Ultrasonic diagnostic apparatus

Abstract

The invention provides an ultrasonic diagnostic apparatus. An ultrasound diagnostic device (1) is provided with: a first blood vessel wall detection unit (10) that analyzes a B-mode image including a short-axis image of a blood vessel and detects a blood vessel wall in the short-axis direction; a first blood vessel diameter calculation unit (11) that calculates a first blood vessel diameter on the basis of the blood vessel wall in the minor axis direction; a second blood vessel wall detection unit (12) that analyzes a B-mode image including a long-axis image of the blood vessel and detects a blood vessel wall in the long-axis direction; a second blood vessel diameter calculation unit (13) that calculates a second blood vessel diameter on the basis of the blood vessel wall in the longitudinal direction; a blood flow velocity calculation unit (15) that calculates a blood flow velocity on the basis of Doppler data within a Doppler gate set in the B-mode image; and a blood flow rate measurement unit (16) that measures the blood flow rate on the basis of the blood flow rate and the blood vessel wall in the long-axis direction or the short-axis direction, and that automatically measures the blood flow rate when the second blood vessel diameter is within a range determined with respect to the first blood vessel diameter.

Description

[0001] This application is a divisional application of a Chinese patent application with application number 202180014732.4 (PCT / JP2021 / 000019), application date January 4, 2021, and invention title "Ultrasonic diagnostic apparatus, control method for ultrasonic diagnostic apparatus, and processor for ultrasonic diagnostic apparatus". Technical Field

[0002] The present invention relates to an ultrasonic diagnostic apparatus for acquiring B-mode data and Doppler data. Background Art

[0003] Conventionally, as an apparatus for obtaining an image of the inside of a subject, an ultrasonic diagnostic apparatus is known. The ultrasonic diagnostic apparatus generally includes an ultrasonic probe having an oscillator array formed by arranging a plurality of elements. In a state where the ultrasonic probe is in contact with the body surface of the subject, an ultrasonic beam is emitted from the oscillator array toward the inside of the subject, and an ultrasonic echo from the subject is received by the oscillator array to acquire element data. Further, the ultrasonic diagnostic apparatus performs electrical processing on the obtained element data to generate an ultrasonic image of the part of the subject.

[0004] For example, Patent Document 1 discloses an ultrasonic diagnostic apparatus that measures the blood flow rate in a specified blood vessel region triggered by a user designating a blood vessel region on an ultrasonic image including a long-axis image of a blood vessel of a subject displayed on a display device.

[0005] Prior Art Documents

[0006] Patent Documents

[0007] Patent Document 1: WO 2019 / 187649 Summary of the Invention

[0008] Technical Problem to be Solved by the Invention

[0009] Here, in order to accurately measure the blood flow rate, it is desired that the long-axis image of the blood vessel included in the ultrasonic image corresponds to the longitudinal cross-section of the blood vessel (i.e., the measured blood vessel diameter) that passes through the center of the blood vessel and is maximized. However, in Patent Document 1, since the ultrasonic image including the long-axis image of the blood vessel is acquired after determining the position of the ultrasonic probe based on the judgment based on the user's experience or the like, an ultrasonic image including an appropriate long-axis image of the blood vessel may not be obtained. Further, in the invention of Patent Document 1, in order to measure the blood flow rate, it is necessary for the user to designate the blood vessel region, and thus there is still room for improvement in terms of simplifying the measurement.

[0010] The present invention is completed to solve such existing problems, and an object thereof is to provide an ultrasonic diagnostic apparatus capable of simply measuring while improving the measurement accuracy of blood flow volume.

[0011] Means for Solving Technical Problems

[0012] In order to achieve the above object, the ultrasonic diagnostic apparatus according to the present invention is characterized by including: an oscillator array that obtains a reception signal by transmitting and receiving ultrasonic waves to and from a subject; a B-mode processing unit that generates a B-mode image in which at least blood vessels are imaged based on the reception signal; a display device that displays the B-mode image generated by the B-mode processing unit; a first blood vessel wall detection unit that detects a blood vessel wall in the short-axis direction by analyzing the B-mode image of the short-axis image in which blood vessels are imaged; a first blood vessel diameter calculation unit that calculates a first blood vessel diameter based on the blood vessel wall in the short-axis direction detected by the first blood vessel wall detection unit; a second blood vessel wall detection unit that detects a blood vessel wall in the long-axis direction by analyzing the B-mode image of the long-axis image in which blood vessels are imaged; a second blood vessel diameter calculation unit that calculates a second blood vessel diameter based on the blood vessel wall in the long-axis direction detected by the second blood vessel wall detection unit; a gate setting unit that sets a Doppler gate in a blood vessel in the B-mode image of the long-axis image; a Doppler processing unit that obtains Doppler data within the Doppler gate; a blood flow velocity calculation unit that calculates a blood flow velocity based on the Doppler data; and a blood flow volume measurement unit that measures a blood flow volume based on any one of the detected blood vessel wall in the long-axis direction and the blood vessel wall in the short-axis direction and the calculated blood flow velocity. After the first blood vessel diameter calculation unit calculates the first blood vessel diameter, the second blood vessel wall detection unit detects the blood vessel wall in the long-axis direction, and the second blood vessel diameter calculation unit determines whether the second blood vessel diameter has a value within a range determined with respect to the first blood vessel diameter. When it is determined that the second blood vessel diameter has a value within the range determined with respect to the first blood vessel diameter, the process automatically transfers to the measurement of the blood flow volume.

[0013] The second blood vessel wall detection unit may set a search line for searching for a blood vessel wall in the long-axis direction on the B-mode image, and detect a blood vessel front wall and a blood vessel rear wall as the blood vessel wall in the long-axis direction based on the luminance distribution of the B-mode image on the set search line.

[0014] In this case, the second blood vessel wall detection unit may set detection point marks on the detected blood vessel front wall and blood vessel rear wall, respectively, and display them on the display device.

[0015] Furthermore, the gate setting unit may set a Doppler gate having a center position and size determined based on the coordinates of the blood vessel front wall and blood vessel rear wall detected by the second blood vessel wall detection unit.

[0016] Further, the second blood vessel wall detection unit can estimate the blood vessel traveling angle based on at least one of the detected blood vessel anterior wall and blood vessel posterior wall, and set the Doppler deflection angle such that the angle correction value with respect to the blood vessel traveling angle is within 60 degrees.

[0017] In this case, the B-mode processing unit can generate a B-mode image based on the B-mode deflection angle, which is set according to the blood vessel traveling angle estimated by the second blood vessel wall detection unit.

[0018] Further, the Doppler processing unit can generate a Doppler waveform image based on the Doppler data, and the display device can display both the B-mode image generated by the B-mode processing unit and the Doppler waveform image generated by the Doppler processing unit.

[0019] Furthermore, the Doppler processing unit generates a Doppler waveform image in parallel when the B-mode processing unit generates a B-mode image, and the blood flow rate is measured by the blood flow rate measurement unit after both the B-mode image and the Doppler waveform image are frozen.

[0020] Alternatively, furthermore, the Doppler processing unit acquires Doppler data within the Doppler gate to generate a Doppler waveform image after the B-mode image is frozen, and the blood flow rate is measured by the blood flow rate measurement unit after the Doppler waveform image is frozen.

[0021] Also, the blood flow rate can be automatically measured when the second blood vessel diameter calculated over a predetermined number of frames is maintained within a range determined with respect to the calculated first blood vessel diameter.

[0022] The control method of the ultrasonic diagnostic apparatus according to the present invention is characterized by including the following steps: generating at least a B-mode image in which a blood vessel is photographed based on a reception signal obtained by transmitting and receiving ultrasonic waves to a subject; displaying the B-mode image; detecting a blood vessel wall in the short-axis direction by analyzing a short-axis image of the blood vessel photographed in the B-mode image; calculating a first blood vessel diameter based on the detected blood vessel wall in the short-axis direction; detecting a blood vessel wall in the long-axis direction by analyzing a B-mode image in which a long-axis image of the blood vessel is photographed; calculating a second blood vessel diameter based on the detected blood vessel wall in the long-axis direction; setting a Doppler gate in the blood vessel on the B-mode image in which the long-axis image is photographed when the calculated second blood vessel diameter is within a predetermined range with respect to the calculated first blood vessel diameter; acquiring Doppler data within the Doppler gate; calculating a blood flow velocity based on the Doppler data; and measuring a blood flow rate based on any one of the detected blood vessel wall in the long-axis direction and the blood vessel wall in the short-axis direction and the calculated blood flow velocity.

[0023] The processor for an ultrasonic diagnostic apparatus according to the present invention is characterized by performing the following processes: generating at least a B-mode image in which blood vessels are captured, based on received signals obtained by transmitting and receiving ultrasonic waves to and from a subject; displaying the B-mode image; detecting the blood vessel wall in the short-axis direction by analyzing the short-axis image of the blood vessel captured in the B-mode image; calculating a first blood vessel diameter based on the detected blood vessel wall in the short-axis direction; detecting the blood vessel wall in the long-axis direction by analyzing the B-mode image of the long-axis image in which the blood vessel is captured; calculating a second blood vessel diameter based on the detected blood vessel wall in the long-axis direction; setting a Doppler gate within the blood vessel in the B-mode image in which the long-axis image is captured, when the calculated second blood vessel diameter is within a range determined relative to the calculated first blood vessel diameter; acquiring Doppler data within the Doppler gate; calculating a blood flow velocity based on the Doppler data; and measuring a blood flow volume based on either the detected blood vessel wall in the long-axis direction or the short-axis direction and the calculated blood flow velocity.

[0024] Advantages of the Invention

[0025] According to the present invention, there are provided: a first blood vessel wall detection unit that detects the blood vessel wall in the short-axis direction by analyzing the B-mode image of the short-axis image in which the blood vessel is captured; a first blood vessel diameter calculation unit that calculates a first blood vessel diameter based on the blood vessel wall in the short-axis direction; a second blood vessel wall detection unit that detects the blood vessel wall in the long-axis direction by analyzing the B-mode image of the long-axis image in which the blood vessel is captured; a second blood vessel diameter calculation unit that calculates a second blood vessel diameter based on the blood vessel wall in the long-axis direction; a gate setting unit that sets a Doppler gate within the blood vessel in the B-mode image in which the long-axis image is captured; a Doppler processing unit that acquires Doppler data within the Doppler gate; a blood flow velocity calculation unit that calculates a blood flow velocity based on the Doppler data; and a blood flow volume measurement unit that measures a blood flow volume based on either the blood vessel wall in the long-axis direction or the short-axis direction and the blood flow velocity. When the second blood vessel diameter calculated by the second blood vessel diameter calculation unit is within a range determined relative to the first blood vessel diameter calculated by the first blood vessel diameter calculation unit, the blood flow volume is automatically measured. Therefore, it is possible to simply perform the measurement while improving the measurement accuracy of the blood flow volume. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a block diagram showing the configuration of an ultrasonic diagnostic apparatus according to the first embodiment of the present invention.

[0027] Figure 2 is a block diagram showing the internal configuration of a receiving circuit in the first embodiment of the present invention.

[0028] Figure 3 is a block diagram showing the internal configuration of a B-mode processing unit in the first embodiment of the present invention.

[0029] Figure 4 It is a diagram schematically showing an example of a B-mode image representing a short-axis image of a blood vessel.

[0030] Figure 5 It is a diagram schematically showing an example of the luminance distribution of an image on a straight line crossing the short-axis image of a blood vessel.

[0031] Figure 6 It is a diagram schematically showing an example of a B-mode image representing a long-axis image of a blood vessel.

[0032] Figure 7 It is a diagram schematically showing an example of the luminance distribution of an image on a straight line crossing the long-axis image of a blood vessel.

[0033] Figure 8 It is a diagram schematically showing the traveling angle of a blood vessel on an estimated B-mode image.

[0034] Figure 9 It is a diagram schematically showing a method for setting a B-mode deflection angle in the first embodiment of the present invention.

[0035] Figure 10 It is a diagram schematically showing a method for setting a Doppler deflection angle in the first embodiment of the present invention.

[0036] Figure 11 It is a graph showing the relationship between the angle between an ultrasonic beam and blood flow and the estimation error of blood flow velocity.

[0037] Figure 12 4]It is a diagram schematically showing a B-mode image displayed on a display device and a Doppler gate set on the B-mode image in the first embodiment of the present invention.

[0038] Figure 13 It is a block diagram showing the internal structure of a Doppler processing unit in the first embodiment of the present invention.

[0039] Figure 14 It is a flowchart showing the operation of an ultrasonic diagnostic apparatus according to the first embodiment of the present invention.

[0040] Figure 15 It is a diagram schematically showing a B-mode image displayed on a display device and a Doppler waveform image in the first embodiment of the present invention.

[0041] Figure 16 It is a flowchart showing the operation of automatic blood flow measurement in the first embodiment of the present invention.

[0042] Figure 17It is a diagram schematically showing the B-mode image, Doppler waveform image, and measured blood flow volume displayed on the display device in the first embodiment of the present invention.

[0043] Figure 18 It is a diagram schematically showing the measurement point markers arranged for the short-axis image of the blood vessel.

[0044] Figure 19 It is a diagram schematically showing the measurement point markers arranged for the long-axis image of the blood vessel.

[0045] Figure 20 It is a flowchart showing the operation of the ultrasonic diagnostic apparatus according to the second embodiment of the present invention.

[0046] Figure 21 It is a block diagram schematically showing the time change of the blood vessel diameter in the second embodiment of the present invention.

[0047] Figure 22 It is a block diagram showing the structure of the ultrasonic diagnostic apparatus according to the third embodiment of the present invention.

[0048] Symbol Explanation

[0049] 1. 1A - Ultrasonic diagnostic apparatus, 2 - Transducer array, 3 - Transmission circuit, 4 - Reception circuit, 5 - Transceiver circuit, 6 - B - mode processing unit, 7 - Doppler processing unit, 8 - Display control unit, 9 - Display device, 10 - First blood vessel wall detection unit, 11 - First blood vessel diameter calculation unit, 12 - Second blood vessel wall detection unit, 13 - Second blood vessel diameter calculation unit, 14 - Gate setting unit, 15 - Blood flow velocity calculation unit, 16 - Blood flow volume measurement unit, 17 - Device control unit, 18 - Input device, 19 - Storage unit, 21 - Ultrasonic probe, 22 - Processor, 23 - Amplification unit, 24 - AD conversion unit, 25 - Beam former, 26 - Signal processing unit, 27 - DSC, 28 - Image processing unit, 29 - Quadrature demodulation unit, 30 - High - pass filter, 31 - High - speed Fourier transform unit, 32 - Doppler waveform image generation unit, 33 - Data memory, 41 - Ultrasonic diagnostic apparatus main body, A1, B1, B2, H - Angles, AL, JL - Lines, B - Blood vessel, BA - Blood vessel traveling angle, BR - Blood vessel region, BL - Blood vessel gradient line, C - Mid - point, E - Estimation error, D1 - Depth direction, D2 - Lateral direction, DA - Minimum diameter, DB - Maximum diameter, DF - First blood vessel diameter, DG - Doppler gate, DS - Second blood vessel diameter, G1, G2, G3, G4 - Curves, J1, J2, J3, J4 - Depths, K1, K2 - Luminance thresholds, L1, L2 - Differences, L1M - Maximum value, LG - Gate width, M1, M2, M3, M4 - Measurement point markers, MV - Measured value, NW - Network, P1 - Systole, P2 - Diastole, R1, R2 - Search regions, SL1, SL2 - Search lines, UB - B - mode image, UD - Doppler waveform image, W1 - Anterior blood vessel wall, W2 - Posterior blood vessel wall, WD - Doppler waveform, X1, X1M, X2, X2M, X3, X4 - Points. Detailed implementation manners

[0050] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0051] The descriptions of the constituent elements described below are based on representative embodiments of the present invention, but the present invention is not limited to such embodiments.

[0052] In addition, in this specification, the numerical range expressed by "~" means a range including the numerical values described before and after "~" as the lower limit value and the upper limit value.

[0053] Moreover, in this specification, "perpendicular" and "parallel" include the error ranges allowed in the technical field to which the present invention pertains. For example, "perpendicular" and "parallel" mean within a range of less than ±10 degrees with respect to strictly perpendicular or parallel, and preferably the error with respect to strictly perpendicular or parallel is 5 degrees or less, more preferably 3 degrees or less.

[0054] In this specification, "identical" and "the same" include the error ranges generally allowed in the technical field. Also, in this specification, when it is described as "all", "both", or "the entire surface", etc., in addition to the case of 100%, it also includes the error ranges generally allowed in the technical field, for example, cases including 99% or more, 95% or more, or 90% or more.

[0055] First Embodiment

[0056] Figure 1 shows the structure of the ultrasonic diagnostic apparatus 1 according to the first embodiment of the present invention. As Figure 1 shown, the ultrasonic diagnostic apparatus 1 includes an oscillator array 2, and a transmission circuit 3 and a reception circuit 4 are respectively connected to the oscillator array 2. Here, a transmission / reception circuit 5 is constituted by the transmission circuit 3 and the reception circuit 4. A B-mode (Brightness mode) processing unit 6 and a Doppler processing unit 7 are connected to the reception circuit 4, and a display device 9 is connected to these B-mode processing unit 6 and Doppler processing unit 7 via a display control unit 8.

[0057] Also, a first blood vessel wall detection unit 10 is connected to the B-mode processing unit 6, and a first blood vessel diameter calculation unit 11 is connected to the first blood vessel wall detection unit 10. Also, a second blood vessel wall detection unit 12 is connected to the B-mode processing unit 6, and a second blood vessel diameter calculation unit 13 and a gate setting unit 14 are connected to the second blood vessel wall detection unit 12. The gate setting unit 14 is connected to the Doppler processing unit 7. Also, a blood flow velocity calculation unit 15 is connected to the Doppler processing unit 7. Also, a blood flow volume measurement unit 16 is connected to the first blood vessel diameter calculation unit 11, the second blood vessel diameter calculation unit 13, and the blood flow velocity calculation unit 15. Also, the first blood vessel wall detection unit 10, the first blood vessel diameter calculation unit 11, the second blood vessel wall detection unit 12, the second blood vessel diameter calculation unit 13, the gate setting unit 14, and the blood flow volume measurement unit 16 are connected to the display control unit 8.

[0058] Also, a device control unit 17 is connected to the transmission / reception circuit 5, the B-mode processing unit 6, the Doppler processing unit 7, the display control unit 8, the first blood vessel wall detection unit 10, the first blood vessel diameter calculation unit 11, the second blood vessel wall detection unit 12, the second blood vessel diameter calculation unit 13, the gate setting unit 14, the blood flow velocity calculation unit 15, and the blood flow volume measurement unit 16. Also, an input device 18 and a storage unit 19 are connected to the device control unit 17. The device control unit 17 and the storage unit 19 are connected to each other so as to be able to perform two-way information exchange.

[0059] Moreover, the oscillator array 2 is included in the ultrasonic probe 21. The processor 22 for the ultrasonic diagnostic apparatus 1 is constituted by a B-mode processing unit 6, a Doppler processing unit 7, a display control unit 8, a first blood vessel wall detection unit 10, a first blood vessel diameter calculation unit 11, a second blood vessel wall detection unit 12, a second blood vessel diameter calculation unit 13, a gate setting unit 14, a blood flow velocity calculation unit 15, and a blood flow volume measurement unit 16.

[0060] Figure 1 The oscillator array 2 of the ultrasonic probe 21 shown has a plurality of oscillators arranged in one dimension or two dimensions. Each of these oscillators emits ultrasonic waves according to a drive signal supplied from the transmission circuit 3, and receives ultrasonic echoes from the subject to output a signal based on the ultrasonic echoes. Each oscillator is constituted, for example, by forming electrodes at both ends of a piezoelectric body including piezoelectric ceramics typified by PZT (Lead Zirconate Titanate), polymer piezoelectric elements typified by PVDF (Poly Vinylidene Di Fluoride), and piezoelectric single crystals typified by PMN-PT (Lead Magnesium Niobate-Lead Titanate solid solution).

[0061] The transmission circuit 3 includes, for example, a plurality of pulse generators, and adjusts the delay amount according to a transmission delay mode to supply respective drive signals to the plurality of oscillators, so that ultrasonic waves emitted from the plurality of oscillators of the oscillator array 2 form an ultrasonic beam. The transmission delay mode is selected according to a control signal from the apparatus control unit 17. Thus, when a pulsed or continuous wave voltage is applied to the electrodes of the oscillators of the oscillator array 2, the piezoelectric body expands and contracts, pulsed or continuous wave ultrasonic waves are generated from each oscillator, and an ultrasonic beam is formed by the combined wave of these ultrasonic waves.

[0062] The emitted ultrasonic beam is reflected, for example, at an object such as a part of the subject, and propagates toward the oscillator array 2 of the ultrasonic probe 21. The ultrasonic waves propagating toward the oscillator array 2 are received by each oscillator constituting the oscillator array 2. At this time, each oscillator constituting the oscillator array 2 expands and contracts by receiving the propagating ultrasonic echoes, thereby generating an electric signal, and outputs these electric signals to the reception circuit 4.

[0063] The reception circuit 4 processes the signal output from the oscillator array 2 according to a control signal from the apparatus control unit 17, thereby generating so-called RF (Radio Frequency) data, that is, reception data. As Figure 2 shown, the reception circuit 4 has a structure in which an amplifier unit 23, an AD (Analog Digital) conversion unit 24, and a beam former 25 are connected in series.

[0064] The amplifier section 23 amplifies the signals input from the respective oscillators constituting the oscillator array 2, and sends the amplified signals to the AD conversion section 24. The AD conversion section 24 converts the signals sent from the amplifier section 23 into digital data, and sends this data to the beam former 25. The beam former 25 performs so-called reception focusing processing by providing respective delays to the respective data converted by the AD conversion section 24 according to the speed of sound or the distribution of the speed of sound, and adding them together. The speed of sound or the distribution of the speed of sound is set according to the reception delay pattern, and the reception delay pattern is selected according to the control signal from the device control section 17. Through this reception focusing processing, reception data is obtained by coherently adding the respective data converted by the AD conversion section 24 and narrowing the focus of the ultrasonic echo.

[0065] As Figure 3 shown, the B-mode processing section 6 has a structure in which a signal processing section 26, a DSC (Digital Scan Converter) 27, and an image processing section 28 are connected in series in this order.

[0066] After correcting the reception data generated by the reception circuit 4 for the attenuation caused by distance according to the depth of the reflection position of the ultrasonic wave, the signal processing section 26 performs envelope detection processing, thereby generating tomographic image information related to the tissue in the subject, that is, a B-mode image signal.

[0067] The DSC 27 converts (raster-converts) the B-mode image signal generated by the signal processing section 26 into an image signal that follows the scanning method of a normal television signal.

[0068] After performing various necessary image processings such as gray-scale processing on the B-mode image signal input from the DSC 27, the image processing section 28 outputs the B-mode image signal to the display control section 8. Hereinafter, the B-mode image signal that has been image-processed by the image processing section 28 will be simply referred to as a B-mode image.

[0069] When the B-mode image generated by the B-mode processing section 6 includes a short-axis image of a blood vessel in the subject, the first blood vessel wall detection section 10 detects the blood vessel wall in the short-axis direction by analyzing the short-axis image of the blood vessel photographed in the B-mode image. Here, the short-axis image of the blood vessel refers to the cross-section of the blood vessel along the direction orthogonal to the traveling direction of the blood vessel.

[0070] When detecting the blood vessel wall in the short-axis direction, for example, as Figure 4As shown, the first blood vessel wall detection unit 10 sets a search area R1 for the blood vessel B at the central part in the azimuth direction, i.e., the lateral direction D2, which is orthogonal to the depth direction D1 of the B-mode image UB. Within the set search area R1, while scanning a virtual search line SL1 extending along the depth direction D1 of the B-mode image UB along the lateral direction D2, the brightness on the search line SL1 is detected to generate the brightness distribution of the image along the search line SL1 within the search area R1. For example, as Figure 5 shown, the brightness distribution of the image represents the relationship between the depth in the B-mode image UB and the brightness of the image on the search line SL1. In Figure 5 the example shown, the depth is plotted on the horizontal axis and the brightness is plotted on the vertical axis.

[0071] In addition, Figure 4 in, as an example of the search line SL1, a dotted line search line SL1 passing through a position relatively far from the center of the blood vessel B on the short-axis image of the blood vessel B and a solid line search line SL1 passing near the center of the blood vessel B are shown. And, Figure 5 in, as an example of the brightness distribution, a dotted line curve graph G1 corresponding to the dotted line search line SL1 and a solid line curve graph G2 corresponding to the solid line search line SL1 are shown.

[0072] Here, the change in the brightness of the image on the search line SL1 passing through the short-axis image of the blood vessel B is greater at two points X1, X2 corresponding to the blood vessel wall than at other points on the search line SL1. Therefore, for example, in Figure 5 the brightness distribution, two depths J1, J2 at which the brightness value becomes the maximum value greater than a constant brightness threshold K1 correspond to the two points X1, X2 corresponding to the blood vessel wall. And, when the search line SL1 is scanned along the lateral direction D2 on the short-axis image of the approximately circular blood vessel B, the value L1 of the difference between the depth J1 and the depth J2 in the brightness distribution, for example, increases from zero to the maximum value corresponding to the diameter of the blood vessel B and then decreases to zero as the search line SL1 is scanned from one end to the other end in the lateral direction D2 of the short-axis image of the blood vessel B. Thus, the value of the difference L1 calculated while scanning the search line SL1 along the lateral direction D2 on the short-axis image of the blood vessel B changes in a manner having a maximum value.

[0073] Therefore, the first blood vessel wall detection unit 10 can determine whether the short-axis image of the blood vessel is included in the B-mode image UB based on the luminance distribution generated while scanning the search line SL1 along the horizontal direction D2. For example, when calculating the difference L1 between the depths J1 and J2 in the luminance distribution while scanning the search line SL1 along the horizontal direction D2 and the calculated value of the difference L1 changes in a way that has a maximum value, the first blood vessel wall detection unit 10 can identify the case where the short-axis image of the blood vessel B exists within the search area R1 of the B-mode image UB. In this case, the first blood vessel wall detection unit 10 detects the trajectories of the points X1 and X2 corresponding to the depths J1 and J2 where the luminance value in the luminance distribution becomes the maximum as the blood vessel wall. And, the first blood vessel wall detection unit 10 detects the information on the positions of the points X1M and X2M corresponding to the depths J1M and J2M where the difference L1 calculated while scanning the search line SL1 along the horizontal direction D2 becomes the maximum value L1M, and sends it to the first blood vessel diameter calculation unit 11. The points X1M and X2M correspond to the intersection points of the search line SL1 passing through the center of the blood vessel B and the contour line of the short-axis image of the blood vessel B.

[0074] The first blood vessel diameter calculation unit 11 calculates the first blood vessel diameter corresponding to the diameter of the blood vessel B based on the information on the positions of the points X1M and X2M on the blood vessel wall received from the first blood vessel wall detection unit 10. As Figure 4 shown, the first blood vessel diameter calculation unit 11 can, for example, display the calculated first blood vessel diameter DF on the display device 9.

[0075] The second blood vessel wall detection unit 12 detects the blood vessel wall in the long-axis direction by analyzing the B-mode image UB that is generated based on the first blood vessel diameter DF calculated by the first blood vessel diameter calculation unit 11 and in which the long-axis image of the blood vessel B is captured. Here, the long-axis image of the blood vessel B refers to the longitudinal section of the blood vessel B along the traveling direction of the blood vessel B.

[0076] When detecting the blood vessel wall in the long-axis direction, for example, as Figure 6 shown, the second blood vessel wall detection unit 12 sets a search area R2 at the central part in the horizontal direction D2 of the B-mode image UB, and within the set search area R2, while scanning a virtual search line SL2 extending along the depth direction D1 along the horizontal direction D2, detects the luminance on the search line SL2 to generate a luminance distribution of the image along the search line SL2 as Figure 7 shown.

[0077] In addition, Figure 6 in, as an example of the search line SL2, a dotted-line search line SL2 and a solid-line search line SL2 arranged at a position different from the search line SL2 are shown. And, Figure 7Among them, as an example of a graph showing the luminance distribution, a dotted-line graph G3 corresponding to the dotted-line search line SL2 and a solid-line graph G4 corresponding to the solid-line search line SL2 are shown. The graph G3 and the graph G4 are offset from each other in the direction parallel to the horizontal axis, but the depth difference between the two points where the luminance becomes maximum is almost the same for both.

[0078] Here, similar to the luminance change of the image on the search line SL1 passing through the short-axis image of the blood vessel B, the luminance change of the image on the search line SL2 passing through the long-axis image of the blood vessel B is greater at two points X3 and X4 corresponding to the blood vessel wall than at other points on the search line SL2. Therefore, for example, in Figure 7 the luminance distribution, two depths J3 and J4 where the luminance value becomes the maximum value greater than the constant luminance threshold K2 correspond to the two points X3 and X4 corresponding to the blood vessel wall. And, as Figure 6 shown, when the search line SL2 is scanned along the lateral direction D2 on the long-axis image of the tubular blood vessel B extending substantially along the lateral direction D2, it is desirable that even when the search line SL2 is scanned along the lateral direction D2, the difference L2 between the depth J3 and the depth J4 in the luminance distribution hardly changes, and even if it changes, the range of change is negligible.

[0079] Therefore, the second blood vessel wall detection unit 12 can determine whether the long-axis image of the blood vessel B is included in the B-mode image UB based on the luminance distribution generated while scanning the search line SL2 along the lateral direction D2. For example, when calculating the difference L2 between the depth J3 and the depth J4 in the luminance distribution while scanning the search line SL2 along the lateral direction D2 and the calculated value of the difference L2 is almost constant, the second blood vessel wall detection unit 12 can determine that the long-axis image of the blood vessel B exists within the search region R2 of the B-mode image UB. Here, the value of the difference L2 being almost constant means, for example, that the difference between the maximum value and the minimum value of the difference L2 is below a specified value.

[0080] And, the second blood vessel wall detection unit 12 detects the position of the relatively shallower depth J3 among the depths J3 and J4 where the detected luminance value becomes the maximum as the position of the blood vessel front wall W1, and detects the position of the relatively deeper depth J4 as the position of the blood vessel rear wall W2. And, the second blood vessel wall detection unit 12 sends the information on the positions of the detected blood vessel front wall W1 and blood vessel rear wall W2 to the second blood vessel diameter calculation unit 13.

[0081] The second blood vessel diameter calculation unit 13 calculates the second blood vessel diameter of the blood vessel B based on the information on the positions of the blood vessel front wall W1 and blood vessel rear wall W2 detected by the second blood vessel wall detection unit 12. For example, the second blood vessel diameter calculation unit 13 calculates the maximum distance among the distances in the depth direction D1 between the blood vessel front wall W1 and the blood vessel rear wall W2 as the second blood vessel diameter. As Figure 6As shown, the second blood vessel wall detection unit 12 displays the calculated second blood vessel diameter DS on the display device 9.

[0082] Furthermore, the second blood vessel diameter calculation unit 13 compares the calculated second blood vessel diameter DS with the first blood vessel diameter DF calculated by the first blood vessel diameter calculation unit 11 to determine whether the second blood vessel diameter DS has a value within a predetermined range including the first blood vessel diameter DF. When it is determined that the second blood vessel diameter DS has a value within the predetermined range, the second blood vessel diameter calculation unit 13 determines that a B-mode image UB including the long-axis image of the blood vessel B representing the longitudinal section passing through the center of the blood vessel B has been obtained, and sends the value of the second blood vessel diameter DS within the predetermined range to the blood flow measurement unit 16.

[0083] Furthermore, the second blood vessel wall detection unit 12 estimates the blood vessel traveling angle in the B-mode image UB. For example, the second blood vessel wall detection unit 12 can estimate the inclination of the blood vessel B by estimating the straight lines passing through a plurality of positions on the detected blood vessel front wall W1 and the straight lines passing through a plurality of positions on the detected blood vessel rear wall W2, and averaging the estimated inclinations of the two straight lines. In Figure 6 the example shown, a virtual blood vessel gradient line BL representing the gradient of the blood vessel B is obtained. Furthermore, the second blood vessel wall detection unit 12 can also estimate the inclination of the blood vessel B based on either the straight line passing through a plurality of positions on the detected blood vessel front wall W1 or the straight line passing through a plurality of positions on the detected blood vessel rear wall W2.

[0084] Furthermore, for example, as Figure 8 shown, the second blood vessel wall detection unit 12 can estimate the angle between the obtained blood vessel gradient line BL and a virtual straight line AL along the depth direction D1 of the B-mode image UB as the blood vessel traveling angle BA.

[0085] Furthermore, the second blood vessel wall detection unit 12 uses the estimated blood vessel traveling angle BA to set the B-mode deflection angle. For example, as Figure 9 shown, an angle A1 or the like is set as the B-mode deflection angle. The B-mode deflection angle is defined as the angle between the scanning line when the B-mode processing unit 6 generates the B-mode image UB and the straight line AL along the depth direction D1 in the B-mode image UB. Here, in order to obtain a B-mode image UB that clearly shows the blood vessel front wall W1 and the blood vessel rear wall W2, the second blood vessel wall detection unit 12 sets the B-mode deflection angle such that the angle between the scanning line when generating the B-mode image UB and the blood vessel gradient line BL is close to 90 degrees.

[0086] For example, the second blood vessel wall detection unit 12 can use the blood vessel traveling angle BA, a predetermined angle A1, and a predetermined angle A2 greater than the angle A1. When the relationship 90 - BA < A1 / 2 is satisfied, the B-mode deflection angle is set to 0 degrees. When the relationship A1 / 2 ≤ 90 - BA < A2 / 2 is satisfied, as Figure 9 shown, the B-mode deflection angle is set to the angle A1. When the relationship A2 / 2 ≤ 90 - BA is satisfied, the B-mode deflection angle is set to the angle A2. Here, for example, the angle A1 can be preset to 7.5 degrees, and the angle A2 can be preset to 15 degrees.

[0087] Moreover, the second blood vessel wall detection unit 12 sets the Doppler deflection angle using the estimated blood vessel traveling angle BA. For example, as Figure 10 shown, the angle B1 or the angle B2, etc. is set as the Doppler deflection angle. Here, the Doppler deflection angle refers to the inclination angle of the scan line when acquiring Doppler data.

[0088] Here, it is known that there is a relationship as Figure 11 shown between the angle H between the ultrasonic beam emitted into the blood vessel B to acquire Doppler data and the blood flow in the blood vessel B and the estimation error E of the blood flow velocity calculated from the acquired Doppler data. According to this relationship, it can be known that the larger the angle H of the ultrasonic beam with respect to the blood flow, the exponentially larger the estimation error E of the blood flow velocity. Also, it can be known that the larger the error of the angle correction with respect to the blood vessel traveling angle, the larger the estimation error E of the blood flow velocity.

[0089] Moreover, regarding the angle H between the ultrasonic beam and the blood flow and the estimation error E of the blood flow velocity, it is known that: for example, as long as the angle H between the ultrasonic beam and the blood flow is kept within 60 degrees, even if there is an error of 3 degrees in the angle correction with respect to the blood vessel traveling angle, the estimation error E of the blood flow velocity will fall within 10%, and thus the blood flow velocity can be accurately obtained. Here, in order to accurately calculate the blood flow velocity, the second blood vessel wall detection unit 12 sets the Doppler deflection angle so that the angle correction value with respect to the blood vessel traveling angle BA, that is, the angle between the scan line and the blood vessel gradient line BL, becomes within 60 degrees.

[0090] For example, the second blood vessel wall detection unit 12 can use the blood vessel traveling angle BA and, as Figure 10 shown, a predetermined angle B1 and an angle B2 greater than the angle B1. When the relationship BA < 60 is satisfied, the Doppler deflection angle is set to 0 degrees. When the relationship 60 ≤ BA < 60 + B1 is satisfied, the Doppler deflection angle is set to the angle B1. When the relationship 60 + B1 ≤ BA is satisfied, the Doppler deflection angle is set to the angle B2. Here, for example, the angle B1 can be preset to 15 degrees, and the angle B2 can be preset to 30 degrees.

[0091] As Figure 12 shown, the gate setting unit 14 sets a Doppler gate DG having a center position and a size determined based on the coordinates of the blood vessel front wall W1 and the coordinates of the blood vessel rear wall W2 detected by the second blood vessel wall detection unit 12 within the blood vessel region BR in the B-mode image UB. At this time, the gate setting unit 14 can, for example, set the midpoint C of the positions of two points X3 and X4 detected by the second blood vessel wall detection unit 12 as the position of the blood vessel front wall W1 and the position of the blood vessel rear wall W2 as the center position of the Doppler gate DG, and set the Doppler gate DG on a virtual straight line JL that passes through the midpoint C and is inclined by the set Doppler deflection angle with respect to the depth direction D1.

[0092] In addition, the straight line JL corresponds to a scan line. And the gate setting unit 14 can set the length calculated by multiplying the second blood vessel diameter DS calculated by the second blood vessel wall detection unit 12 by a predetermined value as the gate width LG of the Doppler gate DG. Here, the predetermined value multiplied by the second blood vessel diameter DS is a number greater than 0 and equal to or less than 1.00, such as 0.75, and is determined, for example, by an input operation of a user via the input device 18.

[0093] And, as Figure 12 shown, the gate setting unit 14 superimposes the set Doppler gate DG on the B-mode image UB and displays it on the display device 9.

[0094] The Doppler processing unit 7 acquires Doppler data within the Doppler gate DG set by the gate setting unit 14 in the blood vessel region BR, and generates a Doppler waveform image based on the acquired Doppler data. As Figure 13 shown, the Doppler processing unit 7 has a structure in which an orthogonal demodulation unit 29, a high-pass filter 30, a fast Fourier transform unit (Fast Fourier Transformer) 31, and a Doppler waveform image generation unit 32 are connected in series in sequence, and a data memory 33 is connected to the output terminal of the orthogonal demodulation unit 29.

[0095] The orthogonal demodulation unit 29 mixes a carrier signal of a reference frequency in the received data generated by the receiving circuit 4, performs orthogonal demodulation on the received data, and converts it into complex data.

[0096] The high-pass filter 30 functions as a so-called wall filter, which removes frequency components originating from the movement of the internal tissues of the subject from the complex data generated by the orthogonal demodulation unit 29.

[0097] The fast Fourier transform unit 31 performs frequency analysis by performing Fourier transform on the complex data of a plurality of sample points, obtains the blood flow velocity, and generates a spectrum signal.

[0098] The Doppler waveform image generation unit 32 generates a Doppler waveform image signal by arranging the spectral signals generated by the high-speed Fourier transform unit 31 on the time axis and representing the magnitudes of the respective frequency components with brightness. Hereinafter, the Doppler waveform image signal generated by the Doppler waveform image generation unit 32 will be simply referred to as a Doppler waveform image.

[0099] Moreover, the data memory 33 stores the complex data converted from the received data by the quadrature detector 29.

[0100] The blood flow velocity calculation unit 15 calculates the blood flow velocity by a so-called pulsed Doppler method based on the Doppler data acquired by the Doppler processing unit 7. In addition, the blood flow velocity calculation unit 15 may also calculate the average blood flow velocity for each cardiac cycle.

[0101] Assuming that the blood vessel has a circular cross section, the blood flow volume measurement unit 16 calculates the cross-sectional area of the blood vessel B based on the second blood vessel diameter DS corresponding to the diameter of the blood vessel B calculated by the second blood vessel diameter calculation unit 13. Then, the blood flow volume measurement unit 16 measures the blood flow volume representing the volume of blood flowing through the blood vessel B per unit time based on the calculated cross-sectional area of the blood vessel B and the blood flow velocity calculated by the blood flow velocity calculation unit 15.

[0102] The device control unit 17 controls each unit of the ultrasonic diagnostic device 1 based on programs pre-stored in the storage unit 19 and the input operations performed by the user via the input device 18.

[0103] Under the control of the device control unit 17, the display control unit 8 performs predetermined processing on the B-mode image UB generated by the B-mode processing unit 6, the Doppler waveform image generated by the Doppler processing unit 7, etc., and displays the B-mode image UB, the Doppler waveform image, etc. on the display device 9.

[0104] The display device 9 displays the B-mode image UB, the Doppler waveform image, etc. under the control of the display control unit 8, and includes, for example, display devices such as an LCD (Liquid Crystal Display) and an organic EL display (Organic Electroluminescence Display).

[0105] The input device 18 is for the user to perform input operations, and may be configured to include a keyboard, a mouse, a trackball, a touchpad, a touch panel, etc.

[0106] The storage unit 19 stores the operation programs of the ultrasonic diagnostic apparatus 1 and the like, and recording media such as flash memories, HDDs (Hard Disk Drives), SSDs (Solid State Drives), FDs (Flexible Disks), MO optical discs (Magneto-Optical discs), MTs (Magnetic Tapes), RAMs (Random Access Memories), CDs (Compact Discs), DVDs (Digital Versatile Discs), SD cards (Secure Digital cards), USB memories (Universal Serial Bus memories), or servers, etc. can be used.

[0107] In addition, the processor 22 having the B-mode processing unit 6, Doppler processing unit 7, display control unit 8, first blood vessel wall detection unit 10, first blood vessel diameter calculation unit 11, second blood vessel wall detection unit 12, second blood vessel diameter calculation unit 13, gate setting unit 14, blood flow velocity calculation unit 15, blood flow volume measurement unit 16, and apparatus control unit 17 is composed of a CPU (Central Processing Unit) and a control program for causing the CPU to perform various processes, but an FPGA (Field Programmable Gate Array), DSP (Digital Signal Processor), ASIC (Application Specific Integrated Circuit), GPU (Graphics Processing Unit), or other ICs (Integrated Circuits) can also be used to compose it, or they can be combined to compose it.

[0108] Moreover, a part or all of the B-mode processing unit 6, Doppler processing unit 7, display control unit 8, first blood vessel wall detection unit 10, first blood vessel diameter calculation unit 11, second blood vessel wall detection unit 12, second blood vessel diameter calculation unit 13, gate setting unit 14, blood flow velocity calculation unit 15, blood flow volume measurement unit 16, and apparatus control unit 17 of the processor 22 can be integrated into one CPU or the like to compose it.

[0109] Hereinafter, Figure 14 the operation of the ultrasonic diagnostic apparatus 1 in the first embodiment will be described in detail using the

[0110] First, in step S1, in order to enable the user to capture a short-axis image of the blood vessel B of the subject, a B-mode image UB is generated in a state where the ultrasonic probe 21 is in contact with the body surface of the subject, and the generated B-mode image UB is displayed on the display device 9. When generating the B-mode image UB, ultrasonic beams are emitted from a plurality of oscillators of the oscillator array 2 according to a drive signal from the transmission circuit 3, and reception signals are output from each oscillator that has received ultrasonic echoes from the subject to the reception circuit 4. After being amplified by the amplifier unit 23 and subjected to AD conversion by the AD conversion unit 24, they are phase-combined and added by the beam former 25 to generate reception data. This reception data becomes a B-mode image signal after being subjected to envelope detection processing by the signal processing unit 26 in the B-mode processing unit 6, and is output to the display control unit 8 via the DSC 27 and the image processing unit 28, so that the B-mode image UB is displayed on the display device 9 under the control of the display control unit 8.

[0111] In step S2, the first blood vessel wall detection unit 10 sets a search area R1 in the B-mode image UB generated in step S1, and determines whether there is a short-axis image of the blood vessel B within the set search area R1. At this time, for example, as Figure 4 shown, the first blood vessel wall detection unit 10 scans the virtual search line SL1 extending in the depth direction D1 in the search area R1 along the lateral direction D2 while detecting the brightness of the image on the search line SL1 to generate a Figure 5 brightness distribution as shown.

[0112] The first blood vessel wall detection unit 10 calculates the difference L1 between two depths J1 and J2 at which the brightness value in the generated brightness distribution becomes greater than a constant brightness threshold K1 while scanning the search line SL1 along the lateral direction D2. For example, when the value of the difference L1 calculated while scanning the search line SL1 from one end to the other end in the lateral direction D2 of the search area R1 changes in such a way as to have a maximum value, the first blood vessel wall detection unit 10 determines that there is a short-axis image of the blood vessel B within the search area R1. And when the value of the difference L1 does not change in such a way as to have a maximum value and is almost constant, the first blood vessel wall detection unit 10 determines that there is no short-axis image of the blood vessel B within the search area R1.

[0113] In step S2, when it is determined that there is no short-axis image of the blood vessel B within the search area R1, the process returns to step S1, and while the user adjusts the position and orientation of the ultrasonic probe 21, the B-mode image UB is generated.

[0114] In step S2, when it is determined that there is a short-axis image of the blood vessel B in the search area R1, the first blood vessel wall detection unit 10 detects the trajectories of the points X1 and X2 corresponding to the depths J1 and J2 at which the luminance value in the luminance distribution becomes maximum as the blood vessel wall. Further, the first blood vessel wall detection unit 10 transmits the information on the positions of the points X1M and X2M corresponding to the depths J1M and J2M at which the difference L1 calculated while scanning the search line SL1 along the horizontal direction D2 becomes the maximum value L1M to the first blood vessel diameter calculation unit 11.

[0115] In step S3, the first blood vessel diameter calculation unit 11 calculates a first blood vessel diameter DF corresponding to the diameter of the blood vessel B by measuring the distance between the points X1M and X2M on the blood vessel wall corresponding to the depths J1M and J2M at which the difference L1 detected in step S2 becomes maximum. As Figure 4 shown, the first blood vessel diameter calculation unit 11 displays the calculated first blood vessel diameter DF on the display device 9.

[0116] In the next step S4, in order to capture a long-axis image of the blood vessel B, the user changes the orientation of the ultrasonic probe 21 to generate a B-mode image UB.

[0117] In step S5, the second blood vessel wall detection unit 12 determines whether there is a long-axis image of the blood vessel B in the B-mode image UB generated in step S4. At this time, for example, as Figure 6 shown, the second blood vessel wall detection unit 12 sets a search area R2 on the B-mode image UB, and within the set search area R2, while scanning a virtual search line SL2 extending along the detection depth direction D1 along the horizontal direction D2, detects the luminance on the search line SL2. Thereby, the second blood vessel wall detection unit 12 generates a luminance distribution as Figure 7 shown.

[0118] The second blood vessel wall detection unit 12 calculates the difference L2 between two depths J3 and J4 at which the luminance value in the luminance distribution generated while scanning the search line SL2 along the horizontal direction D2 becomes the maximum value greater than a constant luminance threshold K2, and when the calculated value of the difference L2 is almost constant, determines that there is a long-axis image of the blood vessel B in the search area R2 of the B-mode image UB, and when the value of the difference L2 does not have an almost constant value, determines that there is no long-axis image of the blood vessel B in the search area R2.

[0119] In step S5, when it is determined that there is no long-axis image of the blood vessel B in the B-mode image UB, the process returns to step S4, and the user adjusts the position and orientation of the ultrasonic probe 21 to generate a new B-mode image UB.

[0120] In step S5, when it is determined that there is a major axis image of blood vessel B in the B-mode image UB, the second blood vessel wall detection unit 12 detects the positions of depths J3 and J4 where the luminance values are maximum in the detected major axis image of blood vessel B as the position of the anterior blood vessel wall W1 and the position of the posterior blood vessel wall W2, respectively.

[0121] In step S6, the second blood vessel diameter calculation unit 13 calculates a second blood vessel diameter DS corresponding to the diameter of blood vessel B based on the major axis image of blood vessel B detected in step S5. For example, the second blood vessel diameter calculation unit 13 calculates the maximum distance among the distances in the depth direction D1 between the anterior blood vessel wall W1 and the posterior blood vessel wall W2 as the second blood vessel diameter DS. As Figure 6 shown, the second blood vessel diameter calculation unit 13 displays the calculated second blood vessel diameter DS on the display device 9.

[0122] In step S7, the second blood vessel diameter calculation unit 13 compares the calculated second blood vessel diameter DS with the first blood vessel diameter DF calculated in step S3 to determine whether the second blood vessel diameter DS has a value within a predetermined range including the first blood vessel diameter DF. The predetermined range is set, for example, to a range having a lower limit value that is a specified value lower than the first blood vessel diameter DF and an upper limit value that is a specified value higher than the first blood vessel diameter DF.

[0123] In step S7, when it is determined that the second blood vessel diameter DS is outside the predetermined range, the process returns to step S4, and the processes of steps S4 to S7 are performed again. At this time, while the user confirms the value of the second blood vessel diameter DS displayed on the display device 9, the user adjusts the position of the ultrasonic probe 21 so that the value of the second blood vessel diameter DS approaches the value of the first blood vessel diameter DF.

[0124] In step S7, when it is determined that the second blood vessel diameter DS is within the predetermined range, it is determined that the B-mode image UB including the major axis image of blood vessel B having the first blood vessel diameter DF, that is, the major axis image of blood vessel B representing a longitudinal section passing through the center of blood vessel B, has been obtained, and the process proceeds to step S8.

[0125] In step S8, the second blood vessel wall detection unit 12 uses the B-mode image UB including the major axis image of blood vessel B having the second blood vessel diameter DS within the predetermined range obtained in step S7 to estimate the gradient of blood vessel B, and estimates the blood vessel traveling angle BA based on the estimated gradient of blood vessel B. The second blood vessel wall detection unit 12 can, for example, estimate the gradient of blood vessel B by estimating a straight line passing through a plurality of positions on the anterior blood vessel wall W1 detected in step S5 and a straight line passing through a plurality of positions on the posterior blood vessel wall W2 and averaging the inclinations of the two estimated straight lines, and thus as Figure 8As shown, a virtual blood vessel gradient line BL representing the gradient of blood vessel B is obtained. The second blood vessel wall detection unit 12 can estimate the angle between the obtained blood vessel gradient line BL and a virtual straight line AL along the depth direction D1 of the B-mode image UB as the blood vessel traveling angle BA.

[0126] In the next step S9, the second blood vessel wall detection unit 12 uses the blood vessel traveling angle BA estimated in step S8 to set a B-mode deflection angle representing the inclination angle of the scan line when the B-mode processing unit 6 generates the B-mode image UB. At this time, for example, the second blood vessel wall detection unit 12 can use the blood vessel traveling angle BA, Figure 9 the predetermined angle A1 shown, and the predetermined angle A2 greater than the angle A1. When the relationship 90 - BA < A1 / 2 is satisfied, the B-mode deflection angle is set to 0 degrees. When the relationship A1 / 2 ≤ 90 - BA < A2 / 2 is satisfied, the B-mode deflection angle is set to the angle A1. When the relationship A2 / 2 ≤ 90 - BA is satisfied, the B-mode deflection angle is set to the angle A2. Here, for example, the angle A1 can be preset to 7.5 degrees, and the angle A2 can be preset to 15 degrees.

[0127] In step S10, the second blood vessel wall detection unit 12 uses the blood vessel traveling angle BA estimated in step S8 to set a Doppler deflection angle representing the inclination angle of the scan line when the Doppler processing unit 7 acquires Doppler data. At this time, for example, the second blood vessel wall detection unit 12 can use the blood vessel traveling angle BA, such as Figure 10 the predetermined angle B1 shown and the angle B2 greater than the angle B1. When the relationship BA < 60 is satisfied, the Doppler deflection angle is set to 0 degrees. When the relationship 60 ≤ BA < 60 + B1 is satisfied, the Doppler deflection angle is set to the angle B1. When the relationship 60 + B1 ≤ BA is satisfied, the Doppler deflection angle is set to the angle B2. Here, for example, the angle B1 can be preset to 15 degrees, and the angle B2 can be preset to 30 degrees.

[0128] In step S11, as Figure 12As shown, the gate setting unit 14 sets a Doppler gate DG having a center position and size determined based on the coordinates of the blood vessel front wall W1 and the coordinates of the blood vessel rear wall W2 detected in step S5 within the blood vessel region BR on the B-mode image UB used for estimating the blood vessel traveling angle BA in step S8. At this time, the gate setting unit 14 can, for example, set the midpoint C of the positions of the two points X3 and X4 detected as the position of the blood vessel front wall W1 and the position of the blood vessel rear wall W2 in step S5 as the center position of the Doppler gate DG, and set the length calculated by multiplying the second blood vessel diameter DS measured in step S6 by a predetermined value as the gate width LG of the Doppler gate DG. Here, the predetermined value multiplied by the second blood vessel diameter DS is a number greater than 0 and equal to or less than 1.00, such as 0.75, and can be determined, for example, by an input operation of the user via the input device 18.

[0129] And, as Figure 12 shown, the gate setting unit 14 superimposes the set Doppler gate DG on the B-mode image UB and displays it on the display device 9.

[0130] In step S12, the Doppler processing unit 7 starts continuous generation of the Doppler waveform image and displays the generated Doppler waveform image on the display device 9. At this time, as Figure 12 shown, the Doppler processing unit 7 acquires the Doppler data within the Doppler gate DG set in step S10, continuously generates the Doppler waveform image based on the acquired Doppler data, and displays the generated Doppler waveform image on the display device 9. Also, the B-mode processing unit 6 starts continuous generation of the B-mode image UB and displays the generated B-mode image UB on the display device 9. Thereby, the two images, the B-mode image UB and the Doppler waveform image, are continuously generated, and as Figure 17 shown, the B-mode image UB and the Doppler waveform image UD are displayed on the display device 9.

[0131] In step S13, adjustment of the Doppler waveform WD in the Doppler waveform image UD generated in step S11 is performed so that the Doppler processing unit 7 can accurately acquire the Doppler data. Usually, as Figure 15As shown, the Doppler waveform WD changes periodically with the heartbeat. Therefore, for example, the adjustment of the Doppler waveform WD is performed starting from the time points of the start position and the end position of the detected heartbeat cycle. Moreover, as the adjustment of the Doppler waveform WD, it includes the adjustment of the position of the baseline which is the horizontal axis of the graph of the Doppler waveform WD and the adjustment of the scale of the vertical axis of the Doppler waveform WD. When adjusting the Doppler waveform WD, not only the display of the Doppler waveform WD in the display device 9 is adjusted, but also the repetition frequency of the ultrasonic pulses emitted from the oscillator array 2 of the ultrasonic probe 21 to the subject's body through the control of the transmission circuit 3 by the device control unit 17 is adjusted. Thus, for example, the Doppler waveform WD is adjusted so that the maximum value and the minimum value of the Doppler waveform WD fall within 70% of the scale of the vertical axis.

[0132] Normally, the blood flow velocity in the blood vessel increases during the systolic phase of the heart and decreases during the diastolic phase of the heart. Therefore, as Figure 15 shown, the change amount of the Doppler waveform WD is larger during the systolic phase P1 and the change amount of the Doppler waveform WD is smaller during the diastolic phase P2. Here, in step S14, the cycle information of the Doppler waveform WD is acquired, and based on the acquired cycle information, it is determined whether the current time point is the diastolic phase P2 of the subject's heart. In the case where it is determined that the current time point is not the diastolic phase P2 of the subject's heart, the process of step S14 is performed again. In the case where it is determined that the current time point is the diastolic phase P2 of the subject's heart, the process proceeds to step S15.

[0133] In step S15, the display of the two images, the B-mode image UB and the Doppler waveform image UD, displayed on the display device 9 is frozen. Here, freezing the display of the B-mode image UB and the Doppler waveform image UD means that in the state where the B-mode image UB continuously generated by the B-mode processing unit 6 and the Doppler waveform image UD continuously generated by the Doppler processing unit 7 are displayed on the display device 9, the display of the B-mode image UB and the Doppler waveform image UD is temporarily stopped, and a static B-mode image UB and a static Doppler waveform image UD are displayed on the display device 9.

[0134] Thus, the Doppler data during the diastolic phase P2 with a smaller change amount of the Doppler waveform WD can be used for the measurement of blood flow volume.

[0135] In the next step S16, the blood flow volume in the blood vessel region BR is automatically measured. The flowchart shown in Figure 16 is used to explain this step S16. Step S16 consists of steps S18 to S20.

[0136] First, in step S18, the blood flow volume measurement unit 16 assumes that the blood vessel B has a circular cross-section, and calculates the cross-sectional area of the blood vessel B based on the second blood vessel diameter DS determined to be within the predetermined range in step S7.

[0137] Next, in step S19, the blood flow velocity calculation unit 15 calculates the blood flow velocity based on the Doppler data acquired by the Doppler processing unit 7 when freezing and displaying the B-mode image UB and the Doppler waveform image UD in step S15. At this time, the blood flow velocity calculation unit 15 may also calculate the average blood flow velocity within the cardiac cycle.

[0138] In the next step S20, the blood flow measurement unit 16 calculates the blood flow rate representing the volume of blood flowing through the blood vessel B per unit time based on the cross-sectional area of the blood vessel B calculated in step S18 and the blood flow velocity calculated in step S19.

[0139] Thus, the automatic measurement of the blood flow rate in step S16 is completed.

[0140] In step S17, the measurement result of the blood flow rate obtained in step S16 is displayed on the display device 9. For example, as Figure 17 shown, the measured value MV of the blood flow rate is displayed on the display device 9 together with the B-mode image UB and the Doppler waveform image UD.

[0141] Thus, if the measured value MV of the blood flow rate is displayed on the display device 9, the operation of the ultrasonic diagnostic apparatus 1 is terminated.

[0142] In summary, according to the ultrasonic diagnostic apparatus 1 according to the first embodiment of the present invention, the first blood vessel diameter DF is calculated based on the B-mode image UB representing the short-axis image of the blood vessel B, the B-mode image UB representing the long-axis image passing through the center of the blood vessel B is accurately obtained based on the first blood vessel diameter DF, and the blood flow rate is measured using the B-mode image UB representing the obtained long-axis image of the blood vessel B. Therefore, it is possible to reduce the fluctuation of the measurement accuracy of the blood flow rate caused by the user adjusting the position of the ultrasonic probe 21 on the surface of the subject, thereby improving the measurement accuracy.

[0143] Moreover, by automatically measuring the blood flow rate by obtaining the B-mode image UB representing the long-axis image passing through the center of the blood vessel B and displaying the measurement result of the blood flow rate on the display device 9, it is possible to simply measure the blood flow rate.

[0144] In particular, although not shown, even in a case where the display device 9 is constituted by a small portable display and the user holds the display device 9 in one hand and the ultrasonic probe 21 in the other hand and the user cannot spare both hands, according to the ultrasonic diagnostic apparatus 1 according to the first embodiment of the present invention, the user does not need to perform an operation via the input device 18 or the like, and thus it is also possible to simply measure the blood flow rate.

[0145] In addition, in step S2, the first blood vessel wall detection unit 10 sets a search area R1 on the B-mode image UB and searches for the short-axis image of the blood vessel B within the set search area R1. However, it is also possible to search for the short-axis image of the blood vessel B within the entire B-mode image UB. However, considering reducing the computational amount required for the search process of the blood vessel B to identify the short-axis image of the blood vessel B as early as possible, it is preferable to search for the short-axis image of the blood vessel B within the search area R1.

[0146] Similarly, in step S5, it is also possible to search for the long-axis image of the blood vessel B within the entire B-mode image UB. However, from the perspective of identifying the long-axis image of the blood vessel B as early as possible, it is preferable to search for the long-axis image of the blood vessel B within the search area R2.

[0147] Moreover, when capturing the short-axis image of the blood vessel B, due to minute inclination changes and position changes of the ultrasonic probe 21 in contact with the subject's body surface, etc., the position on the lateral direction D2 of the short-axis image of the blood vessel B is likely to change on the continuously generated multiple frames of the B-mode image UB. Therefore, the first blood vessel wall detection unit 10 tracks and identifies the short-axis image of the blood vessel B, for example, by detecting the movement of the short-axis image of the blood vessel B between consecutive frames of the B-mode image UB. The movement detection of the short-axis image of the blood vessel B can, for example, use a method of scanning a search line SL1 over the entire B-mode image UB and comparing the obtained brightness distribution with the brightness distribution of the detected short-axis image of the blood vessel B. In addition to this, common image analysis methods such as so-called pattern matching can also be used.

[0148] In this way, by tracking the short-axis image of the blood vessel B, even if the short-axis image of the blood vessel B moves between consecutive frames, it is possible to easily calculate the first blood vessel diameter DF of the short-axis image of the blood vessel B.

[0149] And, for example, in step S2, when the short-axis image of the blood vessel B is identified, as Figure 18 shown, in the display device 9, the measurement point marks M1 and M2 can be displayed at the positions of the two intersections of the search line SL1 passing through the center of the blood vessel B and the contour line of the blood vessel B (that is, the positions of the depths J1 and J2 where the difference L1 in the depth direction D1 between the measured depths J1 and J2 in step S2 becomes the largest). In this way, by displaying the measurement point marks M1 and M2, the user can grasp the situation of identifying the short-axis image of the blood vessel B in step S2 and the measurement positions of the blood vessel diameter.

[0150] And, similarly, in step S5, when the long-axis image of the blood vessel B is identified, as Figure 19 shown, in the display device 9, the measurement point marks M3 and M4 can be displayed at the position of the intersection of the search line SL2 and the front wall W1 of the blood vessel and the position of the intersection of the search line SL2 and the rear wall W2 of the blood vessel.

[0151] Further, when the short-axis image of blood vessel B is recognized, the display mode such as the color and thickness of the contour line of the recognized short-axis image of blood vessel B may be changed instead of displaying the measurement point marks M1 and M2. Similarly, when the long-axis image of blood vessel B is recognized, the display mode such as the color and thickness of the contour line of the recognized long-axis image of blood vessel B may be changed instead of displaying the measurement point marks M3 and M4.

[0152] Further, in steps S2 and S5, the brightness distribution of the images along the search lines SL1 and SL2 is used to recognize the short-axis image and the long-axis image of blood vessel B, but the method for recognizing the short-axis image and the long-axis image of blood vessel B is not limited thereto. For example, a so-called template matching method may be used, in which typical pattern data of the short-axis image and the long-axis image of blood vessel B are stored in advance as templates, and while searching for the templates in the B-mode image UB, the similarity with the pattern data is calculated, and it is regarded that the short-axis image or the long-axis image of blood vessel B exists at the position where the similarity is equal to or higher than the threshold value and is the maximum.

[0153] Further, in addition to simple template matching, the calculation of the similarity may use, for example, the machine learning method described in Csurka et al.: Visual Categorization with Bags of Keypoints, Proc. of ECCV Workshop on Statistical Learning in Computer Vision, pp. 59-74 (2004) or the general image recognition method using deep learning described in Krizhevsk et al.: ImageNet Classification with Deep Convolutional Neural Networks, Advances in Neural Information Processing Systems 25, pp. 1106-1114 (2012).

[0154] Further, in step S3, the first blood vessel diameter DF is calculated based on the information of the blood vessel wall detected for one frame of the B-mode image UB in step S2. However, the first blood vessel diameter DF may also be calculated based on the information of the blood vessel wall detected for multiple frames of the B-mode image UB. For example, when the value of the first blood vessel diameter DF calculated for a predetermined number of frames, such as 5 to 10 frames, is below a specified value, the first blood vessel diameter calculation unit 11 may calculate the largest first blood vessel diameter DF among the first blood vessel diameters DF calculated for the B-mode images UB of the predetermined number of frames as the value of the final first blood vessel diameter DF. Further, for example, the first blood vessel diameter calculation unit 11 may also calculate the average value of the first blood vessel diameters DF calculated for the B-mode images UB of the predetermined number of frames as the value of the final first blood vessel diameter DF.

[0155] Thereby, it is possible to exclude the case where the calculated first blood vessel diameter DF has an abnormal value such as a value extremely larger or smaller than the actual diameter of the blood vessel B, and thus it is possible to accurately calculate the final value of the first blood vessel diameter DF.

[0156] Further, the determination in step S7 may be made based on the second blood vessel diameter DS calculated for multiple frames of the B-mode image UB. For example, when the second blood vessel diameter DS calculated for a predetermined number of frames, such as 5 to 10 frames, maintains a predetermined range including the first blood vessel diameter DF calculated in step S3, the second blood vessel diameter calculation unit 13 may determine that the second blood vessel diameter DS has a value within the predetermined range and proceed to step S8. Thereby, it is possible to improve the determination accuracy in step S7, and thus accurately obtain the B-mode image UB representing the longitudinal section passing through the center of the blood vessel B.

[0157] Further, the second blood vessel diameter calculation unit 13 may calculate the value of the largest second blood vessel diameter DS among the second blood vessel diameters DS calculated for the B-mode images UB of the predetermined number of frames used when it is determined that the second blood vessel diameter DS has a value within the predetermined range as the value of the final second blood vessel diameter DS. At this time, the second blood vessel wall detection unit 12 may perform the processing of steps S8 to S11 using, for example, the B-mode image UB used when calculating the final second blood vessel diameter DS.

[0158] Further, the second blood vessel diameter calculation unit 13 may average the second blood vessel diameters DS calculated for the B-mode images UB of the predetermined number of frames used when it is determined that the second blood vessel diameter DS has a value within the predetermined range, and calculate the calculated average value as the value of the final second blood vessel diameter DS. At this time, the second blood vessel wall detection unit 12 may perform the processing of steps S8 to S11 using, for example, the last acquired B-mode image UB among the B-mode images UB of the predetermined number of frames.

[0159] Further, in steps S5 to S7, the value of the first blood vessel diameter DF calculated in step S3 can also be displayed together with the long axis image of blood vessel B and the value of the second blood vessel diameter DS displayed on the display device 9. In this case, the user can adjust the position of the ultrasonic probe 21 while confirming the value of the first blood vessel diameter DF in such a manner that the second blood vessel diameter DS calculated in step S6 approaches the first blood vessel diameter DF. Therefore, the user can more easily adjust the position of the ultrasonic probe 21.

[0160] Further, when calculating the first blood vessel diameter DF in step S3, the first blood vessel diameter calculation unit 11 can, for example, also calculate the distance between the short axis image of blood vessel B and the body surface of the subject as the first blood vessel depth based on the relatively shallower depth J1 among the depths J1 and J2 corresponding to the positions of the blood vessel walls detected in step S2, and display the calculated first blood vessel depth on the display device 9.

[0161] Further, when calculating the second blood vessel diameter DS in step S6, the second blood vessel diameter calculation unit 13 can, for example, calculate the distance between the anterior blood vessel wall W1 and the body surface of the subject as the second blood vessel depth based on the depth J3 corresponding to the position of the anterior blood vessel wall W1 detected in step S5, and display the calculated second blood vessel depth on the display device 9.

[0162] Here, in steps S4 to S7, both the calculated first blood vessel depth and second blood vessel depth can be displayed on the display device 9. Thereby, the user can confirm whether the long axis image of blood vessel B in the B-mode image UB generated in step S4 corresponds to the short axis image of blood vessel B in the B-mode image UB generated in step S1 by comparing the first blood vessel depth and the second blood vessel depth, and at the same time adjust the position of the ultrasonic probe 21. Thereby, it is possible to prevent capturing a long axis image of blood vessel B that does not correspond to the short axis image of blood vessel B in the B-mode image UB generated in step S1, and thus capture an appropriate long axis image of blood vessel B, and therefore the measurement accuracy of blood flow rate can be improved.

[0163] Further, for example, when identifying the long axis image of blood vessel B in step S5, the first blood vessel depth can be added. For example, when the variation range of the difference L2 between the depths J3 and J4 calculated while the second blood vessel wall detection unit 12 scans the search line SL2 along the lateral direction D2 is below the variation range threshold and the second blood vessel depth has a value within the depth range including the first blood vessel depth, it is determined that there is a long axis image of blood vessel B in the search area R2. And when the variation range of the difference L2 calculated while scanning the search line SL2 along the lateral direction D2 is greater than the variation range threshold or the second blood vessel depth has a value outside the depth range, it is determined that there is no long axis image of blood vessel B in the search area R2.

[0164] Accordingly, it is also possible to prevent the long-axis image of the blood vessel B that is not corresponding to the short-axis image of the blood vessel B in the B-mode image UB generated in step S4 from being captured in step S4.

[0165] Moreover, it is also possible to set a step of continuously generating the B-mode image UB including the long-axis image of the blood vessel B and determining that the position of the long-axis image of the blood vessel B has stabilized between step S11 and step S12, and trigger step S11 when the position of the long-axis image of the blood vessel B has stabilized. For example, when the change in the position of the long-axis image of the blood vessel B in multiple frames of the B-mode image UB generated within a predetermined time such as 1 second is equal to or less than a predetermined value such as 0.2 mm, it is determined that the position of the long-axis image of the blood vessel B has stabilized. And when the change in the position of the long-axis image of the blood vessel B in multiple frames of the B-mode image UB generated within a predetermined time such as 1 second is greater than a predetermined value such as 0.2 mm, it is determined that the position of the long-axis image of the blood vessel B is unstable.

[0166] In this way, triggered by the fact that the position of the long-axis image of the blood vessel B in the B-mode image UB has stabilized (i.e., the position of the ultrasonic probe 21 disposed on the body surface of the subject has stabilized), steps S11 and subsequent processes are performed. Therefore, it is possible to measure the blood flow using a stable image, thereby improving the measurement accuracy of the blood flow.

[0167] Moreover, although the processes of steps S5 to S7 are performed on the B-mode image UB generated in step S4, the processes of steps S5 to S7 can also be performed on the B-mode image UB generated in any one of steps S12 to S14. In this case, for example, instead of the second blood vessel diameter DS determined to be within the predetermined range in step S7, the second blood vessel diameter DS that is calculated using the B-mode image UB generated in any one of steps S12 to S14 and determined to be within the predetermined range including the first blood vessel diameter DF calculated in step S3 can be used to calculate the cross-sectional area of the blood vessel B in step S18.

[0168] Moreover, in step S18, instead of calculating the cross-sectional area of the blood vessel B by the blood flow measurement unit 16 based on the second blood vessel diameter DS determined to be within the predetermined range, the cross-sectional area of the blood vessel B can be calculated based on the first blood vessel diameter DF calculated in step S3. For example, when the first blood vessel diameter DF is greater than the second blood vessel diameter DS determined to be within the predetermined range, the cross-sectional area of the blood vessel B is calculated based on the first blood vessel diameter DF.

[0169] Moreover, in step S12, a Doppler waveform image UD is generated and the generated Doppler waveform image UD is displayed on the display device 9. However, as long as the data of the Doppler waveform WD can be acquired, the Doppler waveform image UD does not necessarily have to be displayed on the display device 9. Thus, even when the Doppler waveform image UD is not displayed on the display device 9, the blood flow rate is measured in step S16 in the same manner as when the Doppler waveform image UD is displayed on the display device 9, based on the data of the Doppler waveform WD acquired in step S13 and the value of the second blood vessel diameter DS determined to be within the predetermined range in step S7. Also, when the Doppler waveform image UD is not displayed on the display device 9, instead of freezing and displaying the Doppler waveform image UD on the display device 9 in step S15, only the acquisition of the data of the Doppler waveform WD can be stopped.

[0170] Moreover, an example is shown in which the adjustment of the Doppler waveform WD is performed starting from the time points when the start position and the end position of the heartbeat cycle in the detected Doppler waveform WD are detected in step S13. However, for example, the adjustment of the Doppler waveform WD in step S13 can also be automatically performed triggered by a specified time such as 2 seconds elapsing from the time point when the generation of the Doppler waveform image UD starts in step S12.

[0171] Moreover, when adjusting the Doppler waveform WD, in addition to the adjustment of the position of the baseline and the scale of the vertical axis of the Doppler waveform WD, the position of the Doppler gate DG can also be readjusted so that the maximum value and the minimum value of the Doppler waveform WD fall within 70% of the scale of the vertical axis.

[0172] Moreover, for example, step S13 can also be omitted. However, by performing the adjustment of the Doppler waveform WD, the accuracy of the blood flow velocity calculated by the blood flow velocity calculation unit 15 can be improved, and the accuracy of the blood flow rate measured by the blood flow rate measurement unit 16 can be improved. Therefore, it is preferable to perform step S12.

[0173] Moreover, in step S14, triggered by the current time point being the diastolic phase P2 of the subject's heart, the next step S15 is entered. However, the trigger for entering step S15 from step S14 is not limited to this.

[0174] For example, instead of determining whether the current time point is the diastolic phase P2, it can also be determined whether the current time point is the systolic phase P1. In this case, when it is determined that the current time point is not the systolic phase P1, the determination of whether the current time point is the systolic phase P1 is performed again. When it is determined that the current time point is the systolic phase P1, the next step S15 is entered. However, regarding the change amount of the Doppler waveform WD, the diastolic phase P2 is smaller than the systolic phase P1. Therefore, compared with using the current time point being the systolic phase P1 as the trigger for entering step S15, it is more preferable to use the current time point being the diastolic phase P2 as the trigger for entering step S15.

[0175] Also, for example, instead of implementing step S14, it is possible to trigger and enter step S15 when a specified time such as 2 seconds has elapsed since the time when the operation of adjusting the Doppler waveform WD in step S13 is completed.

[0176] Also, for example, instead of implementing step S14, it is possible to trigger and enter step S15 when the start and end positions of multiple heartbeat cycles such as two cycles or three cycles are detected in the Doppler waveform WD.

[0177] Also, when the B-mode image UB and the Doppler waveform image UD are frozen and displayed on the display device 9 in step S15, it is possible to scroll back the display of the Doppler waveform image UD so that, for example, the end position of the diastolic phase P2 or the end position of the systolic phase P1 in the Doppler waveform WD is aligned with the right end of the Doppler waveform image UD. In this way, by changing the position of the Doppler waveform WD displayed on the display device 9 after freezing the display of the B-mode image UB and the Doppler waveform image UD, it is possible to align the time phase of the B-mode image UB displayed on the display device 9 with the diastolic phase P2 or the systolic phase P1.

[0178] Also, after determining in step S7 that the second blood vessel diameter DS has a value within a predetermined range, the estimation of the blood vessel traveling angle BA in step S8 is performed. However, it is also possible to perform the process of step S8 between steps S5 and S7. Thus, as long as the estimation of the blood vessel traveling angle BA is performed before the processes of steps S9 to S11, the timing is not particularly limited.

[0179] Also, in step S6, the second blood vessel diameter calculation unit 13 calculates the distance in the depth direction D1 between the blood vessel front wall W1 and the blood vessel rear wall W2 detected in step S5 as the second blood vessel diameter DS. However, for example, it is also possible to perform the process of estimating the blood vessel traveling angle BA in step S8 before performing the process of calculating the second blood vessel diameter DS in step S6, and then set a search line SL2 in a direction orthogonal to the Figure 6 shown blood vessel gradient line BL to calculate the blood vessel diameter in a direction orthogonal to the traveling direction of the blood vessel B as the second blood vessel diameter DS. Thereby, it is possible to calculate the second blood vessel diameter DS more accurately, thus improving the measurement accuracy of the blood flow rate.

[0180] Also, in step S8, the second blood vessel wall detection unit 12 estimates the gradient of the blood vessel based on both the blood vessel front wall W1 and the blood vessel rear wall W2. However, it is also possible to estimate a virtual blood vessel gradient line BL representing the gradient of the blood vessel based on either the blood vessel front wall W1 or the blood vessel rear wall W2.

[0181] Also, after setting the B-mode deflection angle in step S9, the Doppler deflection angle is set in step S10, and after setting the Doppler deflection angle, the Doppler gate DG is set in step S11. However, the order of performing steps S9 to S11 is not particularly limited and can be interchanged. For example, after setting the B-mode deflection angle in step S9, the setting of the Doppler deflection angle in step S10 and the setting of the Doppler gate DG in step S11 can be performed simultaneously. Also, for example, the processes of steps S9 to S11 can be performed in the order of setting the Doppler deflection angle in step S10, setting the Doppler gate DG in step S11, and setting the B-mode deflection angle in step S9.

[0182] Also, in step S10, the second blood vessel wall detection unit 12 sets the Doppler deflection angle such that the angle correction value with respect to the blood vessel traveling angle BA is within 60 degrees. However, the blood vessel traveling angle BA can also be set as the angle correction value of the Doppler deflection angle. In this case, the angle correction value of the Doppler deflection angle may exceed 60 degrees. However, when the angle correction value of the Doppler deflection angle exceeds 60 degrees, information indicating that the angle correction value exceeds 60 degrees can be displayed on the display device 9. For example, by the user confirming the information indicating that the angle correction value exceeds 60 degrees and adjusting the inclination of the ultrasonic probe 21 in contact with the subject, etc., the automatic measurement of the blood flow velocity using the ultrasonic diagnostic device 1 can be performed again.

[0183] Also, after setting the Doppler gate DG in step S11, the blood vessel region BR including the Doppler gate DG in the B-mode image UB can be enlarged and displayed on the display device 9. Therefore, the blood vessel region BR on the enlarged B-mode image UB can be clearly confirmed. Also, in this case, the blood vessel diameter is measured based on the enlarged B-mode image UB. For example, due to the resolution of the B-mode image UB, compared with detecting the blood vessel wall based on the B-mode image UB before enlargement, the position of the blood vessel wall can be detected more accurately by detecting the blood vessel wall based on the enlarged B-mode image UB. Therefore, by measuring the blood vessel diameter based on the enlarged B-mode image UB, the measurement accuracy of the blood flow volume can be improved.

[0184] Also, although not shown, a guiding unit for guiding the user can be set in the ultrasonic diagnostic device 1, and in step S1, a message for aligning the short-axis image of the blood vessel B within the search area R1 is displayed on the display device 9 through the guiding unit. Thereby, the accuracy of the first blood vessel wall detection unit 10 in recognizing the short-axis image of the blood vessel B can be improved, and the search line SL can be set at a more appropriate position. Therefore, the blood vessel diameter and the cross-sectional area of the blood vessel can be accurately obtained, and the measurement accuracy of the blood flow volume can be improved.

[0185] Also, in this case, similarly, in step S4, a message indicating the content of aligning the longitudinal axis image of blood vessel B within the search area R2 can be displayed on the display device 9. Thereby, the accuracy of the second blood vessel wall detection unit 12 in recognizing the longitudinal axis image of blood vessel B can be improved.

[0186] Also, generally, it is known that the blood vessel diameter periodically changes between the minimum diameter and the maximum diameter with the heartbeat. Therefore, although not shown, the second blood vessel diameter calculation unit 13 can, for example, also superimpose a graph showing the time change of the second blood vessel diameter DS corresponding to the diameter of blood vessel B (that is, the second blood vessel diameter DS calculated for the B-mode image UB including the longitudinal axis image equivalent to the longitudinal cross-section passing through the center of blood vessel B) on the B-mode image UB and display it on the display device 9. Thereby, the user can easily grasp the time change of the second blood vessel diameter DS corresponding to the diameter of blood vessel B.

[0187] Also, by obtaining information on the time change of the second blood vessel diameter DS corresponding to the diameter of blood vessel B, the minimum diameter and the maximum diameter of blood vessel B in the longitudinal axis image can be easily measured. Here, for example, an elastic index calculation unit (not shown) can be set in the ultrasonic diagnostic apparatus 1. The elastic index calculation unit measures the minimum diameter and the maximum diameter of blood vessel B based on the information on the time change of the second blood vessel diameter DS corresponding to the diameter of blood vessel B, and calculates an elastic index representing the elasticity of the blood vessel based on the measured minimum diameter and maximum diameter. The elastic index calculation unit can, for example, calculate the difference between the maximum diameter and the minimum diameter of the blood vessel as the elastic index. Also, the elastic index calculation unit can calculate a value obtained by normalizing the difference between the maximum diameter and the minimum diameter of the blood vessel by dividing it by the minimum diameter of the blood vessel as the elastic index.

[0188] Also, by using a sphygmomanometer (not shown) to measure the blood pressure Q1 of the subject at the time when the diameter of the blood vessel becomes the minimum and the blood pressure Q2 of the subject at the time when the diameter of the blood vessel becomes the maximum, the elastic index calculation unit can also calculate the stiffness parameter X = {Log(Q2 / Q1)} / {(DB / DA)-1} described in Japanese Patent Publication No. 5384919 as the elastic index using the blood pressures Q1, Q2, the minimum diameter DA of the blood vessel, and the maximum diameter DB of the blood vessel.

[0189] Second Embodiment

[0190] In step S12 in the operation of the ultrasonic diagnostic apparatus 1 of the first embodiment, the B-mode image UB and the Doppler waveform image UD were generated simultaneously, but the generation of the B-mode image UB can be temporarily stopped, and only the Doppler waveform image UD can be generated.

[0191] Hereinafter, Figure 20 the flowchart is used to explain the operation of the ultrasonic diagnostic apparatus 1 according to the second embodiment. In addition, this flowchart isFigure 14 In the flowchart of the first embodiment shown, steps S21 to S23 are added in place of step S12, and step S24 is added in place of step S15.

[0192] Therefore, the description of the processing of steps S1 to S11 is omitted.

[0193] In step S21, which follows step S11, the continuous generation of the B-mode image UB is started, and based on the value of the second blood vessel diameter DS determined to be within the predetermined range in step S7, it is determined whether the current time is the diastolic phase P2 of the subject's heart. Here, as Figure 21 shown, generally, the blood vessel diameter periodically varies between the minimum diameter DA and the maximum diameter DB with the heartbeat, and has the maximum diameter DB during the systolic phase P1 of the heart and the minimum diameter DA during the diastolic phase P2 of the heart. Therefore, for example, by measuring the minimum diameter DA of the blood vessel, it can be determined that the current time is the diastolic phase P2 of the subject's heart. If it is determined that the current time is not the diastolic phase P2 of the subject's heart, the processing of step S21 is re-executed. If it is determined that the current time is the diastolic phase P2 of the subject's heart, the process proceeds to step S22.

[0194] In step S22, the B-mode image UB displayed on the display device 9 is frozen and displayed.

[0195] In the next step S23, the Doppler processing unit 7 starts the continuous generation of the Doppler waveform image UD and displays the generated Doppler waveform image UD on the display device 9. Thus, on the display device 9, the Doppler waveform image UD is displayed in a state where the B-mode image UB is frozen and displayed.

[0196] In this way, when the Doppler waveform image UD is displayed on the display device 9, the process proceeds to step S13, and the Doppler waveform WD in the Doppler waveform image UD generated in step S23 is adjusted.

[0197] Next, in step S14, the period information of the Doppler waveform WD is obtained, and based on the obtained period information, it is determined whether the current time is the diastolic phase P2 of the subject's heart. If it is determined that the current time is not the diastolic phase P2 of the subject's heart, the processing of step S14 is re-executed. If it is determined that the current time is the diastolic phase P2 of the subject's heart, the process proceeds to step S24.

[0198] In step S24, the Doppler waveform image UD displayed on the display device 9 is frozen. Thereby, it is possible to freeze and display the B-mode image UB and the Doppler waveform image UD in the diastolic phase P2 on the display device 9, and use the Doppler data in the diastolic phase P2 with a smaller change amount of the Doppler waveform WD for the measurement of blood flow volume.

[0199] In the next step S16, based on the value of the second blood vessel diameter DS determined to be within the predetermined range in step S7 and the Doppler waveform image UD frozen and displayed in step S24, the blood flow volume within the blood vessel region BR is automatically measured. And in step S17, as Figure 17 shown, the measured value MV of the blood flow volume is displayed on the display device 9 together with the B-mode image UB and the Doppler waveform image UD.

[0200] Thus, when the measured value MV of the blood flow volume is displayed on the display device 9, the operation of the ultrasonic diagnostic apparatus 1 is terminated.

[0201] In summary, according to the ultrasonic diagnostic apparatus 1 according to the second embodiment of the present invention, even when temporarily stopping generating the B-mode image UB and only generating the Doppler waveform image UD, similar to the case of simultaneously generating the two images of the B-mode image UB and the Doppler waveform image UD in the first embodiment, the first blood vessel diameter DF is calculated based on the B-mode image UB representing the short-axis image of the blood vessel B, the B-mode image UB representing the long-axis image passing through the center of the blood vessel B is accurately obtained based on the first blood vessel diameter DF, and the blood flow volume is measured using the B-mode image UB representing the obtained long-axis image of the blood vessel B. Therefore, it is possible to reduce the fluctuations in the measurement accuracy of the blood flow volume caused by the user adjusting the position of the ultrasonic probe 21 on the body surface of the subject, thereby improving the measurement accuracy.

[0202] In addition, in step S21, triggered by the current time point being the diastolic phase P2 of the subject's heart, the next step S22 is entered, but the trigger for entering step S22 from step S21 is not limited thereto.

[0203] For example, instead of determining whether the current time point is the diastolic phase P2, it is also possible to determine whether the current time point is the systolic phase P1. In this case, when it is determined that the current time point is not the systolic phase P1, the determination of whether the current time point is the systolic phase P1 is re-performed. When it is determined that the current time point is the systolic phase P1, the next step S22 is entered. However, regarding the change amount of the Doppler waveform WD, the diastolic phase P2 is smaller than the systolic phase P1. Therefore, compared with using the current time point being the systolic phase P1 as the trigger for entering step S22, it is more preferable to use the current time point being the diastolic phase P2 as the trigger for entering step S22.

[0204] Further, for example, step S21 may also be omitted. In this case, triggered by setting the Doppler gate DG on the B-mode image UB in step S11, the B-mode image UB is frozen and displayed on the display device 9 in step S22.

[0205] Further, for example, a specified time such as 2 seconds elapsed since the time when the setting of the Doppler gate DG in step S11 is completed may be used as the trigger for entering step S22.

[0206] Also, in step S23, a Doppler waveform image UD is generated and the generated Doppler waveform image UD is displayed on the display device 9. However, as long as the data of the Doppler waveform WD can be acquired in the same manner as in step S12 of the first embodiment, the Doppler waveform image UD does not necessarily have to be displayed on the display device 9.

[0207] Third Embodiment

[0208] The ultrasonic diagnostic apparatus 1 of the first embodiment has a structure in which the display device 9, the input device 18, and the ultrasonic probe 21 are directly connected to the processor 22. However, for example, the display device 9, the input device 18, the ultrasonic probe 21, and the processor 22 may be indirectly connected via a network.

[0209] As Figure 22 shown, the display device 9, the input device 18, and the ultrasonic probe 2 from the third embodiment are connected to the ultrasonic diagnostic apparatus main body 41 via a network NW. The ultrasonic diagnostic apparatus main body 41 removes the display device 9, the input device 18, and the ultrasonic probe 21 from the ultrasonic diagnostic apparatus 1 of the first embodiment shown in Figure 1 and is composed of a transceiver circuit 5, a storage unit 19, and a processor 22.

[0210] Even when the ultrasonic diagnostic apparatus 1A has such a structure, similar to the ultrasonic diagnostic apparatus 1 of the first embodiment, the first blood vessel diameter DF is calculated based on the B-mode image UB representing the short-axis image of the blood vessel B, the B-mode image UB representing the long-axis image passing through the center of the blood vessel B is accurately acquired based on the first blood vessel diameter DF, and the blood flow rate is measured using the B-mode image UB representing the acquired long-axis image of the blood vessel B. Therefore, it is possible to reduce the fluctuation in the measurement accuracy of the blood flow rate caused by the user adjusting the position of the ultrasonic probe 21 on the surface of the subject, thereby improving the measurement accuracy.

[0211] Moreover, since the display device 9, the input device 18, and the ultrasonic probe 21 are connected to the ultrasonic diagnostic apparatus main body 41 via the network NW, the ultrasonic diagnostic apparatus main body 41 can be used as a so-called remote server. Thus, for example, by preparing the display device 9, the input device 18, and the ultrasonic probe 21 near the user, the user can perform the diagnosis of the subject, and thus the convenience during ultrasonic diagnosis can be improved.

[0212] Moreover, for example, when a portable thin computer called a so-called tablet computer is used as the display device 9 and the input device 18, the user can more easily perform the ultrasonic diagnosis of the subject, and the convenience of ultrasonic diagnosis can be further improved.

[0213] In addition, the display device 9, the input device 18, and the ultrasonic probe 21 are connected to the ultrasonic diagnostic apparatus main body 41 via the network NW. At this time, the display device 9, the input device 18, and the ultrasonic probe 21 can be connected to the network NW either wired or wirelessly.

[0214] Moreover, the method described in the third embodiment can be applied to the first embodiment, but can also be similarly applied to the second embodiment.

Claims

1. An ultrasonic diagnostic device comprising: A transducer array transmits and receives ultrasonic waves to a subject and obtains a received signal; A B-mode processing unit that generates a B-mode image in which at least a blood vessel is captured based on the received signal; a display device that displays the B-mode image generated by the B-mode processing unit; a first blood vessel wall detection unit configured to detect the blood vessel wall in a short-axis direction by analyzing the B-mode image in which the short-axis image of the blood vessel is captured; a first blood vessel diameter calculation unit configured to calculate a first blood vessel diameter based on the blood vessel wall in the short-axis direction detected by the first blood vessel wall detection unit; a second blood vessel wall detection unit configured to detect the blood vessel wall in the longitudinal direction by analyzing the B-mode image in which the longitudinal image of the blood vessel is captured; a second blood vessel diameter calculation unit configured to calculate a second blood vessel diameter based on the blood vessel wall in the longitudinal direction detected by the second blood vessel wall detection unit; a gate setting unit that sets a Doppler gate within the blood vessel on the B-mode image in which the long-axis image is captured; A Doppler processing unit, which obtains Doppler data within the Doppler gate; a blood flow velocity calculation unit, which calculates the blood flow velocity based on the Doppler data; as well as a blood flow measurement unit configured to measure the blood flow based on either the detected blood vessel wall in the long axis direction or the detected blood vessel wall in the short axis direction and the calculated blood flow velocity; After the first blood vessel diameter is calculated by the first blood vessel diameter calculation unit, the second blood vessel wall detection unit detects the blood vessel wall in the longitudinal direction. The second blood vessel diameter calculation unit determines whether the second blood vessel diameter has a value within a range determined with respect to the first blood vessel diameter. When it is determined that the second blood vessel diameter has a value within the range determined with respect to the first blood vessel diameter, the process automatically shifts to the measurement of the blood flow rate.

2. The ultrasonic diagnostic apparatus according to claim 1, wherein The second vascular wall detection unit sets a search line for searching for the vascular wall in the longitudinal direction on the B-mode image. Based on the brightness distribution of the B-mode image on the set search line, a front blood vessel wall and a back blood vessel wall are detected as blood vessel walls in the long-axis direction.

3. The ultrasonic diagnostic apparatus according to claim 2, wherein: The second vascular wall detection unit sets detection point marks on each of the detected anterior vascular wall and posterior vascular wall and displays the marks on the display device.

4. The ultrasonic diagnostic apparatus according to claim 2 or 3, wherein: The gate setting unit sets the Doppler gate having a center position and a size determined based on coordinates of the anterior vascular wall and the posterior vascular wall detected by the second vascular wall detection unit.

5. The ultrasonic diagnostic apparatus according to claim 2 or 3, wherein: The second vascular wall detection unit estimates a blood vessel running angle based on at least one of the detected anterior and posterior vascular walls, and sets a Doppler deflection angle so that an angle correction value relative to the blood vessel running angle falls within 60 degrees.

6. The ultrasonic diagnostic apparatus according to claim 5, wherein, the B-mode processing unit generates the B-mode image according to a B-mode deflection angle, and the B-mode deflection angle is set according to the blood vessel traveling angle estimated by the second blood vessel wall detection unit.

7. The ultrasonic diagnostic apparatus according to any one of claims 1 to 3, wherein, the Doppler processing unit generates a Doppler waveform image according to the Doppler data, and the display device displays the B-mode image generated by the B-mode processing unit and the Doppler waveform image generated by the Doppler processing unit.

8. The ultrasonic diagnostic apparatus according to claim 7, wherein, the Doppler processing unit generates the Doppler waveform image in parallel when the B-mode processing unit generates the B-mode image, and the blood flow rate is measured by the blood flow rate measurement unit after the B-mode image and the Doppler waveform image are frozen.

9. The ultrasonic diagnostic apparatus according to claim 7, wherein, the Doppler processing unit acquires the Doppler data within the Doppler gate after the B-mode image is frozen, generates a Doppler waveform image, and the blood flow rate is measured by the blood flow rate measurement unit after the Doppler waveform image is frozen.

10. The ultrasonic diagnostic apparatus according to any one of claims 1 to 3, wherein, the blood flow rate is automatically measured when the second blood vessel diameter calculated over a predetermined number of frames is maintained within a range determined relative to the calculated first blood vessel diameter.

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