JP2009119134A - Ultrasonic imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ultrasonic imaging apparatus capable of acquiring blood flow distribution information in a subject along with contrast medium distribution information in the subject while retaining a real-time property and easily simultaneously comparing the information. <P>SOLUTION: This ultrasonic imaging apparatus acquires B mode information, contrast mode image information and CFM (Color Flow Mapping) image information, where a B mode processing section 103, a contrast mode processing section 110, and a CFM processing section 109 are optimized, respectively, using a received echo train of a plurality of times of transmission pulses, and displays the CFM image and the B mode image on a display section 106 along with the image of the contrast medium, so that an operator precisely acquires the position of the contrast medium by the comparison with the B mode image information while retaining the real-time property and estimate the subsequent movement of the contrast medium by the comparison with the CFM image information. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an ultrasonic imaging apparatus that acquires one sound ray information in a subject to which a contrast medium has been administered by ultrasonic transmission and reception a plurality of times.

  In recent years, contrast agents are being used in inspection of ultrasonic imaging apparatuses. Contrast agents include bubbles having a diameter of several μm, which can be destroyed by ultrasonic irradiation, and those that can be repeatedly irradiated with ultrasonic waves and can be observed for a long time.

  Here, when observing the distribution image of the contrast agent, a B-mode image depicting the morphology of the tissue part or blood vessel where the contrast agent is located is rendered as a background image. By this depiction, an operator can grasp the position of the contrast agent more accurately.

  The distribution image of the contrast agent is imaged by extracting the harmonic component of the transmission ultrasound reflected from the contrast agent. At this time, the sound pressure of the transmission ultrasonic wave is set low in order to generate a harmonic component in the contrast agent without destroying the contrast agent. When transmission ultrasonic waves with low sound pressure are used, a contrast agent distribution image using harmonics is rendered, but a B-mode image forming a background image has low sensitivity and is difficult to see.

Therefore, when transmission ultrasonic waves having a low sound pressure are used, the received echo (echo) train is separately displayed in the B-mode processing unit by contrast adjustment and superimposed on the contrast agent distribution image. Is called. As a result, the background image is clearly depicted even when transmission ultrasonic waves having a low sound pressure are used.
Edited by Japan Electronic Machinery Manufacturers Association, “Revised Medical Ultrasound Handbook”, Corona, January 20, 1997, p. 212-213

  However, according to the above background art, the relationship between the distribution of the contrast medium and the blood flow cannot be grasped. That is, since the contrast agent is conveyed to the imaging region by the blood flow, the blood flow distribution information is important for knowing the destination of the subsequent contrast agent. However, the blood flow information is not included in the B-mode image forming the contrast medium distribution image and the background image described above, and the prediction of the movement destination from only the contrast medium distribution image has low accuracy. It becomes.

  Further, when acquiring a distribution image of a contrast agent, performing imaging for separately acquiring blood flow information such as CFM (Color Flow Mapping) leads to extension of imaging time, and real time (real time) of these image information. Impairs sex. This is not preferable when observing a temporal change occurring in a contrast medium distribution image.

  Therefore, an ultrasonic imaging apparatus capable of acquiring blood flow distribution information in a subject together with contrast agent distribution information in the subject while maintaining real-time characteristics and simultaneously comparing and contrasting the information. It is important how to achieve this.

  This invention has been made to solve the above-described problems caused by the background art, and acquires blood flow distribution information in a subject together with contrast agent distribution information in the subject while maintaining real-time properties. At the same time, an object is to provide an ultrasonic imaging apparatus capable of easily comparing and contrasting these pieces of information.

  In order to solve the above-described problems and achieve the object, the ultrasonic imaging apparatus according to the first aspect of the invention provides a plurality of times when acquiring one sound ray information in a subject to which a contrast agent is administered. A transmission / reception unit that performs ultrasonic transmission / reception, a contrast mode processing unit that forms contrast mode image information in which the contrast agent is rendered using the reception echo train acquired by the plurality of times of ultrasonic transmission / reception, and the plurality B-mode processing unit for forming B-mode image information in the imaging region of the contrast mode image information using reception echo trains acquired by the number of times of ultrasonic transmission / reception, and reception acquired by the plurality of times of ultrasonic transmission / reception Using an echo train, the CFM processing unit for forming CFM image information in the imaging area, and the contrast mode image information, the B mode image information, and the CFM image information are displayed on one display screen. A display unit to be displayed.

  In the invention according to the first aspect, the transmission / reception unit performs transmission / reception a plurality of times to acquire one sound ray information, and using these received echo trains, contrast mode image information, B mode image information, and CFM image information The image information is simultaneously displayed on one display screen.

  Further, an ultrasonic imaging apparatus according to the invention of the second aspect is the ultrasonic imaging apparatus according to the second aspect, wherein the CFM processing unit acquires the plurality of times obtained by the plurality of times of ultrasonic transmission / reception. The CFM image information is formed by correlation calculation between received echo trains.

  In the invention of the second aspect, the CFM processing unit performs a plurality of correlation calculations for performing ultrasonic transmission / reception when acquiring one ray information.

  The ultrasonic imaging apparatus according to the invention of the third aspect is the ultrasonic imaging apparatus according to the first or second aspect, wherein the B-mode processing unit is acquired by the plurality of times of ultrasonic transmission / reception. The B-mode image information is formed by using one received echo train among a plurality of times.

  In the invention of the third aspect, the B-mode image information is easily formed.

  An ultrasonic imaging apparatus according to the invention of a fourth aspect is the ultrasonic imaging apparatus according to any one of the first to third aspects, wherein the transmission / reception unit uses the ultrasonic transmission / reception a plurality of times. The transmission pulse includes a transmission pulse whose phase is inverted.

  In the invention of the fourth aspect, the inversion pulse for forming the contrast mode image information is included in the transmission pulse used in the ultrasonic transmission / reception a plurality of times.

  The ultrasonic imaging apparatus according to the fifth aspect of the invention is the ultrasonic imaging apparatus according to the fourth aspect, wherein the CFM processing unit performs quadrature detection of the received echo train by the inverted transmission pulse. It is characterized by using a reference waveform having an inverted phase.

  In the fifth aspect of the invention, even when the phase of the transmission pulse is inverted, the CFM process is performed in the same manner as before the inversion.

  An ultrasonic imaging apparatus according to a sixth aspect of the invention is the ultrasonic imaging apparatus according to the fifth aspect, wherein the contrast mode processing unit performs the reception echo train and the inversion of the inverted transmission pulse. The contrast mode image information is formed using a reception echo train of transmission pulses that are not performed.

  In the invention according to the sixth aspect, the contrast mode processing unit extracts a harmonic component using a pulse inversion method.

  An ultrasonic imaging apparatus according to a seventh aspect of the invention is the ultrasonic imaging apparatus according to any one of the first to sixth aspects, wherein the display unit includes a contrast mode image of the contrast mode image information. The B-mode image of the B-mode image information and the CFM image of the CFM image information are displayed in an overlapping manner.

  In the invention of the seventh aspect, the display unit facilitates comparison and contrast of the contrast mode image, the B mode image, and the CFM image.

  The ultrasonic imaging apparatus according to the invention of the eighth aspect is the ultrasonic imaging apparatus according to any one of the first to sixth aspects, wherein the display unit is a contrast mode image of the contrast mode image information. Any two of the B mode image of the B mode image information and the CFM image of the CFM image information are displayed side by side.

  In the invention of the eighth aspect, the display unit makes it easy to compare and contrast the contrast mode image, the B mode image, and the CFM image.

  According to the present invention, the CFM image information, the B mode image information, and the contrast mode image information are formed from the same received echo train, and the CFM image, the B mode image, and the contrast mode image are displayed on the display unit. Without extending the imaging time, in addition to the position information of the contrast agent recognized in comparison with the B-mode image, the movement information after this comparison of the contrast agent inferred compared with the CFM image can be obtained.

  The best mode for carrying out an ultrasonic imaging apparatus according to the present invention will be described below with reference to the accompanying drawings. Note that the present invention is not limited thereby.

  First, the overall configuration of the ultrasonic imaging apparatus 100 according to the present embodiment will be described with reference to FIG. FIG. 1 is a block diagram showing the overall configuration of the ultrasonic imaging apparatus 100 according to the present embodiment. The ultrasonic imaging apparatus 100 includes a probe unit 101, an image acquisition unit 122, a B mode processing unit 103, a CFM processing unit 109, a contrast mode processing unit 110, a cine memory unit 104, an image display control unit 105, a display Unit 106, input unit 107, and controller unit 108. The image acquisition unit 122 includes a transmission / reception unit 102 and a beam former 112.

  The probe unit 101 irradiates ultrasonic waves in a specific direction of an imaging cross section of the subject 1, that is, a part for transmitting and receiving ultrasonic waves, and occasionally receives a received echo train of ultrasonic waves reflected from the inside of the subject 1. Received as sequential sound rays. On the other hand, the probe unit 101 performs electronic scanning while sequentially switching the irradiation direction of ultrasonic waves. In the probe unit 101, piezoelectric elements (not shown) are arranged in an array.

  The transmission / reception unit 102 is connected to the probe unit 101 by a coaxial cable, and generates an electrical signal for driving the piezoelectric element of the probe unit 101. On the other hand, the transmitting / receiving unit 102 is also a part that performs first-stage amplification of a reflected echo train of reflected ultrasonic waves.

  The beam former 112 forms a timing signal for generating a drive waveform applied to the piezoelectric element based on the depth of focus information and the aperture width information from the controller unit 108. The beam former 112 delays and adds ultrasonic signals from a plurality of piezoelectric element arrays (arrays) having an aperture width that are received almost simultaneously, thereby forming one piece of sound ray information.

  The B-mode processing unit 103 performs logarithmic conversion, contrast adjustment, and the like for correcting the ultrasonic attenuation according to the reflection depth position in the subject, on the received echo string output from the beamformer 112, and the B-mode image information The sound ray information is output to the image display control unit 105 in real time.

  The contrast mode processing unit 110 is a mode for rendering a distribution image of the contrast medium administered to the subject 1, and details of a configuration using a pulse inversion method will be described later.

  The CFM processing unit 109 extracts phase change information from the received echo train amplified by the transmission / reception unit 102, and captures each imaging position in the imaging region such as the average frequency, the power value of the frequency shift, and the variance of the frequency shift in real time. The blood flow distribution image information at is calculated. Details of the configuration of the CFM processing unit 109 will be described later. The B mode processing unit 103, the contrast mode processing unit 110, and the CFM processing unit 109 are turned ON / OFF according to an instruction from the controller unit 108 described later. In the ON state, the B mode processing, the contrast mode processing, and the CFM processing operate. In the OFF state, the B mode processing, the contrast mode processing, and the CFM processing are stopped.

  The cine memory unit 104 is an image memory that stores time-varying images, and stores B-mode image information, contrast-mode image information, and CFM image information together with acquisition time information.

  The image display control unit 105 performs display frame rate conversion such as B-mode image information, contrast mode image information, and CFM image information, and controls the shape and position of the display image. Details of the configuration of the image display control unit 105 will be described later.

  The display unit 106 includes a CRT (Cathode Ray Tube), an LCD (Liquid Crystal Display), or the like, and displays a B-mode image, a contrast mode image, a CFM image, and the like. These images are displayed side by side or superimposed on the display screen of the display unit 106.

  The input unit 107 includes a keyboard and the like, and an operation input signal is input by an operator. For example, information such as an operation input for selecting display of B-mode image information or display of CFM image information is transmitted to the controller unit 108.

  The controller unit 108 controls the operation of each unit of the ultrasonic imaging apparatus described above based on the operation input signal input from the input unit 107 and a program (program) or data (data) stored in advance.

  FIG. 2 is a block diagram illustrating configurations of the CFM processing unit 109, the transmission / reception unit 102, and the controller unit 108. The controller unit 108 includes an oscillator 81 and phase inverting means 80, and the transmission / reception unit 102 includes a burst generator 12 and a driver 11. The CFM processing unit 109 includes a quadrature detection unit 201, a gain adjuster 202, a wall filter (Wall filter) unit 203, an autocorrelator 204 and a calculation unit 205.

  The oscillator 81 is a sine wave generation circuit having a frequency for exciting resonance vibration in the piezoelectric element. This frequency is determined based on automatic detection information of the type of the probe unit 101 attached to the ultrasonic imaging apparatus 100, instruction input information from the input unit 107, and the like.

  The phase inversion means 80 inverts the phase of the reference waveform having a sine waveform output to the quadrature detection unit 201, the wall filter unit 203, and the burst generator 12, which will be described later, so that the phases are different by 180 degrees. This phase inversion is switched based on a scan sequence table (scan sequence table) described later.

  The burst generator 12 generates a sine wave burst waveform having a frequency for exciting resonance vibration in the piezoelectric element.

  The driver 11 uses the waveform generated by the burst generator 12 as the waveform of the voltage for driving the piezoelectric element. Note that the sound pressure of the transmitted ultrasonic wave is a low sound pressure that does not destroy the contrast agent and generates harmonics, so this voltage is also set to a low value that does not destroy the contrast agent.

  The quadrature detection unit 201 performs quadrature detection on the received echo train from the transmission / reception unit 102 using a reference waveform having a phase difference of 0 degrees and 90 degrees (not shown), and an electric signal composed of two detection outputs I and Q Is output. The two detection outputs I and Q are gain-adjusted by the gain adjuster 202 and transmitted to the wall filter unit 203.

  The wall filter unit 203 is a high-pass filter composed of a digital filter, which removes low-frequency clutter components included in the motion of blood vessel walls and heart valves and passes only blood flow signals. Let

  The autocorrelator 204 performs autocorrelation calculation using the output of the wall filter unit 203. This autocorrelation calculation is performed at a high speed, and outputs blood flow information, that is, a plurality of intermediate calculation results serving as a basis for calculating blood flow power value, average frequency, and variance thereof in real time.

  Since the autocorrelation calculation is performed between the received echo trains of ultrasonic waves repeatedly irradiated with the period T, the autocorrelator 204 includes a delay circuit with a period T, a multiplier, and the like. In addition, the autocorrelator 204 repeats the averaging of the transmission of ultrasonic waves about 8 to 10 times when acquiring blood flow information of one sound ray in order to reduce the variation in correlation calculation.

  The calculation unit 205 calculates blood flow information using the intermediate calculation result that is the output of the autocorrelator 204. At this time, the calculation unit 205 calculates the power value, average frequency, and variance thereof according to the mode designation selected from the input unit 107 and outputs the calculated value to the image display control unit 105. This output is displayed on the display unit 106 together with the B mode image and the contrast mode image.

  FIG. 3 is a block diagram illustrating a configuration of the contrast mode processing unit 110. As an example, the contrast mode processing unit 110 shows a block diagram when performing a contrast scan using the pulse inversion method. The contrast mode processing unit 110 includes a switch 33, a delay unit 34, an addition unit 35, and a contrast harmonic B mode processing unit 36.

  In the contrast harmonic B mode, transmission and reception of a normal-phase transmission pulse whose sound pressure changes from positive to negative, and transmission and reception of a reverse-phase transmission pulse whose sound pressure changes from negative to positive are continuously performed. Only the second harmonic component generated when the contrast agent is present is extracted from the sum of the received waveforms.

  FIG. 4 is an explanatory diagram schematically showing transmission pulses and reception echoes used in the contrast harmonic B mode. Waveform a is an example of a positive-phase transmission pulse, and waveform b is a reception echo from a contrast agent acquired after transmitting waveform a. The waveform c is an example of a reverse-phase transmission pulse that forms a waveform, and the waveform d is a reception echo from a contrast agent acquired after transmitting the waveform c. A waveform e illustrates the difference between the waveforms b and d and is a second-order harmonic component generated by the contrast agent. The waveform e is converted into a luminance signal, thereby forming a tomographic image in which the contrast agent is depicted.

  Returning to FIG. 3, the delay unit 34 delays a series of reception echo sequences received after the transmission pulse is transmitted by one cycle of the transmission pulse. The delay unit 34 includes a shift register or the like when the received echo train is A / D converted by the beamformer 112. The switch 33 is an electronic switch whose connection position is switched depending on whether the transmission pulse is in the normal phase or in the reverse phase. As a result, the reception echo string acquired first input to the delay unit 34 and the reception echo string acquired later are added by the adding unit 35, and only the second harmonic component is extracted from the reception echo string.

  The contrast harmonic B-mode processing unit 36 performs logarithmic conversion, contrast adjustment, and the like for correcting the ultrasonic attenuation according to the reflection depth position in the subject, and controls the display of the sound ray information. Output to the unit 105.

  FIG. 5 is a block diagram illustrating a configuration of the image display control unit 105. The image display control unit 105 includes a writing unit 61, an image memory 62, and a reading unit 63. The image memory 62 is a memory that can be accessed at high speed, and has CFM image information, contrast mode image information, and B mode image information for one frame in a predetermined memory area. The writing unit 61 acquires tomographic image information for one sound ray in real time from the B-mode processing unit 103, the contrast mode processing unit 110, and the CFM processing unit 109, and writes it in a predetermined area of the image memory 62. The reading unit 63 sequentially reads the CFM image information, contrast mode image information, and B mode image information in the image memory 62 on the display unit 106 independently of the writing unit 61. The reading unit 63 can display the CFM image information, the contrast mode image information, and the B mode image information so as to overlap each other by controlling the display position of the display unit 106.

  Next, the operation of the ultrasonic imaging apparatus 100 according to the present embodiment will be described. FIG. 6 is a flowchart illustrating the operation of the ultrasonic imaging apparatus 100 that performs imaging of the subject 1 to which a contrast agent has been administered. The operation of the ultrasonic imaging apparatus 100 includes a contrast agent imaging process (step S501) and a subsequent contrast agent display process (step S502).

  First, the contrast agent imaging process in step S501 will be described.

  FIG. 7 is an example of a scan sequence table 50 showing the control performed by the controller unit 108 when scanning the piezoelectric element array of the probe unit 101. In the scan sequence table 50, the horizontal axis indicates the sound ray number, and the scan number written in the table means transmission of one transmission pulse and reception of a reception echo train of reflected ultrasound. is doing. This scan number is updated in order until one frame of image information corresponding to one tomographic image information is completely acquired.

  Here, the sound ray indicates a line along the transmission / reception direction of the ultrasonic wave when the ultrasonic wave is irradiated in the depth direction of the subject 1. The imaging apparatus 100 collects tomographic image information on this line. FIG. 8 is an explanatory diagram showing the relationship between the tomographic image 60 displayed on the display unit 106 and the sound ray number. The sound ray numbers 1, 2,..., N-1, N are sequentially numbered from the right side of the tomographic image 60, and the tomographic image information on the line of this sound ray number is sequentially acquired.

  Returning to FIG. 7, the order of transmission and reception performed within one frame is the same for all frames, and the scan number does not differ from frame to frame. Therefore, the frame No. shown in FIG. 1 and No. The second scan sequence table 50 has exactly the same scan number. The scan sequence table 50 is the same as the scan sequence table when performing the CFM processing, and for the sake of simplicity, the case where the number of times of averaging for performing autocorrelation when performing the CFM processing is set to four is illustrated. This number of times is the number of times of transmission / reception when acquiring one sound ray information as will be described later, and is also the number of received echo trains received.

  In the scan sequence table 50, since the autocorrelation averaging times are four, for example, when acquiring the tomographic image information of the sound ray number 1, four transmissions and receptions indicated by the scan numbers 1 to 4 are the same. Perform at the sound ray number position, and then move to the next sound ray number. The scan sequence table 50 repeats four transmissions / receptions at the same sound ray number position, acquires tomographic image information up to the sound ray number N, and sets it as one frame information. The scan sequence table 50 acquires tomographic image information of a plurality of frames while repeating similar transmission and reception.

  FIG. 9 is an explanatory diagram showing the operation of each processing unit when transmission / reception is controlled based on the scan sequence table 50. In FIG. 9, the horizontal axis represents time, and the vertical axis represents ON / OFF in each part of the B mode processing unit 103, the contrast mode processing unit 110, the CFM processing unit 109, and the phase inversion unit 80 on the common time axis. The operation is shown. In the lower part of FIG. 9, the scan numbers shown in the scan sequence table 50 of FIG. 7 are displayed along the time axis. The ON / OFF operation of the processing unit is switched using a single transmission / reception indicated by one scan number as a minimum unit of time to change. Note that the ON / OFF state of each processing unit repeats the same state every time the scan number increases by four.

  The CFM processing unit 109 is turned on for all the scan numbers 1 to 4N. As a result, autocorrelation is averaged four times for each sound ray, and CFM image information of the blood flow optimized for CFM is obtained for all sound rays 1 to N. FIG. 10 illustrates transmission pulses 81 to 84 when scan numbers 1 to 4 are executed. The transmission pulses 81 to 84 are substantially composed of a sine wave burst waveform having a resonance frequency of a piezoelectric element, and each pulse is repeatedly irradiated with a period of time T when the ultrasonic waves reciprocate a predetermined depth in the subject 1. The

  Here, the transmission pulses 81 to 84 correspond to the transmission pulses of the scan numbers 1 to 4, and particularly the waveform of the transmission pulse 81 has the scan number 1 and the phase inversion unit 80 is in the ON state. It has an inverted waveform whose phase is 180 degrees different from the waveform of ~ 84. As described above, the phase inversion means 80 inverts the phase of the output waveform of the burst generator 12 and at the same time inverts the phase of the sine wave input to the quadrature detection unit 201 and the wall filter unit 203. The phase inversion has no effect on the output result of the CFM processing performed by the processing unit 109.

  The contrast mode processing unit 110 is turned on with scan numbers 1 and 2. In scan numbers 1 and 2, the transmission pulse is phase-inverted, the transmission pulse 81 corresponds to the waveform a shown in FIG. 4, and the transmission pulse 82 corresponds to the waveform b shown in FIG. Then, the contrast mode processing unit 110 extracts the second harmonic component from the received echo train of the sound ray number 1 acquired in the scan numbers 1 and 2, and the contrast medium positioned on the line of the sound ray number 1 is extracted. Get image information.

  The B-mode processing unit 103 is turned on at the scan number 1, performs contrast adjustment using the reception echo train of the transmission pulse 81, and corresponds to the line of the sound ray number 1 optimized for the B-mode image. B-mode image information is acquired.

  The controller unit 108 switches the ON / OFF state of the contrast mode processing unit 110, the B mode processing unit 103, and the phase inversion unit 80 corresponding to the scan numbers as described above from scan numbers 1 to 4N, and CFM image information, contrast mode image information, and B mode image information for line numbers 1 to N are acquired. As a result, one frame of CFM image information, contrast mode image information, and B mode image information is scanned once. Get in the time required by.

  The CFM image information acquired using the scan sequence table 50 shown in FIG. 7 has a frequency band at the cut-off frequency of the high-pass filter of the wall filter unit 203 in the case of low-speed blood flow. Have. In this case, a defect occurs in blood flow information, which is not preferable.

  Here, the controller unit 108 lowers the cutoff frequency of the high-pass filter and reduces the loss of blood flow information. In order to lower the cutoff frequency, for example, the maximum detection frequency of the digital high-pass filter is reduced. By reducing the maximum detection frequency, the cut-off frequency of the high-pass filter is also reduced, and loss of low-speed blood flow information is reduced.

  On the other hand, when performing the CFM processing, the period T in which the correlation operation is repeatedly performed and the averaging is performed has a maximum blood flow detection frequency fmax detected by the Doppler effect, and

fmax∝1 / T
The maximum detection frequency fmax is matched with the maximum detection frequency of the high-pass filter.

  Accordingly, when the cut-off frequency is lowered, the averaging period T is made long, and at the same time the maximum detection frequency fmax is made small. Here, there is an interleave scan as a method of lengthening the period T for performing the average of the correlation calculation repeatedly without waste.

  FIG. 11 is an explanatory diagram illustrating a case where the scan sequence table 90 in the case of performing the interleave scan is performed under the same conditions as the scan sequence table 50 illustrated in FIG. In the scan sequence table 90, scans of scan numbers 1 to 4 that are initially performed are performed while changing the sound ray numbers from 1 to 4. Thereafter, the scans of scan numbers 5 to 8 are repeated while changing the sound ray numbers from 1 to 4. After repeating such a scan four times, the process proceeds to the next scan of sound ray numbers 5-8.

  FIG. 12 is an explanatory diagram showing the operation of each processing unit when the controller unit 108 controls transmission / reception based on the scan sequence table 90. The horizontal axis in FIG. 12 represents time, and the vertical axis represents ON / OFF operation in each part of the B mode processing unit 103, the contrast mode processing unit 110, the CFM processing unit 109, and the phase inversion unit 80 on a common time axis. Is shown. In the lower part of FIG. 12, the scan numbers shown in the scan sequence table 90 of FIG. 11 are displayed along the time axis.

  FIG. 12 shows the scan numbers shown in the scan sequence table 90 of FIG. 11 whose numbers increase with time at the bottom of the figure. FIG. 12 shows the ON / OFF state of each processing unit corresponding to the scan number. The ON / OFF state of each processing unit repeats the same state every time the scan number increases by 16. The ON / OFF states of the processing units shown in FIG. 12 are exactly the same as those obtained by replacing the states of the scan numbers 1 to N shown in FIG. 9 with four consecutive scan numbers.

  Here, in the acquisition of the CFM image information of the sound ray number 1, four transmissions of scan numbers 1, 5, 9, and 13 are performed. The repetition cycle of these scan numbers for which the correlation calculation is performed is 4T, where T is one scan repetition cycle, and the repetition cycle is quadrupled without wasting acquisition time. The maximum detection frequency fmax of the high-pass filter is automatically set to ¼, and the cut-off frequency is lowered.

  Note that the phase of the transmission pulse is the same for scan numbers 1 to 4, and the phase is inverted when shifting to scan numbers 5 to 8. The contrast mode image information is formed between scan numbers 1 and 5, scan numbers 2 and 6,... Having the same sound ray number.

  Next, the contrast agent display process in step S502 will be described. The CFM image information, the contrast mode image information, and the B mode image information acquired by executing the scan sequence table 50 or 90 are read into the image memory 62 of the image display control unit 105.

  FIG. 13 is an explanatory diagram showing an example of the CFM image information 64, the contrast mode image information 65, and the B mode image information 66 in the image memory 62. FIG. 13A is a diagram illustrating an example of the B-mode image information 66. In the drawing, a blood vessel 67 that travels against the background of the tissue part 70 and a branch of the blood vessel 67 are shown. FIG. 13B is an example of a CFM image at the same position as in FIG. In FIG. 13B, the blood flow 68 flowing through the blood vessel 67 is displayed in blue to red having light and dark according to the speed. FIG. 13C shows a contrast agent 69 that flows into the imaging section together with the blood flow 68.

  FIG. 14 is an explanatory diagram illustrating examples of CFM image information 64, contrast mode image information 65, and B mode image information 66 displayed on the display unit 106. FIG. 14A is an example in which B-mode image information 66 is displayed side by side on superimposed image information 71 obtained by superimposing CFM image information 64 and contrast mode image information 65. B mode image information 66 is displayed on the left side of FIG. 14A, and superimposed image information 71 is displayed on the right side of FIG.

  The operator recognizes the form of the imaging region based on the B-mode image information 66 displayed on the left side of FIG. 14A, and the blood flow flows based on the superimposed image information 71 displayed on the right side of FIG. And the position of the contrast agent. Here, the operator accurately grasps the position of the contrast agent 69 by comparing and comparing the B-mode image information 66 and the superimposed image information 71, and the CFM image information 64 and the contrast-mode image information indicated by the superimposed image information 71 are displayed. From the comparison, the subsequent movement of the contrast agent 69 can be inferred. For example, when the hue at the contrast medium position in the CFM image information 64 is red, the contrast medium 69 moves upward in FIG. 14A where the probe unit 101 exists.

  FIG. 14B is an example in which C-mode image information 64 and contrast-mode image information 65 are superimposed on B-mode image information 66 and displayed as one piece of tomographic image information. In this case, it becomes easier for the operator to compare and contrast the blood vessel 67, the blood flow 68 and the contrast agent 69, and the subsequent movement of the contrast agent 69 can be grasped more accurately.

  As described above, in the present embodiment, the B-mode image in which the B-mode processing unit 103, the contrast mode processing unit 110, and the CFM processing unit 109 are optimized using the reception echo trains of the transmission pulses 81 to 84, respectively. Information 66, contrast mode image information 65, and CFM image information 64 are acquired, and the CFM image and the B mode image are displayed on the display unit 106 together with the image of the contrast agent 69. The position of the contrast agent 69 can be accurately grasped by comparison with the image information 66, and the subsequent movement of the contrast agent 69 can be inferred by comparison with the CFM image information 64.

  In the present embodiment, the B-mode image information 66, the CFM image information 64, and the contrast-mode image information 65 are displayed on the display unit 10, but at this time, the B-mode image information 66, the CFM image information 64, and It is also possible to provide a threshold value for each pixel value of the contrast mode image information 65, to provide a threshold value exceeding this threshold value, to a value below this threshold value, or to provide two threshold values, and to display only those values between these threshold values. Thereby, the pixel value region of particular interest in the B-mode image information 66, the CFM image information 64, and the contrast mode image information 65 can be extracted and displayed. Further, by using this threshold value, it is possible to adjust the superposition ratio and the like when superimposing the B-mode image information 66, the CFM image information 64, and the contrast mode image information 65.

  In the present embodiment, an example in which the superimposed image information 71 and 72 in which the contrast mode image information 65 is superimposed on the CFM image information 64 is displayed has been shown. However, the pixel value of the contrast mode image information 65 represents the CFM image information. The information on the blood flow direction at the same position acquired at 64 can be added and displayed. For example, the contrast mode image information 65 may be color-coded in the same manner as the CFM image information 64 to visualize the blood flow direction together with the intensity information of the contrast agent 69.

  In the present embodiment, an example of the contrast agent 69 that moves in the blood vessel 67 is shown. However, when the contrast agent is phagocytosed by a Kupffer cell or the like of the tissue part 70, the superimposed image is exactly the same. Information can be formed.

  In this embodiment, CFM image information, contrast mode image information, and B mode image information of all sound rays 1 to N constituting the tomographic image 61 are acquired. The number can be limited by a ROI (Region Of Interest) on the display screen, and the imaging time can be shortened.

It is a block diagram which shows the whole structure of an ultrasonic imaging device. It is a block diagram which shows the structure of a CFM process part, a transmission / reception part, and a controller part. It is a block diagram which shows the structure of a contrast mode process part. It is explanatory drawing which shows typically the reception echo at the time of inverting and non-inverting the phase of a transmission pulse, and its difference. It is a block diagram which shows the structure of an image display control part. It is a flowchart which shows operation | movement of an ultrasonic imaging device. It is explanatory drawing which shows an example of a scan sequence table (the 1). It is explanatory drawing which shows the sound ray and sound ray number of a tomographic image. It is explanatory drawing which shows a response | compatibility with a scan number and ON / OFF operation | movement of each process part (the 1). It is explanatory drawing which shows an example of the transmission pulse of multiple times used when acquiring one sound ray information. It is explanatory drawing which shows an example of a scan sequence table (the 2). It is explanatory drawing which shows a response | compatibility with a scan number and ON / OFF operation | movement of each process part (the 2). It is explanatory drawing which shows an example of B mode image information, CFM image information, and contrast mode image information. It is explanatory drawing which shows an example of B mode image information, CFM image information, and contrast mode image information displayed on a display part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Subject 10 Display part 12 Burst generator 33 Switch 34 Delay part 35 Addition part 36 Contrast harmonic B mode processing part 50, 90 Scan sequence table 60 Tomographic image 61 Writing part 62 Image memory 63 Reading part 64 Image information 65 Contrast mode image Information 66 B-mode image information 67 Blood vessel 68 Blood flow 69 Contrast agent 70 Tissue part 71 Superimposed image information 81 Oscillator 80 Phase inversion means 81 to 84 Transmission pulse 100 Ultrasound imaging device 101 Probe part 102 Transmission / reception part 103 B mode processing part 104 Cine memory unit 105 Image display control unit 106 Display unit 107 Input unit 108 Controller unit 109 CFM processing unit 110 Contrast mode processing unit 112 Beamformer 122 Image acquisition unit 201 Quadrature detection unit 202 Gain adjuster 203 Wall filter unit 204 Autocorrelation Unit 205 Operation Unit

Claims (8)

When acquiring one sound ray information in a subject to which a contrast agent is administered, a transmission / reception unit that performs ultrasonic transmission / reception a plurality of times,
A contrast mode processing unit that forms contrast mode image information in which the contrast agent is rendered using the received echo train acquired by the plurality of times of ultrasonic transmission and reception;
Using the reception echo train acquired by the ultrasonic transmission and reception a plurality of times, a B mode processing unit that forms B mode image information in the imaging region of the contrast mode image information;
A CFM processing unit that forms CFM image information in the imaging region using reception echo trains acquired by the ultrasonic transmission and reception a plurality of times;
A display unit that displays the contrast mode image information, the B mode image information, and the CFM image information on one display screen;
An ultrasonic imaging apparatus comprising:   3. The ultrasonic imaging according to claim 2, wherein the CFM processing unit forms the CFM image information by a correlation calculation between the plurality of received echo trains acquired by the plurality of times of ultrasonic transmission / reception. apparatus.   The B-mode processing unit forms the B-mode image information using one received echo train of the plurality of times acquired by the plurality of times of ultrasonic transmission / reception. 2. The ultrasonic imaging apparatus according to 2.   4. The ultrasonic imaging apparatus according to claim 1, wherein the transmission / reception unit includes a transmission pulse having an inverted phase in a transmission pulse used in the plurality of times of ultrasonic transmission / reception. .   5. The ultrasonic imaging apparatus according to claim 4, wherein the CFM processing unit performs quadrature detection of a received echo train using the inverted transmission pulse using a reference waveform having an inverted phase.   6. The contrast mode processing unit forms the contrast mode image information using the reception echo train of the inverted transmission pulse and the reception echo train of the transmission pulse that is not inverted. The ultrasonic imaging apparatus described in 1.   The display unit displays the contrast mode image of the contrast mode image information, the B mode image of the B mode image information, and the CFM image of the CFM image information in an overlapping manner. The ultrasonic imaging apparatus as described in one.   The display unit displays two of the contrast mode image of the contrast mode image information, the B mode image of the B mode image information, and the CFM image of the CFM image information side by side. 6. The ultrasonic imaging apparatus according to any one of 6.

Images