JPH07241290A - Ultrasonic diagnostic system - Google Patents

Abstract

PURPOSE:To provide an ultrasonic diagnostic system capable of easily detecting the true peak from a trace line and ultrasonic waveforms. CONSTITUTION:The trace line information obtd. when an auto-tracing circuit 34 traces Doppler waveforms is outputted to a peak detecting circuit 36. A dividing section in this peak detecting circuit 36 divides the trace line in an assigned range to a plurality for each of prescribed sections. Next, a shift section shifts the respective sections cooperatively plural times on a time base and a section peak detecting section detects the section peaks in the respective sections at every shift. A true peak detecting section detects the peak having the invariable coordinates among the coordinates of the plural section peaks as the true peak of the trace line in the assigned range. Then, the true peak of high accuracy is detected with simple device constitution. As a result, the reliability of diagnoses of blood vessel functions and cardiac functions, is improved and the shortening of the diagnostic time is made possible.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a calculation function performed on a Doppler waveform trace line or an ultrasonic waveform in an ultrasonic diagnostic apparatus.

[0002]

2. Description of the Related Art Generally, as an ultrasonic diagnostic apparatus for diagnosing a heart function, a blood vessel function, etc., it is an ultrasonic diagnostic apparatus utilizing a fact that a received signal obtained by scanning an ultrasonic beam undergoes Doppler shift by a moving body such as a blood flow. Acoustic diagnostic devices are known.

In this ultrasonic diagnostic apparatus, a predetermined quadrature detection is performed on the obtained reception signal to extract a Doppler signal, and the Doppler signal is further subjected to autocorrelation processing and speed calculation processing. The shift frequency is calculated.

Then, in order to observe the temporal change of the obtained Doppler shift frequency, that is, the Doppler waveform (Doppler spectrum), the horizontal axis represents time t and the vertical axis represents the Doppler shift frequency ψ.
The Doppler waveform is displayed on the monitor as d, and a predetermined diagnosis is performed from the waveform.

A so-called trace measurement is known as a Doppler waveform diagnosis method. The trace measurement is performed by, for example, an operator using a trackball or the like to trace the displayed Doppler waveform to partition the Doppler waveform by a trace line. Then, based on this trace line, the average motion velocity of the moving body within a predetermined period and the blood vessel volume etc. are calculated by integrating the separately obtained cross-sectional area of the blood vessel, and the heart function and the blood vessel function are calculated from the obtained calculation results. Etc. can be diagnosed.

[0006]

When the operator manually executes the Doppler waveform trace, there is a problem that the individual difference occurs in the trace, the diagnostic result varies, and the reliability decreases.

Therefore, in order to reduce this variation, it has been proposed to provide an ultrasonic diagnostic apparatus with an auto trace function for automatically tracing a Doppler waveform.

On the other hand, when the subject is a circulatory system such as the heart, for example, one heartbeat (one of the systole-diastole of the heart)
It is known that when the blood outflow during a cycle is displayed as a Doppler waveform, this Doppler waveform has a bimodal peak. Then, the heart function and the like can be diagnosed by measuring the ratio of the two peaks of the Doppler waveform and the like.

However, in general, much noise is generated in an ultrasonic image, and a Doppler waveform with high smoothness cannot be obtained. Therefore, the trace line obtained by tracing this Doppler waveform also has low smoothness, and particularly in the case of auto tracing, there is a strong tendency to be affected by noise.

In order to detect the above-mentioned bimodal peak from such a trace line, a method of differentiating the trace line can be considered. However, since the smoothness of the trace line is low as described above, there is a problem that an extremely large number of inflection points are detected when differentiating, and the apparatus becomes complicated to detect a true peak.

The present invention has been made to solve these problems, and an object thereof is to provide an ultrasonic diagnostic apparatus capable of easily detecting a true peak from a trace line.

[0012]

In order to achieve the above object, the ultrasonic diagnostic apparatus according to the present invention has the following features.

An ultrasonic diagnostic apparatus for transmitting and receiving an ultrasonic beam to and from an object and displaying an ultrasonic waveform based on the received wave, wherein the ultrasonic waveform is displayed at predetermined intervals on a time axis. A dividing means for dividing, a shift means for interlocking each section by a predetermined number of times in conjunction with each other on the time axis, and a coordinate of a section peak of an ultrasonic waveform in each section for each predetermined number of shifts. It is characterized by having section peak detection means for detecting, and peak detection means for determining invariant coordinates among the coordinates of the plurality of section peaks and detecting this as a true peak of the ultrasonic waveform. .

An ultrasonic diagnostic apparatus for transmitting and receiving an ultrasonic beam to and from a subject and displaying a Doppler waveform representing a change with time of the Doppler shift frequency based on the received wave obtained, wherein the Doppler waveform is traced. Tracing means, dividing means for dividing the trace line into predetermined intervals on the time axis, shift means for interlocking each of the intervals on the time axis by a predetermined amount by a predetermined number of times, and the predetermined number of shifts For each time, the section peak detection means for detecting the section peak of the trace line in each section, and the invariant coordinate among the coordinates of the plurality of section peaks are determined, and this is detected as the true peak of the Doppler waveform. Peak detection means,
It is characterized by having.

[0015]

In the ultrasonic diagnostic apparatus of the present invention, the Doppler waveform trace line and the ultrasonic waveform are divided into predetermined sections on the time axis, and the section peaks (maximum and minimum) of each section are divided.
Detect the coordinates of. This section is interlocked on the time axis and is shifted a predetermined number of times by a predetermined amount. And every shift,
The section peak in each section is detected.

In such a process, even if the point of the inclined portion of the trace line is detected as the section peak in each section, if the section is shifted and the section peak is detected again in each shifted section. , The point with the same coordinates is not detected again as a section peak.

Therefore, if the invariant coordinates are determined regardless of the shift processing among the coordinates of the obtained plurality of section peaks and they are detected as the trace line or the true peak of the ultrasonic waveform, the above trace line is obtained. And the true peak can be easily detected from the ultrasonic waveform. That is, even if the smoothness of the trace line or the ultrasonic waveform is low, the true peak can be accurately and automatically detected with a simple device configuration.

Further, since the true peak can be accurately detected, the accuracy of the result of the predetermined calculation (the ratio between the peaks, etc.) performed based on this true peak, that is, the reliability of the diagnosis performed based on the calculation result, Improve to each stage.

Furthermore, since peak detection can be performed by automatic calculation processing, it is possible to contribute to shortening the diagnosis time.

[0020]

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

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

The transmission / reception circuit 12 is a circuit for controlling transmission / reception of the ultrasonic beam of the probe 10. Quadrature detection circuit 14
Is a detection unit which is connected to the transmission / reception circuit 12 and which performs quadrature detection by multiplying a received signal by a predetermined reference wave signal.

A Doppler signal composed of two signals of a real number part and an imaginary number part obtained by quadrature detection is a high-speed (high frequency band) Doppler signal by a predetermined high-pass filter (not shown) or the like. Only is extracted. If the subject is a blood vessel, the Doppler signal extracted by this high-pass filter is a signal related to blood flow.
If this filter is a low-pass filter, a low-speed Doppler signal, for example, a signal related to living tissue such as myocardium can be extracted.

The autocorrelation circuit 16 is a circuit for performing a well-known correlation calculation process on the extracted Doppler signal in the high frequency band to obtain an autocorrelation. A speed calculation circuit 18 is connected to calculate the motion speed of the subject as a Doppler shift frequency based on the calculated correlation signal. A memory 20 controlled by a control circuit (CPU) 24 is connected to the speed calculation circuit 18, stores the calculated Doppler shift frequency for each frame, and a noise level detection circuit 32 of the trace processing unit 30. Output to.

On the other hand, the input unit 22 is a keyboard, a trackball or the like for the operator to set predetermined conditions for measurement and diagnosis, and to set a display state on the monitor 42. The various conditions set by the input unit 22 depend on the CPU
It is output to the graphic display circuit 26 via 24.

The graphic display circuit 26 includes a CPU 24.
Controlled by the trace processing unit 3 for line data, scale data, characters, etc. according to various set conditions.
It is a circuit that outputs 0.

The trace processing unit 30 detects a noise level detection circuit 32 for detecting a reference noise level, an auto trace circuit 34 for auto tracing a Doppler waveform, and a peak of the obtained trace, and based on this, a predetermined value. It is composed of a peak detection circuit 36 that performs arithmetic processing.

Although the noise level detection circuit 32 is a circuit for detecting the reference noise level from the luminance distribution of each pixel in the image area where the existence probability of the Doppler waveform is low, it is not always necessary.

The auto-trace circuit 34 is a circuit that auto-traces a Doppler waveform indicating the change over time of the Doppler shift frequency with reference to the reference noise level.

The peak detection circuit 36, based on the trace line information output from the auto trace circuit 34,
This is a circuit for obtaining the coordinates of the maximum and minimum peaks (true peaks) of the trace line and calculating the ratio of the true peaks from the coordinates of the true peaks. Then, the peak detection circuit 36 specifically includes a division unit that divides the trace line, a shift unit that interlocks the divided sections a plurality of times, and a section peak in each section for each shift. It is composed of a section peak detecting section for detecting and a true peak detecting section for detecting a peak having invariant coordinates among the coordinates of a plurality of section peaks as a true peak of the trace line.

Here, the true peak is, for example, Pulsatilit.
y Index (pulsation index), LVIF (Left Valve in Flo)
w: Used to perform trace measurement of blood flow in the left ventricle of the heart). These trace measurements are for bimodal peaks, that is, the ratios of two peaks.
In the atility Index, when the Doppler waveform of the peripheral blood vessel is taken, the first peak P1 shows the systolic peak of the heart and the second peak P2 shows the diastolic peak. Then, the difference ((P1−P2) / 2) between these two peaks can be calculated, and the blood circulation state and the like can be diagnosed from the calculated value.

On the other hand, in LVIF, when a Doppler waveform is taken for the blood flow in the left ventricle of the heart, the first peak is the E wave (the blood flow when the left ventricle is dilated) and the second peak. Shows the peak of A wave (blood flow during systole of the left atrium). Then, the motion state of the heart can be diagnosed by obtaining the ratio of these two peaks.

The trace processing unit 30 is additionally provided with an average velocity calculation circuit to calculate the average velocity of motion within a predetermined period from the trace line, measure the cross-sectional area of the blood vessel, and integrate it with the average velocity of motion. Alternatively, the blood flow rate may be calculated.

The calculation information such as the calculated peak ratio is as follows:
The trace line information and the like are combined and displayed on a monitor 42 via a DSC (digital scan converter) 40.

Next, a data processing procedure in the trace processing section 30 will be described with reference to FIGS. 1, 2 and 3. Here, FIG. 2 shows an auto-trace procedure in the auto-trace circuit 34 of FIG. Further, FIG. 3 shows a peak detection procedure in the peak detection circuit 36 of FIG. 1 which is a feature of this embodiment.

First, when the noise level detecting circuit 32 is provided as required in order to reduce the influence of noise in the trace processing, the noise level detecting circuit 32 is provided.
, The data sample area for detecting the reference noise level is obtained based on the baseline position of the Doppler waveform. Then, the reference noise level is detected in this data sample area and output to the auto trace circuit 34.

The auto trace circuit 34 performs the following auto trace processing based on this reference noise level (see FIG. 2).

First, 1 including the Doppler waveform from the memory 20
The graphic display circuit 26 outputs the scale condition, the character data, etc. set by the operator operating the input unit 22 by taking in the ultrasonic image data for a frame (S1). Further, in accordance with this, predetermined image processing such as moving averaging is performed on the ultrasonic image data (S2). Then, freeze display (still image display) is performed as an ultrasonic image on the monitor 42.

The operator operates the input section 22 on the freeze-displayed ultrasonic image to trace the range (in this embodiment, the range of the bimodal Doppler spectrum),
Conditions such as the tracing direction (trace reference: tracing the maximum value / minimum value of the Doppler shift frequency, for example) are selected (S3).

Next, when the reference noise level is further obtained based on the set predetermined trace condition, the pixels to be traced sequentially from the past Doppler waveform are judged using this reference noise level as a threshold (S4), Trace lines are sequentially displayed on the monitor 42 (S5). The trace line may be combined with the Doppler waveform and displayed on the monitor 42. When the above processing for the designated range is completed (S6), the obtained trace line information is output to the peak detection circuit 36 of FIG. 1, and peak detection is performed here.

The peak detection procedure in the peak detection circuit 36 will be described below by taking the case of bimodal peak detection as an example (see FIG. 3).

First, as shown in FIG. 4A, the dividing unit divides the trace line within the specified range into predetermined intervals on the time axis (6 to 8 in this embodiment) (S1).
0). Note that FIG. 4 shows a trace line of a bimodal Doppler spectrum, where the horizontal axis represents time t and the vertical axis represents the Doppler shift frequency ψd representing the motion velocity information of the subject.

Next, the section peak detector detects the coordinates of the section peaks of the trace lines in each of the divided sections, that is, the maximum point / minimum point (S11). Here, the section peak to be obtained may be maximum or minimum depending on the purpose of diagnosis. Alternatively, both may be detected at the same time.

When a section peak in each section is detected, each section is then shifted, and this is repeated a predetermined number of times (for example, 5).
Repeat) (S12). Note that the number of times of this section peak detection processing is a value for preventing false detection of a true peak, and is not limited to this.

Until the number of section peak detections reaches 5,
As shown in FIGS. 4B and 4C, the shift unit interlocks each section with a predetermined amount (2 in the monitor 42 in this embodiment).
Up to 4 pixels) in the time axis direction (S1
3). Then, after the shift, the section peaks in each section are detected (S11), and when the number of detections reaches 5, the section peak detection ends.

Next, among the coordinates of a plurality of section peaks obtained by a plurality of detection processes, the coordinates of a point having the same coordinates, that is, the coordinates of an invariant point regardless of the shift process are determined and traced. The line is detected as a true peak (S14). The determination of the coordinates of the invariant point is performed not by each section but by searching the entire section of the trace line.

Further, with respect to the maximum and minimum points obtained in each section, those having a small difference are excluded (S1
5) By detecting the true peak, the accuracy of detecting the true peak is further improved.

In the present embodiment, the number of divisions of the trace line is set to 6 to 8 when the bimodal Doppler spectrum is used, but the number of divisions is not limited to this and may be increased. On the other hand, the shift amount of the section is set to 2-3 pixels,
This value is determined in consideration of the noise fluctuation amount in the ultrasonic image, and its optimum value differs depending on the noise state of the image.

Next, a predetermined calculation process is performed on the true peak detected by the above procedure. Then, the calculation result is displayed on the monitor 42. The obtained true peak can be displayed on the monitor 42 like a black dot on the trace line in FIG. 4 upon request. By displaying the true peak on the monitor 42, the operator can confirm the position of the true peak which is the reference of the calculation result.

When a bimodal Doppler spectrum is designated as the designated range of the trace line, the true peak becomes a bimodal peak. In this case, the pulsation index and LVI described above are calculated by calculating the ratio of the obtained two peaks.
It is possible to measure F and the like, and it is possible to diagnose a blood circulation state, a heart motion state, and the like.

The trace condition can be changed by operating the input section 22, and the true peak can be detected again by changing the condition.

As described above, in this embodiment, the true peak can be accurately detected even if the smoothness of the trace line is low. Therefore, the reliability of the result of the predetermined calculation performed based on the detected true peak, that is, the accuracy of diagnosis is improved. Moreover, since peak detection can be performed automatically, it is possible to contribute to shortening the diagnosis time.

Further, in the present embodiment, since the trace processing is also automatically performed, it is possible to further contribute to shortening the diagnosis time. By detecting the reference noise level prior to auto trace processing and performing auto trace processing with reference to this value, trace lines with less noise influence and high smoothness can be obtained, and true peak detection accuracy can be obtained. Is further improved.

Further, since the differential operation is not performed in detecting the true peak, the problem that the device configuration becomes complicated does not occur.

In the present embodiment, an example in which the true peak is obtained for the Doppler waveform trace line has been described, but the present invention is not limited to the Doppler waveform trace line, and the luminance information (echo signal) of the subject tissue can be obtained. It is also possible to obtain the true peak of an ultrasonic wave waveform (so-called A-mode or M-mode ultrasonic diagnosis) that represents a temporal change.

[0056]

As described above, according to the ultrasonic diagnostic apparatus of the present invention, even if the smoothness of the trace line is low, the true peak can be accurately detected with a simple apparatus configuration. Therefore, the accuracy of the result of the predetermined calculation performed based on the detected true peak, that is, the reliability of the diagnosis is further improved. Moreover, since peak detection can be performed automatically, it is possible to contribute to shortening the diagnosis time.

[Brief description of drawings]

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

FIG. 2 is a diagram showing an auto-trace procedure in an auto-trace circuit 34 of FIG.

FIG. 3 is a diagram showing a peak detection procedure in a peak detection circuit 36 of FIG.

FIG. 4 is a conceptual diagram showing a peak detection procedure from a trace line of a bimodal Doppler spectrum according to an embodiment of the present invention.

[Explanation of symbols]

 30 Trace Processing Unit 32 Noise Level Detection Circuit 34 Auto Trace Circuit 36 Peak Detection Circuit 42 Monitor

Claims (2)

[Claims] 1. An ultrasonic diagnostic apparatus that transmits and receives an ultrasonic beam to and from a subject and displays an ultrasonic waveform based on the received wave, wherein the ultrasonic waveform is a predetermined section on a time axis. A dividing means for dividing each of the sections, a shift means for interlocking each section by a predetermined number of times in conjunction with each other on the time axis, and a section peak of the ultrasonic waveform in each section for each predetermined number of shifts. Section peak detecting means for detecting coordinates, and peak detecting means for determining an invariant coordinate among the coordinates of the plurality of section peaks and detecting it as a true peak of the ultrasonic waveform. And ultrasonic diagnostic equipment. 2. An ultrasonic diagnostic apparatus for transmitting and receiving an ultrasonic beam to and from a subject and displaying a Doppler waveform representing a change with time of a Doppler shift frequency based on the received wave obtained. Tracing means for tracing, dividing means for dividing a trace line into predetermined intervals on the time axis, shift means for interlocking each of the intervals on the time axis by a predetermined amount by a predetermined number of times, and the predetermined number of times For each shift of, the section peak detection means for detecting the section peak of the trace line in each section, and the invariant coordinates among the coordinates of the plurality of section peaks are determined, and this is used as the true peak of the Doppler waveform. An ultrasonic diagnostic apparatus comprising: a peak detecting unit for detecting.