JP5231768B2 - Ultrasonic diagnostic apparatus and data processing program for ultrasonic diagnostic apparatus - Google Patents

Description

  The present invention relates to an ultrasonic diagnostic apparatus that acquires Doppler signals from a subject and obtains three-dimensional blood flow information, and a data processing program for the ultrasonic diagnostic apparatus, and in particular, is obtained by integrating blood flow velocity information. The present invention relates to an ultrasonic diagnostic apparatus that displays a temporal change in blood flow and a data processing program for the ultrasonic diagnostic apparatus.

  An ultrasound diagnostic apparatus is an image diagnostic apparatus that non-invasively obtains a tomographic image of a tissue in a subject by transmitting and receiving ultrasound within the subject. Among ultrasonic diagnostic methods, a method for measuring blood flow and tissue velocity in a subject using the ultrasonic Doppler effect is called an ultrasonic Doppler method. Furthermore, an ultrasonic Doppler method using an ultrasonic pulse is known as a pulsed wave Doppler method (PWD).

  Conventionally, the flow rate is obtained from the blood flow velocity by PWD. In a general blood flow measurement method, the blood flow velocity is obtained by two-dimensional scanning using PWD.

  FIG. 21 is a diagram showing temporal changes in blood flow velocity measured by conventional two-dimensional scanning.

  In FIG. 21, the horizontal axis indicates time, and the vertical axis indicates the blood flow velocity. As shown in FIG. 21, the flow rate of the blood flow changes periodically and peaks at regular intervals. Then, the blood flow rate is obtained from the peak value Vp of the blood flow velocity.

  FIG. 22 is a schematic diagram for explaining a general method for obtaining a blood flow rate using a blood flow velocity measured by a conventional two-dimensional scan.

As shown in FIG. 22, it is assumed that the velocity distribution of blood flow at a certain moment is an axisymmetric elliptic paraboloid. Then, using the peak value Vp of the blood flow velocity corresponding to the central axis of the elliptical parabolic velocity distribution, the instantaneous flow rate of the two-dimensional blood flow can be obtained as shown in Equation (1).
[Equation 1]
V _2D = Vp × S (1)
However, in Formula (1),
V _2D : _2D instantaneous blood flow (cm ³ / s)
Vp: Peak value of blood flow velocity on the central axis (cm / s)
S: Blood flow cross section (cm ² )

  Furthermore, in recent years, a three-dimensional ultrasonic diagnostic apparatus has been devised that can easily and accurately measure blood flow (see Patent Document 1, for example). In this three-dimensional ultrasonic diagnostic apparatus, blood flow is calculated from color Doppler blood flow velocity information obtained by three-dimensional scanning. The method for obtaining the blood flow volume from the three-dimensional blood flow velocity information can obtain a stable result with higher accuracy than the method of estimating the volume from the two-dimensional tomographic image with processing such as interpolation. The flow rate value of the blood flow obtained in this way is displayed numerically on the monitor.

In addition, a technique for measuring cardiac output by automatically integrating color Doppler velocity information obtained by three-dimensional scanning has been devised.
JP 2000-201930 A

  However, in the three-dimensional color Doppler method using the conventional ultrasonic diagnostic apparatus, only the component in the sound axis direction, which is the traveling direction of the ultrasonic wave, is detected from the obtained blood flow velocity information. For this reason, when the angle formed between the direction in which the blood flows and the sound axis of the ultrasonic wave is close to 90 degrees, there is a problem that the detection accuracy of the blood flow velocity is extremely lowered. As a result, the blood flow velocity may be erroneously recognized.

  Therefore, even if a method of obtaining the blood flow rate with high accuracy from the three-dimensional blood flow velocity information is adopted, the scanning method, that is, the relative inclination between the direction of blood flow and the sound axis of the ultrasonic wave In some cases, it may be difficult to accurately determine the blood flow.

  In order to solve this problem, it is necessary to perform scanning so that the relative angle between the direction of blood flow and the sound axis of ultrasonic waves is as small as possible. However, the ultrasonic diagnosis can be scanned only from a limited position of the subject. For example, bones and lungs do not pass ultrasound and must be avoided.

  On the other hand, as a method for improving the measurement accuracy of the blood flow velocity as much as possible in a state where the angle between the flow direction of the blood flow and the sound axis of the ultrasonic wave is large, it is detected while moving the scanning position. A method of searching for a position where the absolute value of the flow rate obtained by calculating from the blood flow velocity or the blood flow velocity is maximized is known.

  In a state where the blood flow obtained by the conventional three-dimensional scanning is numerically displayed, when trying to find a scanning position where the maximum blood flow can be obtained, the scanning position is changed to change the blood flow. It is necessary to maximize the numerical display. For this reason, the operator pays attention simultaneously to the ultrasonic image and the numerically displayed blood flow. In addition, the operator must memorize the scanning position where the maximum value of blood flow is obtained. And since such a burden generate | occur | produces, it is in the situation where it is difficult to catch the maximum flow velocity and the maximum flow rate of blood flow easily.

  The cardiac output also changes depending on the scanning position of the ultrasonic wave. As described above, this is due to the scan angle dependency unique to the ultrasonic Doppler method. Therefore, when measuring the cardiac output by integrating the blood flow at a certain scanning position in the time direction, it is difficult to determine whether the cardiac output has been measured with appropriate accuracy. .

  The present invention has been made to cope with such a conventional situation, and provides an ultrasonic diagnostic apparatus and a data processing program for the ultrasonic diagnostic apparatus capable of measuring a blood flow rate at a more appropriate site. For the purpose.

In order to achieve the above-described object, an ultrasonic diagnostic apparatus according to the present invention includes a Doppler velocity information acquisition unit that acquires three-dimensional Doppler velocity information from a subject by three-dimensional scanning by transmitting and receiving ultrasonic waves , and a region of interest. and region of interest setting means for setting spatially, and instantaneous flow rate calculating means for calculating the instantaneous flow rate of blood flow in the region of interest by using the Doppler velocity information of the three-dimensional, from the instantaneous blood flow rate of the blood flow And graph display means for generating graph information indicating a time change and displaying the graph information in real time .

  In the ultrasonic diagnostic apparatus and the data processing program of the ultrasonic diagnostic apparatus according to the present invention, the blood flow rate can be measured at a more appropriate site.

  Embodiments of an ultrasonic diagnostic apparatus and a data processing program of the ultrasonic diagnostic apparatus according to the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a functional block diagram showing an embodiment of an ultrasonic diagnostic apparatus according to the present invention.

  The ultrasonic diagnostic apparatus 1 includes a transmission circuit 2, a two-dimensional (2D) array probe (2D array probe) 3, a reception circuit 4, a color Doppler calculation unit 5, and a three-dimensional digital scan converter (3D-DSC). : three-dimensional-digital scan converter) coordinate conversion unit 6, region of interest (ROI) input unit 7, flow rate calculation unit 8, flow rate-time graph processing unit 9, cardiac output calculation unit 10, input device 11 and a display unit 12. Each component can be constructed by a circuit or by causing a computer to read a program.

  The transmission circuit 2 generates a pulse signal as a transmission signal so that an ultrasonic wave is transmitted from the 2D array probe 3 in a desired direction at a desired transmission timing and transmission interval, and the generated transmission signal is applied to the 2D array probe 3. It has the function to do.

  The 2D array probe 3 includes a plurality of ultrasonic transducers for transmitting and receiving ultrasonic waves. Each ultrasonic transducer is arranged two-dimensionally. The 2D array probe 3 is configured to perform three-dimensional scanning by electronic scanning by controlling the delay time using each ultrasonic transducer. The 2D array probe 3 transmits the transmission signal given as an electric signal from the transmission circuit 2 as an ultrasonic wave into the subject, while receiving an ultrasonic echo generated in the subject and receiving an echo as an electric signal. The signal is converted into a signal and is provided to the receiving circuit 4. In particular, in addition to echo signals for B-mode images, which are ultrasonic tomographic images, a 3D Doppler signal for generating a blood flow image by the ultrasonic Doppler method is received by the 2D array probe 3, and the received Doppler signal is: It is output to the receiving circuit 4.

  The receiving circuit 4 obtains the Doppler signal and the B-mode image echo signal from the 2D array probe 3 and supplies the B-mode image echo signal to a B-mode image processing system (not shown), while supplying the Doppler signal to the color Doppler calculation unit. 5 is provided.

  The color Doppler calculation unit 5 has a function for obtaining color Doppler velocity information, which is three-dimensional velocity information of blood flow, from the Doppler signal obtained from the receiving circuit 4, and the 3D-DSC coordinate transformation unit 6 It has the function to give to.

  The 3D-DSC coordinate conversion unit 6 has a function of performing a coordinate conversion process for converting the scanning method of the color Doppler velocity information acquired from the color Doppler calculation unit 5 from the scanning method by the 2D array probe 3 to the television scanning method. A function of giving color Doppler velocity information after coordinate conversion to the display unit 12 and the flow rate calculation unit 8; Further, the 3D-DSC coordinate conversion unit 6 is provided with necessary image processing functions such as freeze and interpolation processing.

  In other words, the color Doppler image is displayed on the display unit 12 by outputting the color Doppler speed information from the 3D-DSC coordinate conversion unit 6 to the display unit 12 in a television scanning manner. Further, when B-mode image information generated in a B-mode image processing system (not shown) is given to the display unit 12, a color Doppler image can be superimposed on the B-mode image on the display unit 12.

  The ROI input unit 7 has a function of setting the ROI according to the instruction information from the input device 11 and a function of giving the set ROI to the flow rate calculation unit 8. The ROI can be spatially set as a two-dimensional region on an arbitrary plane or curved surface.

  The flow rate calculation unit 8 calculates the instantaneous flow rate of blood flow in the ROI acquired from the ROI input unit 7 based on the three-dimensional color Doppler velocity information acquired from the 3D-DSC coordinate conversion unit 6, and is obtained by calculation. A function of giving the instantaneous flow rate of the obtained blood flow to the flow rate-time graph processing unit 9. Further, when the color Doppler velocity information for calculating the instantaneous blood flow in the ROI is insufficient, the flow rate calculation unit 8 interpolates the insufficient color Doppler velocity information from the other acquired color Doppler velocity information. It is configured so that it can be obtained.

  The flow rate-time graph processing unit 9 is graph information for causing the display unit 12 to display a graph indicating a temporal change in the blood flow rate from the instantaneous flow rate value of the blood flow at each time in the ROI acquired from the flow rate calculation unit 8. And a function for displaying the graph by giving the created graph information to the display unit 12. The flow rate-time graph processing unit 9 is configured to give the created graph information to the cardiac output calculation unit 10.

  The flow rate-time graph processing unit 9 can be provided with a biological signal acquisition unit 9a. The biological signal acquisition unit 9a has a function of acquiring a signal indicating a time change of a desired biological signal from the subject. The biological signal acquisition unit 9a can be configured by, for example, an ECG signal acquisition unit that acquires an ECG (electro cardiogram) signal from a subject.

  When a biological signal such as an ECG signal is acquired, a flow rate-time graph processing unit so that the temporal change of the blood flow is synchronized with the time phase and the temporal change of the biological signal is displayed in parallel in the graph. 9 is configured to create graph information.

  The cardiac output calculation unit 10 has a function for determining the cardiac output for one heartbeat in the heart, that is, the cardiac output based on the graph information acquired from the flow rate-time graph processing unit 9, and the calculated cardiac output. Is provided on the display unit 12 for display.

  Next, the operation and action of the ultrasonic diagnostic apparatus 1 will be described.

  FIG. 2 is a flowchart showing a procedure for acquiring and displaying a temporal change in blood flow along with an ultrasound image by the ultrasound diagnostic apparatus 1 shown in FIG. 1, and reference numerals with numerals in the figure indicate steps in the flowchart. Indicates.

  First, in step S1, Doppler signals from the subject are collected by three-dimensional scanning. That is, the transmission circuit 2 generates a pulse signal as a transmission signal and applies the generated transmission signal to the 2D array probe 3. Then, the 2D array probe 3 converts a transmission signal, which is an electrical signal, into an ultrasonic wave and transmits it to a position at a predetermined depth in the subject along the scanning line. Then, the Doppler signal generated in the subject is received by the 2D array probe 3, and the received Doppler signal is converted into an electric signal and output to the receiving circuit 4. The receiving circuit 4 gives the Doppler signal received from the 2D array probe 3 to the color Doppler calculation unit 5.

  Such Doppler signal acquisition is performed three-dimensionally by three-dimensional scanning. One unit of ultrasonic image data obtained by three-dimensional scanning is called Volume. In order to obtain one Volume, the ultrasonic signal is transmitted and received as many times as necessary on the same scanning line with the 2D array probe 3 directed to the region where the blood flow image is to be generated, and scanning is performed a plurality of times. Is called. The color Doppler calculation unit 5 accumulates a plurality of Doppler signals from each position in the three-dimensional space in the subject.

  Next, in step S2, the color Doppler calculation unit 5 obtains three-dimensional color Doppler velocity information from the collected Doppler signals. The color Doppler velocity information has a unit of spatial size at each position in the three-dimensional space, and the unit size at each position of the color Doppler velocity information is called a pixel. In general, all pixels required for displaying a blood flow image are treated as a uniform size.

  FIG. 3 is a schematic diagram showing an example of three-dimensional color Doppler velocity information obtained by the color Doppler computing unit 5 shown in FIG.

  As shown in FIG. 3, a plurality of pixels of the same size are formed at each position on a cross section A. The color Doppler calculation unit 5 obtains three-dimensional color Doppler velocity information having a size and a direction for each pixel from a plurality of Doppler signals on the same scanning line. The obtained color Doppler velocity information for each pixel is arranged at a corresponding position in the three-dimensional space.

  Next, the three-dimensional color Doppler velocity information obtained by the color Doppler calculation unit 5 is given to the 3D-DSC coordinate conversion unit 6. In the 3D-DSC coordinate conversion unit 6, the scanning method of the color Doppler velocity information acquired from the color Doppler calculation unit 5 is converted from the scanning method by the 2D array probe 3 to the television scanning method. Thus, color Doppler velocity information after coordinate conversion is generated as blood flow image data for displaying the blood flow image on the display unit 12. The 3D-DSC coordinate conversion unit 6 performs necessary image processing such as freezing and interpolation processing.

  The color Doppler velocity information after the coordinate conversion generated in the 3D-DSC coordinate conversion unit 6 is given to the flow rate calculation unit 8 and the display unit 12. As a result, a color Doppler image is displayed on the display unit 12. Further, when B-mode image information generated in a B-mode image processing system (not shown) is given to the display unit 12, a color Doppler image can be superimposed on the B-mode image on the display unit 12.

  The color Doppler image is generated from the Doppler signal for 1 Volume as described above. The time required to complete the construction of a color Doppler image of 1 Volume is the propagation speed of ultrasound within the subject, the transmission time interval of the ultrasound signal, and the scan to collect 3 volume Doppler signals for 1 Volume. It is determined by conditions such as the number of lines (number of times of transmission of ultrasonic waves). The number of Volumes that can be configured per second determined by these conditions is called the Volume rate. The unit of Volume rate is Volume / second.

  Then, by repeating the configuration of each color Doppler image for each volume, temporally continuous images are created. Then, the created images are sequentially displayed on the display unit 12, so that real-time display of the images is realized.

  Next, in step S <b> 3, instruction information is input to the ROI input unit 7 by operating the input device 11, and a desired region for obtaining blood flow is set as the ROI in the ROI input unit 7. At this time, the display unit 12 displays a screen for setting the ROI. The screen information for setting the ROI can be created in the ROI input unit 7. The ROI can be easily set by operating the input device 11 such as a mouse while referring to a screen displayed on the display unit 12 by GUI (Graphical User Interface) technology.

  On the screen for setting the ROI, for example, a three-dimensional image such as a volume rendering image, a surface rendering image, or a single or a plurality of multi-planar reconstruction (MPR) images can be displayed. This ROI setting three-dimensional image can be created from volume data for ultrasonic images obtained by three-dimensional scanning.

  Then, for example, by specifying a point at an arbitrary position on the three-dimensional image by operating the input device 11 such as a mouse and inputting a radius, the two-dimensional region in the circle centered on the specified point is ROI. Can be set as However, the two-dimensional region is not limited to a circle, and may have any shape. A plane or curved surface in the three-dimensional space for creating a two-dimensional region can be arbitrarily determined by operating the input device 11.

  Furthermore, the ROI once created by the operation of the input device 11 can be enlarged or reduced at an arbitrary magnification, and the ROI can be moved in parallel in any direction or rotationally moved about an arbitrarily selected axis. It can be performed. Further, not only one ROI but also a plurality of ROIs can be set. It is also possible to set the entire range in which data is collected as ROI.

  Then, the ROI input unit 7 gives the finally set ROI to the flow rate calculation unit 8.

Next, in step S4, the flow rate calculation unit 8 obtains the instantaneous blood flow rate from the color Doppler velocity information in the set ROI. That is, the flow rate calculation unit 8 integrates (adds) the color Doppler velocity information obtained by the three-dimensional scanning every 1 Volume, and multiplies the result of integration (addition) by the size of the color pixel. Thereby, an instantaneous flow rate of a three-dimensional blood flow is obtained. When the instantaneous blood flow is obtained from the three-dimensional color Doppler velocity information on the cross section A shown in FIG. 3, the calculation shown in Expression (2) is performed in the flow calculation unit 8.

However, in Formula (2),
V _3D : Three-dimensional instantaneous flow (cm ³ / s) of blood flow through section A
Vp: Color Doppler velocity information on pixel (cm / s)
Sp: Pixel size (cm ² )
It is.

  Thus, if the instantaneous blood flow is obtained from the color Doppler velocity information obtained by the three-dimensional scanning, the accuracy is higher than that obtained when the instantaneous blood flow is obtained from the color Doppler velocity information obtained by the two-dimensional scanning. Can be used to determine the instantaneous blood flow. The reason is as described below.

  The blood flow in a general subject has a complicated velocity distribution because blood vessels travel in various directions. For this reason, it is difficult to calculate an accurate blood flow rate by a simple calculation using color Doppler velocity information obtained by two-dimensional scanning as in Expression (1). That is, the normal blood flow velocity distribution is not a rotationally symmetric distribution around the center line as shown in FIG. For this reason, there is a limit in accuracy in the measurement of blood flow by two-dimensional scanning.

  On the other hand, in the blood flow measurement by three-dimensional scanning, it is possible to obtain a more appropriate complex blood flow velocity distribution three-dimensionally even if the blood vessel is traveling in various directions. For this reason, blood flow measurement by three-dimensional scanning is more advantageous than blood flow measurement by two-dimensional scanning in terms of accuracy.

  The instantaneous blood flow obtained from the three-dimensional color Doppler velocity information is calculated for each volume. Accordingly, the instantaneous blood flow is sequentially calculated from the three-dimensional color Doppler velocity information for each continuous Volume.

  Here, the instantaneous blood flow can also be calculated from color Doppler velocity information on a plurality of cross sections different from the cross section where the ROI is set.

  FIG. 4 is a diagram showing an example of a plurality of cross sections that are three-dimensionally scanned by the ultrasonic diagnostic apparatus 1 shown in FIG. 1, and FIG. 5 is a diagram of the plurality of cross sections shown in FIG. is there.

  As shown in FIG. 4, for example, a plurality of cross sections Sscan in a direction perpendicular to the cross section where the ROI is set can be set as the scanning target. In such a case, there is a possibility that a region where data of color Doppler velocity information is insufficient is generated between the cross sections Sscan to be scanned. Therefore, when the color Doppler velocity information is insufficient for calculating the instantaneous blood flow, the insufficient color Doppler velocity information is estimated by interpolation from other obtainable color Doppler velocity information. .

  When the color Doppler velocity information is estimated by interpolation, it is necessary to sufficiently reduce the space R between the cross sections Sscan to be scanned in order to ensure estimation accuracy. Therefore, the flow rate calculation unit 8 may be provided with a function for obtaining a scanning section Sscan necessary for sufficiently obtaining the interpolation accuracy of the color Doppler velocity information. Then, the scanning section Sscan obtained by the flow rate calculation unit 8 can be given to the transmission circuit 2 so that the ultrasonic transmission conditions can be controlled.

  Further, when the flow rate calculation unit 8 is not provided with a function for obtaining the scanning section Sscan, the section Sscan to be scanned by ultrasonic transmission / reception in advance is obtained by the operator so that the color Doppler velocity information can be obtained with sufficient interpolation accuracy. Is set.

  6 is a diagram illustrating an example in which the size of a space between a plurality of cross-sections to be scanned is set in accordance with the ROI by the ultrasonic diagnostic apparatus 1 illustrated in FIG. 1, and FIG. It is the figure which looked at the cross section of from above.

  As shown in FIG. 6, in the region where the ROI is set, if the scanning section Sscan is set so that the distance between the plurality of sections Sscan to be scanned locally becomes small, the increase in the number of scanning lines is suppressed. Interpolation accuracy of color Doppler speed information can be ensured.

  Then, the instantaneous blood flow for each Volume obtained with interpolation processing as necessary is provided from the flow rate calculation unit 8 to the flow rate-time graph processing unit 9.

  Next, in step S <b> 5, the flow rate-time graph processing unit 9 creates graph information indicating the temporal change in the blood flow rate from the instantaneous blood flow value in the ROI acquired from the flow rate calculation unit 8. That is, the flow rate-time graph processing unit 9 plots the time change of the instantaneous blood flow for each 1 Volume sequentially acquired from the flow rate calculation unit 8. This makes it possible to create a graph with the instantaneous blood flow and time as axes. Then, the flow rate-time graph processing unit 9 displays the graph by giving the created graph information to the display unit 12.

  The flow value on the graph is obtained every time the instantaneous blood flow is calculated from the three-dimensional color Doppler velocity information. That is, the flow rate of blood flow can be obtained every 1 Volume as in the color Doppler image. Therefore, it is possible to continuously update the time change graph of the blood flow for each Volume. For this reason, if the time change graph of the blood flow is displayed on the display unit 12 while updating every 1 Volume, the graph can be displayed in real time in the same manner as the color Doppler image.

  The graph can be displayed and updated on the display unit 12 in an arbitrary manner.

  FIG. 8 is a diagram showing an example in which a time change graph of the blood flow is displayed on the display unit 12 shown in FIG. 1 by the moving bar method.

  In FIGS. 8A and 8B, the horizontal axis represents time, and the vertical axis represents blood flow. As shown in FIGS. 8A and 8B, the temporal change in the blood flow rate can be displayed using, for example, a moving bar (moving cursor) B that moves in the time direction. That is, as shown in FIG. 8A, the time change of the blood flow before a certain time indicated by the moving bar B is displayed. Then, when time elapses, the moving bar B moves in the time direction as shown in FIG. 8B, and the time change of the blood flow rate is additionally displayed sequentially.

  That is, in the moving bar method, the image update position is indicated by the movement cursor. The graph display method by the moving bar method is a display method generally used in the ultrasonic diagnostic apparatus 1, and is often used for displaying an image obtained by an M mode image or a pulse Doppler mode. For this reason, it can be said that it is suitable for an operator's interpretation.

  FIG. 9 is a diagram showing an example in which a time change graph of the blood flow is displayed on the display unit 12 shown in FIG. 1 by a scroll method.

  9A and 9B, the horizontal axis indicates time, and the vertical axis indicates blood flow. As shown in FIGS. 9A and 9B, the time change of the blood flow rate can be displayed by, for example, a scroll method in which a waveform W indicating the blood flow rate change is moved with time. That is, as shown in FIG. 9A, the time change of the blood flow before a certain time is displayed on the display unit 12. Then, as time passes, as shown in FIG. 9 (b), the waveform W indicating the change in blood flow moves toward the left side (past direction), and the flow rate of blood flow before the time after the elapse of time. The time change is displayed on the display unit 12. That is, in the scroll method, the latest blood flow is always fixedly displayed at the left end.

  Further, when a plurality of ROIs are set, the time change of the blood flow is displayed on the display unit 12 as a graph for each ROI.

  FIG. 10 is a diagram showing an example in which a plurality of ROIs are set in the ROI input unit 7 shown in FIG. 1, and FIG. 11 is a graph for displaying temporal changes in blood flow in each ROI shown in FIG. It is a figure which shows the example.

  As shown in FIG. 10, for example, two cross sections can be set as ROI 1 and ROI 2 so as to include a part of regions R 1 and R 2 where blood flow exists in the scanning range.

  Then, as shown in FIG. 11, the temporal change graphs of the blood flow rates in ROI 1 and ROI 2 shown in FIG. 10 can be displayed in parallel in synchronization with the ECG waveform. That is, in FIG. 11, the horizontal axis indicates time. In addition, the vertical axis in the upper part of FIG. 11 represents the blood flow rate at ROI 1, the vertical axis in the middle part represents the blood flow rate in ROI 2, and the vertical axis in the lower part represents the value of the ECG waveform.

  Thus, it is useful for diagnosis to obtain an instantaneous blood flow velocity using only velocity information in a limited space among color Doppler velocity information obtained by three-dimensional scanning. Therefore, the convenience of the operator can be improved by enabling the ROI to be set by the operator's designation.

  In addition, heretofore, an example of a time change graph of the blood flow when the 2D array probe 3 is fixed has been shown. As described above, the flow between the flow direction of the blood flow and the sound axis of the ultrasonic wave is shown. When the angle is large, it is necessary to find a scanning position at which the maximum blood flow rate can be obtained while moving the scanning position by the 2D array probe 3 in order to improve the measurement accuracy of the blood flow velocity. When scanning is performed while moving the 2D array probe 3, the instantaneous flow rate of the blood flow does not repeat the waveform of the same amplitude, and the amplitude greatly changes.

  FIG. 12 is a diagram illustrating an example of a time change graph of blood flow obtained when scanning is performed while moving the 2D array probe 3 illustrated in FIG. 1.

  In FIG. 12, the horizontal axis indicates time, and the vertical axis indicates blood flow. When scanning is performed while moving the 2D array probe 3 as shown in FIG. 12, the angle between the flow direction of the blood flow and the sound axis of the ultrasonic wave changes, so that the flow rate of the blood flow changes. Then, the operator needs to grasp the scanning position where the blood flow is maximized.

  In such work, by allowing the operator to refer to the time change graph of the blood flow as shown in FIG. 12, the operator can easily grasp the maximum value and the undulation of the blood flow. Is possible. Further, since there is a correlation between the time and the scanning position, if the relationship between the time and the scanning position is known, the blood flow rate value at each scanning position can be indirectly recorded as a graph. . For this reason, the operator can grasp the relationship between the blood flow rate value and the scanning position not only during the scanning but also after the fact. Therefore, the operator can focus closely on the ultrasonic image during scanning. If the time and the scanning position are determined in advance, the operator does not need to store the blood flow corresponding to the scanning position or the scanning position. And it can be expected that an appropriate scanning position and blood flow rate are acquired by reducing the burden on the operator.

  Further, the graph information created in this way is also given from the flow rate-time graph processing unit 9 to the cardiac output calculation unit 10. When the 2D array probe 3 is fixed, the cardiac output calculation unit 10 can determine the cardiac output.

  That is, in step S6, the cardiac output calculation unit 10 obtains the cardiac output from the graph information indicating the temporal change in the blood flow. The cardiac output is the sum of the flow rates for one heartbeat corresponding to the output for one heartbeat in the heart, and is used for diagnosis of cardiac function. In general, blood flow in a subject moves periodically as the heart beats. For this reason, the color Doppler velocity information obtained from the Doppler signal and the instantaneous blood flow are periodically changed in synchronization with the heartbeat.

  Therefore, the period for one heartbeat is obtained by using the temporal change of the instantaneous blood flow, and the cardiac output can be obtained from the blood flow in the obtained period.

  FIG. 13 is a diagram for explaining a method for calculating the cardiac output from the temporal change graph of the blood flow rate in the cardiac output calculation unit 10 shown in FIG. 1, and FIG. 14 shows the blood flow shown in FIG. 13. It is an enlarged view which shows the time change of the blood flow volume between the time selected in the time change graph of this flow rate.

  In FIG. 13, the horizontal axis indicates time, and the vertical axis indicates the blood flow rate. From the time change graph of the blood flow rate as shown in FIG. 13, the time when the blood flow rate becomes the lowest value or the time when the blood flow rate becomes the highest value is automatically detected by the cardiac output calculation unit 10. . As a method for detecting the time when the blood flow rate becomes the lowest value or the time when the blood flow rate becomes the highest value, for example, a method for detecting using a known algorithm generally used for processing such as automatic tracing of pulse Doppler Is mentioned.

  FIG. 13 shows an example in which the time at which the blood flow rate becomes the lowest value is automatically detected, and the marker M1 is displayed at the time when the automatically detected flow rate becomes the lowest value. In this manner, the cardiac output calculation unit 10 may create image information for displaying the marker M1 on the display unit 12, and display the marker M1 on the graph.

  Next, the cardiac output calculation unit 10 performs periodicity confirmation using the detected time. That is, a period between a time when a stable period is obtained, that is, a period from a certain time when the blood flow is lowest to a time when the blood flow is lowest next is selected as a section for one period. As shown in FIG. 14, the blood flow rate between the times selected as sections for one cycle is composed of instantaneous flow rates every time Tv corresponding to 1 Volume. And the cardiac output calculating part 10 calculates cardiac output by integrating | accumulating each instantaneous flow volume of the blood flow in the area for the selected 1 period.

  Such a method for detecting one cardiac cycle based on a change in blood flow has an advantage that it is less affected by the movement of the subject's body position than a method for detecting one cardiac cycle in synchronization with an ECG signal of an electrocardiogram. is there.

  FIG. 15 shows an electrocardiogram exhibiting a normal stable ECG waveform that is normally used for detection of one cardiac cycle, and FIG. 16 is a diagram showing an example of an electrocardiogram in which the ECG waveform is disturbed due to a change in the posture of the subject.

  15 and 16, the horizontal axis indicates time, and the vertical axis indicates the value of the ECG signal. As shown in FIG. 15, a technique for detecting one cardiac cycle from an electrocardiogram exhibiting a normal and stable ECG waveform is often used. However, when the posture changes due to the movement of the subject, the ECG waveform is disturbed as shown in FIG. For this reason, if one cardiac cycle is detected from an ECG waveform as shown in FIG. 16, there is a possibility that one cardiac cycle cannot be detected properly due to the influence of the body position movement of the subject.

  On the other hand, if one cardiac cycle is detected based on the change in blood flow, the influence of the subject's body position movement can be suppressed, and one cardiac cycle can be detected appropriately.

  Furthermore, the cardiac output can be calculated by a method other than the method for calculating the cardiac output by integrating the instantaneous blood flow in the section of one cardiac cycle as described above. For example, by adding the instantaneous blood flow included in the sections for a plurality of cycles and dividing by the heart rate included in the section to be added, the heart rate average can be obtained, and a more stable cardiac output can be obtained. Can be calculated.

  The cardiac output thus obtained is given to the display unit 12 from the cardiac output calculation unit 10 and displayed. For this reason, the operator can know the cardiac output of the subject as a numerical value by visually observing the display unit 12 of the ultrasonic diagnostic apparatus 1. The color Doppler image and the time change graph of the blood flow displayed together with the cardiac output are constantly updated with the passage of time required to generate an image for one volume. Thus, for example, the cardiac output can be calculated for each heartbeat, and the cardiac output displayed as a numerical value on the display unit 12 can be constantly updated.

  Here, when the cardiac output is calculated from the instantaneous blood flow included in the sections for a plurality of cycles by the heartbeat average, the range of the instantaneous blood flow used for calculating the cardiac output is displayed on the display unit. 12 may be useful for diagnosis. Therefore, the range of the instantaneous blood flow used for calculating the cardiac output can be visually shown on the display unit 12 using symbols and colors. Image information for visually displaying the range of the instantaneous blood flow can be created in the cardiac output calculation unit 10 and output to the display unit 12.

  FIG. 17 is a diagram showing an example in which the range of the instantaneous blood flow used for calculating the cardiac output is displayed on the display unit 12 shown in FIG. 1 by a marker indicated by a dotted line, and FIG. 18 is a diagram showing FIG. FIG. 19 is a diagram showing an example in which the range of the instantaneous blood flow used for the calculation of cardiac output is displayed on the display unit 12 by a marker indicated by a triangle symbol. FIG. 19 shows a color or pattern on the display unit 12 shown in FIG. It is a figure which shows the example which displayed the range of the instantaneous blood flow used for calculation of cardiac output by display.

  In FIGS. 17, 18, and 19, the horizontal axis represents time, and the vertical axis represents blood flow. As shown in FIG. 17, the section of the instantaneous blood flow used for calculating the cardiac output can be visually displayed on the display unit 12 by the marker M2 indicated by a dotted line. In addition, as shown in FIG. 18, the section of the instantaneous blood flow used for calculating the cardiac output can be visually displayed on the display unit 12 by two markers M3 indicated by triangular symbols. Further, as shown in FIG. 19, the section of the instantaneous blood flow used for calculating the cardiac output can be visually displayed on the display unit 12 by coloring or displaying a pattern.

  Then, the three-dimensional color Doppler image, the blood flow time change graph, and the cardiac output obtained as described above can be displayed in parallel on the display unit 12.

  FIG. 20 is a diagram showing an example of a screen when a three-dimensional color Doppler image, a time change graph of blood flow, and a cardiac output are displayed in parallel on the display unit 12 of the ultrasonic diagnostic apparatus 1 shown in FIG. It is.

  As shown in FIG. 20, a color Doppler image Id is displayed on the left side of the display unit 12 together with a three-dimensional scanning range. A separately created B-mode image can be superimposed on the color Doppler image Id. On the color Doppler image Id, ROI is set as a calculation range of blood flow. Further, on the right side of the display unit 12, a time change graph of the blood flow rate on a certain cross section set as the ROI is displayed. It is also possible to display a graph showing a time change of a biological signal such as an electrocardiogram in synchronization with a time change graph of a blood flow rate.

  Further, the cardiac output is displayed numerically at the bottom of the display unit 12. In addition, the range of the instantaneous blood flow used for calculating the cardiac output is visually indicated on the time change graph of the blood flow by the marker M4 indicated by a dotted line. For this reason, the operator can easily know the blood flow rate and the cardiac output together with the color Doppler image Id in real time or afterwards by referring to the display unit 12.

  That is, the ultrasonic diagnostic apparatus 1 as described above obtains temporal changes in blood flow using color Doppler velocity information obtained by three-dimensional scanning, and visually displays the obtained temporal changes in blood flow as a graph. is there. The time that is the horizontal axis of the graph displayed on the ultrasonic diagnostic apparatus 1 has a correlation with the scanning position.

  For this reason, according to the ultrasonic diagnostic apparatus 1, it is possible to easily refer to the flow rate change history due to the movement of the scanning position without depending on the memory of the operator. Then, if scanning is performed while referring to the time change graph of blood flow, or if the time change graph of blood flow is referred to after scanning, the scanning position where the blood flow becomes maximum can be found in a short time. For this reason, it is possible to perform stable scanning at a scanning position where the maximum blood flow rate can be measured.

  Moreover, according to the ultrasonic diagnostic apparatus 1, the cardiac output can be obtained based on the temporal change of the blood flow. For this reason, compared with the case where the cardiac output is obtained based on the electrocardiogram, it is possible to suppress the influence of the movement of the subject's body position and the movement due to breathing. This makes it possible to measure blood flow with good accuracy in a short time. Furthermore, it is possible to improve the efficiency of diagnosis and reduce the burden on the operator. Specifically, the reliability shown as values such as the diagnostic efficiency of cardiac function and the measurement accuracy of cardiac output can be significantly improved.

  In the above-described embodiment, an example of performing so-called real-time processing in which blood flow is immediately calculated from color Doppler velocity information obtained by scanning by transmission and reception of ultrasonic waves, and a time change graph of blood flow is immediately displayed. Although shown, each process can be performed not only in real time processing but at arbitrary timing. For example, blood flow can be calculated from color Doppler velocity information and a time change graph of blood flow can be displayed at any timing after ultrasonic scanning.

  As a more specific example, after acquiring color Doppler velocity information by ultrasonic scanning, a color Doppler image is stored in a cine image memory for a predetermined time or stored in an HDD (hard disk drive). Usually, the display time of a plurality of color Doppler images over several heartbeats is about 2 to 30 seconds, and is often stored in a cine image memory or stored in an HDD. In such a case, at a desired opportunity after the color Doppler image is stored, a necessary color Doppler image can be read and a spatial region in which blood flow is to be measured can be set as the ROI. Then, using the color Doppler velocity information in the spatial region set as the ROI, the instantaneous blood flow can be obtained by integrating (adding) the same method as in the real-time processing described above. Furthermore, if the instantaneous blood flow in the ROI is obtained for a plurality of color Doppler images in the same manner, a time change graph of the blood flow is created from the instantaneous blood flow corresponding to each color Doppler image. be able to.

  In the above-described embodiment, the data group of color Doppler velocity information obtained by three-dimensional scanning has been described as being Volume data arranged at equal intervals. However, the color Doppler velocity information data group does not necessarily have to be Volume data arranged at equal intervals, and the data interval in any direction among the vertical, horizontal, and depth directions toward the color Doppler image is different. Even if the data interval is different from that in the direction, it is possible to create a similar time change graph of blood flow.

  Moreover, although the example which sets ROI in the heart and calculates | requires the flow volume of the blood flow in the heart was demonstrated, ROI can be set not only in a heart but in arbitrary site | parts. And the flow volume in the blood vessel in arbitrary site | parts other than the heart can be calculated | required, and it can display on a graph.

1 is a functional block diagram showing an embodiment of an ultrasonic diagnostic apparatus according to the present invention. The flowchart which shows the procedure which acquires and displays the time change of a blood flow rate with an ultrasound image by the ultrasound diagnosing device shown in FIG. FIG. 3 is a schematic diagram illustrating an example of three-dimensional color Doppler velocity information obtained in a color Doppler calculation unit illustrated in FIG. 1. The figure which shows the example of the several cross section used as the three-dimensional scanning object by the ultrasonic diagnosing device shown in FIG. The figure which looked at a plurality of sections shown in Drawing 4 from the upper part. The figure which shows the example which set the magnitude | size of the space between several cross sections used as scanning object according to ROI by the ultrasonic diagnosing device shown in FIG. The figure which looked at a plurality of sections shown in Drawing 6 from the upper part. The figure which shows the example in the case of displaying the time change graph of the blood flow rate on the display part shown in FIG. 1 by a moving bar system. The figure which shows the example in the case of displaying the time change graph of the flow volume of a blood flow by a scroll system on the display part shown in FIG. The figure which shows the example which set several ROI in the ROI input part shown in FIG. The figure which shows the example which each displayed the time change of the flow volume of the blood flow in each ROI shown in FIG. The figure which shows the example of the time change graph of the blood flow rate obtained when it scans, moving the 2D array probe shown in FIG. The figure explaining the method of calculating cardiac output from the time change graph of the blood-flow rate in the cardiac output calculating part shown in FIG. The enlarged view which shows the time change of the blood flow between the time selected in the time change graph of the flow rate of the blood flow shown in FIG. An electrocardiogram showing a normal and stable ECG waveform usually used for detection of one cardiac cycle. The figure which shows the example of the electrocardiogram where the ECG waveform was disturb | confused by the posture change of the subject. The figure which shows the example which displayed the range of the instantaneous flow volume of the blood flow used for the calculation of cardiac output by the marker shown with a dotted line on the display part shown in FIG. The figure which shows the example which displayed the range of the instantaneous flow volume of the blood flow used for the calculation of cardiac output by the marker shown with a triangle symbol on the display part shown in FIG. The figure which shows the example which displayed the range of the instantaneous blood flow used for calculation of cardiac output by coloring or pattern display on the display part shown in FIG. The figure which shows an example of the screen at the time of displaying in parallel the three-dimensional color Doppler image, the time change graph of the blood flow, and the cardiac output on the display part of the ultrasonic diagnostic apparatus shown in FIG. The figure which shows the time change of the blood flow velocity measured by the conventional two-dimensional scan. The schematic diagram explaining the general method of calculating | requiring the flow volume of the blood flow using the blood flow velocity measured by the conventional two-dimensional scan.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ultrasonic diagnostic apparatus 2 Transmission circuit 3 Two-dimensional (2D) array probe 4 Reception circuit 5 Color Doppler calculation part 6 Three-dimensional digital scan converter (3D-DSC) coordinate conversion part 7 Region of interest (ROI) input part 8 Flow rate calculation part 9 Flow rate-time graph processing unit 9a Biological signal acquisition unit 10 Cardiac output calculation unit 11 Input device 12 Display unit

Claims (10)

Doppler velocity information acquisition means for acquiring three-dimensional Doppler velocity information from the subject by three-dimensional scanning by transmission and reception of ultrasonic waves;
A region of interest setting means for spatially setting the region of interest;
Instantaneous flow rate calculating means for obtaining an instantaneous flow rate of blood flow in the region of interest using the three-dimensional Doppler velocity information;
Creating graph information indicating temporal changes in blood flow from the instantaneous blood flow, and graph display means for displaying the graph information in real time;
An ultrasonic diagnostic apparatus comprising: The ultrasonic diagnostic apparatus according to claim 1, wherein the region-of-interest setting unit is configured to set the region of interest as a two-dimensional region. The graph display means, claims, characterized in that it is configured so that the time variation of the time change and the time phase to synchronize with the biological signal of the flow rate of the blood flow creates the graph the information to be displayed The ultrasonic diagnostic apparatus according to 1. The ultrasonic diagnostic apparatus according to claim 1 , wherein the graph display unit is configured to display the graph information in real time together with a Doppler image obtained from the three-dimensional Doppler velocity information. When the three-dimensional Doppler velocity information is insufficient for obtaining the instantaneous flow rate of the blood flow, the instantaneous flow rate calculating means obtains another insufficient three-dimensional Doppler velocity information. The ultrasonic diagnostic apparatus according to claim 1, wherein the ultrasonic diagnostic apparatus is configured to be obtained by interpolation from information. When the three-dimensional Doppler velocity information is insufficient for obtaining the instantaneous flow rate of the blood flow, the instantaneous flow rate calculating means obtains another insufficient three-dimensional Doppler velocity information. The ultrasonic diagnostic apparatus according to claim 1, wherein the ultrasonic diagnostic apparatus is configured to determine a scanning section that is obtained by interpolation from information and obtains necessary interpolation accuracy. The ultrasonic diagnostic apparatus according to claim 1 , further comprising a cardiac output calculating means for obtaining a blood flow for one heart rate from the graph information. By detecting an interval of one cycle of the blood flow that periodically changes from the graph information, and integrating the instantaneous blood flow of the blood flow in the detected interval of the one cycle, The ultrasonic diagnostic apparatus according to claim 1 , further comprising a cardiac output calculating means for obtaining a flow rate. Detecting a period of a plurality of periods of the blood flow that periodically changes from the graph information, and using the detected number of periods, the integrated value of the instantaneous blood flow in the section of the plurality of periods detected. The ultrasonic diagnostic apparatus according to claim 1 , further comprising a cardiac output calculating means for calculating a blood flow rate for one heart rate by performing an average process. Computer
Region-of- interest setting means for spatially setting the region of interest;
Instantaneous flow rate calculating means for determining an instantaneous flow rate of blood flow in the region of interest using three-dimensional Doppler velocity information acquired from a subject by three-dimensional scanning by transmitting and receiving ultrasonic waves; and
Creating graph information indicating temporal changes in blood flow from the instantaneous blood flow, and graph display means for displaying the graph information in real time;
A data processing program for an ultrasonic diagnostic apparatus, characterized in that

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