JPWO2006126485A1 - Ultrasonic diagnostic equipment - Google Patents

Abstract

An ultrasonic diagnostic apparatus that accurately measures an elastic modulus using a non-invasive blood pressure monitor transmits an ultrasonic wave to a subject and receives the ultrasonic wave reflected inside the subject and the reception unit 102 Unit 103, tissue tracking unit 105 that tracks the movement of the tissue in the subject from the received signal created based on the received ultrasound, non-invasive blood pressure measurement unit 111 that measures the blood pressure of the subject, A control unit 100 that outputs a first operation signal S1 to the transmission unit to drive the transmission unit, outputs a second operation signal S2 to the blood pressure measurement unit 111 to drive the blood pressure measurement unit, and a tissue tracking unit 105 A tissue property value calculation unit 108 that calculates a tissue property value (for example, elastic modulus and viscosity) of the subject from the tracked tissue movement and the blood pressure measured by the blood pressure measurement unit is provided. The blood pressure measurement unit measures the blood pressure of the subject based on the second operation signal output from the control unit, and transmits the measured blood pressure to the tissue property calculation unit 108.

Description

  The present invention relates to an ultrasonic diagnostic apparatus that obtains tissue properties based on information obtained by tracking the movement of a subject tissue (for example, a biological tissue).

  The ultrasonic diagnostic apparatus transmits an ultrasonic wave to a subject and receives an ultrasonic wave (reflected echo signal) reflected by the tissue of the subject, and converts the intensity of the received ultrasonic wave into a luminance. A tomographic image of the specimen is obtained. As one form of ultrasonic diagnostic equipment, the motion of the subject tissue is accurately measured by analyzing the phase of the reflected echo signal, and the distortion, elastic modulus and viscosity of the subject tissue are based on the measurement result. Attempts have been made to determine the tissue properties.

  For example, in Japanese Patent Laid-Open No. 10-5226, the tissue of a subject is tracked by determining the instantaneous position of the subject using the amplitude and phase of the output signal obtained by detecting the reflected echo signal. A method is described which is performed with high accuracy and captures minute vibrations superimposed on large-amplitude displacement motion caused by pulsation.

従って、ΔＴ後の計測点の位置ｘ’は次の式（２）で与えられる。

The subject tissue tracking method disclosed in Japanese Patent Laid-Open No. 10-5226 will be described with reference to FIG. For the same direction of the subject, the received echo signal of the ultrasonic pulse transmitted at time t = 0 is y (t), and the echo signal of the ultrasonic pulse transmitted at time t = ΔT is y (t + ΔT). To do. In addition, the reception time tx of the echo reflected from the measurement point at a certain position (depth) x is tx = x / (C / 2) [C: propagation in the subject, where t = 0 is the pulse transmission time. The speed of the ultrasound to be given]. Next, assuming that the phase difference between the received echo signals y (tx) and y (tx + ΔT) is Δθ and the center frequency of the ultrasonic wave near the reception time tx is f, the movement amount Δx of the measurement point within this time ΔT is It is given by equation (1).

Therefore, the position x ′ of the measurement point after ΔT is given by the following equation (2).

  By repeating this calculation, the position of a specific measurement point in the subject can be tracked. That is, assuming that the reception time of the echo reflected from the position (depth) x ′ is tx ′, the expression (1) is obtained based on the phase difference between the reception echo signals y (tx ′ + ΔT) and y (tx ′ + 2ΔT). And the position x ″ of the measurement point after 2ΔT can be obtained from the equation (2).

  Japanese Patent Laid-Open No. 2000-229078 further develops the method disclosed in Japanese Patent Laid-Open No. 10-5226, and accurately tracks each large-amplitude displacement movement of the inner and outer surfaces of the blood vessel wall due to a heartbeat, A method for obtaining the motion velocity of micro vibrations superimposed on motion, measuring the strain amount of the blood vessel wall from the difference, and obtaining the local elastic modulus from the strain amount and the blood pressure difference, and an apparatus for displaying the spatial distribution of the elastic modulus as an image Is described.

  With reference to FIG. 7, the elastic modulus calculation method disclosed in Japanese Patent Laid-Open No. 2000-229078 will be described. According to this document, the probe 101 irradiates a subject with ultrasonic waves and receives echoes from blood vessels, particularly arteries. Measurement points A and B (two points on the cross section including the central axis of the blood vessel and having different distances in the radial direction from the central axis) are set on the blood vessel wall, and the received signals from the measurement points A and B are specified. Analysis is performed by the method disclosed in Japanese Utility Model Laid-Open No. 10-5226, and the movement of the measurement points A and B is tracked. Here, the artery repeatedly contracts and dilates due to the heartbeat, and during the systole, the blood vessel itself expands and the thickness of the blood vessel wall decreases rapidly, and during the diastole, the blood vessel itself contracts and slowly The thickness of the vessel wall increases. Therefore, the measurement points A and B exhibit a periodic behavior indicated by the tracking waveforms TA and TB, and a thickness (distance) change waveform W between the measurement points A and B is obtained from the difference between the tracking waveforms TA and TB.

Therefore, assuming that the change amount of the thickness change waveform W is ΔW and the reference thickness at the time of measurement point initialization is Ws, the strain amount ε between the measurement points A and B is given by Expression (3).

そして、以上の計算を断層画像上の複数点に対して行なうことで、弾性率の分布画像が得られる。Assuming that this strain amount ε is caused by the blood pressure difference ΔP applied to the blood vessel wall, the elastic modulus Er between the measurement points A and B is given by the equation (4).

The elastic modulus distribution image is obtained by performing the above calculation on a plurality of points on the tomographic image.

  However, in the method disclosed in Japanese Patent Laid-Open No. 2000-229078, the blood pressure value is measured in advance, and the examiner manually inputs the blood pressure value into the ultrasonic diagnostic apparatus through an input unit such as a numeric keypad. However, there is a considerable time difference between the measurement and the distortion amount measurement. For example, although the blood pressure value is input once, the strain amount is measured at several locations, so there is a time difference of several minutes to several tens of minutes between the blood pressure measurement and the last strain amount measurement. It changes every moment even at rest. Therefore, there has been a problem that the accuracy of elastic modulus measurement is reduced. In addition, measuring and inputting blood pressure every time the strain amount is measured is a heavy burden on the examiner. JP 2000-229078 discloses a method for continuously obtaining blood pressure values using a continuous blood pressure monitor. However, since a continuous blood pressure monitor is directly inserted into an artery, Therefore, an excessive burden is imposed, and the advantage of ultrasonic diagnosis that is non-invasive and simple is greatly reduced.

  An object of the present invention is to provide an apparatus for measuring an elastic modulus with high accuracy while using a general non-invasive blood pressure monitor.

In order to achieve this object, an ultrasonic diagnostic apparatus according to the present invention includes:
(A) transmitting / receiving means for transmitting ultrasonic waves to the subject and receiving ultrasonic waves reflected inside the subject;
(B) a tissue tracking means for tracking the movement of the tissue in the subject from the received signal created by the transmission / reception means based on the received ultrasound;
(C) noninvasive blood pressure measuring means for measuring the blood pressure of the subject;
(D) a control unit that outputs a first operation signal to the transmission / reception unit to drive the transmission / reception unit, and outputs a second operation signal to the blood pressure measurement unit to drive the blood pressure measurement unit;
(E) comprising tissue property value calculating means for calculating the tissue property value of the subject from the movement of the tissue tracked by the tissue tracking means and the blood pressure measured by the blood pressure measuring means;
(F) The blood pressure measuring means measures the blood pressure of the contributor based on the second operation signal output from the control means, and transmits the measured blood pressure to the tissue property calculating means. It is characterized by.

In an ultrasonic diagnostic apparatus according to another aspect of the present invention,
The blood pressure measurement means includes a blood pressure measurement unit that measures the blood pressure of the subject, and a sphygmomanometer control unit that operates the blood pressure measurement unit to acquire the blood pressure of the subject from the blood pressure measurement unit,
The control unit operates the blood pressure measurement unit based on the second operation signal to cause the blood pressure monitor control unit to acquire the blood pressure of the subject and transmit the blood pressure to the tissue property calculation unit. To do.

  In the ultrasonic diagnostic apparatus of these forms, it is preferable that the blood pressure measurement unit measures the blood pressure of the subject while or after the transmission / reception unit receives the ultrasound reflected by the subject.

  In addition, the blood pressure measurement unit obtains a plurality of blood pressures by measuring the blood pressure a plurality of times, and obtains an average value of the acquired plurality of blood pressures or a value obtained by estimating the blood pressure value at the time of acquiring the strain amount from the plurality of acquired blood pressures. The blood pressure may be transmitted as blood pressure to the tissue property value calculation means.

  The ultrasonic diagnostic apparatus according to claim 1, wherein the tissue property value is an elastic modulus of the tissue.

  According to the ultrasonic diagnostic apparatus having such a configuration, the noninvasive blood pressure measurement unit measures the blood pressure based on a command from the control unit, and the measured blood pressure value is automatically input to the tissue property calculation unit. Is done. Therefore, if necessary, the blood pressure of the subject can be acquired without delay and the tissue property value can be calculated. Therefore, the tissue property value of the subject can be obtained with high accuracy and useful information for diagnosis can be provided.

1 is a block diagram of an ultrasonic diagnostic apparatus according to an embodiment of the present invention. The block diagram of the ultrasonic diagnosing device concerning other embodiments of the present invention. The block diagram of the ultrasonic diagnosing device concerning other embodiments of the present invention. The block diagram of the ultrasonic diagnosing device concerning other embodiments of the present invention. The figure which shows the measurement result displayed on the display part of an ultrasonic diagnosing device. The figure explaining the basic operation | movement which performs structure | tissue tracking from a phase difference. The figure explaining the basic operation | movement which calculates | requires distortion amount from a tissue tracking waveform.

Explanation of symbols

100: control unit, 101: probe, 102: transmission unit, 103: reception unit, 104: tomographic image processing unit, 105: tissue tracking unit, 106: image synthesis unit, 107: display unit, 108: elastic modulus calculation Part, 111: blood pressure measurement part, 112: sphygmomanometer control part, 120, 121: storage part.

  Hereinafter, specific embodiments of the present invention will be described with reference to the accompanying drawings.

  1 and 2 are block diagrams showing the functional configuration of the ultrasonic diagnostic apparatus. As shown in the figure, the ultrasonic diagnostic apparatus includes a control unit 100 as control means. Although not shown, a user interface (input means) such as a keyboard, a trackball, a switch, and a button is connected to the control unit 100. A probe 101 that is used in contact with a subject (not shown but is usually a person) is connected to a transmitter 102 and a receiver 103. When receiving the ultrasonic wave transmission command (first operation signal) S1 from the control unit 100, the transmission unit 102 generates a signal for driving the probe 101 at a designated timing and transmits the signal to the probe 101. The probe 101 emits an ultrasonic wave based on the signal output from the transmission unit 102 and irradiates the subject. The probe 101 converts an ultrasonic echo reflected from the inside of the subject into an electric signal.

  The reception unit 103 constitutes a transmission / reception unit together with the transmission unit 102, processes a reception signal reflected from the inside of the subject, and outputs the processed signal to the tomographic image processing unit 104 and the tissue tracking unit 105. Although not shown in the drawing, a plurality of piezoelectric transducers for mutually converting ultrasonic waves and electrical signals are arranged in the probe 101. These piezoelectric transducers are selected, and the timing for applying a voltage to the piezoelectric transducer is determined. Adjust and control the deflection angle and focus of ultrasonic waves to be transmitted and received. The receiving unit 103 also amplifies the received signal and detects only ultrasonic waves from a predetermined position (focus) or direction (deflection angle).

  The tomographic image processing unit 104 includes a filter, a detector, a logarithmic amplifier, and the like. The tomographic image processing unit 104 analyzes mainly the amplitude of the signal transmitted from the receiving unit 103 and images the internal structure of the subject. The imaged image data is transmitted to the image composition unit 106. Further, the image data can be transmitted to and stored in the storage unit 120 and output to the image composition unit 106 as appropriate in response to a request from the control unit 100.

  The tissue tracking unit 105 obtains the amount of movement of the subject tissue along the ultrasonic wave transmission / reception direction using the above-described equation 1 from a plurality of configurations (not shown), for example, a memory for storing the received signals, and the phase difference between the received signals. A movement amount calculation unit, and a position tracking calculation unit that adds the movement amount to the original position to obtain a position after movement are tracked. The movement of the subject tissue along the ultrasonic transmission / reception direction is tracked, and tracking position information ( Information indicating the movement of the subject tissue). The tracking position information acquired by the tissue tracking unit 105 is output to the elastic modulus calculation unit 108. Further, the tracking position information acquired by the tissue tracking unit 105 can be transmitted to and stored in the storage unit 121 and output to the elastic modulus calculation unit 108 as appropriate in response to a request from the control unit 100.

  Based on the tracking position information transmitted from the tissue tracking unit 105 or the storage unit 121, the elastic modulus calculation unit 108 calculates the strain amount of the examination tissue based on the above-described Expression 3. The calculated distortion amount may be temporarily transmitted to and stored in the storage unit 121 and acquired from the storage unit 121 as necessary. The elastic modulus calculation unit 108 also calculates the elastic modulus of the tissue based on the above equation 4 based on the calculated strain amount and the blood pressure (blood pressure value) of the subject transmitted from the blood pressure measurement unit 111 described later. Calculate. The elastic modulus is converted into numerical data indicating the value of the elastic modulus or two-dimensional distribution image data in which the elastic modulus value is converted into color data and developed into two-dimensional coordinates, and is transmitted to the image composition unit 106. These numerical data and image data are stored in the storage unit 121 and can be output to the image composition unit 106 as necessary.

  The image synthesizing unit 106 synthesizes the numerical value data or image data of the elastic modulus output from the elastic modulus calculating unit 108 or the storage unit 121 and the image data output from the tomographic image processing unit 104 or the storage unit 120, and combines them. The image is output to the image display unit 107 and displayed. The storage unit 120 can also store a composite image.

  The blood pressure measurement unit 111 has a non-invasive blood pressure measurement device. The blood pressure measurement device includes, for example, a measurement unit attached to the upper arm or wrist of the subject and a control unit that controls the operation of the measurement unit, and a blood pressure measurement command (second output) output from the control unit 100. The blood pressure (blood pressure value) of the subject is acquired at the timing instructed by the control unit 100 based on the operation signal S2 and the blood pressure value is output to the elastic modulus calculation unit 108.

  Blood pressure measurement in the blood pressure measurement unit 111 can be performed during transmission / reception of ultrasonic waves. In this case, transmission / reception of ultrasonic waves is stopped after blood pressure measurement, after a preset time, or after a preset heart rate. Further, the blood pressure measurement unit 111 measures the blood pressure a plurality of times, averages the plurality of measurement results (blood pressure values), or a value obtained by estimating the blood pressure at the time of strain measurement from the plurality of measurement results, The blood pressure value may be output to the elastic modulus calculation unit 108. The blood pressure value provided to the elastic modulus calculation unit 108 is transmitted to the storage unit 121 and stored therein, and is appropriately taken out to the elastic modulus calculation unit 108 in an ultrasonic transmission / reception stop state (hereinafter referred to as “freeze state”). Used for rate calculation.

  FIG. 5 is a display screen of the display unit 107 that displays an example of the result of measuring the elastic modulus of the blood vessel wall using the above-described ultrasonic diagnostic apparatus. In FIG. 5, on the display screen, an elastic modulus image 201 representing the distribution of elastic modulus of the relevant part is displayed in color, superimposed on the monochrome tomographic image 200 of the blood vessel wall. At the time of ultrasonic transmission / reception (hereinafter referred to as “live state”), the monochrome tomographic image 200 is updated and displayed every several tens of frames / second, and the elastic modulus image 201 is updated once per heartbeat, as in the conventional ultrasonic diagnostic apparatus. Is displayed. In the frozen state, the tracking position information and the distortion amount are read from the storage unit 121, and the elastic modulus is recalculated based on the information. In addition, a tomographic image synchronized in time with the elastic modulus is read from the storage unit 120 and displayed on the display unit 107. In FIG. 5, reference numeral 202 denotes a tomographic image reflection intensity scale, reference numeral 203 denotes an elastic modulus image elasticity scale, and reference numeral 204 denotes a biological signal waveform (for example, an electrocardiogram waveform).

  In the frozen state, the past elastic modulus and tomographic image can be read from the storage units 121 and 120. In this case, a tomographic image synchronized with the elastic modulus and the elastic modulus, or a tomographic image of a heartbeat period required for calculating the elastic modulus and the elastic modulus is read from the storage units 121 and 120 and displayed.

  The ultrasonic diagnostic apparatus configured as described above, particularly the control of the blood pressure measurement unit 111 will be described in more detail. The ultrasonic diagnostic apparatus automatically measures blood pressure using an external or internal sphygmomanometer at the same time as the measurement of the amount of distortion ends and the freeze state is reached. Then, the currently displayed elastic modulus value and elastic modulus image are corrected using the measured blood pressure value. When the tracking position information or strain amount stored in the storage unit 121 is read and the elastic modulus measured in the past is updated, the latest blood pressure value is used.

  In addition, the ultrasonic diagnostic apparatus measures blood pressure periodically during measurement of the amount of distortion (that is, every predetermined time interval or every predetermined heart rate), and always uses the latest blood pressure value. To calculate the elastic modulus automatically. By estimating the blood pressure at the time of strain measurement by predicting fluctuations in blood pressure from regularly measured blood pressure values, or by using the blood pressure obtained by averaging the blood pressure values measured multiple times, the modulus of elasticity is further increased. Calculation accuracy can be improved.

  Furthermore, in the ultrasonic diagnostic apparatus, after the examiner determines the measurement cross section by the ultrasonic wave, the blood pressure is measured by an operation of a switch or the like, and then the elastic modulus is calculated by measuring the distortion amount by the ultrasonic wave over several heartbeats. Also good. You may make it stop ultrasonic transmission / reception automatically after elastic modulus measurement.

  Furthermore, by measuring blood pressure again after stopping ultrasonic transmission / reception, and using the blood pressure value estimated from the blood pressure value before and after measuring the amount of distortion using an operation such as linear interpolation or averaging, the elastic modulus is further calculated. Can improve the accuracy.

  In the above description, the blood pressure measurement unit 111 (that is, a sphygmomanometer) is provided inside the ultrasonic diagnostic apparatus, the control unit 100 and the blood pressure measurement unit 111 are connected, and the blood pressure measurement unit 111 is directly connected based on a command from the control unit 100. As shown in FIG. 2, the blood pressure measurement unit 111 (that is, the sphygmomanometer) is provided outside the ultrasonic diagnostic apparatus, and only the sphygmomanometer control unit (blood pressure acquisition unit) 112 is provided inside for control. Unit 100 and sphygmomanometer control unit 112 are connected, and sphygmomanometer control unit 112 acquires a blood pressure value from blood pressure measurement unit 111 based on a command from control unit 100, and the blood pressure value acquired by sphygmomanometer control unit 112 You may make it output to the elasticity modulus calculating part 108. FIG.

したがって、この実施形態の場合、図３，４に示すように、粘性率演算部１０８’では、組織追跡部１０５又は記憶部１２１から送信される追跡位置情報と血液測定部１１１又は血圧計制御部１１２から送信される血圧をもとに歪み量εと弾性率Ｅｒを計算するとともに、これら歪み量εと血圧τから粘性率ηを計算する。粘性率は、弾性率と同様に、数値データ又は画像データとして画像合成部１０６に送信され、そこで断層画像データと合成されて表示部１０７に表示される。なお、弾性率と粘性率を同時に表示するようにしてもよい。これにより、診断に有用な情報を同時にさらに多く提供することができる。In the above description, the elastic modulus is taken as an example of the tissue property value. However, the tissue property value may be a tissue viscosity. More specifically, pressure (stress), strain, elastic modulus, and viscosity have the relationship shown in Equation 5 below.

Therefore, in the case of this embodiment, as shown in FIGS. 3 and 4, in the viscosity calculation unit 108 ′, the tracking position information transmitted from the tissue tracking unit 105 or the storage unit 121 and the blood measurement unit 111 or the sphygmomanometer control unit Based on the blood pressure transmitted from 112, the strain amount ε and the elastic modulus Er are calculated, and the viscosity η is calculated from the strain amount ε and the blood pressure τ. Like the elastic modulus, the viscosity is transmitted as numerical data or image data to the image composition unit 106, where it is combined with tomographic image data and displayed on the display unit 107. Note that the elastic modulus and viscosity may be displayed simultaneously. Thereby, more useful information for diagnosis can be provided at the same time.

  By the way, in FIG. 1 to FIG. 4, the functions of the ultrasonic diagnostic apparatus are shown as independent blocks. For example, the control unit 100, tomographic image processing unit 104, tissue tracking unit 105, image synthesis unit 106, elastic modulus calculation The unit 108, the viscosity calculation unit 108 ′, and the like may be realized as software incorporated in the CPU.

  The present invention relates to an ultrasonic diagnostic apparatus that obtains tissue properties based on information obtained by tracking the movement of a subject tissue (for example, a biological tissue).

  The ultrasonic diagnostic apparatus transmits an ultrasonic wave to a subject and receives an ultrasonic wave (reflected echo signal) reflected by the tissue of the subject, and converts the intensity of the received ultrasonic wave into a luminance. A tomographic image of the specimen is obtained. As one form of ultrasonic diagnostic equipment, the motion of the subject tissue is accurately measured by analyzing the phase of the reflected echo signal, and the distortion, elastic modulus and viscosity of the subject tissue are based on the measurement result. Attempts have been made to determine the tissue properties.

  For example, in Patent Document 1, the tissue of a subject is tracked with high accuracy by determining the instantaneous position of the subject using the amplitude and phase of an output signal obtained by detecting a reflected echo signal. A method for capturing minute vibrations superimposed on large-amplitude displacement motion due to pulsation is described.

従って、ΔＴ後の物体Ａの位置ｘ’は次の式（２）で与えられる。

The subject tissue tracking method disclosed in Patent Document 1 will be described with reference to FIG. For the same direction of the subject, the received echo signal of the ultrasonic pulse transmitted at time t = 0 is y (t), and the echo signal of the ultrasonic pulse transmitted at time t = ΔT is y (t + ΔT). To do. In addition, the reception time tx of the echo reflected from the measurement point at a certain position (depth) x is tx = x / (C / 2) [C: propagation in the subject, where t = 0 is the pulse transmission time. The speed of the ultrasound to be given]. Next, assuming that the phase difference between the received echo signals y (tx) and y (tx + ΔT) is Δθ and the center frequency of the ultrasonic wave near the reception time tx is f, the movement amount Δx of the measurement point within this time ΔT is It is given by equation (1).

Therefore, the position x ′ of the object A after ΔT is given by the following equation (2).

  By repeating this calculation, the position of a specific measurement point in the subject can be tracked. That is, assuming that the reception time of the echo reflected from the position (depth) x ′ is tx ′, the expression (1) is obtained based on the phase difference between the reception echo signals y (tx ′ + ΔT) and y (tx ′ + 2ΔT). And the position x ″ of the measurement point after 2ΔT can be obtained from the equation (2).

  In Patent Document 2, the method of Patent Document 1 is further developed to accurately track the large amplitude displacement motions of the inner and outer surfaces of the blood vessel wall due to the heartbeat, and the motion speed of micro vibrations superimposed on the large amplitude displacement motions. And a method of measuring the strain amount of the blood vessel wall from the difference, obtaining the local elastic modulus from the strain amount and the blood pressure difference, and an apparatus for displaying an image of the spatial distribution of the elastic modulus.

  With reference to FIG. 7, the elastic modulus calculation method disclosed in Patent Document 2 will be described. According to this document, the probe 101 irradiates a subject with ultrasonic waves and receives echoes from blood vessels, particularly arteries. Measurement points A and B (two points on the cross section including the central axis of the blood vessel and having different distances in the radial direction from the central axis) are set on the blood vessel wall, and the received signals from the measurement points A and B are patented. Analysis is performed by the method shown in Document 1, and the movement of the measurement points A and B is tracked. Here, the artery repeatedly contracts and dilates due to the heartbeat, and during the systole, the blood vessel itself expands and the thickness of the blood vessel wall decreases rapidly, and during the diastole, the blood vessel itself contracts and slowly The thickness of the vessel wall increases. Therefore, the measurement points A and B exhibit a periodic behavior indicated by the tracking waveforms TA and TB, and a thickness (distance) change waveform W between the measurement points A and B is obtained from the difference between the tracking waveforms TA and TB.

Therefore, assuming that the change amount of the thickness change waveform W is ΔW and the reference thickness at the time of measurement point initialization is Ws, the strain amount ε between the measurement points A and B is given by Expression (3).

そして、以上の計算を断層画像上の複数点に対して行なうことで、弾性率の分布画像が得られる。
特開平１０−５２２６号公報 特開２０００−２２９０７８号公報 Assuming that this strain amount ε is caused by the blood pressure difference ΔP applied to the blood vessel wall, the elastic modulus Er between the measurement points A and B is given by the equation (4).

The elastic modulus distribution image is obtained by performing the above calculation on a plurality of points on the tomographic image.
Japanese Patent Laid-Open No. 10-5226 JP 2000-229078 A

  However, in the method disclosed in Patent Document 2, the examiner manually inputs a blood pressure value that has been measured in advance into the ultrasonic diagnostic apparatus through an input unit such as a numeric keypad. However, there is a considerable time difference between the measurement and the distortion amount measurement. For example, although the blood pressure value is input once, the strain amount is measured at several locations, so there is a time difference of several minutes to several tens of minutes between the blood pressure measurement and the last strain amount measurement. It changes every moment even at rest. Therefore, there has been a problem that the accuracy of elastic modulus measurement is reduced. In addition, measuring and inputting blood pressure every time the strain amount is measured is a heavy burden on the examiner. Note that Patent Document 2 discloses a method of continuously obtaining blood pressure values using a continuous blood pressure monitor. However, since the continuous blood pressure monitor is directly inserted into an artery, an excessive burden is placed on the subject. Therefore, the advantage of ultrasonic diagnosis that is non-invasive and simple is greatly reduced.

  An object of the present invention is to provide an apparatus for measuring an elastic modulus with high accuracy while using a general non-invasive blood pressure monitor.

In order to achieve this object, an ultrasonic diagnostic apparatus according to the present invention includes:
(A) transmitting / receiving means for transmitting ultrasonic waves to the subject and receiving ultrasonic waves reflected inside the subject;
(B) a tissue tracking means for tracking the movement of the tissue in the subject from the received signal created by the transmission / reception means based on the received ultrasound;
(C) a non-invasive blood pressure measuring means for measuring the blood pressure of the subject;
(D) a control unit that outputs a first operation signal to the transmission / reception unit to drive the transmission / reception unit, and outputs a second operation signal to the blood pressure measurement unit to drive the blood pressure measurement unit;
(E) comprising tissue property value calculating means for calculating the tissue property value of the subject from the movement of the tissue tracked by the tissue tracking means and the blood pressure measured by the blood pressure measuring means;
(F) The blood pressure measurement means measures the blood pressure of the contributor based on the second operation signal output from the control means, and transmits the measured blood pressure to the tissue property calculation means. It is characterized by.

An ultrasonic diagnostic apparatus according to another aspect of the present invention
(A) transmitting / receiving means for transmitting ultrasonic waves to the subject and receiving ultrasonic waves reflected inside the subject;
(B) a tissue tracking means for tracking the movement of the tissue in the subject from the received signal created by the transmission / reception means based on the received ultrasound;
(C) a non-invasive blood pressure measuring means for measuring the blood pressure of the subject;
(D) blood pressure acquisition means for acquiring the blood pressure of the subject from the blood pressure measurement means;
(E) Control that outputs the first operation signal to the transmission / reception means to drive the transmission / reception means, and outputs the second operation signal to the blood pressure acquisition means to acquire the blood pressure measured by the blood pressure measurement means. Means,
(F) comprising tissue property value calculating means for calculating the tissue property value of the subject from the movement of the tissue tracked by the tissue tracking means and the blood pressure acquired by the blood pressure acquiring means;
(G) The blood pressure acquisition unit acquires the blood pressure of the donated body from the blood pressure measurement unit based on the second operation signal output from the control unit, and transmits the acquired blood pressure to the tissue property calculation unit. In this way, it is characterized by that.

  In the ultrasonic diagnostic apparatus of these forms, it is preferable that the blood pressure measurement unit measures the blood pressure of the subject while or after the transmission / reception unit receives the ultrasound reflected by the subject.

  In addition, the blood pressure measurement unit obtains a plurality of blood pressures by measuring the blood pressure a plurality of times, and obtains an average value of the acquired plurality of blood pressures or a value obtained by estimating the blood pressure value at the time of acquiring the strain amount from the plurality of acquired blood pressures. The blood pressure may be transmitted as blood pressure to the tissue property value calculation means.

  Further, the tissue property value is an elastic modulus of the tissue.

  According to the ultrasonic diagnostic apparatus having such a configuration, the noninvasive blood pressure measurement unit measures the blood pressure based on a command from the control unit, and the measured blood pressure value is automatically input to the tissue property calculation unit. Is done. Therefore, if necessary, the blood pressure of the subject can be acquired without delay and the tissue property value can be calculated. Therefore, the tissue property value of the subject can be obtained with high accuracy and useful information for diagnosis can be provided.

  Hereinafter, specific embodiments of the present invention will be described with reference to the accompanying drawings.

  1 and 2 are block diagrams showing the functional configuration of the ultrasonic diagnostic apparatus. As shown in the figure, the ultrasonic diagnostic apparatus includes a control unit 100 as control means. Although not shown, a user interface (input means) such as a keyboard, a trackball, a switch, and a button is connected to the control unit 100. A probe 101 that is used in contact with a subject (not shown but is usually a person) is connected to a transmitter 102 and a receiver 103. When receiving the ultrasonic wave transmission command (first operation signal) S1 from the control unit 100, the transmission unit 102 generates a signal for driving the probe 101 at a designated timing and transmits the signal to the probe 101. The probe 101 emits an ultrasonic wave based on the signal output from the transmission unit 102 and irradiates the subject. The probe 101 converts an ultrasonic echo reflected from the inside of the subject into an electric signal.

  The reception unit 103 constitutes a transmission / reception unit together with the transmission unit 102, processes a reception signal reflected from the inside of the subject, and outputs the processed signal to the tomographic image processing unit 104 and the tissue tracking unit 105. Although not shown in the drawing, a plurality of piezoelectric transducers for mutually converting ultrasonic waves and electrical signals are arranged in the probe 101. These piezoelectric transducers are selected, and the timing for applying a voltage to the piezoelectric transducer is determined. Adjust and control the deflection angle and focus of ultrasonic waves to be transmitted and received. The receiving unit 103 also amplifies the received signal and detects only ultrasonic waves from a predetermined position (focus) or direction (deflection angle).

  The tomographic image processing unit 104 includes a filter, a detector, a logarithmic amplifier, and the like. The tomographic image processing unit 104 analyzes mainly the amplitude of the signal transmitted from the receiving unit 103 and images the internal structure of the subject. The imaged image data is transmitted to the image composition unit 106. Further, the image data can be transmitted to and stored in the storage unit 120 and output to the image composition unit 106 as appropriate in response to a request from the control unit 100.

  The tissue tracking unit 105 obtains the amount of movement of the subject tissue along the ultrasonic wave transmission / reception direction using the above-described equation 1 from a plurality of configurations (not shown), for example, a memory for storing the received signals, and the phase difference between the received signals. A movement amount calculation unit, and a position tracking calculation unit that adds the movement amount to the original position to obtain a position after movement are tracked. The movement of the subject tissue along the ultrasonic transmission / reception direction is tracked, and tracking position information ( Information indicating the movement of the subject tissue). The tracking position information acquired by the tissue tracking unit 105 is output to the elastic modulus calculation unit 108. In addition, the tracking position information acquired by the tissue tracking unit 105 can be transmitted to and stored in the storage unit 121 and output to the elastic modulus calculation unit 108 as appropriate in response to a request from the control unit 100.

  Based on the tracking position information transmitted from the tissue tracking unit 105 or the storage unit 121, the elastic modulus calculation unit 108 calculates the strain amount of the examination tissue based on the above-described Expression 3. The calculated distortion amount may be temporarily transmitted to and stored in the storage unit 121 and acquired from the storage unit 121 as necessary. The elastic modulus calculation unit 108 also calculates the elastic modulus of the tissue based on the above equation 4 based on the calculated strain amount and the blood pressure (blood pressure value) of the subject transmitted from the blood pressure measurement unit 111 described later. Calculate. The elastic modulus is converted into numerical data indicating the value of the elastic modulus or two-dimensional distribution image data in which the elastic modulus value is converted into color data and developed into two-dimensional coordinates, and is transmitted to the image composition unit 106. These numerical data and image data are stored in the storage unit 121 and can be output to the image composition unit 106 as necessary.

  The image synthesis unit 106 synthesizes the elastic modulus numerical data or image data output from the storage unit 121 and the elasticity image output from the tomographic image processing unit 104 or the storage unit 120, and combines them. The image is output to the image display unit 107 and displayed. The storage unit 120 can also store a composite image.

  The blood pressure measurement unit 111 has a non-invasive blood pressure measurement device. The blood pressure measurement device includes, for example, a measurement unit attached to the upper arm or wrist of the subject and a control unit that controls the operation of the measurement unit, and a blood pressure measurement command (second output) output from the control unit 100. The blood pressure (blood pressure value) of the subject is acquired at the timing instructed by the control unit 100 based on the operation signal S2 and the blood pressure value is output to the elastic modulus calculation unit 108.

  Blood pressure measurement in the blood pressure measurement unit 111 can be performed during transmission / reception of ultrasonic waves. In this case, transmission / reception of ultrasonic waves is stopped after blood pressure measurement, after a preset time, or after a preset heart rate. Further, the blood pressure measurement unit 111 measures the blood pressure a plurality of times, averages the plurality of measurement results (blood pressure values), or a value obtained by estimating the blood pressure at the time of strain measurement from the plurality of measurement results, The blood pressure value may be output to the elastic modulus calculation unit 108. The blood pressure value provided to the elastic modulus calculation unit 108 is transmitted to the storage unit 121 and stored therein, and is appropriately taken out to the elastic modulus calculation unit 108 in an ultrasonic transmission / reception stop state (hereinafter referred to as “freeze state”). Used for rate calculation.

  FIG. 5 is a display screen of the display unit 107 that displays an example of the result of measuring the elastic modulus of the blood vessel wall using the above-described ultrasonic diagnostic apparatus. In FIG. 5, on the display screen, an elastic modulus image 201 representing the distribution of elastic modulus of the relevant part is displayed in color, superimposed on the monochrome tomographic image 200 of the blood vessel wall. At the time of ultrasonic transmission / reception (hereinafter referred to as “live state”), the monochrome tomographic image 200 is updated and displayed every several tens of frames / second, and the elastic modulus image 201 is updated once per heartbeat, as in the conventional ultrasonic diagnostic apparatus. Is displayed. In the frozen state, the tracking position information and the distortion amount are read from the storage unit 121, and the elastic modulus is recalculated based on the information. In addition, a tomographic image synchronized in time with the elastic modulus is read from the storage unit 120 and displayed on the display unit 107. In FIG. 5, reference numeral 202 denotes a tomographic image reflection intensity scale, reference numeral 203 denotes an elastic modulus image elasticity scale, and reference numeral 204 denotes a biological signal waveform (for example, an electrocardiogram waveform).

  In the frozen state, the past elastic modulus and tomographic image can be read from the storage units 121 and 120. In this case, a tomographic image synchronized with the elastic modulus and the elastic modulus, or a tomographic image of a heartbeat period required for calculating the elastic modulus and the elastic modulus is read from the storage units 121 and 120 and displayed.

  The ultrasonic diagnostic apparatus configured as described above, particularly the control of the blood pressure measurement unit 111 will be described in more detail. The ultrasonic diagnostic apparatus automatically measures blood pressure using an external or internal sphygmomanometer at the same time as the measurement of the amount of distortion ends and the freeze state is reached. Then, the currently displayed elastic modulus value and elastic modulus image are corrected using the measured blood pressure value. When the tracking position information or strain amount stored in the storage unit 121 is read and the elastic modulus measured in the past is updated, the latest blood pressure value is used.

  In addition, the ultrasonic diagnostic apparatus measures blood pressure periodically during measurement of the amount of distortion (that is, every predetermined time interval or every predetermined heart rate), and always uses the latest blood pressure value. To calculate the elastic modulus automatically. The elasticity modulus can be further increased by predicting blood pressure fluctuations from regularly measured blood pressure values and estimating blood pressure at the time of strain measurement, or by using blood pressure obtained by averaging blood pressure values measured multiple times. Calculation accuracy can be improved.

  Furthermore, in the ultrasonic diagnostic apparatus, after the examiner determines the measurement cross section by the ultrasonic wave, the blood pressure is measured by an operation of a switch or the like, and then the elastic modulus is calculated by measuring the distortion amount by the ultrasonic wave over several heartbeats. Also good. You may make it stop ultrasonic transmission / reception automatically after elastic modulus measurement.

  Furthermore, by measuring blood pressure again after stopping ultrasonic transmission / reception, and using the blood pressure value estimated from the blood pressure value before and after measuring the amount of distortion using an operation such as linear interpolation or averaging, the elastic modulus is further calculated. Can improve the accuracy.

  In the above description, the blood pressure measurement unit 111 (that is, a sphygmomanometer) is provided inside the ultrasonic diagnostic apparatus, the control unit 100 and the blood pressure measurement unit 111 are connected, and the blood pressure measurement unit 111 is directly connected based on a command from the control unit 100. As shown in FIG. 2, the blood pressure measurement unit 111 (that is, the sphygmomanometer) is provided outside the ultrasonic diagnostic apparatus, and only the sphygmomanometer control unit 112 is provided therein, and the control unit 100 and the sphygmomanometer are controlled. The control unit 112 is connected, and the sphygmomanometer control unit 112 acquires the blood pressure value from the blood pressure measurement unit 111 based on a command from the control unit 100, and the blood pressure value acquired by the sphygmomanometer control unit 112 is used as the elastic modulus calculation unit 108. May be output.

したがって、この実施形態の場合、図３，４に示すように、粘性率演算部１０８’では、組織追跡部１０５又は記憶部１２１から送信される追跡位置情報と血液測定部１１１又は血圧計制御部１１２から送信される血圧をもとに歪み量εと弾性率Ｅｒを計算するとともに、これら歪み量εと血圧τから粘性率ηを計算する。粘性率は、弾性率と同様に、数値データ又は画像データとして画像合成部１０６に送信され、そこで断層画像データと合成されて表示部１０７に表示される。なお、弾性率と粘性率を同時に表示するようにしてもよい。これにより、診断に有用な情報を同時にさらに多く提供することができる。 In the above description, the elastic modulus is taken as an example of the tissue property value, but the tissue property value may be a tissue viscosity. More specifically, pressure (stress), strain, elastic modulus, and viscosity have the relationship shown in Equation 5 below.

Therefore, in the case of this embodiment, as shown in FIGS. 3 and 4, in the viscosity calculation unit 108 ′, the tracking position information transmitted from the tissue tracking unit 105 or the storage unit 121 and the blood measurement unit 111 or blood pressure monitor control unit Based on the blood pressure transmitted from 112, the strain amount ε and the elastic modulus Er are calculated, and the viscosity η is calculated from the strain amount ε and the blood pressure τ. Like the elastic modulus, the viscosity is transmitted as numerical data or image data to the image composition unit 106, where it is combined with tomographic image data and displayed on the display unit 107. Note that the elastic modulus and viscosity may be displayed simultaneously. Thereby, more useful information for diagnosis can be provided at the same time.

  By the way, in FIG. 1 to FIG. 4, the functions of the ultrasonic diagnostic apparatus are shown as independent blocks. For example, the control unit 100, tomographic image processing unit 104, tissue tracking unit 105, image synthesis unit 106, elastic modulus calculation The unit 108, the viscosity calculation unit 108 ′, and the like may be realized as software incorporated in the CPU.

1 is a block diagram of an ultrasonic diagnostic apparatus according to an embodiment of the present invention. The block diagram of the ultrasonic diagnosing device concerning other embodiments of the present invention. The block diagram of the ultrasonic diagnosing device concerning other embodiments of the present invention. The block diagram of the ultrasonic diagnosing device concerning other embodiments of the present invention. The figure which shows the measurement result displayed on the display part of an ultrasonic diagnosing device. The figure explaining the basic operation | movement which performs a tissue tracking from a phase difference. The figure explaining the basic operation | movement which calculates | requires distortion amount from a tissue tracking waveform.

Explanation of symbols

100: control unit, 101: probe, 102: transmission unit, 103: reception unit, 104: tomographic image processing unit, 105: tissue tracking unit, 106: image synthesis unit, 107: display unit, 108: elastic modulus calculation Part, 111: blood pressure measurement part, 112: sphygmomanometer control part, 120, 121: storage part.

Claims (6)

(A) transmitting / receiving means for transmitting ultrasonic waves to the subject and receiving ultrasonic waves reflected inside the subject;
(B) a tissue tracking means for tracking the movement of the tissue in the subject from the received signal created by the transmission / reception means based on the received ultrasound;
(C) noninvasive blood pressure measuring means for measuring the blood pressure of the subject;
(D) a control unit that outputs a first operation signal to the transmission / reception unit to drive the transmission / reception unit, and outputs a second operation signal to the blood pressure measurement unit to drive the blood pressure measurement unit;
(E) comprising tissue property value calculating means for calculating the tissue property value of the subject from the movement of the tissue tracked by the tissue tracking means and the blood pressure measured by the blood pressure measuring means;
(F) The blood pressure measuring means measures the blood pressure of the contributor based on the second operation signal output from the control means, and transmits the measured blood pressure to the tissue property calculating means. An ultrasonic diagnostic apparatus characterized by the above. The blood pressure measurement means includes a blood pressure measurement unit that measures the blood pressure of the subject, and a sphygmomanometer control unit that operates the blood pressure measurement unit to acquire the blood pressure of the subject from the blood pressure measurement unit,
The control unit operates the blood pressure measurement unit based on the second operation signal to cause the blood pressure monitor control unit to acquire the blood pressure of the subject and transmit the blood pressure to the tissue property calculation unit. The ultrasonic diagnostic apparatus according to claim 1.   3. The super blood pressure measurement unit according to claim 1, wherein the blood pressure measurement unit measures the blood pressure of the subject while or after the transmission / reception unit receives the ultrasound reflected by the subject. Ultrasonic diagnostic equipment.   The blood pressure measurement means performs blood pressure measurement a plurality of times to acquire a plurality of blood pressures, and obtains an average value of the acquired plurality of blood pressures or a value obtained by estimating a blood pressure value at the time of obtaining a strain amount from the acquired plurality of blood pressures. The ultrasonic diagnostic apparatus according to claim 1, wherein blood pressure is transmitted as a blood pressure to the property value calculation means.   The ultrasonic diagnostic apparatus according to claim 1, wherein the tissue property value is an elastic modulus of the tissue.   The ultrasonic diagnostic apparatus according to claim 1, wherein the tissue property value is a tissue viscosity.

Images