JPH1033535A - Ultrasonic Doppler diagnostic apparatus and method of ultrasonic Doppler diagnostic - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To enable high-resolution observation of blood flow information of a localized region in a CDI tomographic image which can be viewed as an overall image without lowering a frame rate. An apparatus for displaying an image of Doppler data based on a color Doppler imaging method. Means (1) for setting a first ROI indicating a region of interest of an image and a second ROI indicating another region of interest of the image within the first ROI, respectively;
3B, 13, 31, 27) and first transmission / reception means (31) for obtaining Doppler data of at least an area outside the second ROI within the first ROI based on the first transmission / reception conditions of the ultrasonic signal. , 21, 12, 22, 25, 26) and second transmission / reception means (31, 21) for obtaining Doppler data of at least an area in the second ROI based on a second transmission / reception condition different from the first transmission / reception condition. 21, 12, 22, 25, 26) and means (27, 2) for combining and displaying both Doppler data.
8, 31).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to performing color Doppler imaging (CDI) using an ultrasonic Doppler method,
The present invention relates to an ultrasonic Doppler diagnostic apparatus and an ultrasonic Doppler diagnostic method for obtaining blood flow information, and more particularly to a ROI (Region of Interes).
The present invention relates to improvement of a function of controlling transmission / reception conditions of an ultrasonic signal by making full use of t).

[0002]

2. Description of the Related Art Ultrasound diagnostic apparatuses that obtain an image signal by transmitting and receiving an ultrasonic signal are used in various modes utilizing the non-invasiveness of the ultrasonic signal. The mainstream of this ultrasonic diagnostic apparatus is of a type that obtains a tomographic image of a soft tissue of a living body using an ultrasonic pulse reflection method. This imaging method is non-invasive and obtains a tomographic image of the tissue, and can be displayed in real time compared to other medical modalities such as X-ray diagnostic equipment, X-ray CT scanner, MRI equipment, and nuclear medicine diagnostic equipment, It has many advantages, such as a small and relatively inexpensive device, no exposure to X-rays and the like, and blood flow imaging based on the ultrasonic Doppler method. Because of this, the heart, abdomen, mammary glands, urology,
It is suitable for diagnosis in obstetrics and gynecology. Especially,
The simple operation of simply touching the ultrasonic probe to the body surface enables real-time observation of the heartbeat and fetal movement, and no exposure to radiation, allowing for repeated examinations, and moving the device to the bedside There is also an advantage that the inspection can be easily performed.

[0003] An ultrasonic Doppler method utilizing the Doppler effect of ultrasonic waves has attracted attention in blood flow diagnosis and the like. As one mode of an ultrasonic diagnostic apparatus based on the ultrasonic Doppler method, a color imaging apparatus is known (for example, see Japanese Patent Publication No. 6-13031, "Ultrasonic blood flow imaging apparatus"). As shown in FIG. 1 of the publication, this apparatus is provided with frequency analysis means such as an autocorrelator, and performs two-dimensional multipoint frequency analysis in real time. Thereby, the velocity distribution or the power distribution of the blood flow is modulated into the luminance or saturation distribution from the ultrasonic echo signal including the Doppler shift due to the blood flow, and this distribution image is converted into a B-mode image (an image of a tissue structure). Is superimposed and displayed. Thereby, the velocity distribution of the blood flow toward or away from the ultrasonic probe and / or the distribution of the power value of the blood flow echo signal based on the power Doppler method are displayed. In particular, when the power Doppler method is used, perfusion of the vascular system can be detected with higher sensitivity, and thus it is being used for diagnosis of abnormal blood flow at the peripheral level of the kidney and liver cancer.

[0004]

However, the conventional color imaging apparatus has the following problems.

First, there is a problem regarding the frame rate.

In order to obtain velocity information by frequency analysis, it is necessary to irradiate ultrasonic waves several times in the same direction (scanning line) to obtain data. Therefore, the number of frames per unit time (frame rate) There is a problem that falls. Conversely, it is known that if the number of times of irradiation on the same scanning line is reduced in order to increase the frame rate, the accuracy of frequency analysis and the low flow velocity detection ability will be reduced. Similarly, if the time interval between scanning lines is increased, the frame rate is improved, but the image quality is coarse and the resolution is reduced.

Second, there is the problem of resolution related to the ultrasonic probe. Each transducer of the array type probe is delayed by a delay circuit, the focus point of the transmission wave is determined, and by changing the delay information, the position of the focus point or the state of the sound pressure power concentrated at the focus point can be changed Is possible. The spatial distribution (sound field) of sound pressure also changes depending on the total area of the transducer used for transmission.

Therefore, the power of the transmission wave is concentrated on the focus point by adjusting the delay information and the vibrator area value (hereinafter, referred to as the focus point).
The sound field in the case of a beam is, of course, higher at the focus point than when the power is not concentrated at the focus point. I do. That is, when the irradiation beam is narrowed, an image with high sensitivity and high resolution can be obtained near the focus point, but the image quality is not uniform in the depth direction. On the other hand, when the beam is not stopped down, the image quality is relatively low, but it can be said that the image is more uniform in the depth direction.

In CDI, like B-mode images, 2
It is often desirable to have spatially uniform sensitivity and resolution because a two-dimensional tomographic image is displayed, but on the other hand, it enhances the blood flow of small blood vessels flowing into a localized liver tumor. Observation with resolution also arises. A technique such as multi-step focusing, in which transmission with a narrowed beam and transmission / reception several times on the same scanning line while further changing the depth of the focus point, is effective in the B mode, but the frame rate is reduced to 1/2/3. .., Which is not a realistic method in the case of CDI whose frame rate is lower than that in the B mode.

The present invention has been made in view of the various situations described above, and has as its object to reduce the frame rate without reducing the blood flow information of a localized region in a CDI tomographic image that can be viewed as a whole image. Is to be observed with high resolution.

[0011]

In order to achieve the above-mentioned object, an ultrasonic Doppler diagnostic apparatus according to the present invention raster-scans a cross section of an object using an ultrasonic signal to obtain an image of Doppler data based on a color Doppler imaging method. Is an ultrasonic Doppler diagnostic apparatus that displays. A first indicating a region of interest of the image
ROI and ROI setting means for setting a second ROI indicating another region of interest of the image in the first ROI, and the first ROI based on a first transmission / reception condition relating to transmission / reception of the ultrasonic signal. A first transmitting / receiving means for obtaining the Doppler data in an area at least outside the second ROI within the ROI, and at least the second transmitting / receiving means based on a second transmitting / receiving condition different from the first transmitting / receiving condition. A second transmitting / receiving means for obtaining the Doppler data of an area in an ROI,
And display means for combining and displaying both the Doppler data obtained by the second transmitting / receiving means.

For example, the second transmission / reception condition includes parameters for obtaining the Doppler data having a higher resolution than the first transmission / reception condition.

Further, for example, the first and second transmission / reception conditions include a repetition frequency associated with transmission / reception of the ultrasonic signal,
A transmission frequency, a reference frequency, a transmission drive element, the number of transmission waves, the number of times of transmission / reception per raster, a raster density, or a focal position are included as parameters.

Further, a third transmitting / receiving means for obtaining the Doppler data based on a third transmitting / receiving condition relating to the transmission / reception of the ultrasonic signal in an area within the first ROI, and a third transmitting / receiving means. It is preferable that the apparatus further comprises another display means for displaying the Doppler data as the image, and switching means for selectively driving the first and second transmitting / receiving means and the third transmitting / receiving means. In this case, the degree of the resolution of the Doppler data obtained based on the first, second, and third transmission / reception conditions increases in the order of the first transmission / reception condition, the third transmission / reception condition, and the second transmission / reception condition. Is set to

Preferably, the ROI setting means stores the first and second ROIs in an ROI position and R
This is a means for setting independently including the OI size.

Preferably, the first transmitting / receiving means includes:
A means for raster-scanning an area inside the first ROI and outside an area formed by a raster of the ultrasonic signal passing through the second ROI, wherein the second transmitting / receiving means comprises:
A means for raster-scanning an area formed by a raster of the ultrasonic signal passing through the second ROI is provided. In this case, both of the raster scanning means of the first and second transmission / reception means are means for continuously performing scanning so that each of the raster scans forms a raster scan of one frame. In another aspect, the ROI setting unit is a unit that can set a plurality of the second ROIs in an area of the first ROI. At this time, preferably, the raster scanning means of the second transmission / reception means determines whether or not there is the same raster which passes through the plurality of second ROIs in common, and the element determines the When it is determined that the same raster exists,
An element for setting a raster area based on the second transmission / reception condition for each of the plurality of second ROIs and an element for individually raster-scanning the raster area set by the element are provided.

Further, for example, the first transmitting / receiving means has means for raster-scanning the entire area in the first ROI, and the second transmitting / receiving means has an area formed by a raster passing through the second ROI. Means for raster-scanning the inside, wherein the display means extracts Doppler data corresponding to an area in the second ROI from the Doppler data obtained by the second transmitting / receiving means, and extracts the extracted Doppler data. This is a means for displaying data by overwriting the Doppler data obtained by the first transmitting / receiving means.

Further, for example, the first transmission / reception condition includes a parameter optimized according to the size of the first ROI, and the second transmission / reception condition includes a parameter optimized according to the size of the second ROI. Contains the parameters to be optimized.

On the other hand, the ultrasonic Doppler diagnosis method of the present invention is a method of raster-scanning a cross section of a subject with an ultrasonic signal to display an image of Doppler data based on a color Doppler imaging method. First showing the area
And a second ROI indicating another region of interest of the image in the first ROI, respectively, and then the first ROI based on a first transmission / reception condition related to transmission / reception of the ultrasonic signal. Within at least the second ROI
Obtaining the Doppler data of the outside area,
By obtaining the Doppler data of at least an area in the second ROI based on a second transmission / reception condition different from the transmission / reception conditions of the above, then combining and displaying both the obtained Doppler data, Achieve the above objectives.

[0020]

Embodiments of the present invention will be described below with reference to the drawings.

[First Embodiment] FIG.
This will be described with reference to FIGS. The ultrasonic Doppler diagnostic apparatus according to this embodiment converts the diagnostic information of the blood flow state to the heart, particularly the muscle of the left ventricular system, into CDI (color Doppler imaging).
An abnormal site is identified by the method. However, the ultrasonic Doppler diagnostic apparatus of the present invention is not necessarily limited to such a case where the state of blood flow to the myocardium is to be diagnosed.

The ultrasonic Doppler diagnostic apparatus shown in FIG. 1 includes an apparatus main body 11, an ultrasonic probe 12 connected to the apparatus main body 11, and an operation panel 13.

The operation panel 13 gives various instructions and information from the operator to the apparatus main body 11, and includes a keyboard 13A, a trackball 13B, and a mode changeover switch 13C. The trackball 13B is used, for example, to function as a pointing device on a monitor screen and to set an ROI (region of interest) on an image. As described later, the mode changeover switch 13C is set to “B mode”, “normal CFM (Color F
low mapping) mode ”and“ RIR ”according to the present invention.
(ROI in ROI) mode. The normal CFM mode is a type of the blood flow color Doppler mode that has been conventionally used. The RIR mode also belongs to the category of the CFM mode, but since the usage of the ROI is different from that of the normal CFM mode, the RIR mode is referred to as such, and the details will be described later.

The ultrasonic probe 12 has a piezoelectric vibrator such as a piezoelectric ceramic as an electromechanical reversible conversion element. A plurality of piezoelectric vibrators are arranged in an array and mounted at the tip of the probe, and a phased array type probe 12 is configured. Thus, the probe 12 converts the pulse drive voltage supplied from the apparatus main body 11 into an ultrasonic pulse signal, transmits the ultrasonic pulse signal in a desired direction in the subject, and responds to the ultrasonic echo signal reflected from the subject. Convert to voltage echo signal.

The apparatus main body 11 includes a probe 12 as shown in FIG.
Transmitting unit 21 and receiving unit 2 connected to
2. A receiver unit 23 placed on the output side of the ultrasonic receiving unit 22, a B-mode DSC (digital scan converter) 24, a CFM unit 25, and a CFM D
An SC 26, a memory synthesis unit 27, and a display unit 28 are provided. A frame memory 29 is connected to the memory synthesis unit 27. The apparatus main body 11 further includes a CPU (central processing unit) 31 for receiving operation data from the operation panel 13 and a transmission / reception condition memory 3 connected to the CPU 31.
2. A program memory 33 is provided.

The ultrasonic transmitter 21 includes a pulse generator 41,
It has a transmission delay circuit 42 and a pulser 44. The pulse generator 41 has a rate frequency fr [H
z] (period 1 / fr [sec]). The rate pulses are distributed to the number of transmission channels and sent to the transmission delay circuit 42. The transmission delay circuit 42 is supplied with a timing signal for determining a delay time from the CPU 31 for each transmission channel. Thereby, the transmission delay circuit 42 gives a command delay time to the rate pulse for each channel. The rate pulse provided with the delay time is supplied to the pulser 43 for each transmission channel. The pulser 43 applies a voltage pulse to each piezoelectric vibrator (transmission channel) of the probe 12 at the timing of receiving the rate pulse. As a result, the ultrasonic signal is
Radiated from The ultrasonic signal transmitted from the ultrasonic probe 12 is focused in a beam shape in the subject, and the transmission directivity is set in the command scanning direction.

In the subject, beamforming is performed according to the above-described delay time. The transmitted ultrasonic pulse signal is reflected by a discontinuous surface of acoustic impedance in the subject. This reflected ultrasonic signal is transmitted to the probe 12 again.
And is converted into an echo signal of a corresponding voltage amount. This echo signal is captured from the probe 12 to the ultrasonic receiving unit 22 for each receiving channel.

The ultrasonic receiving section 22 includes a preamplifier 51, a reception delay circuit 52, and an adder 53 in order from the input side. Preamplifier 51 and reception delay circuit 52
Each include an amplifier circuit or a delay circuit for the reception channel. The delay time of the reception delay circuit 52 is given as a signal of a delay time pattern from the COU 31 according to the desired reception directivity. Therefore, the echo signal is
After being amplified by the preamplifier 51 for each reception channel and given a delay time by the reception delay circuit 52, the adder 5
3 is added. As a result, a reflection component from a direction corresponding to a desired reception directivity is emphasized, and a reception beam is formed in calculation. An overall ultrasonic beam for transmission and reception is formed by the total of the transmission directivity and the reception directivity.

The output end of the adder 53 reaches the memory synthesizing unit 27 via the receiver unit 23 and the B-mode DSC 24, and also outputs the CFM unit 25 and the CFM.
To the memory synthesizing unit 27 via the dedicated DSC 26. The receiver unit 23 and the B-mode DSC 24 are signal routes for generating a B-mode grayscale image, while the CFM unit 25 and the CFM DSC 2
Reference numeral 6 denotes a signal route for a color Doppler image.

Although not shown, the receiver unit 23
A logarithmic amplifier, an envelope detector, and an A / D converter are provided. As a result, echo data in the direction to which the reception directivity is given is formed in a digital amount and sent to the B-mode DSC 24. The B-mode DSC 24 converts the scan method of the echo data from the ultrasonic method to the standard TV method, and sends it to the memory synthesis unit 27.

Although not shown, the CFM unit 25 includes a quadrature detector, a clutter removing filter, a Doppler shift frequency analyzer, and the like, and obtains Doppler shift frequency, that is, blood flow velocity information and power information thereof. Speed information is CFM
Receiving a process such as noise cancellation in the DSC 26, the scanning method is converted, and the memory synthesis unit 27
Sent to

The memory synthesizing unit 27 includes a B-mode DSC 2
4 and BFM image data (gray scale image) sent from CFM DSC 26
The mode image data (color Doppler image) is reconstructed into one frame of image data by processing such as arranging or overlapping. This frame image data is displayed on the display unit 28
Are sequentially read. The display unit 28 has a built-in D
It is converted to an analog quantity by the / A converter and displayed on the TV monitor.

As a result, on the TV monitor, the spatial distribution of the tissue shape of the subject (in the B mode) and the spatial distribution of the blood flow velocity at the diagnosis site of the subject (the B-mode image is used as a background image: Normal CFM mode and RIR mode: this mode will be described later) are displayed visually. Note that a frame memory 29 is connected to the memory synthesizing unit 27, and can store a B-mode image and / or image data in the normal CFM mode and the RIR mode.

A CPU (Central Processing Unit) 31 is a controller which operates according to a predetermined procedure stored in a program memory 33 in advance and forms a control center of the entire apparatus. That is, the CPU 31 reads the operation information of the operator via the operation panel 13 and manages and changes the operation itself such as transmission, reception, display, and various calculations of ultrasonic waves.

In particular, the control of the operating state during transmission / reception relates to the present invention, and the transmission / reception conditions are controlled for each mode. In order to perform this control, data representing transmission conditions such as a transmission / reception focal length, a transmission frequency, and a transmission sound pressure is stored in the transmission / reception condition memory 32 in advance for each mode. The CPU 31 determines the mode change while monitoring the state of the switch signal of the mode changeover switch 13C of the operation panel 13, and when there is a mode change, reads out the transmission / reception conditions corresponding to the mode from the transmission / reception condition memory 32, and The transmission / reception conditions are instructed to a target circuit (unit) to be transmitted. More specifically, the focus point, the position and the number (the number of channels) of the transmission vibrating elements and the like are designated as transmission conditions for the transmission delay circuit 42, and the focus point and the like are designated as reception conditions for the reception delay circuit 52. For the pulse generator 41, the number of driving waves, the driving frequency and the like are commanded as transmission conditions. Also, CFM
Parameters such as the repetition frequency and the number of Doppler data are transmitted to the unit 25 as transmission conditions. Note that information as to what mode is being commanded is stored in the CPU 31.
Is transmitted to the memory synthesizing unit 27, whereby the memory synthesizing unit 27 performs pixel selection corresponding to the display mode in the command mode, and reconstructs frame image data.

Here, the CFM mode (RIR mode) characteristic of the present invention is replaced with a conventional CFM mode (normal CFM mode).
FM mode).

FIG. 2 shows an example of an image in the normal CFM mode.
(A). Normally, a blood flow image is superimposed on a B-mode image as shown in the figure, and observation is performed while changing the size and position of one ROI. The main reason for this is that frequency analysis is required in the case of the Doppler method, so that a plurality of received signals are required for the same raster. Therefore, a longer image generation time is required than in the B mode, and the frame rate is reduced in the normal CFM mode. For this reason, the operator actively controls the ROI and narrows down the size to the region of interest, thereby obtaining the most efficient frame rate.

FIG. 6B shows an example of an image in the CFM mode according to the present invention in which the normal CFM mode is dramatically improved. That is, according to this mode, the conventional ROI (first
ROI: another another ROI in ROI ^# 1)
(Second ROI: ROI ^# 2) is displayed. This mode will be referred to as “RIR (ROI in ROI) mode”. In the case of the “RIR mode”, the first ROI is specified to have a size that can roughly grasp the entire blood flow distribution,
On the other hand, the second ROI is set to scrutinize a site of local interest. The RIR mode is a mode obtained by switching from the normal CFM mode, and the second ROI is displayed in the first ROI according to the switching.

The transmission scan in the RIR mode state is as follows.
As shown in FIG. 3, two ROIs: ROI ^# 1, ROI
Raster range I divided by position and size of ^# 2
ＩＩＩIII is continuously performed as one frame scan. Here, the scan in the B mode is omitted to simplify the description. Now, RO in normal CFM mode
It is assumed that the number of rasters defined by I (first ROI: ROI ^# 1) is 1, 2, 3,..., N−1, n. In any of the CFM modes (Doppler method), transmission / reception of ultrasonic beams is required a plurality of times, for example, 16 times per raster. Therefore, while complying with this requirement, RIR
In the case of the mode, a uniform transmission condition is not imposed on all the n rasters, but an advanced transmission and reception condition is imposed on the raster included in the position of the second ROI: ROI ^# 2.

[0040] Specifically, the second ROI: ROI ^# rasters are not included in the 2 1,2,3, ..., k-1 , k and m, m + 1, m + 2, ... n-1, n raster range I and
Second ROI: raster k + 1, k included in ROI ^# 2
+2,..., M−2, m−1.
For example, the first transmission condition shown in the upper part of FIG. 4B is applied to one raster range I, and the second transmission condition shown in the lower part of FIG. 4B is applied to the other raster range II. Apply. FIG. 3A shows a normal C which has been conventionally implemented.
An example of a transmission condition in the FM mode will be described. That is, when the mode is changed from the normal CFM mode to the RIR mode,
The transmission conditions that were uniform until then are changed for each raster range.

When the mode is changed in this way, for example, in the case of FIG. 4, the number of times of transmission / reception per raster is changed from 16 to 8 and the raster density is also reduced to 1/2 with respect to the first transmission condition.
And coarse. As a result, the time required for image generation is about 1 /
It becomes 4. On the other hand, the image is coarse and the accuracy is reduced. Second
With regard to the transmission condition (1), the number of times of transmission / reception is 32, the accuracy is improved, the raster density is doubled, and the resolution in the azimuth direction is improved. On the other hand, the image generation time increases, and in this example, it is about four times. In addition, the number of channels under the second transmission condition is increasing. As described above, in this case, the distance resolution and sensitivity near the focal point are improved, while the resolution at a distance away from the focal point is deteriorated.

Next, an example of controlling the transmission / reception conditions for each mode will be described with reference to FIG.

First, the CPU 31 reads a switch signal from the mode changeover switch 13C (step 60 in FIG. 5), and determines whether the designated mode is the B mode or the normal CFM mode. In the present embodiment, the designation of the RIR mode is performed via the normal CFM mode.
If it is determined in step 60 that the B mode has been designated, predetermined transmission (reception) conditions for the B mode are designated (step 61). When it is determined that the normal CFM mode has been designated, for example, predetermined transmission (reception) conditions shown in FIG. 4A are designated (step 62).

Thus, for example, a CFM image (blood flow image) as shown in FIG. 2A is displayed with the B-mode image as a background.
Therefore, the CPU 31 sets the ROI (first ROI: ROI
Control the size of ^# 1) as needed (step 6)
3). This control is performed by dialogue with the operator. Next, the CPU 31 returns to the mode switch 13
The switch signal from C is monitored, and it waits while judging whether or not the mode has been changed from the normal CFM mode to the RIR mode (step 64).

When it is determined in step 64 that the mode has been changed to the RIR mode, the CPU 31 adds the second RO to the currently displayed image in the normal CFM mode.
I: ROI ^# 2 is superimposed and displayed (step 65). The superimposed display at this stage is performed by designating a predetermined initial position of a second ROI of a predetermined shape and size, for example, a circle (see FIG. 2B).

When the superimposed display is completed, the CPU 31
The range II of the raster included in the ROI and the range I outside the raster are specified based on the current position and size of the ROI (steps 66 and 67, FIG. 3).
reference). When the division of the raster range is completed, the CPU 31 determines the first and second transmission / reception conditions (see FIG. 4B) corresponding to the raster ranges I and II, respectively, by the pulse generator 41, the transmission delay circuit 42, and the reception delay circuit. 52, and related circuits and units such as the CFM unit 25 (step 6).
8). With this command, even in the image of one frame, the local region of particular interest, that is, the second RO
I: In the range of the raster passing through ROI ^# 2, a more precise scan is performed than in the case of the normal CFM mode, and in other raster ranges, the coarse scan is performed in consideration of the frame rate.

Next, the CPU 31 sets the trackball 1
The position of the second ROI based on the operation signal of 3B and / or
Alternatively, it is determined whether or not the size has been changed (step 69). The position and size of the second ROI can be changed independently of the first ROI. If yes,
The processing is returned to step 66, and steps 66 to 6
Step 8 is repeated. On the other hand, if NO, the switch signal of the mode changeover switch 13C is read, and it is determined whether or not the mode has been returned to the normal CFM mode again (step 70). If there is no mode return to the normal CFM mode (NO), the process proceeds to step 6
Returned to 9. For this reason, when there is no change in the position and size of the second ROI, and when such a mode return is not instructed, the apparatus stands by while monitoring any of the instructions. This state is a transmission / reception state in the RIR mode, and if a local region of interest changes, the second R
By changing (moving) the position and / or size of the OI, another part can be finely scanned.

In this state, when a command to return to the normal CFM mode is issued via the mode changeover switch 13C, the processing shifts from step 70 to step 71, and the superimposed display of the second ROI is released. Next, the routine proceeds to step 72, where the normal CF
The transmission (reception) conditions in the M mode are commanded again. After this,
The process returns to step 63 described above.

In the transmission (reception) condition, at least the focus at the time of reception in the RIR mode is controlled by the delay time pattern to the reception delay circuit 52 so that the second ROI: RO
In order to match the center position (depth) of I ^# 2, the second ROI
The depth is controlled in synchronization with the movement of the object.

In this embodiment, since the transmission (reception) control is performed as described above, the CFM in the areas out of the focus of the first transmission / reception condition range and the second transmission / reception condition range is performed.
The image is coarse in both accuracy and resolution and can be used to obtain approximate blood flow information. On the other hand, in an area near the focal point in the second transmission / reception condition range, that is, in an area surrounded by ROI ^# 2, a CFM image with higher resolution and higher sensitivity than before is generated. In addition, in the example shown above, the frame rate is not improved if the first and second transmission (reception) condition areas are 1: 1. However, the ROI ^# 2 is small, and the second transmission / reception condition is small. If the ratio of the conditions is made relatively small, there is an advantage that the frame rate is improved as compared with the related art. In this manner, the RIR mode of the present invention has an advantage that finer blood flow information can be detected and displayed by ROI ^# 2 while displaying rough blood flow information by ROI ^# 1.

In the first embodiment, the number of transmissions and receptions, the raster density, and the like under the first and second transmission / reception conditions can be changed to desired values by the operator. In addition, since the number of transmission channels is related to the depth of focus (the length of the focal region), it is desirable that the number of transmission channels be automatically changed when the size of ROI ^# 2 is changed.
As a method for this, the relationship between the size of ROI ^# 2 and the number and position of transmission channels is stored in advance in the transmission condition table as a table value, and the CPU 31 stores the second ROI:
The above adjustment can be performed automatically by referring to the table value when the change in the size of ROI ^# 2 is recognized. Of course, the CPU 31 may calculate the number / position of transmission channels corresponding to the size of the second ROI each time. Specifically, for example, if ROI ^# 2 becomes smaller, transmission is performed on 80 channels with the center of ROI ^# 2 as the focal point, and adjustment is made so that the ROI is covered with the focal region. If the ROI ^# 2 becomes large, a mode such as compensating the sensitivity in the depth direction by transmitting 40 channels can be considered. Although the shape of ROI ^# 2 has been described as being circular, the shape may be other than circular.

Further, in the first embodiment, ROI ^#
The number of ROI ^# 2s present in one is not limited to one, and a plurality may be present. However, in this case, a plurality of ROIs
^# 2 (for example, ROI ^# 2A, ROI ^# 2B shown in FIG. 6)
Is effective when there is no overlapping on the same raster, but when rasters overlap, high-resolution transmission and reception cannot be performed at two points in depth at the same time, so the second embodiment described below is effectively used. Become.

[Second Embodiment] An ultrasonic Doppler diagnostic apparatus according to a second embodiment will be described with reference to FIGS. This ultrasonic Doppler diagnostic apparatus is configured to withstand the case where a plurality of second ROIs: ROI ^# 2 are set as described above. Its hardware configuration is the same as that shown in FIG.

The CPU 31 replaces the above-described processing of FIG. 5 with the processing of FIG. 7 (processing of a flowchart partially shown).
Is to be executed. That is, as in the case of FIG. 5, switching to the RIR mode is confirmed in steps 64 and 65, the initial display of the second ROI: ROI ^# 2 is performed, and then the process proceeds to step 80 and subsequent steps. First,
It is determined whether or not the number of the displayed second ROIs is plural (step 80). In the case of NO, since the number of the second ROI is one, the same processing (not shown) as shown in steps 66 to 70 in FIG. 5 is performed. On the other hand, if the determination is YES, then it is determined whether or not a state where a plurality of second ROIs exist on one raster (raster overlapping state) (step 81). If this determination is NO, the result is equivalent to the case where the number of the second ROI of the first embodiment is one, and therefore, the same processing as steps 66 to 70 in FIG. 5 is performed. When it is determined in step 81 that the rasters overlap, processing unique to the second embodiment is performed (steps 82 to 86).

First, the relationship between the size and position of each second ROI and the raster position is determined (step 8).
2). Next, the raster range of the first transmission (reception) condition is specified (step 83). For example, as shown in FIG. 8A, two second ROIs (ROI ^# 2A, ROI ^# 2
In the case of B), rasters 1, 2, 3,..., N−2, n that are regions on the first ROI: ROI ^# 1 and do not overlap with the second ROI: ROI ^# 2A, ROI ^# 2B -1, n
Form such a raster range.

Next, the raster range of the second transmission (reception) condition is specified (step 84). This identification is the second R
This is performed for each OI. In conjunction with this, the second RO
Focus F1 (F2) on the depth of the center position for each I
Are determined so that the transmission and reception conditions match. For example, as shown in FIGS. 8B and 8C, for one second ROI: ROI ^# 2A, rasters 1, 2,..., K1-1, k1 (all of which are the first)
Rasters 1, 2,..., N−1, n for the ROI of the second ROI ^# 2B, and rasters 1, 2,. Are also rasters 1, 2, ..., n-1, n for the first ROI.
Are included in the raster range of the second transmission / reception condition.

Next, the raster range for each transmission (reception) condition is transmitted to a related circuit (unit). Since the first and second transmission (reception) conditions are, for example, as shown in FIG. 4B described above, this command corresponds to the second ROI: ROI ^# 2A and ROI ^# 2B in the RIR mode. An ultrasonic beam is transmitted and received with high accuracy in the raster range. The reception focal points F1 and F2 are determined according to the positions (depths) of the second ROIs: ROI ^# 2A and ROI ^# 2B.

Further, in step 86, the second ROI
The information of each position and size is also transmitted to the memory synthesizing unit 27 (the information of the raster range is also transmitted to the memory synthesizing unit 27 in step 85). Therefore, when the number of second ROIs is two, the memory synthesis unit 27
For example, the image data of one frame is reconstructed by re-synthesizing the image data obtained by the three types of scans shown in FIGS.

In the re-combining process, any part of the raster area (the part D in FIG. 8D) that overlaps between the second ROIs is discarded, and The discarded raster side (ROI ^{# in} the figure (d))
2B side) (the ROI in FIG.
^# 2B) is overwritten again (only the data in the cross-hatched portion in FIG. 3D). Also, for example, the raster area of one second ROI ^# 2A is
Widely set to cover OI ^# 2B (ROI ^# 2B
The raster area of FIG. 8D is the same as described above), and the hatched portion in FIG. 8D is basically covered by the ROI ^# 2A raster,
ROI ^# 2B can also be recombined so as to display the ROI area (only in the circle).

Next, in step 87, it is determined whether or not any position and / or size of the second ROI has been changed.
86 is repeated. If no, step 88
It is determined whether or not to switch to the normal CFM mode in NO.
In the case of (1), the RIR mode is maintained.
Return to 6.

As a result, as shown in FIG.
The image for ROI: ROI ^# 1 is a dotted line area, and the area for the second ROI: ROI ^# 2A, ROI ^# 2B is a hatched area in the figure. If there are a plurality of second ROIs and the raster is Even in the case of overlapping, an image equivalent to that of the first embodiment can be displayed.

According to the present embodiment, two second Rs
OI: While moving the ROI ^# 2A and ROI ^# 2B while acquiring images, it is automatically determined whether or not raster overlap has occurred. If not, transmission and reception according to the first embodiment The condition also has the advantage that when raster overlap occurs, the transmission and reception control according to the second embodiment is automatically switched.

[Third Embodiment] A third embodiment will be described with reference to FIGS. The ultrasonic Doppler diagnostic apparatus according to this embodiment is designed to simplify the ultrasonic scanning and image synthesis.

FIG. 9 shows an example of a series of processes performed by the CPU 31. This processing is obtained by replacing steps 67 and 68 in the processing of FIG. 5 with steps 90 to 94. That is, in steps 64-66, the RI
When the mode is switched to the R mode, the second ROI is initially displayed, and when the positional relationship between the position size of one or more of the second ROIs and the raster position is determined, it takes a relatively long time to scan. The raster range of the first transmission / reception condition (for example, see FIG. 4B) that is not applied is specified (step 90). Here, for example, as shown in FIG.
ROI: rasters 1, 2,..., N of the entire range of ROI ^# 1
The range is assigned to −1 and n.

Next, the processing of the CPU 31 proceeds to step 91, in which the raster range of the second transmission / reception condition (see, for example, FIG. 4B) is set to the second ROI, for example, as shown in FIG.
As shown in (b), rasters 1, 2,..., K1-1, and k1 are specified. At this time, at least the focus at the time of reception is also set according to the ROI position. When there are a plurality of second ROIs, the process of step 91 is repeated (step 92, see FIG. 10C).

Further, for each ROI, the information on the transmission / reception conditions and the raster range is output to the related circuit (unit) (step 93). Therefore, scanning by the ultrasonic beam is sequentially performed according to the output transmission and reception conditions,
The corresponding image data is collected in the memory combining unit 27 each time. In the example of FIG. 10, the image data is obtained by three types of scans shown in FIGS.

Further processing is performed, and all the second RO
Information on the position and size of I is sent to the memory synthesis unit 27 (step 94). Therefore, as shown in FIG. 10D, the memory combining unit 27 extracts the image data of each of the second ROIs, and overwrites the extracted image data on the image data related to the first ROI. Compositing is performed.

After the process of step 94, the processes of steps 69 and 70 described above are sequentially performed.

Therefore, according to this embodiment, although the frame rate is reduced as compared with the method of the previous embodiments, the same and relatively simple image processing and simple processing can be performed irrespective of the number of second ROIs. There is an advantage that a simple scanning method can be used.

It should be noted that various modifications can be added to the above-described embodiment. Some examples are shown in FIGS.

The second ROI: ROI ^# 2 aims to provide higher resolution and higher sensitivity information. Therefore, as shown in FIG. 11, ROI ^# 2 is smaller than ROI ^# 1.
Can be increased to increase the frame rate of only ROI ^# 2. Extreme examples include displaying ROI ^# 1 as a frozen image.

Next, a modified example of the display screen is shown in FIG.
This will be described based on FIG. As described in FIG. 2B, ROI ^# 1 and ROI ^# 2 are superimposed on the display screen. These can be independently changed in position and size using a trackball or the like. At this time, the ROI in the variable state may be indicated by changing the color of the ROI, or the number of the ROI in the variable state may be displayed on the display screen as shown in the figure. When the transmission frequencies of ROI ^# 1 and ROI ^# 2 are different, the color maps of the speed display are also different, so that both color maps can be displayed as shown in the figure.

The parameters of the transmission / reception conditions according to the present invention include a repetition frequency, a transmission frequency, a reference frequency, a transmission drive element (the number of transmission channels), a transmission wave number, a transmission / reception number per raster, Either the density or the focal position may be used. Among these, one example of the first and second transmission / reception conditions of the number of times of transmission / reception per raster, the number of transmission channels, and the raster density are shown in FIG. 4 described above. An example of the first and second transmission / reception conditions for the remaining parameters is as follows. That is, in the order of the first and second transmission / reception conditions, repetition frequency: 4.0 kHz; 6.0 kHz, transmission frequency: 2.0 MHz; 2.5 MHz, reference frequency: 2.0 MHz; 2.5 MHz, number of transmission waves: 4 2, focal position: center of ROI ^# 1, center of ROI ^# 2, and so on.

The second ROI applied to the present invention is 1
The number is not limited to two or three, and may be three or more. The shape is arbitrary.

[0075]

According to the ultrasonic Doppler diagnostic apparatus and the ultrasonic Doppler diagnostic method of the present invention, a first ROI indicating a region of interest of an image and another region of interest of the image within the first ROI are indicated. A second ROI is set, and Doppler data of at least an area outside the second ROI within the first ROI is obtained based on the first transmission / reception condition of the ultrasonic signal. Obtains Doppler data of at least an area in the second ROI based on different second transmission / reception conditions and combines and displays both Doppler data. The blood flow information can be roughly observed over a wide scan range of the first ROI while maintaining the same level as that of the first ROI, and at the same time, the Doppler with high precision and high resolution of the minute blood flow portion where the second ROI is set image The blood flow can be observed and diagnosis in detail. Thereby, for example, there is an advantage that blood flow detection of a blood vessel or the like to a tumor in a living organ can be performed more efficiently, and high-resolution blood flow information can be obtained at the same time.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration of an ultrasonic Doppler diagnostic apparatus common to each embodiment of the present invention.

2A is a diagram illustrating an image in a normal CFM mode, and FIG. 2B is a diagram illustrating an image in a RIR mode.

FIG. 3 is a view for explaining division between a transmission / reception condition and a raster range according to the first embodiment;

FIG. 4 is a table showing a specific example of transmission / reception conditions for each mode.

FIG. 5 is a flowchart illustrating a control example of transmission / reception conditions of the CPU according to the first embodiment;

FIG. 6 is a diagram showing an example of a case where there are a plurality of second ROIs.

FIG. 7 is a flowchart illustrating a control example of transmission / reception conditions of a CPU according to the second embodiment;

FIGS. 8A to 8D are explanatory diagrams respectively showing a transmission / reception condition, a raster range, and a correspondence relationship of a synthesized image thereof according to the second embodiment.

FIG. 9 is a flowchart illustrating a control example of transmission / reception conditions of a CPU according to the third embodiment;

FIGS. 10A to 10D are explanatory diagrams respectively showing a transmission / reception condition, a raster range, and a correspondence relationship of a composite image thereof according to the third embodiment.

FIG. 11 is an explanatory view showing one of modified examples.

FIG. 12 is an explanatory view showing another modification.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Device main body 12 Probe 13 Operation panel 13B Trackball 13C Mode change switch 21 Ultrasonic transmission part 22 Ultrasonic reception part 25 CFM unit 26 CFM DSC 27 Memory synthesis part 28 Display part 31 CPU 32 Transmission / reception condition memory

Claims (13)

[Claims] An ultrasonic Doppler diagnostic apparatus for displaying an image of Doppler data based on a color Doppler imaging method by raster-scanning a cross section of a subject with an ultrasonic signal, wherein a first ROI indicating a region of interest of the image and This first
Second RO showing another region of interest of said image within the ROI of
ROI setting means for setting I and at least the second R in the first ROI based on a first transmission / reception condition relating to transmission / reception of the ultrasonic signal.
First transmission / reception means for obtaining the Doppler data in an area outside the OI, and obtaining at least the Doppler data in an area in the second ROI based on a second transmission / reception condition different from the first transmission / reception condition. 2. An ultrasonic Doppler diagnostic apparatus, comprising: a transmitting / receiving unit; and a display unit that combines and displays both of the Doppler data obtained by the first and second transmitting / receiving units. 2. The ultrasonic Doppler diagnostic apparatus according to claim 1, wherein said second transmission / reception condition comprises a parameter for obtaining said Doppler data with higher resolution than said first transmission / reception condition. 3. The first and second transmission / reception conditions include a repetition frequency, a transmission frequency, a reference frequency, a transmission drive element, a transmission wave number, the number of transmissions / receptions per raster, a raster density, 3. The ultrasonic Doppler diagnostic apparatus according to claim 2, wherein a focal position is included as a parameter. 4. A third transmission / reception means for obtaining the Doppler data based on a third transmission / reception condition relating to transmission / reception of the ultrasonic signal in an area within the first ROI, and obtained by the third transmission / reception means. 2. A display device, further comprising: another display means for displaying the Doppler data as the image; and switching means for selectively driving the first and second transmission / reception means and the third transmission / reception means. Ultrasonic Doppler diagnostic device. 5. The degree of resolution of the Doppler data obtained based on the first, second and third transmission / reception conditions is:
The ultrasonic Doppler diagnostic apparatus according to claim 4, wherein the first transmission / reception condition, the third transmission / reception condition, and the second transmission / reception condition are set so as to increase in order. 6. The ultrasonic Doppler diagnostic apparatus according to claim 1, wherein said ROI setting means is means for setting said first and second ROIs independently of each other, including a ROI position and an ROI size. 7. The first transmitting / receiving means, wherein the first R
Means for raster-scanning an area within the OI and outside the area formed by the raster of the ultrasonic signal passing through the second ROI, wherein the second transmitting / receiving means comprises
2. The ultrasonic Doppler diagnostic apparatus according to claim 1, further comprising a raster scanning unit that scans an area formed by a raster of the ultrasonic signal passing through the OI. 8. The raster scanning means of both the first and second transmission / reception means is means for performing scanning continuously so that each of the raster scans forms a raster scan of one frame. 8. The ultrasonic Doppler diagnostic apparatus according to 7. 9. The ROI setting means according to claim 1, wherein the first RO
8. The ultrasonic Doppler diagnostic apparatus according to claim 7, wherein said means is capable of setting a plurality of said second ROIs in an area I. 10. The raster scanning means of the second transmission / reception means determines whether or not there is the same raster which passes through the plurality of second ROIs in common, and the same raster is determined by the element. When it is determined that there is an element for setting a raster area based on the second transmission / reception condition for each of the plurality of second ROIs, and an element for individually raster-scanning the raster area set by this element The ultrasonic Doppler diagnostic apparatus according to claim 9, further comprising: 11. The method according to claim 11, wherein the first transmission / reception means is the first R
Means for raster-scanning the entire area within the OI, the second transmitting / receiving means having means for raster-scanning an area formed by a raster passing through the second ROI, and the display means comprising: Extracting Doppler data corresponding to an area in the second ROI from the Doppler data obtained by the transmitting / receiving means, and overwriting the extracted Doppler data with the Doppler data obtained by the first transmitting / receiving means 2. The ultrasonic Doppler diagnostic apparatus according to claim 1, wherein the ultrasonic Doppler diagnostic apparatus is a means for displaying. 12. The first transmission / reception condition is the first R
Including parameters optimized according to the size of the OI,
The ultrasonic Doppler diagnostic apparatus according to claim 1, wherein the second transmission / reception condition includes a parameter optimized according to a size of the second ROI. 13. An ultrasonic Doppler diagnostic method for displaying an image of Doppler data based on a color Doppler imaging method by raster-scanning a cross section of an object with an ultrasonic signal, wherein a first ROI indicating a region of interest of the image and This first
Second RO showing another region of interest of said image within the ROI of
I, respectively, and then, in the first ROI, at least the second R
Obtaining the Doppler data of the region outside the OI, obtaining the Doppler data of at least the region within the second ROI based on a second transmission / reception condition different from the first transmission / reception condition, An ultrasonic Doppler diagnostic method, wherein both Doppler data are combined and displayed.