JP2863624B2 - Ultrasound diagnostic equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Effect of the Invention] (Industrial application field) The present invention relates to an ultrasonic diagnostic apparatus capable of accurately detecting abnormalities in coronary blood flow.

2. Description of the Related Art In recent years, cardiovascular mortality has increased. For example, myocardial infarction occurs when the coronary artery blood flow (coronary blood flow) is obstructed and the movement of a part of the myocardium becomes rough. If blood does not flow through the myocardium for a long time (several minutes to several hours), the myocardium suffers fatal damage and does not move.

83.9% of myocardial infarcts have been reported to have 90% or more lumen stenosis or complete occlusion in the main branch of the coronary artery. It is essential to clarify the state of stenosis and occlusion in selecting a surgical method.

A common symptom that occurs when blood flow to the coronary arteries is impaired is angina. A case of abnormal movement of the myocardium due to coronary artery blood flow alienation, such as angina, is called ischemic heart disease (ischemia). In this case, there was no sign of pain at rest and there was a load of exercise etc. Occasionally, sudden death from ischemic heart disease occurs.

This is called painless (silent) ischemic heart disease, but it shows an increasing tendency and is a social problem. Efforts have been made to detect them in advance by monitoring the electrocardiogram 24 hours and exercise tests, but for early detection and prevention of painless coronary artery disease, along with such exercise ECG, It is also useful to identify coronary artery stenosis and occlusion conditions, such as in the case of myocardial infarction.

However, coronary blood flow, which divides right and left at the first branch of the aorta and runs in a coronal groove surrounding the ventricle and atrium in a headband shape, shows a significant decrease in blood flow at rest even if 75% of the blood vessels are narrowed. Is not expected to appear. Therefore, in order to distinguish between stenotic sites and normal blood vessels, and to discover painless ischemic heart disease,
Heterogeneity of coronary blood flow (hete
stress echo examinations have been performed to detect the changes in the myocardium on ultrasound images. This test is also used to diagnose the prognosis of those who have had revascularization.

The load for the stress echo test includes a load caused by exercise such as walking on a belt conveyor, and a load caused by a drug for administering a coronary dilator. Then, the ultrasonic images (moving images) of the long axis and short axis of the heart before loading and the long axis and short axis after loading are compared. For this purpose, the monitor screen is divided into, for example, four screens as a multi-frame, and these screens are reproduced and displayed simultaneously.

In other words, before and after the load, regarding the long axis and short axis of the heart, which is one index of the heterogeneity of coronary blood flow,
In other words, the data (ultrasound image) was converted to an electrocardiogram (EC
G) For several heartbeats in synchronization, between one heartbeat, for example, as shown in FIG. 5, a maximum of 64 frames (maximum 2.1 seconds) are collected at a frame rate of 30 frames / second and stored in an appropriate storage means (for example, a hard disk). I do. By the way, in case of 64 frames per heartbeat, 4 MB at 256 x 256 pixels x 64 frames
Memory is required.

Then, during image reproduction, the time phases of the frames before and after the load are adjusted. In general, after the load, the time between one heartbeat is shortened, so that the number of frames collected during one heartbeat is reduced as shown in FIG. ). Therefore, during playback, the maximum number of frames after loading (0.53sec / 16 for 16 frames)
(Corresponding to a frame (1 heartbeat), 113 beats / min), the monitor displays the long axis before and after the load as shown in FIG.
A multi-frame display cine repetitive reproduction in the 4-screen B mode corresponding to the short axis repeatedly compares and diagnoses abnormalities (rigidity of the myocardium) during myocardial contraction / dilation.

(Problems to be Solved by the Invention) However, in this stress echo examination, the coronary artery can only be seen in a thick blood vessel wall, and cannot be seen until the blood flow. In other words, since abnormalities in blood flow are indirectly detected by abnormalities in the myocardium, heterogeneity in coronary blood flow cannot be directly observed, and subtle changes in coronary blood flow due to abnormalities in coronary arteries are taken. There was no disadvantage.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an ultrasonic diagnostic apparatus that can accurately detect abnormalities in coronary blood flow.

[Configuration of the invention]

(Means for Solving the Problems) In order to solve the above problems, the present invention provides an ultrasonic transmission / reception that transmits an ultrasonic wave to a portion including a heart of a subject in synchronization with a heartbeat and receives a reflected signal thereof. Means, signal processing means for detecting a Doppler signal from the received signal to obtain blood flow information, storage means for storing the blood flow information for a predetermined period before and after load application to the heart, And a display unit that reads out the blood flow information before and after the load is applied from the storage unit and displays the blood flow information side by side.

For example, the blood flow information is a two-dimensional color Doppler image. Further, for example, the blood flow information is a one-point Doppler signal.

Further, when the ultrasonic transmitting / receiving means and the signal processing means operate on at least two parts of the heart, the storage means stores the blood flow information of the at least two parts in the load application. The display means reads out the blood flow information of the at least two parts before and after the load application from the storage means, and stores the blood flow information for each of the parts before and after the load application. It is also possible to configure so that it is a means for arranging and displaying the information before and after the application.

(Operation) The ultrasonic diagnostic apparatus of the present invention performs imaging of coronary blood flow using, for example, a two-dimensional Doppler moving image using Doppler signals of high-frequency ultrasonic waves. Further, since the storage means and the multi-frame display means are provided, images before and after the application of the load and images of a plurality of parts can be simultaneously compared following the stress echo test. Therefore, according to the ultrasonic diagnostic apparatus of the present invention, the heterogeneity of the coronary blood flow (the speed of blood flow between each part) before and after the application of the load can be directly grasped through the change in hue. In addition, by chronologically following, for example, a one-point Doppler signal of each part of the coronary blood flow, a quantitative diagnosis of the blood flow velocity becomes possible. For this reason, in the ultrasonic diagnostic apparatus of the present invention, it is possible to obtain an image corresponding to a subtle change in coronary blood flow, and it is possible to reduce various abnormalities and diseases of the coronary artery in a short time as compared with the conventional stress echo examination. Can be accurately determined.

(Embodiment) Hereinafter, an embodiment of the present invention will be described with reference to FIGS.

FIG. 1 is a configuration diagram of an ultrasonic diagnostic apparatus 1 according to one embodiment of the present invention. In the ultrasonic diagnostic apparatus 1, the operation unit 2 is used for the diagnostic area setting unit, the ultrasonic probe 3 and the transmitting / receiving unit 4 are used for the ultrasonic transmitting / receiving unit, and the signal processing / control unit 5 is used for the signal processing unit. The storage unit corresponds to a storage unit (such as a magnetic disk) 6, and the display unit corresponds to the image forming unit 7 and the monitor 8. Note that the monitor 8 of the present embodiment can also display a one-point Doppler signal.

The operation unit 2, the transmission / reception unit 4, the storage unit 6, and the image forming unit 7 are connected to the signal processing / control unit 5, and the ultrasonic probe 3 is connected to the transmission / reception unit 4, and the image forming unit 7 is connected to the signal processing / control unit 5. The monitor 8 connects. Further, an ECG (electrocardiograph) 9 is connected to the signal processing / control unit 3 connected to the transmitting / receiving unit 4 so that the transmitting / receiving unit 4 can transmit / receive an ultrasonic wave in synchronization with a heartbeat.

Hereinafter, a procedure for examining the heterogeneity of coronary blood flow between the right coronary artery and the left coronary artery using the ultrasonic diagnostic apparatus 1 of the present embodiment will be described.

Diagnosis of the coronary artery by the ultrasonic diagnostic apparatus 1 of the present embodiment is to obtain an ultrasonic image related to the heterogeneity of coronary blood flow before and after the load, similarly to the stress echo examination. It will be about coronary blood flow.

Therefore, before applying a load such as exercise to the subject, the storage unit 6 stores the B-mode tomographic images of the left and right coronary arteries and the Doppler signal of the blood flow.

That is, the ultrasonic probe 3 is sent from the esophagus using, for example, a transesophageal echocardiography (TEE) method. Then, the transducer of the ultrasonic probe 3 is driven under the control of the transmission / reception unit 4, and the ultrasonic pulse is transmitted toward the living body.

Then, the ultrasonic wave is reflected in the living body and received by the ultrasonic probe 3. If this transesophageal echocardiography is used, the distance between the ultrasonic probe 3 and the heart can be shortened, so that attenuation of the ultrasonic waves is small and high-frequency ultrasonic waves can be received. If a high-frequency ultrasonic wave can be obtained, a high-resolution ultrasonic image can be formed.

The in-vivo reflected wave signal is sent to the transmission / reception unit 4, and then the signal processing / control unit 5 calculates the reflection intensity at each point in the in-vivo depth direction and performs frequency analysis of the Doppler signal by fast Fourier transform (FFT). Then, the obtained reflection intensity and Doppler frequency of the ultrasonic signal are input to the storage unit 6.

On the other hand, in parallel with the input to the storage unit 6, the image forming unit 7 outputs a B-mode image (ultrasonic tomographic image) from the reflection intensity and a Doppler signal at a plurality of sites in the depth direction in the living body.
By two-dimensionally integrating, a two-dimensional color Doppler image of the blood flow is formed. On the other hand, by continuously acquiring the ultrasonic Doppler signal at one point (one point), the time-series blood flow velocity at that point is also obtained.

Then, a two-dimensional color Doppler image (ultrasonic probe 3
Are displayed in red, flows that are moving away are displayed in blue, and the intensity of each Doppler frequency component is represented by luminance.
To display simultaneously. The B-mode image is stored in the storage unit 6 via the signal processing / control unit 5.

In this state, the doctor moves the ultrasonic probe 3 on the monitor 8 so as to obtain, for example, an image of the right coronary artery while viewing the two-dimensional color Doppler image on the monitor 8. Then, when an appropriate position of the ultrasonic probe 3 is determined, a time range (ultrasonic scanning range, that is, an echo signal in a living body) in which the ultrasonic reflected signal (echo signal) is extracted by the vibrator of the ultrasonic probe 3 in the operation unit 2. Depth range).

FIG. 2 is an electrocardiogram shown on the electrocardiograph 9. Therefore, in the ultrasonic diagnostic apparatus 1 of the present embodiment, at this stage, the R wave (a waveform reflecting the excitation (depolarization) of the ventricle) of the electrocardiogram waveform shown in FIG. In synchronization with one heartbeat from one R-wave to the next R-wave, transmission and reception of ultrasonic waves for 16 frames of ultrasonic images (in the figure,... Are frame numbers) are performed at a predetermined frame rate. From the obtained ultrasonic signal, the reflection intensity and the Doppler frequency are obtained in the signal processing / control section 5 in the manner described above.

As a result, the ultrasound reflection intensity, Doppler signal, and electrocardiogram waveform of the unit 1 (right coronary artery) in units of 16 frames per heart beat are stored in the recording unit 6 before loading as shown in FIG.

Thereafter, the same procedure as described above is performed for the left coronary artery (site 2), and data is stored in units of 16 frames per heartbeat before loading as shown in FIG.

Thus, the operation before the loading is completed, and then the subject is given a load of exercise, drug, and the like. Then, after the load, for the right coronary artery and the left coronary artery, according to the ultrasonic scanning range previously determined by the operation unit 2 and the heart rate by the electrocardiograph 9,
The ultrasound reflection intensity, the Doppler signal, and the electrocardiogram waveform are collected and processed in the same manner as before the loading, and are stored in the storage unit 6 as data of the portions 1 and 2 after the loading as shown in FIG.

When the data collection before and after the load for a plurality of parts (part 1 and part 2) is completed in this way, the operation unit 2 is operated to call out the data of each part before and after the load stored in the storage unit 6, and The image forming unit 7 forms a two-dimensional Doppler image from the data according to the above-described procedure.

FIG. 4A shows a screen when a two-dimensional Doppler image is displayed on the monitor 8. That is, the monitor 8 is capable of multi-frame (multi-screen) display, and in this embodiment, displays four frames (screens) each of two screens vertically and horizontally. Top left, top right,
The lower left and lower right screens show the pre-load right coronary artery,
It corresponds to the pre-load left coronary artery, the post-load right coronary artery and the post-load left coronary artery.

The monitor 8 displays the blood flow of the coronary artery in color on these four screens. That is, the hue is changed according to the direction and speed of the flow velocity. In addition, since the speed dispersion can be displayed by coloring, it is possible to easily identify a constricted portion where turbulence occurs. An electrocardiogram waveform is also displayed at the bottom of each screen for reference.

Then, the moving image is reproduced on the monitor 8 according to the reproduction speed adjusted by the operation unit 2. Therefore, the heterogeneity of the coronary blood flow (the speed of the blood flow) becomes apparent by comparing the left and right coronary arteries before and after the load. It is known that a patient with painless ischemic heart disease gives a blood flow heterogeneity when a load is applied. Therefore, according to the ultrasonic diagnostic apparatus 1 of the present embodiment, this can be easily diagnosed. it can. This diagnosis can be performed in a shorter time and more accurately than a stress echo test in which the myocardium is indirectly viewed.

By the way, since the heart rate increases after applying a load,
Under a constant frame rate, the number of frames per heart beat decreases. Therefore, it is desirable that the number of frames after loading is matched with the number of frames before loading while performing frame insertion by interpolation, so that the time phases before and after loading are aligned.

In addition, if the Doppler filter separates unnecessary low-frequency Doppler signals from a relatively slow-moving blood vessel wall, heart wall, valve, or the like, artifacts can be removed, and centering of a site of interest is also desirable for convenience of diagnosis.

FIG. 4 (B) shows a one-point Doppler signal together with an electrocardiogram waveform on four screens of the monitor 8 corresponding to FIG. 4 (A). Because it represents, it is also useful for quantitative diagnosis.

〔The invention's effect〕

As described above, according to the ultrasonic diagnostic apparatus of the present invention, the blood flow imaging of a plurality of parts of the coronary artery before and after the application of the load can be simultaneously displayed by, for example, a two-dimensional Doppler image. Tee, including subtle changes, can be captured directly through hue. Further, for example, by following the one-point Doppler signal in time series, it is possible to make a quantitative diagnosis of the blood flow velocity. Therefore, in the ultrasonic diagnostic apparatus of the present invention, abnormalities and diseases of the coronary arteries can be accurately determined in a short time as compared with the conventional stress echo examination.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an ultrasonic diagnostic apparatus according to an embodiment of the present invention, FIG. 2 is a graph showing the correspondence between an electrocardiogram waveform and an ultrasonic image frame, and FIG. 3 is a storage unit of the ultrasonic diagnostic apparatus. FIG. 4 is a data image diagram showing a form of data stored in
Figures (A) and (B) respectively show a two-dimensional Doppler image and a one-point Doppler signal diagram displayed on the monitor of the ultrasonic diagnostic apparatus, and FIG. 5 shows correspondence between an electrocardiogram waveform and an ultrasonic image frame in a stress echo test. FIG. 6 is a graph showing the correspondence between an electrocardiogram waveform and an ultrasonic image frame before and after a load in the stress echo test, and FIG. 7 is a B-mode image in the stress echo test. 2 ... operation unit, 3 ... ultrasonic probe, 6 ... storage unit,
7 ... image forming unit, 8 ... monitor, 9 ... ECG.

Claims (4)

(57) [Claims] An ultrasonic transmitting / receiving means for transmitting an ultrasonic wave to a portion including a heart of a subject in synchronization with a heartbeat and receiving a reflected signal thereof, and detecting a Doppler signal from the received signal to obtain a blood flow. Signal processing means for obtaining information; storage means for storing the blood flow information for a predetermined period before and after the load on the heart; and storage means for storing the blood flow information before and after the load on the heart. And a display unit for reading out and displaying side by side. 2. The ultrasonic diagnostic apparatus according to claim 1, wherein said blood flow information is a two-dimensional color Doppler image. 3. The ultrasonic diagnostic apparatus according to claim 1, wherein said blood flow information is a one-point Doppler signal. 4. When the ultrasonic transmitting / receiving means and the signal processing means operate on at least two parts of the heart, the storage means stores the blood flow information of the at least two parts. Means for storing the predetermined time period before and after the load application, wherein the display means reads out the blood flow information of the at least two parts before and after the load application from the storage means, and 2. The ultrasonic diagnostic apparatus according to claim 1, wherein said ultrasonic diagnostic apparatus is a means for arranging and displaying the load before and after the application of the load.