correction part

Claims (7)

A transmit beam control unit for setting a control signal for controlling the transmit beam shape;
A transmission beam forming unit for calculating a transmission delay amount for creating the transmission beam shape;
A vibration element that transmits ultrasonic waves based on the transmission delay amount and receives ultrasonic waves reflected in the subject; and
A reception beam forming unit that forms an addition signal from the received ultrasonic signal;
A display control unit for creating a luminance signal from the addition signal;
A display unit for presenting the luminance signal to an operator;
A tissue information storage unit for storing tissue information constituting the subject ;
A tissue boundary detection unit for detecting at least a boundary between the first composition located under the subject and the second composition located deeper;
The tissue boundary detection unit calculates a time range in which a reflected signal from the boundary appears based on information in the tissue information storage unit and a sound ray signal that does not give a delay amount in the transmission beam forming unit, and A signal intensity range is calculated based on the tissue information in the tissue information storage unit and the control signal, and in the sound ray signal, a signal peak that satisfies the time range and the signal intensity range is determined as the first composition and the second. An ultrasonic diagnostic apparatus, characterized in that it is extracted as a reflected signal from the boundary with the composition. The ultrasonic diagnostic apparatus further includes
A sound velocity distribution creating unit for calculating a sound velocity distribution in the region of interest from the sound velocity information in the tissue information storage unit and the tissue boundary calculated by the tissue boundary detecting unit;
A sound speed correction unit that performs sound speed correction from the sound speed distribution,
The sound speed correction unit performs sound speed correction by individually setting the sound speed of each vibration element using a ratio of a tissue constituting the vibration element and a focus point, and performs transmission / reception focus in a narrow range. The ultrasonic diagnostic apparatus according to claim 1. The display unit simultaneously presents the luminance signal and the tissue boundary to the operator,
The ultrasonic diagnostic apparatus according to claim 1, wherein the display unit displays the luminance signal and the tissue boundary individually or in a superimposed manner, and changes the color for each tissue. The tissue boundary detection unit is determined as an exceptional value when a difference in reception time corresponding to the thickness at which the tissue is broken due to the destruction resistance characteristics of the tissue due to external force occurs when the signals of adjacent vibration elements are compared. The ultrasonic diagnostic apparatus according to any one of claims 1 to 3 , wherein interpolation processing is performed at the time of creating a tissue boundary. The ultrasonic diagnostic apparatus further includes
An operator has a personal tissue information calculation unit that calculates the thickness of the tissue at the diagnostic site by setting the sex, weight, or body fat percentage of the subject,
Enter the thickness of the tissue that has been calculated by the personal organization information calculation unit in the organization information storage unit, wherein the tissue boundary detection unit and performs the determination of the boundary of the tissue, according to claim 1-4 The ultrasonic diagnostic apparatus according to any one of the above. The ultrasonic diagnostic apparatus further includes
It has a temperature measurement unit that measures the temperature of the subject surface,
Wherein estimating the temperature distribution from the temperature within the subject of the subject surface that is measured by the temperature measuring section, if the temperature distribution is lower than the standard temperature than the standard speed of sound speed of sound woven set that put on the organization information storage unit slow set, if the temperature distribution is higher than the standard temperature and sets the sound velocity of woven set that put on the organization information storage unit earlier than the standard speed of sound, one of claims 1-5 one The ultrasonic diagnostic apparatus as described in one . The refraction of the tissue boundary using a sound velocity distribution calculated in the sound speed correction unit calculates the sound velocity difference between the tissues, characterized that you perform sound velocity correction for each transducer element, super according to claim 2 Ultrasonic diagnostic equipment.

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