JPH03159640A - Ultrasonic doppler diagnostic apparatus - Google Patents

Abstract

PURPOSE:To rapidly and visually grasp the timewise change pattern of a speed vector by displaying the speed and direction of the moving reflecting body in a living body as vectors by arrows and displaying the terminal loci of the respective vectors. CONSTITUTION:The receiving signal issued from a receiver 14 is inputted to a radius vector operation part 16 and a tangential speed operation part 18 to obtain radius vector speed and tangential speed and the magnitude V and direction phi of speed are calculated by an absolute flow velocity operation part 20 and the length and direction of a vector are calculated corresponding to the magnitude V and direction phi of the input signal in vector length and vector direction operators 22, 24. These vector data are temporarily held to a graphic memory 26 and the stored data of a speed vector Vn is converted to analogue data through a control circuit 28 by the keyboard operation of a user to be displayed on a CRT 34 by an arrow. At the same time, the terminal data of the speed vector Vn and speed vector Vn-1 stored and held in the memory 26 are drawn by the command from the circuit 28 as the terminal loci of the vectors through a vector terminal tracing device 36.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is an ultrasonic Doppler diagnostic device, particularly for observing motion reflectors such as blood flow in a living body, and detecting the direction and speed of motion of the motion reflectors. The present invention relates to an ultrasonic Doppler diagnostic device that displays images.

[Prior Art] An ultrasonic Doppler diagnostic apparatus is well known that transmits an ultrasound beam into a subject and forms an image by receiving reflected light obtained from a difference in acoustic impedance within the subject. This has the advantage of being able to observe the inside of a living body without adversely affecting the human body, and plays a very important role as a means of image diagnosis of affected parts of the human body.

This ultrasonic Doppler diagnostic device sends an ultrasonic pulse beam to the subject, and uses the Doppler effect that occurs when this pulse beam reaches a motion reflector such as blood flow within the subject to display an image of the velocity of movement. It is something to do. and,
The velocity obtained with this ultrasonic Doppler diagnostic device is displayed as a color image.
30503 in detail.

According to this device, images are displayed by applying different dyes to the positive and negative directions of blood flow velocity. For example, the velocity approaching the probe is displayed as positive in red, and the velocity moving away from the probe is indicated as negative in blue-green. it's shown.

In addition to this pigment display, two-dimensional display is performed in which the magnitude of speed corresponds to changes in brightness. Thereby, the state of the moving part in the living body can be read extremely easily, and information useful for image diagnosis can be provided.

Further, Japanese Patent Application Laid-Open No. 152439/1983 discloses a configuration in which vector quantities in all directions of motion of a motion reflector are displayed in color by hue and brightness.

This device displays the blood flow direction in different colors in all directions, and is extremely effective especially when observing the movement of blood flow in an organ in correspondence with a tomographic image.

[Problems to be Solved by the Invention] However, although these methods provide a unique pigment corresponding to each direction of motion, in practice it is difficult for an observer to determine the actual direction of motion from the pigment displayed on the screen. It is not easy to recognize accurately and quickly, and it is often difficult to connect changes in pigment and changes in direction of movement.

In addition, since the conventional device described above displays the entire ultrasonic beam radiation site in real time, it is not possible to extract and clearly recognize the velocity time change (velocity change pattern) of only a desired specific region in the living body. It was possible.

Furthermore, since the velocity vector continuously changes over time, there is a problem in that it is not possible to respond to detailed diagnostic conditions such as specifically displaying only the velocity vector at a certain arbitrary time.

Purpose of the Invention The present invention was made in view of the above-mentioned conventional problems, and its purpose is to realize an image display that allows accurate and prompt recognition of the movement direction and speed of a movement reflector in a living body at any location and time. An object of the present invention is to provide an ultrasonic Doppler diagnostic device that provides the following features.

[Means for Solving the Problems] In order to achieve the above object, the present invention radiates ultrasonic waves into the subject at a constant repetition period, determines the Doppler deviation frequency from the reflected echo signal, and calculates the Doppler deviation frequency from the reflected echo signal. In an ultrasound Doppler diagnostic device that displays an image of the motion state of a motion reflector based on the deflection frequency, there is a radial velocity calculator that calculates the velocity component in the ultrasound beam radiation direction, and a radial velocity calculator that calculates the velocity component in the ultrasound beam radiation direction. A tangential velocity calculator that calculates the velocity component of the direction, an absolute flow velocity calculator that calculates the motion direction and speed of the motion reflector based on the velocity components of both, and an arrow that calculates the motion direction and speed of the motion reflector. A vector direction calculator and a vector length calculator that display the direction and length of the vector, a graphic memory that temporarily stores the data calculated by the vector direction calculator and the vector length calculator, and It includes a graphic memory control circuit for controlling, an arrow display for displaying the output of the graphic memory as an arrow on a CRT, and a vector end point tracer for connecting the end points of the displayed arrows, and a vector end point tracer for connecting the end points of the displayed arrows, In addition to displaying the direction as a vector with an arrow,
It is characterized by displaying the end point locus of each vector.

[Operation] According to the device of the present invention configured as described above, the reflected echo signal of the ultrasonic beam emitted to a motion reflector such as a blood flow in a living body is first processed by a radial velocity calculator and a tangential velocity calculator. The velocity components in the ultrasonic beam radiation direction and in the direction perpendicular to the ultrasonic beam radiation direction are calculated in the calculation unit, respectively, and the calculation results are output to the absolute specific velocity calculation unit, where the velocity component is calculated. The size and direction are required.

Then, a vector length calculator and a vector direction calculator calculate the length component and direction of the vector according to the magnitude based on the velocity component and direction from the absolute flow velocity calculator, and calculate these data. is temporarily held in graphics memory.

Thereafter, when the velocity vector data in the graphic memory is read out from a predetermined control means in response to a command from the operator, this is converted into data as a specific vector by an arrow indicator, and then the D/A The image is displayed on a CRT via a converter.

At the same time, end point position information of a plurality of velocity vectors having a predetermined time interval is read out from data in the graphic memory to a vector end point tracer, and a line segment connecting the end points of the plurality of vectors is read out in the vector end point tracer. A signal power for displaying < g, I is supplied to the CRT via a corresponding D/A converter, thereby displaying the locus of the end point of the velocity vector.

[Example] Hereinafter, preferred embodiments of the present invention will be described based on the drawings.

FIG. 1 shows a block diagram of an example of the structure of the apparatus of the present invention.

The characteristic feature of the present invention is that it utilizes the shape of a vector, that is, an arrow, as a parameter for displaying the velocity distribution of a movement reflector in a living body, whereas conventionally it was considered a technical limit to use changes in pigment. The idea is that this allows the observer to directly and quickly grasp and recognize the velocity and direction of the movement reflector at a glance, and also allows for the observation of time-varying patterns of velocity at fixed specific sites within the body, as well as arbitrary Only the velocity vector at the time can be confirmed very easily.

In FIG. 1, the probe 12 is connected to the probe 2 via a connecting cable and a driving pulse is supplied from a transmitter 10 disposed inside the main body of the device to the probe 2 via a connecting cable. The ultrasonic beam is sent into the living body by exciting the probe, and the reflected signal from within the living body enters the receiver 14 in the main body of the apparatus through the same probe 12.

The received signal output from the receiver 14 is supplied to both the radial velocity calculation unit 16 and the tangential velocity calculation unit 18, and both calculation units 16.18
A radial velocity Vr and a tangential velocity Vt are obtained within the range. These Vr and Vt are input to the absolute flow velocity calculating section 20, where the velocity magnitude V and its direction φ are calculated, thereby detecting the velocity vector. ■ and φ are expressed by the following formula.

φ-jan' (Vt /Vr) The direction φ is a reference direction K as shown in FIG.
It means the angle that the velocity vector makes with respect to this K.

Then, the speed signal ■ and the direction φ are sent to the vector length calculator 22 and the vector direction calculator 24, respectively, and both the calculators 22 and 24 respond according to the magnitudes of the input signals V and φ. Calculate the length and direction of the vector.

The vector data thus obtained is temporarily held in the graphic memory 26. Then, the data of the velocity vector Vn stored through the graphic memory control circuit 28 is read out toward the arrow indicator 30 by the user's keyboard operation, and the output of the arrow indicator 30 is converted into a D/A converter. After being converted into analog information by the device 32, it is displayed on the CRT 34, and the magnitude and direction of the velocity at each site within the body are displayed on the screen as graphic arrows.

At the same time, the graphic memory control circuit 28
The data of the end point of the velocity vector Vri stored and held in the graphic memory 26 according to the command from Vn
-1 end point data is read out to the vector end point tracer 36, and the vector end point tracer 36 outputs a signal indicating a line segment connecting the end points of a plurality of vectors to the CRT 34 via the D/A converter 38. , the end point locus of the vector will be drawn.

FIG. 3 shows an example of vector display of the speed and direction of a moving anti-U=J body drawn on the CRT 34 with respect to a specific region V inside a living body. Vl, V2,...Vn (n; integer) are velocity vectors expressed at each time interval Δt, and the displayed end point of Vn and the end point of Vn-1 displayed Δt time ago are connected, It can be seen that a terminal locus (L) of the velocity vector V is formed.

As a result, it is possible to clearly recognize at a glance the pattern of changes in blood flow velocity and direction on a fixed one-time axis in a desired part of an in-vivo tissue, particularly the heart.

The display of the end point locus of the velocity vector thus displayed is cleared in predetermined time units, and the operation of tracing a new end point of the velocity vector and displaying the locus is repeated.

With the above configuration, it is possible to accurately recognize the amount of velocity, direction, and pattern of velocity change of the movement reflector at the specific site P in the living body using the clearest and simplest indicators of arrows and their trajectories.

Next, a second embodiment will be described in which the above-mentioned arrow display technique is applied to the ultrasonic B-mode tomographic image-L to display a velocity vector at an arbitrary time in a specific part of the body.

As shown in Fig. 4, a specific observation point P in the living body is
The mode is set on the tomographic image, and velocity vector data for a certain period of time is stored in the graphic memory 26.

Then, at the same time as the B-mode tomographic image is displayed, the direction of motion φ and speed V of the motion reflector are plotted in M-mode, with the vertical axis of motion direction φ and speed ■ as shown in FIG. 5, and the horizontal axis of time, respectively.
It is displayed as a bright line on T.

Then, by operating the joystick or trackball, set an arbitrary time Tl with the cursor on the M-mode image, and display the velocity vector at that time on the B-mode tomographic image in the direction and length of the arrow as shown in Figure 4. Display in .

It is also possible to set an arbitrary time T1 using an electrocardiogram and similarly display the velocity vector on the B-mode tomographic image.

FIG. 6 shows an example of an apparatus configuration for carrying out this second embodiment.

Three memories are interposed to store and hold for a predetermined time the magnitude and direction V and φ of the velocity vector obtained in the absolute flow velocity calculation unit 20 in FIG. 1, and the data stored in the memory 39 As a result, the velocity vector at an arbitrary time is displayed on the B-mode tomographic image. The processing steps after the memory 38 are basically the same as the operations of the embodiment shown in FIG. 1, so the explanation thereof will be omitted.

Next, a third embodiment of the present invention will be described based on FIG. 7.

The characteristic feature of this example is that the velocity vector display is applied to the M-mode image itself, and the velocity amount and direction of the motion reflector at a specific part of the body are continuously displayed on a predetermined time axis as time passes. This allows the velocity vector changes of a predetermined part of the body to be recognized continuously, accurately and quickly over a certain period of time.

In FIG. 7, the temporal change in blood flow velocity at a point P at an arbitrary depth on the M-mode image 40 is represented by a velocity vector 42 at a predetermined time period, and the direction of the blood flow velocity at a specific site in the living body is expressed by a velocity vector 42. It can be understood that it is possible to grasp at a glance how the size changes over time.

Note that a point P at an arbitrary depth in the figure can be set with a cursor on the M-mode image by operating a joystick, trackball, or the like.

[Effects of the Invention] As explained below, according to the present invention, an arrow that directly and visually indicates the velocity direction and amount of a motion reflector in a living body is used as a parameter, and this arrow can be directly and visually displayed on a CRT.
By using the structure shown above, the trajectory can be easily recognized by connecting the end points of multiple velocity vectors drawn at predetermined time intervals at a desired site in the body, and the temporal change pattern of velocity vectors can be quickly visualized. It becomes possible to understand,
For example, it is possible to easily determine whether blood flow is normal or abnormal.

Furthermore, by temporarily storing speed data in the memory and then displaying it with an arrow, it is also possible to recognize the speed vector at any given time.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a first configuration example of the device of the present invention, FIG. 2 is an explanatory diagram showing the definition of a velocity vector, and FIG. 3 is a diagram showing a velocity vector displayed on a CRT and its end point trajectory. FIG. 4 is an explanatory diagram showing an arrow displayed on an ultrasound B-mode tomographic image; FIG. 5 is an explanatory diagram showing a state in which an arbitrary time T1 is set on an ultrasound M-mode image; FIG. 6 is a Bronnoch diagram showing a configuration example of the second embodiment of the apparatus of the present invention, and FIG. 7 is an explanatory diagram showing a display example in which velocity vector display is applied to an ultrasound M-mode image. 10 ... Transmitter l2 ... Probe 14 - Receiver ko 6 ... Motion speed calculating section 18 ... Tangential speed calculating section 20 ... Absolute flow velocity a calculating section 22 ... Vector Length calculator 24...Vector direction calculator 26...Graphic memory 28...3 graphic memory control circuits...Arrow display 32 38...D/A converter 34...
CRT 36... Vector end point tracer 38... Ultrasonic B-mode tomographic image 39... Memory 40... Ultrasonic M-mode image 42. Velocity vector.

Claims (1)

[Claims] (1) Ultrasonic waves are emitted into the subject at a constant repetition rate, the Doppler deflection frequency is determined from the reflected echo signal, and the motion state of the motion reflector is displayed as an image based on this Doppler deflection frequency. In a Doppler diagnostic device, a radial velocity calculator calculates the velocity component in the ultrasound beam radiation direction, a tangential velocity calculator calculates the velocity component in the direction perpendicular to the ultrasound beam radiation direction, and a tangential velocity calculator calculates the velocity component in the direction of ultrasound beam radiation. Absolute flow velocity calculator that calculates the motion direction and speed of the motion reflector based on the motion reflector, and a vector direction calculator and vector length calculator that display the calculated motion direction and speed of the motion reflector as the direction and length of an arrow. a graphic memory that temporarily stores data calculated by the vector direction calculator and the vector length calculator; a graphic memory control circuit that controls the operation of the graphic memory; and an arrow that displays the output of the graphic memory on a CRT. It includes an arrow indicator for displaying, and a vector end point tracer that connects the end points of the displayed arrows, and displays the speed and direction of the motion reflector as a vector as an arrow, and displays the end point locus of each vector. An ultrasonic Doppler diagnostic device featuring: