JPS61263442A - Method for displaying blood stream state in ultrasonic diagnostic apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (a) Industrial Application Field The present invention is an ultrasonic diagnostic device that uses the ultrasonic Doppler effect to measure the blood flow velocity in a living body and can display the measurement results as an image. S Mizuzui Tsuji 7-Ronas (b) Conventional techniques and their problems Conventionally, when diagnosing blood flow dynamics inside the heart, the ultrasound pulsed Doppler method has been widely applied.

This ultrasonic pulse Doppler method utilizes the fact that when an ultrasound pulse is emitted into a living body, the frequency of the ultrasound echo reflected from inside the living body is slightly shifted from the frequency of the emitted ultrasound pulse due to the Doppler effect. This method measures the blood flow velocity within a living body.

In this case, to make the diagnosis of hemodynamics easier, CR
A blood flow map may be displayed on a screen such as a T. To create this blood flow map, one heartbeat's worth of tomographic echo signals are captured in memory in synchronization with the heartbeat, one heartbeat's worth of tomographic images are obtained, and then an ultrasound beam is scanned every one heartbeat. In this way, Doppler signals in a predetermined direction are extracted for each heartbeat, and the frequency spectrum is determined from the extracted Doppler signals using methods such as fast Fourier transform (FFT).
Furthermore, the average blood flow velocity in each region is calculated from this frequency spectrum, and this frequency spectrum, that is, the blood flow velocity and the average blood flow velocity are stored in a memory.

This average blood flow velocity is, for example, a red color signal when the blood flow is approaching the emitted ultrasound beam, and a blue color signal when it is moving away from the emitted ultrasound beam. The blood flow dynamics are displayed together with the previously captured tomographic image by applying brightness modulation.

Therefore, by observing the blood flow map image displayed in this way, the direction and distribution of blood flow can be grasped.

By the way, although the brightness of the displayed image of the blood flow map corresponds to the blood flow velocity, this is only the average velocity in each region, and from this we can directly measure the change in blood flow velocity within a certain section of the diagnostic region. It is difficult to grasp.

The present invention has been made in view of these circumstances, and makes it easier to understand blood flow dynamics by displaying distance changes in blood flow velocity within a predetermined section set on a blood flow map. The purpose is to enable analysis.

(c) Means for solving the problem In order to achieve the above object, the present invention emits an ultrasonic pulse into a living body and obtains a Doppler signal from an ultrasound echo reflected from the living body. In a display method for displaying blood flow dynamics in a living body as a blood flow map on a CRT screen based on An observation position on the diagram is specified, and changes in blood flow velocity within a certain section located on the specified cursor are separately displayed as a distribution curve.

(d) Examples Hereinafter, the present invention will be explained in detail based on examples shown in the drawings.

FIG. 1 is a block diagram of an ultrasonic diagnostic apparatus for applying the method of the present invention. In the figure, l indicates the entire ultrasonic diagnostic device, 2 indicates an ultrasonic sector device that performs sector scanning with ultrasonic waves on a living body, and 4 digitizes the ultrasonic echo signal output from the ultrasonic sector device. 1st A/D
It is a converter.

Further, 6 is a phase detector that phase-detects the ultrasonic echo signal outputted from the ultrasonic sector device 2, and 8 is a second A/D that digitizes the Doppler signal extracted by phase-detecting the phase detector 6. converter, 10 is the second A/D converter 8
Buffer memory that temporarily stores Doppler signals from
12 is an FF7 circuit that performs fast Fourier transform on the Doppler signal read out from the buffer memory IO; 14 is an FFT
This is an arithmetic circuit that obtains a frequency spectrum based on the Doppler signal subjected to fast Fourier transform in the circuit 12, and further calculates the average blood flow velocity, dispersion, etc. from this data.

Reference numeral 16 indicates a data memory that stores the echo signal digitized by the first A/D converter 4, tomographic data, and data of the calculation result of the calculation circuit 14, and also stores character data, etc.; A display circuit converts the read data into an image display signal, and 20 is a CRT that displays the output from the display circuit 18 as an image. Further, 22 is a control circuit that controls each operation of the arithmetic circuit 14, data memory 16, and display circuit 18, and 24 is a control circuit 22.
25 is an electrocardiograph that provides an R-wave trigger signal to the control circuit 24.

In order to display a blood flow map diagram in the ultrasonic diagnostic apparatus l having the above configuration, first, the ultrasonic sector apparatus 2 continuously scans an ultrasonic beam using an R-wave trigger signal given from the electrocardiograph 25. The ultrasonic echo signal output from the sonic sector device 2 is digitized by the first A/D converter 4 and stored in the data memory 16 for one heartbeat as tomographic data.

On the other hand, after importing the tomographic data, the ultrasound sector device 2
The direction of the ultrasonic beam can be changed for each R-wave trigger signal, that is, every one heartbeat, so that an ultrasonic echo signal in a predetermined beam direction can be obtained for each heartbeat. The ultrasonic echo signal is phase-detected by a phase detector 6 to extract a Doppler signal, and the extracted Doppler signal is digitized by a second A/D converter 8 and stored in a buffer memory 10. Then, appropriate Doppler data is read from the buffer memory IO, and the read Doppler data is fast Fourier transformed (FFT) by the FFT circuit 12.
1. Next, a frequency spectrum is obtained by the arithmetic circuit 14 at the next stage, and the average blood flow velocity in each region is calculated from this frequency spectrum, and these calculation results are stored in the data memory 16.

The tomographic data and average blood flow velocity data stored in the data memory 16 are read out at predetermined timing, and the read out data is converted into an image display signal by the display circuit 18 and then output to the CRT. As a result, the CRT20 has
As shown in FIG. 2, a blood flow map is displayed superimposed on the tomographic image of that time phase, color-coded red and blue and whose brightness is modulated in accordance with the average blood flow velocity.

In order to display the distance change in blood flow velocity within a certain section of the diagnostic region on the blood flow map displayed in this manner, the following procedure is performed.

First, by operating the keyboard 24 to give a command signal to the control circuit 22 and reading character data stored in advance in the data memory 16, a straight line having a predetermined length is superimposed on the displayed blood flow map. shaped cursor 3
Display 0. When the keyboard 24 is operated, the position of the displayed cursor 30 moves, thereby specifying a desired position necessary for observing blood flow dynamics on the blood flow map.

Next, when a command signal for displaying a distance change in blood flow velocity is input from the keyboard 24, the control circuit 22 specifies a read address corresponding to the position on the cursor 30, and reads the specified address position from the data memory 16. Since the data of the frequency spectrum is read out, the read data is outputted to the CRT 20 via the display circuit 18. In this way, a distribution curve 32 is displayed on the same screen of the CRT 20 or on another monitor, as shown in FIG. 3, with the horizontal axis representing distance and the vertical axis representing blood flow velocity. Therefore, from this distribution curve 32, it is possible to directly grasp the distance change in blood flow dynamics within the fixed section a-b located on the cursor 30.

In this embodiment, the shape of the cursor 30 is linear, but it is not limited to this; if it is set to a curved shape, the distance distribution of blood flow velocity along the heart wall can be grasped. It also becomes possible.

(E) Effect As described above, according to the present invention, changes in blood flow velocity within a certain section specified by a cursor on a blood flow map are represented by a distribution curve with the horizontal axis representing distance and the vertical axis representing blood flow velocity. , it is possible to more easily analyze the dynamics of blood flow in the living body.

[Brief Description of the Drawings] Fig. 1 is a block diagram of an ultrasonic diagnostic apparatus for applying the method of the present invention, Fig. 2 is a blood flow map displayed on the screen, and Fig. 3 is a blood flow velocity diagram. FIG. 3 is a diagram illustrating an example of displaying a change in distance. 1... Ultrasonic diagnostic device, 16... Data memory, 2
0...CRT.

Claims (1)

[Claims] (1) Ultrasonic pulses are emitted into the living body, and blood flow dynamics within the living body are displayed on a screen such as a CRT as a blood flow map based on Doppler signals obtained from ultrasound echoes reflected from the living body. In the display method, a cursor of a predetermined length is displayed superimposed on the blood flow map, an observation position on the blood flow map is specified by the cursor, and each point within a certain section located on the designated cursor is A method for displaying blood flow dynamics in an ultrasonic diagnostic apparatus, characterized in that changes in blood flow velocity are separately displayed as a distribution curve.