JPH02152445A - Ultrasonic diagnostic apparatus - Google Patents

Abstract

PURPOSE:To display the timewise change of a blood flow rate in real time and to reduce the operation load of an operator by obtaining the data of the diameter of a blood vessel and blood flow velocity at an arbitrary point and successively calculating the blood flow rate at the arbitrary point in a B-mode image on the basis of said data by a blood flow rate calculation means. CONSTITUTION:A blood vessel diameter measuring circuit 12 is provided to determine the blood flow direction in a B-mode image and the white and black data or color data at each point is judged from an arbitrary point in a blood vessel wall direction. On the basis of the judge results, the distance from the arbitrary point to the wall of a blood vessel is calculated to measure the diameter of a blood vessel at the arbitrary point. On the basis of the obtained blood vessel diameter and blood flow velocity data, the blood flow rate at the arbitrary point in the B-mode image is successively calculated by a blood flow rate calculation circuit 13. As a result, a blood flow rate can be displayed real time and it is unnecessary to trace the diameter of a blood vessel and the operation load of an operator can be reduced.

Description

Detailed Description of the Invention [Objective of the Invention] (Industrial Application Field) The present invention uses ultrasonic waves to obtain anatomical information such as a B-mode image of a living body, and to obtain in-vivo information such as an M-mode image. Regarding ultrasonic diagnostic equipment that obtains and visualizes functional information associated with the movement of moving objects within a living body, such as motion information of moving organs and two-dimensional blood flow velocity information using the Doppler effect, it is particularly important to use B or M mode images in black and white. The present invention relates to an ultrasonic diagnostic apparatus that displays information in color while superimposing two-dimensional blood flow velocity information thereon.

(Prior art) Ultrasonic diagnostic methods use anatomical information, typically represented by B-mode images, movement information of in-vivo organs, typically represented by M-mode images, and the Doppler effect, typically represented by blood flow imaging. Functional information, etc., which is the basis for the movement of a moving object within a living body using this method, is used to make decisions.

Here, the M-mode image obtained by fixing in the same direction represents temporal changes in the ultrasound transmitting and receiving region, and is particularly suitable for diagnosing moving organs such as the heart.

On the other hand, the ultrasonic Doppler method, of which blood flow imaging is a typical example, is a method of obtaining and visualizing functional information based on the movement of a moving object within a living body, and this will be explained below. The ultrasonic Doppler method utilizes the ultrasonic Doppler effect in which when an ultrasonic wave is reflected by a moving object, the frequency of the reflected wave shifts in proportion to the moving speed of the moving object.

Specifically, by transmitting ultrasonic rate pulses or continuous waves into a living body and obtaining a frequency shift due to the Doppler effect due to the phase change of the reflected echo, it is possible to obtain a frequency shift due to the Doppler effect. Exercise information can be obtained. This allows the state of blood flow such as the direction of blood flow, state of blood flow, pattern of blood flow, absolute value of velocity, etc. at a certain position in the living body to be known.

Next, the device will be explained. That is, as shown in FIGS. 9 and 10, ultrasonic waves are transmitted in the direction A in the figure from the probe 21 driven by the wave transmitting/receiving circuit 22, and from the ultrasonic echoes received by the wave transmitting/receiving circuit 22, The phase detector 23 detects the Doppler shift signal.

In this case, the Doppler shift signal is captured at each of, for example, 256 sample points SP provided in the direction of the ultrasound beam. The Doppler shift signal captured at each sample point SP in this way is calculated by the blood flow calculation unit 24, and the obtained blood flow signal is converted to D S
C25 and the display unit 26, and the blood flow image in the A direction is displayed on the monitor of the display unit 26.

Next, the ultrasound beam is shifted in direction B and the same operation as described above is performed to scan the display range in real time, detecting blood flow information in each direction and displaying blood flow signals, thereby detecting two-dimensional blood flow. To obtain flow images in real time.

In this case, the wave transmitting/receiving circuit 22 separates the ultrasound echo into an echo component from a stationary object such as tissue and an echo component from a moving object such as blood flow, and the former is used for B or M mode image formation. , the latter is used by the phase detector 23 to detect the Doppler shift signal. There is a configuration in which an echo component from a stationary object is formed as a B or M mode image and displayed by changing the brightness level between black and white, and the two images are displayed in a superimposed manner.

On the other hand, information on blood flow rate is also important as ultrasonic diagnostic information as well as information on blood flow velocity. This blood flow causes the displayed image to freeze (stand still) at a certain point, and the operator traces the diameter of the blood vessel in this still image. Then, the cross-sectional area of the blood vessel is determined from this blood vessel diameter, and the blood flow rate is further measured from this blood vessel cross-sectional area and the blood flow velocity information.

(Problem to be Solved by the Invention) However, while the blood flow rate changes over time, the above-mentioned blood flow rate could not be calculated until after freezing. For this reason, there is a problem in that blood flow information is measured with a time delay, that is, blood flow cannot be displayed in real time. In addition, the operator had to trace the diameter of the blood vessel one by one, which placed a burden on the operator.

SUMMARY OF THE INVENTION An object of the present invention is to provide an ultrasonic diagnostic apparatus that can display temporal changes in blood flow in real time and that can reduce the operating burden on the operator.

[Configuration of the Invention (Means for Solving the Problems) The present invention takes the following measures to solve the above problems. The present invention provides ultrasound diagnostics that displays a B-mode image of a subject in black and white based on reflected components of ultrasound waves transmitted towards the subject, and displays blood flow information in color superimposed on this B-mode image. In the device, specify an arbitrary point of the blood flow in the color-displayed B-mode image, and set a plurality of points at a predetermined interval in the direction of the blood vessel wall from the arbitrary point at a predetermined angle with respect to the blood flow direction. At this time, the blood vessel diameter is obtained by determining the black and white data or color data at each point sequentially from the arbitrary point in the direction of the blood vessel wall, and calculating the distance from the arbitrary point to the blood vessel wall based on this determination result. The blood vessel diameter measuring means includes a blood vessel diameter measuring means, and a blood flow rate calculating means for calculating the blood flow rate at the arbitrary point based on the blood vessel diameter obtained by the blood vessel diameter measuring means and the blood flow velocity information.

(Effects) By taking such measures, the following effects are achieved. The blood flow direction is determined in the B-mode image, and black-and-white data or color data at each point is determined from an arbitrary point toward the blood vessel wall. Then, based on the determination result, the distance from the arbitrary point to the blood vessel wall is calculated, and the blood vessel diameter at the arbitrary point can be measured. Therefore, using this blood vessel diameter and blood flow velocity information, the distance from the arbitrary point to the blood vessel wall can be calculated. Blood flow is calculated sequentially. As a result, the blood flow rate can be displayed in real time, and there is no need to trace the diameter of the blood vessel, reducing the operational burden on the operator.

(Embodiment) ￥S1 Figure is a block diagram showing the configuration of essential parts of an embodiment of the ultrasonic diagnostic apparatus according to the present invention. In FIG. 1, a color frame memory 1 stores blood flow data detected from echo data obtained by transmitting and receiving ultrasonic waves as a digital signal. The black-and-white frame memory 2 stores echo data, for example, for forming a B-mode image by transmitting and receiving ultrasonic waves, in the form of digital signals. The ROM (read-on memory) 3 converts the blood flow data in the color frame memory 1 into RGB signals corresponding to the size thereof. The latch circuit 4 temporarily holds the RGB signalized blood flow data from the ROM 3, and the latch circuit 5 temporarily holds the echo data from the monochrome frame memory 2. (2) The threshold value setting circuit 6 sets a color brightness threshold for forming a two-dimensional blood flow velocity image, and the value can be set to a desired value. The comparator 8 uses the color luminance threshold set by the threshold value setting circuit 6 as a comparison signal C0LTH, and uses the color frame memory l
Input the data of the blood flow velocity V from as the compared signal,
Blood flow velocity V data is color brightness threshold C0LTH
When the blood flow velocity V data is greater than the color luminance threshold C0LTH, an H level signal is output, and when the blood flow velocity V data is less than the color luminance threshold C0LTH. It outputs L level. The B/W threshold setting circuit 7 is
For example, a black-and-white luminance threshold is set for echo data for B-mode image formation, and its value can be set to a desired value. The comparator 9 uses the black and white luminance threshold set by the B/W threshold value setting circuit 7 as a comparison signal B/HTH, and uses the black and white frame memory 2 as a comparison signal B/HTH.
The echo data B/W according to 7 is input as the compared signal, and the echo data B/W is the black and white luminance threshold B/H.
When the echo data B/H is greater than TH, an H level is output, and when the echo data B/H is less than a monochrome luminance threshold B/HTH, an L level is output. The switching logic generating circuit 10 outputs a select signal to an input terminal S of a multiplexer 11, which will be described later, based on the outputs of the comparators 8 and 9. In other words, the output of comparator 8 is “H”
And only when the output of the comparator 9 is 'L', the output of the switching logic generating circuit 10 is 'H', and in all other states, it is 'L'. The multiplexer 11 is a switching logic circuit 1
Depending on the content of the select signal of 0, either the latch circuit 4 or 5 is output. In other words, when S-"L", the output of the multiplexer 11 is sent to the echo data latch circuit 5.
is generated, and when S-“H”, multiplexer 1
The output 1 is generated from the latch circuit 4 for blood flow data (two-dimensional blood flow velocity image).

FIG. 2 is a diagram showing monochrome brightness display or color brightness display based on the threshold settings described above.

FIG. 3 is a diagram showing a state in which arbitrary points are set in the blood flow in the B-mode image. In FIG. 3, an arbitrary point P is manually set at the position of the blood flow, and the blood flow direction X and the ultrasound beam direction Y form an angle θ. FIG. 4 shows B based on black and white data output from the black and white frame memory 2.
5 is a diagram showing a mode image, and FIG. 5 is a diagram showing blood flow velocity according to color data output from the color frame memory 1. FIG.

FIG. 6 is a diagram showing a method fPJ of measuring the blood vessel diameter using the blood vessel diameter measuring means 12 shown in FIG. In (a), an arbitrary point in the color-displayed B-mode image is specified, and the blood vessel wall Qf, Q is reached from the arbitrary point PL at right angles to the blood flow direction Xt.
2 is a diagram showing a state in which a plurality of points P2... are set at predetermined intervals in two directions.

(b) is the blood vessel wall Ql from the arbitrary point PI.

FIG. 6 is a diagram showing a state in which black-and-white data or color data input from the switching logic generating circuit 10 at each point P2 . As described above, color data is "H" and black and white data is "L".

The blood vessel diameter measurement circuit 12 determines the black and white data or color data input from the color frame 1 for blood flow data at an arbitrary point pt of the blood flow in the B-mode image and each point P2..., and calculates the result of this determination. When black and white data is repeatedly detected as 0 points, it is determined that these are the blood vessel walls Ql and Q2, and the blood vessel walls Ql on both sides from the arbitrary point Pi to this arbitrary point PI.

The blood vessel diameter is determined by measuring the distance to Q2.

The blood flow calculation circuit 13 calculates the blood flow at the arbitrary point P1 based on the blood vessel diameter obtained by the blood vessel diameter measurement circuit 12 and the blood flow velocity information from the multiplexer 11.

The ultrasonic diagnostic apparatus configured in this way operates as follows. First, the blood flow velocity V is the color brightness threshold C
When it is smaller than 0LTH, the output of comparator 8 is “L”
", and when the echo data B/W is smaller than the monochrome luminance threshold B/HTH, the output of the comparator 9 becomes "L", so the output of the switching logic generation circuit 10 becomes "L".
becomes.

Since the output of the latch circuit 5 is applied to the output of the multiplexer 11, the contents of the monochrome frame memory 2 for echo data are output based on FIG. Therefore, the B-mode image is displayed in black and white in this area. Similarly, V<
It is also displayed in black and white when C0LTH and B/W>B/WTH, and when V>C0LTH and B/W>B/WTH. Further, when v>C0LTH and B/W×B/WTH, the two-dimensional blood flow velocity image is displayed in color.

Next, as shown in FIG. 3, an arbitrary point in the B-mode image displayed in color is specified. Then, the blood flow direction X at this arbitrary point is determined manually, and the angle between the ultrasound beam Y and the blood flow direction X is set to be θ. Then, from an arbitrary point PI set by the blood vessel diameter measuring circuit 12 as shown in FIG. 6, the blood vessel wall Q1.
Each point P2. Black and white data B/W or color data C input from the switching logic generating circuit IO at P3 . . . is detected. That is, it is determined whether black and white data B/W of L" or color data C of 'H" at each point is blood flow using the threshold shown in FIG. Then, black-and-white data B/W or color data C at each point P2... is determined from the set point P1 toward the double-sided tube walls Ql, Q2, and when black-and-white data B/W is detected continuously for n or more points, , blood vessel wall Ql, Q2
It is determined that and both blood vessel walls Q1. The distance to Q2 is calculated and the blood vessel diameter is determined. Further, this blood vessel diameter and the maximum flow velocity vwax, which is blood flow information from the color frame memory 1 for blood flow data, are input to the blood flow calculation circuit 13, which calculates the flow rate (m3/s) k Pot Vmax -3・1/cosθ...
(1) is calculated. Here, S is the cross-sectional area and θ is the angle between the beam and the blood flow. S-π・(Vessel diameter/2)2
It is.

In this way, according to the present embodiment, it is no longer necessary to freeze the ultrasound image, trace the ultrasound image to determine the blood vessel diameter, and then calculate the blood flow volume, as in the conventional method.
The blood flow rate calculated by the formula 1) is calculated from the blood vessel diameter needle IP1 circuit 12. Since the blood flow rate calculation circuit 13 quickly calculates the blood flow rate, temporal changes in blood flow rate can be displayed as images in real time, as shown in FIG.

Also, since there is no need to trace the diameter of the surgeon's blood vessels,
The operational burden on the operator can be reduced.

Note that the present invention is not limited to the embodiments described above. In the embodiment described above, the blood flow direction XI is manually set, but the blood flow direction may be set automatically, for example. In other words, as shown in Fig. 8, the blood flow direction is determined by detecting the blood flow profile of the blood vessel of interest at least at two points R1 and R2 in real time, connecting their peaks, centers of gravity, etc., and automatically determining the blood flow direction X2. I am aware of this. It goes without saying that various other modifications can be made without departing from the gist of the present invention.

[Effects of the Invention] According to the present invention, the blood flow direction is determined in a B-mode image, and the blood vessel diameter measuring means determines black and white data or color data at each point from an arbitrary point toward the blood vessel wall.

Then, based on the determination result, the distance from the arbitrary point to the blood vessel wall is calculated, and the blood vessel diameter at the arbitrary point can be measured. Based on this blood vessel diameter and blood flow velocity information, the blood flow calculation means uses the B-mode image. The blood flow rate at arbitrary points inside is calculated sequentially. As a result, it is possible to provide an ultrasonic diagnostic apparatus that can display temporal changes in blood flow in real time, eliminates the need to trace blood vessel diameters, and can reduce the operating burden on the operator.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of essential parts of an embodiment of an ultrasonic diagnostic apparatus according to the present invention, FIG. 2 is a diagram showing monochrome brightness display or color brightness display depending on threshold settings,
Figure 3 is a diagram showing a state in which arbitrary points are set in the blood flow in the B-mode image, Figure 4 is a diagram showing a B-mode image based on black and white data output from the black and white frame memory, and Figure 5 is a color frame. FIG. 6 is a diagram showing the blood flow velocity based on color data output from the memory. FIG. 6 is a diagram showing the measurement method of the blood vessel diameter measuring means shown in FIG. 1. FIG. FIG. 8 is a diagram showing a case where the blood flow direction is automatically set, and FIGS. 9 and 10 are diagrams showing a conventional ultrasonic diagnostic apparatus. ■...Color frame memory for blood flow data, 2...
Black and white frame memory for echo data, 3... RGB conversion ROM, 4.5... Latch circuit, 6... V threshold setting circuit, 7... B/W threshold setting circuit, 8.9... Comparator, IO... switching logic generation circuit, 11...
Multiplexer, 12... Blood vessel diameter measurement circuit, 13...
・Blood flow calculation circuit, 21... Probe, 22... Wave transmitting/receiving circuit, 23... Phase detection circuit, 24... Blood flow calculation unit, 25... DSC, 2B... Monitor . Applicant's representative Patent attorney Takehiko Suzue Figure 2 Ivy Figure 3 Figure 4 Leap Figure 5

Claims (1)

[Claims] In an ultrasonic diagnostic apparatus that displays a B-mode image of a subject in black and white based on reflected components of ultrasound waves transmitted toward the subject, and displays blood flow information in color superimposed on this B-mode image, When an arbitrary point of the blood flow in the color-displayed B-mode image is specified and a plurality of points are set at a predetermined interval in the direction of the blood vessel wall from the arbitrary point at a predetermined angle with respect to the blood flow direction, Blood vessel diameter measuring means for determining the blood vessel diameter by sequentially determining black and white data or color data at each point in the direction of the blood vessel wall from an arbitrary point and calculating the distance from the arbitrary point to the blood vessel wall based on the determination result. and a blood flow calculation means for calculating the blood flow at the arbitrary point based on the blood vessel diameter obtained by the blood vessel diameter measuring means and the blood flow velocity information. .