JP3332089B2 - Ultrasound imaging device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic imaging apparatus for non-destructively imaging the inside of an object, and more particularly to an ultrasonic imaging apparatus capable of clearly imaging the inside from a gap.

[0002]

2. Description of the Related Art Conventionally, various ultrasonic imaging apparatuses for nondestructively observing the inside of an object have been developed and put to practical use. As the ultrasonic imaging apparatus, for example, an ultrasonic imaging apparatus that emits an ultrasonic wave having a frequency of several to several tens of MHz into a subject, and mainly forms and displays an image using a reflected wave of the incident ultrasonic wave. There is. In addition, various methods of displaying captured images in such an ultrasonic imaging apparatus are provided depending on the purpose of use.

[0003] For example, in order to render a captured image of a heart in real time, a sector scan is used. In this sector-type scan, as shown in FIG. 4, ultrasonic waves are sequentially scanned in a fan shape from the probe 9 (in the direction of the arrow S shown in FIG. 4) and emitted. It is suitable for avoiding obstacles near the table and looking into the heart from the gap between the ribs R.

[0004]

However, even when the sector-type scan is employed, a part of the ultrasonic beam actually strikes the ribs and lungs as shown by the dotted line in FIG. However, it is not possible to prevent the influence of the image and the lungs, etc., and a virtual image on the image, so-called artifact, multiple reflection and pseudo echo occurs, which is an obstacle in diagnosis based on a captured image.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and an ultrasonic beam is generated so as to avoid ribs, lungs, and the like. It is an object of the present invention to provide an ultrasonic imaging apparatus capable of performing the following.

[0006]

In order to achieve the above object, according to the present invention, an ultrasonic wave is transmitted and received between the ribs of a subject, and based on the obtained ultrasonic echo signal. In an ultrasonic diagnostic apparatus that displays an ultrasonic image, an ultrasonic probe that has a large number of transducers and transmits and receives ultrasonic waves to and from a subject, so that ultrasonic transmission is performed avoiding the ribs, The vibrator is driven by sequentially moving the position of the vibrating element to be driven together with the change in the deflection of the ultrasonic beam, and the number of vibrators to be driven is set based on a result of a pre-scan performed in advance. An ultrasonic imaging apparatus comprising: a transmission unit configured as described above.

[0007]

[0008]

The ultrasonic imaging apparatus according to the first aspect of the present invention automatically sets the number of vibrators driven by a large number of vibrating elements constituting the probe in accordance with the result of the prescan, and removes ribs (obstacles). Since the ultrasound transmission is performed while avoiding the obstacle, an ultrasound image of the subject that is less affected by the obstacle can be obtained.

[0009]

[0010]

An embodiment according to the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a scan state of the ultrasonic imaging apparatus according to the present invention, and FIG. 2 is a block diagram illustrating a schematic configuration of the ultrasonic imaging apparatus. First, the schematic configuration of the ultrasonic imaging apparatus according to the present embodiment will be described with reference to the block diagram of FIG.

The scan control unit 1 is connected to the transmission control unit 3, the reception control unit 15, and the DSC 19, and controls the scanning state of the probe 9 by controlling them. Specifically, the scan control unit 1 controls the transmission control unit 3 and the reception control unit 15 so as to control the delay unit, that is, to each of the vibrating elements of the probe 9 in the T-DELAY unit 5 and the R-DELAY unit 13. The amount of delay given to a signal from each vibration element is controlled.

The transmission control unit 3 has a T.DELAY
The delay section 5 is connected to the section 5 and controls the amount of delay when the delay time is generated in the T-DELAY section 5. The T-DELAY section 5 generates a delay time for giving a time difference corresponding to the deflection of the ultrasonic beam to each of the vibrating elements of the probe 9 described later. ●

That is, in the first raster, data relating to a delay and an aperture for giving a time difference corresponding to the deflection of the first ultrasonic beam (indicated by C1 in FIG. 1) are output. The second ultrasonic beam (C in FIG. 1)
a) to output a delay and a data relating to the aperture for giving a time difference corresponding to the deflection of the deflection. The data relating to the delay and the aperture are data set in order to avoid the influence of the bone and the lung, and the delay amount based on the data relating to the delay and the aperture is given to each of the vibrating elements of the probe 9 and FIG. The scan shown in FIG. 3 is performed. The output of this data is performed by a reception control unit 1 described later.
5 is performed in the same manner.

The T-DELAY section 5 includes a PU
The LSER unit 7 is connected, and outputs a high-frequency pulse signal to the probe 9 at a timing based on the delay time generated by the T-DELAY unit 5.

In this embodiment, the probe 9 is a sector scan type in which a large number, for example, n, vibrating elements are linearly arranged on the body contact surface. According to the high-frequency pulse signal subjected to the delay control, m continuous elements (where m <
The vibrating elements of the vibrating element group of n) sequentially generate a ultrasonic wave with a predetermined time difference, and the continuous vibrating element groups sequentially move in one direction at a predetermined speed.

Thus, the ultrasonic waves generated by the respective vibrating elements are synthesized, and the synthesized ultrasonic beam having a predetermined aperture as a whole is deflected in a predetermined direction and is incident on the subject. At this time, the center point C of the scan is, for example, on the vibrating element of the probe 9 located at the center between the ribs. Further, the probe 9 receives ultrasonic information obtained through the subject on which the ultrasonic beam is incident, in particular, an ultrasonic echo reflected inside the subject.

The preamplifier 11 amplifies the signal related to the ultrasonic echo received by the probe 9 and
Output to the LAY unit 13. At this time, the log signal is log-compressed by the log amplifier and the STC (Se) connected to the log amplifier is compressed.
Sensitivity correction with respect to the distance in the living body is performed by the Nsitity Time Control.

The R-DELAY section 13 is provided with a probe 9
A signal having the same delay time difference as the delay time difference provided by the T-DELAY unit 5 is given to the signal received by the preamplifier unit 11 and amplified by the preamplifier unit 11, and the reception control unit 15 controls the delay time and the like. This R ・ DELAY part 1
3 is output to the DSC 19 via the receiver 17.

DSC (Digital Scan Co.)
The A / D converter 19 converts an echo signal of an analog signal input from a log amplifier (not shown) into a digital signal by A / D conversion, further writes the digital echo signal in a XY coordinate system in a digital memory, and then stores the XY coordinate in the digital memory. The data written in coordinates is standard T
It is read by V scanning. Further, the data read from the digital memory via the color processing section and the D / A conversion section is D / A converted into an analog signal, and then output to the display section 21 for display. The display 21 has a CR
In addition to T, an appropriate display device is used. Also, VT
R may be connected to record image data output from the D / A conversion unit.

Next, the operation of the first embodiment will be described with reference to FIG. In the first embodiment, when an ultrasonic beam is incident from a gap between the ribs R, the ribs R and the lungs L shown on the right side in FIG. In accordance with the position, deflection of the ultrasonic beam, which is a sector scan, and control of the aperture are performed. That is, as shown by the center axis A of the ultrasonic beam in FIG. 1, when deflected to the right, the left m-channel vibrating element of the n vibrating elements of the probe 9 is delayed by a delay time indicated by C1. It is driven and received by the m-channel vibrating element. The reception implements so-called dynamic focus.

Next, m vibrating element groups continuous from the 1st channel to the mth channel generate ultrasonic waves while sequentially moving in one direction at a predetermined speed. For example, when the left end is the channel a, the right end is the (m + a) channel (a to (m
+ A)), the amount of delay is Ca. Hereinafter, similarly, scanning is performed in the direction of arrow S to channels b to (m + b) (delay amount Cb) at the right end of the vibrating element. Here, m + b = n
However, m + b <n may be set according to the condition of the subject such as a small gap distance between the ribs R.

At this time, the diameter of the ultrasonic beam is
The spread of the ultrasonic beam when the ultrasonic beam passes through the gap between the ribs R is set and controlled so as to be smaller than the distance between the ribs R. At this time, the spread of the ultrasonic beam is minimum at the focus point FP, and the rib R
Since the center axis A of the ultrasonic beam is oblique due to the deflection of the ultrasonic beam, the width is larger than the actual spread of the ultrasonic beam. ●

Although the setting of the aperture needs to be appropriately changed in accordance with the gap distance between the ribs R and the deflection amount of the ultrasonic beam, in the present embodiment, these are set by a pre-scan performed in advance. Is provided, the setting can be automated. Further, the adjustment may be appropriately performed by the operator during imaging. This allows the center beam not to move but to avoid the effects of bone. In the case of the first embodiment, the ultrasonic beam is asymmetric with respect to the center axis A of the ultrasonic beam.

Next, a second embodiment will be described with reference to FIG. In the second embodiment, when an ultrasonic beam is incident from the gap between the ribs R, in order to avoid the influence of the ribs R and the lung L shown on the right side in FIG. The start point of the ultrasonic beam is moved according to the position, and the m continuous vibration element groups generate ultrasonic waves while sequentially moving in one direction at a predetermined speed. Thereby, the ultrasonic waves generated by the respective vibrating elements are synthesized, and the synthesized ultrasonic beam having a predetermined diameter as a whole is deflected in a predetermined direction and is incident on the subject.

At this time, the center point C of the sector scan is
For example, in the subject on the center line between the ribs, for example, at the center of the gap between the ribs R, the center axis A of the ultrasonic beam
It is possible to perform a scan so as to rotate about the approximate center between the ribs R, and it is possible to obtain a captured image that is not affected by the ribs R and the lungs L at all.

The deflection of the ultrasonic beam and the control of the aperture in the first embodiment shown in FIG. 1 and the second embodiment shown in FIG. This is performed by setting the number of vibrating elements, whereby the position of the scan center point C is also determined. During imaging, the position of the center point C of the scan may be appropriately adjusted by the operator. Further, the amount of delay of each vibrating element and the number of driven vibrating elements are appropriately calculated according to the state of the subject, and depending on the case, data obtained in advance by experiments or pre-scanning may be used. A table may be created based on this, and the table may be set based on the table.

Further, by alternately or simultaneously displaying the display based on the first embodiment and the display based on the second embodiment described above, a virtual image on an image, so-called artifact, multiple reflection and pseudo echo can be reduced. Even if they occur, they can be easily identified,
More accurate diagnosis and the like can be performed.

In the above embodiment, a medical ultrasonic imaging apparatus for imaging a heart from a gap between ribs has been described as an example. However, the present invention is not limited to this. It goes without saying that the present invention can be applied to any ultrasonic imaging apparatus such as the above.

As described above, in the ultrasonic imaging apparatus according to the present invention, the number of transducers driven by a large number of transducers constituting the probe is automatically set according to the result of the pre-scan, and the ribs are avoided. Since ultrasonic transmission is performed, an ultrasonic image of the subject that is less affected by the obstacle can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram showing a scan state according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a schematic configuration of an embodiment according to the present invention.

FIG. 3 is a diagram illustrating a scan state according to another embodiment of the present invention.

FIG. 4 is a diagram showing a state of scanning in a conventional example.

[Description of Signs] 1 Scan control unit 3 Transmission control unit 5 T • DELAY unit 7 PULSER unit 9 Probe 11 Preamplifier unit 13 R • DELAY unit 15 Reception control unit 17 Receiver unit 19 DSC 21 Display unit L Lung R Rib

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) A61B 8/00-8/15

Claims (1)

(57) [Claims] An ultrasonic diagnostic apparatus for transmitting and receiving ultrasonic waves between ribs of a subject and displaying an ultrasonic image based on an obtained ultrasonic echo signal, comprising: a plurality of transducers. An ultrasonic probe that transmits and receives ultrasonic waves to and from the subject, and sequentially moves the position of the vibrating element that is driven with a change in the deflection of the ultrasonic beam so that ultrasonic transmission is performed avoiding the ribs. An ultrasonic imaging apparatus for driving the vibrator, comprising: transmitting means configured to set the number of vibrators to be driven based on a result of a pre-scan performed in advance. .