JP2001252271A - Ultrasonic imaging method and ultrasound diagnostic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To image an ultrasonic image which enables observation of the behav ior of a contrast medium attributed to a heart beat. SOLUTION: An ultrasonic wave is transmitted with the intensity thereof enough to vanish a contrast medium to the whole or a part of a number of sound rays forming one frame to generate one frame of ultrasonic image from a received signal corresponding thereto. At this point, the transmission of the ultrasonic wave is repeated at timings D1, D2, etc., being shifted by a specified value (including 0) from natural number times the cycle of heart beat while varying the specified value bit by bit. The subject is administered continuously with the contrast medium. The behavior of the contrast medium can be preferably observed in a different time phase during the period of one heart beat.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic image capturing method and an ultrasonic diagnostic apparatus, and more particularly, to an ultrasonic image capable of generating an ultrasonic image capable of suitably observing the behavior of a contrast agent due to a heartbeat. The present invention relates to an ultrasonic image generation method and an ultrasonic diagnostic apparatus.

[0002]

2. Description of the Related Art When obtaining an ultrasonic image of a blood flow, microbubbles are used as a contrast agent. However, these microbubbles disappear when exposed to strong ultrasonic waves. For this reason, as shown in FIG. 5, after capturing an image of a high transmission intensity frame (a frame captured using an ultrasonic wave that is strong enough to eliminate the contrast agent), a low transmission intensity frame (contrast agent does not disappear). Continue to capture an image of the frame using a weak ultrasonic wave, and after a time period in which the blood flow containing the contrast agent is refilled in the field of view, capture an image of the high transmission intensity frame again, Repeat. In FIG. 5, vertical lines arranged on the time axis represent the transmission time and transmission intensity of each sound ray forming each frame.

FIG. 6A shows each sound ray forming a high transmission intensity frame, and a bold line indicates that the ultrasonic wave is strong enough to cause the contrast agent to disappear. In addition, FIG.
Indicates sound rays forming a low transmission intensity frame, and is a thin line indicating that the ultrasonic waves are weak enough that the contrast agent does not disappear.

On the other hand, ECG (ElectroCardioGraph)
A technique called synchronization is known. In this method, transmission of an ultrasonic wave for generating an ultrasonic image of one frame is repeated at a timing synchronized with a heartbeat.

[0005]

By combining the conventional technique shown in FIG. 5 with ECG synchronization, it is possible to observe a contrast agent in one time phase during one heartbeat period. However, if the contrast agent is 1
There is a problem that you cannot observe how it behaves during the heartbeat period. Therefore, an object of the present invention is to provide an ultrasonic image generating method and an ultrasonic diagnostic apparatus capable of generating an ultrasonic image capable of appropriately observing the behavior of a contrast agent due to a heartbeat.

[0006]

SUMMARY OF THE INVENTION In a first aspect, the present invention transmits and responds to ultrasonic waves at such a strength that the contrast agent disappears for all or some of a number of sound rays forming one frame. An ultrasonic image generating method for generating an ultrasonic image of one frame from a received signal, wherein the predetermined amount is gradually changed at a timing shifted by a predetermined amount (including 0) from a natural number multiple of the heartbeat cycle. Provided is an ultrasonic image generation method characterized by repeating transmission. In the above configuration, “all or a part of a large number of sound rays forming one frame” means that all of the many sound rays forming a frame transmit ultrasonic waves at a strength enough to eliminate the contrast agent. Also, it is possible to transmit an ultrasonic wave with a strength that eliminates the contrast agent only for a part of a large number of sound rays forming one frame and transmit an ultrasonic wave with a strength that does not lose the contrast agent for other sound rays. It means good. The “heartbeat cycle” may be a value actually measured using an electrocardiograph or the like, or may be a rough heartbeat cycle (for example, one second). Further, “predetermined amount (including 0)” means that a timing coincident with a natural number multiple of the heartbeat cycle may be included.

In the ultrasonic image generation method according to the first aspect, since the transmission is basically performed at intervals of a natural number times the heartbeat period, the blood flow containing the contrast agent newly enters the visual field. Therefore, the contrast agent can be effectively photographed. In addition, since the timing is changed little by little, it is possible to image a contrast agent at different time phases during one heartbeat period. Therefore, the contrast agent is 1
How to behave over the heartbeat period can be suitably observed.

It is to be noted that a frame for transmitting an ultrasonic wave at such an intensity that the contrast agent is not lost may be interposed between frames to be photographed at the above timing. This makes it possible to improve the real-time property of updating the image of the portion other than the contrast agent.

In a second aspect, the present invention provides an ultrasonic probe, transmitting / receiving means for transmitting an ultrasonic wave from the ultrasonic probe and obtaining a received signal corresponding thereto, and a frame of one frame from the received signal. Image generation means for generating an ultrasonic image, and transmission for controlling the transmission intensity of the ultrasonic wave so as to transmit the ultrasonic wave at such a level that the contrast agent disappears for all or a part of a large number of sound rays forming one frame. Transmitting the intensity control means and repeating the transmission of the ultrasonic wave for generating the one-frame image at a timing shifted by a predetermined amount (including 0) from a natural number multiple of the heartbeat cycle and by gradually changing the predetermined amount. An ultrasonic diagnostic apparatus comprising: a timing control unit. In the ultrasonic diagnostic apparatus according to the second aspect, the ultrasonic image generating method according to the first aspect can be suitably implemented.

In a third aspect, the present invention provides the ultrasonic diagnostic apparatus according to the second aspect, further comprising a heart rate measuring means for measuring a heart rate. In the ultrasonic diagnostic apparatus according to the third aspect, the heart rate measured using an electrocardiograph or the like can be used.
The accuracy of the imaging phase can be improved.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the embodiments shown in the drawings. Note that the present invention is not limited by this. FIG. 1 is a configuration diagram illustrating an ultrasonic diagnostic apparatus according to an embodiment of the present invention. The ultrasonic diagnostic apparatus 100 transmits an ultrasonic pulse into an object and receives an ultrasonic echo from the object. The ultrasonic probe 1 drives the ultrasonic probe 1 to generate an ultrasonic wave. A transmission / reception unit 2 that outputs a reception signal corresponding to an echo, a signal processing unit 3 that generates an ultrasonic image such as a B-mode image from the reception signal, an image storage unit 4 that stores the ultrasonic image, DSC (DigitalSca) that converts sound wave images into display images
n Converter) 5 and a CRT 6 for displaying the display image
And a heartbeat detecting unit 7 for detecting the heartbeat of the subject, an input unit 8 for an operator to give an instruction, and a control unit 9 for controlling the entire operation. The control unit 9 particularly performs the following control. (1) transmitting an ultrasonic wave with a strength that eliminates the contrast agent for all or a part of a large number of sound rays forming one frame;
An ultrasonic image of one frame is generated from the corresponding received signal. (2) The heartbeat period T is measured, and the above-mentioned (1) is repeated at an imaging timing shifted from the natural number n times by a predetermined amount τ (including τ = 0) and by gradually changing the predetermined amount τ. (3) An ultrasonic wave is transmitted between the frames according to the above (2) at an intensity that does not cause loss of the contrast agent, and an ultrasonic image of one frame is generated from a corresponding received signal.

FIG. 2 is a flowchart showing an ultrasonic image generation process of the ultrasonic diagnostic apparatus 100. In step S1, the operator inputs from the input unit 8 a natural number n for determining a basic interval of imaging and a number of time phases k to be observed in one heartbeat cycle. For example, assume that n = 1 and k = 8 are input. In step S2, the ultrasonic probe 1 is applied to a desired portion of the subject to which the contrast agent is continuously administered, and the operator waits for the operator to press a capture start button (not shown) of the input unit 8. When the capture start button is pressed, the process proceeds to step S4.

In step S4, a natural number n of the heartbeat period T
The time τ for shifting the shooting timing from the double is initialized to “0”.

In step S5, when the heartbeat detection unit 7 detects the R wave n times, the process proceeds to step S6. In step S6, transmission is started at a timing delayed by time τ, and a received signal for one frame is obtained. An ultrasonic image is generated from the received signal and stored in the image storage unit 4. For example, n
If = 1, τ = 0, transmission is performed at the timing D1 immediately after the detection of the R wave R1 in FIG. 3, and the ultrasonic image G1 in FIG. 4 is generated and stored. In addition, each ultrasonic image G1 of FIG.
The thick line portion of G5 represents the contrast agent.

In step S7, the heartbeat period T is set to the phase number k.
The value obtained by adding the value α divided by the time to the time τ is defined as a new time τ. In step S8, it is determined whether or not the time τ is smaller than the heartbeat period T. If it is shorter, the process returns to step S5, and if not, the process proceeds to step S9.

For example, in the second step S6, n =
Since 1, τ = α, transmission is performed at a timing D2 delayed by α after the detection of the R wave R2 in FIG. 3, and the ultrasonic image G2 in FIG. 4 is generated and stored. In the third step S6, since n = 1 and τ = 2α, the R wave R3 in FIG.
Is transmitted at a timing D3 which is delayed by 2α after the detection, and the ultrasonic image G3 of FIG. 4 is generated and stored.
In the fourth step S6, since n = 1 and τ = 3α, the transmission is performed at a timing D3 delayed by 3α after detecting the R wave R3 in FIG. 3, and the ultrasonic image G4 in FIG. 4 is generated. Is stored. In the fifth step S6, since n = 1 and τ = 4α, transmission is performed at a timing D3 delayed by 4α after detecting the R wave R3 in FIG.
The ultrasonic image G5 of FIG. 4 is generated and stored. Similarly, an ultrasonic image of 8 (= k) time phases up to τ = 7α is generated and stored. When τ = 8τ, the process proceeds to step S9.

In step S9 of FIG. 2, if the termination method is set to a, the process returns to step S4, and the same is repeated from the first time phase in one cycle. If the termination method is set to b, the process proceeds to step S10. If the setting of the termination method is c, the process is terminated.

In step S10, if the operator presses the capture end button (not shown) of the input unit 8, the process is terminated. If not, the process returns to step S4, and the same process starts from the first phase in one cycle. Repeat that.

According to the above ultrasonic diagnostic apparatus 100, ultrasonic images G1, G2,... As shown in FIG. If these ultrasonic images G1, G2,... Are displayed in a list or in a cine display, the movement of the contrast agent at different time phases during one heartbeat period can be suitably observed.

When n = 1, if the contrast agent does not reach the desired portion, n may be set to 2 or more. Also, while waiting in step S5 of FIG.
A process of transmitting an ultrasonic wave at an intensity that does not cause the contrast agent to disappear and generating an ultrasonic image of one frame from a corresponding received signal may be performed.

[0021]

According to the ultrasonic image generating method and the ultrasonic diagnostic apparatus of the present invention, it is possible to suitably observe the movement of the contrast agent at different time phases during one heartbeat period.

[Brief description of the drawings]

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

FIG. 2 is a flowchart of an ultrasonic image generation process according to an embodiment of the present invention.

FIG. 3 is an explanatory diagram of shooting timing according to an embodiment of the present invention.

FIG. 4 is an exemplary view of an ultrasonic image obtained by the present invention.

FIG. 5 is an explanatory diagram of a conventional imaging method using a contrast agent.

FIG. 6 is another explanatory diagram of a conventional imaging method using a contrast agent.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 ultrasonic probe 2 transmission / reception unit 3 signal processing unit 4 image storage unit 5 DSC 6 CRT 7 heartbeat detection unit 8 input unit 9 control unit 100 ultrasonic diagnostic apparatus

Claims (3)

[Claims] 1. An ultrasonic wave which transmits an ultrasonic wave with a strength enough to eliminate a contrast agent for all or a part of a large number of sound rays forming one frame and generates an ultrasonic image of one frame from a corresponding received signal. An ultrasonic image generation method, wherein the transmission is repeated at a timing shifted by a predetermined amount (including 0) from a natural number multiple of the heartbeat period and by gradually changing the predetermined amount. 2. An ultrasonic probe, transmission / reception means for transmitting an ultrasonic wave from the ultrasonic probe and obtaining a corresponding reception signal, and image generation for generating an ultrasonic image of one frame from the reception signal Means for controlling the transmission intensity of the ultrasonic wave so as to transmit the ultrasonic wave at such a level that the contrast medium disappears for all or a part of a large number of sound rays forming one frame; Transmission timing control means for repeating transmission of ultrasonic waves for generating the one-frame image at a timing shifted by a predetermined amount (including 0) from a natural number multiple and by changing the predetermined amount little by little. An ultrasonic diagnostic apparatus characterized by the above-mentioned. 3. The ultrasonic diagnostic apparatus according to claim 2, further comprising a heart rate measuring means for measuring a heart rate.