JPH05192337A - Ultrasonic diagnostic device - Google Patents

Abstract

PURPOSE:To provide a tomographic image having a wide visual field width extending from a shallow part near the body surface to a deep part and immediately conform to the case requiring high sensitivity of Doppler mode or having a limitation of acoustic opening width. CONSTITUTION:An ultrasonic probe 1 having a plurality of oscillators, a means for driving each oscillator of the ultrasonic probe 1 according to a determined driving system to transmit and receive ultrasonic waves, a means for providing a tomographic image by use of the receipt signal obtained by the transmission and receipt of the transmitting and receiving means, and a system control circuit 7 for instructing the transmitting and receiving means to change the determined driving system to another driving system.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic diagnostic apparatus which can use a plurality of ultrasonic scanning methods together.

[0002]

2. Description of the Related Art An ultrasonic diagnostic apparatus transmits ultrasonic waves into a living body, receives reflected waves generated by mismatch of acoustic impedance, and obtains a tomographic image using the received signals. In order to obtain a tomographic image, it is necessary to scan with an ultrasonic beam. The scanning system includes an electronic system and a mechanical system, and further includes a sector system, a linear system, a convex system, etc. for each system.
The scanning method has advantages and disadvantages, respectively, as shown below, and the operator considers those advantages and disadvantages and selects and uses them appropriately.

The sector system has a wide field of view in the deep part, and even if the acoustic opening is limited to see the movement of the heart through the ribs, the scanning operation is disturbed. While it has the advantage that it is small, the visual field width is narrow at a relatively shallow portion near the body surface, the spatial resolution decreases with the deflection (steering) of the ultrasonic beam, and at the same time, the level of the grating lobe increases. It has the disadvantage that the artifacts are enhanced by the phenomenon of angle.

On the other hand, the linear method generally has a relatively wide field of view and has an advantage that the spatial resolution is good because the ultrasonic beam is not deflected. On the other hand, the field of view in the deep portion is acoustic. It has a disadvantage that the scanning operation is hindered when the acoustic opening is limited by the width of the opening and the movement of the heart is seen through the ribs. It should be noted that the convex method has been relatively improved in the disadvantage of the linear method, that is, when the acoustic aperture is limited. However, the spatial resolution is lower than that of the linear method.

Therefore, as described above, the operator considers the advantages and disadvantages of each scanning method and appropriately selects and uses the scanning method. In that case, an operator corresponding to the selected scanning method is used. It is necessary to replace the ultrasonic probe with the ultrasonic diagnostic apparatus main body, and naturally it is necessary to previously provide a plurality of ultrasonic probes with different scanning systems. However, even when this scanning method is selected,
The disadvantages of the scanning method are tolerated, i.e. the eyes closed. Therefore, development of an ultrasonic probe having the advantages of each scanning method and an ultrasonic diagnostic apparatus main body capable of complying therewith has been desired.

[0006]

Therefore, an object of the present invention is to immediately cope with a case where a tomographic image having a wide field of view from a shallow portion to a deep portion near the body surface is obtained and the acoustic aperture width is limited. It is an object of the present invention to provide such an ultrasonic diagnostic apparatus.

[0007]

An ultrasonic diagnostic apparatus according to the present invention is an ultrasonic probe in which a plurality of transducers are provided side by side, and each transducer of the ultrasonic probe is driven according to a predetermined driving method. A means for transmitting and receiving ultrasonic waves, a means for obtaining a tomographic image using a reception signal obtained by transmission and reception of the transmitting and receiving means, and an instruction for the transmitting and receiving means to change the predetermined driving method to another driving method. And means.

[0008]

According to the present invention, by using an ultrasonic probe having a plurality of transducers arranged side by side, each transducer can be changed from a predetermined driving method to another driving method without replacing the ultrasonic probe. You can

[0009]

Embodiments will be described below with reference to the drawings.

FIG. 1 is a block diagram showing a configuration of an ultrasonic diagnostic apparatus according to an embodiment of the present invention, and FIG. 2 is a diagram showing a transducer array of the ultrasonic probe shown in FIG. This ultrasonic diagnostic apparatus is characterized in that the scanning method of the ultrasonic beam can be appropriately switched, for example, the linear scanning method and the sector scanning method can be switched mutually.

The ultrasonic probe 1 is a normal linear probe, that is, as shown in FIG. 2, a plurality of piezoelectric vibrators T1 to T14, here 14 piezoelectric vibrators, are arranged in a straight line at a pitch P0. These transducers transmit and receive ultrasonic pulses to and from the subject.

The vibrator switching circuit 2 receives an instruction from the system control circuit 7 to be described later to use the linear scanning method or the sector scanning method, and switches the driving vibrator group in accordance with the instruction. That is, when an instruction to use the linear scanning method is received, electrical connection with the oscillator 4, the amplifier 5 and the like is permitted to drive all the vibrators T1 to T14.
On the other hand, when an instruction to use the sector scanning method is received, electrical connection with the oscillator 4 and the amplifier 5 is allowed so that only the oscillators T5 to T10 included in the central portion E0 are driven, and the other ends are driven. Part of the oscillators T1 to T4 and T11
About ~ T14, the electrical connection is cut off and it is not driven.

In response to the instruction from the system control circuit 7, the transmission delay circuit 3 makes the drive timing of the simultaneously driven transducer groups the same in the linear scanning system, and in a predetermined direction in the sector scanning system. A predetermined delay time is given to each of the oscillators T5 to T10 in the central portion E0 in order to focus the ultrasonic beam, and this delay rate pulse is sent to the oscillator 4.
The oscillator 4 repeatedly drives each transducer of the ultrasonic probe 2 a predetermined number of times based on the delay rate pulse received from the transmission delay circuit 3.

As described above, when the ultrasonic probe 1 is driven to transmit, the ultrasonic pulse transmitted from the ultrasonic probe 1 to the subject is reflected at the boundary portion of different acoustic impedances in the subject and transmitted. It is received by the same transducer as and is received as an echo signal.

The amplifier 5 amplifies the echo signal to a predetermined level and sends the amplified signal to the reception delay circuit 6.
The reception delay circuit 6 receives a command from the system control circuit 7 which will be described later, and delays each of the vibrations so that the amplified reception signal received from the amplifier 6 is returned based on the delay time given by the transmission delay circuit 3. The signal is given to each child and the phase is adjusted. The adder circuit 9 adds and combines the received signals from the transducers that have passed through the reception delay circuit 6 and outputs the combined signal to the detection circuit 10.

Although not shown, the selection circuit 8 is provided with a selection switch. By switching the selection switch,
The operator inputs an instruction for selecting the linear scanning method or the sector scanning method, and the instruction is given to the system control circuit 7. In response to the instruction, the system control circuit 7 instructs the transmission delay circuit 3 and the reception delay circuit 6 to set the transmission / reception delay time according to the selected ultrasonic scanning method,
The transducer switching circuit 2 drives the transducers according to the selected ultrasonic scanning method, that is, all the transducers T1 to T14 in the linear scanning method, and the transducers T5 to T14 in the scanning method. T10 is instructed to be driven, and storage position information according to the selected ultrasonic scanning method is given to the digital scan converter 11 described later. Before and after the talk, in addition to the above instruction, the selection circuit 8 can input an instruction to synthesize and display a linear tomographic image obtained by the linear scanning method and a sector tomographic image obtained by the sector scanning method. is there. When the system control circuit 7 inputs the instruction for the composite display from the selection circuit 8, the image configuration instruction information is supplied to the digital scan converter 11 so as to synthesize the linear tomographic image and the sector tomographic image obtained at different times. give.

When the sector scanning method is selected in the selection circuit 8, the transducer group to be driven is set to the transducers T5 to T5.
Although it is assumed that the transducer group to be driven is set to 10 in advance, the operator may be allowed to appropriately designate the transducer group to be driven according to the aperture restriction of the diagnosis site or the like.

Although not shown, the detection circuit 10 includes a logarithmic amplifier, an envelope detection circuit, and an A / D converter,
The logarithmic amplifier logarithmically amplifies the combined signal received from the adder circuit 9, the envelope detection circuit detects the envelope of the signal, and the A / D converter converts the signal into a digital signal. As a result, an ultrasonic tomographic image (B-mode image) is obtained.

Digital scan converter 11
Under the control of the system control circuit 7, takes in an ultrasonic tomographic image of an ultrasonic scanning method of a linear scanning method or a sector scanning method received from the detection circuit 10, converts it into a television scanning method of the monitor 12, and outputs it to the monitor 12. Then, the monitor 12 displays the image after converting its output into an analog signal by a D / A converter (not shown).

Next, the operation of the apparatus of this embodiment configured as described above will be described. When the operator starts the operation of the apparatus of this embodiment in order to observe the ultrasonic tomographic image of the subject, along with that, the operator uses a scanning method of either a linear scanning method or a sector scanning method that is preset in advance. The sound wave transmission / reception operation is started. If this is a linear scanning method, the transmission delay circuit 3, the transducer switching circuit 2, the reception delay circuit 6 and the digital scan converter 11 operate under the instruction of the system control circuit 7 according to the linear scanning method. Then, a linear tomographic image TL having a rectangular display range as shown in FIG. 3 is displayed on the monitor 12. Here, a linear scan is performed when the diagnosis site is the chest (heart) and its opening is limited by ribs, when the depth of field is to be expanded, or when blood flow information is to be obtained by Doppler mode (not shown). When the system is not applicable or the linear scanning system is not suitable, the operator instructs the selection circuit 8 to switch the scanning system from the current linear scanning system to the sector scanning system. In response to the switching instruction, the transmission delay circuit 3, the transducer switching circuit 2, the reception delay circuit 6, and the digital scan converter 11 are operated under the instruction of the system control circuit 7 from the operation according to the current linear scanning method to the sector. The operation is switched to the scanning method, and the sector tomographic image TS having the rectangular display range as shown in FIG. 4 is displayed on the monitor 12. This allows
When the linear scanning method is not applicable or the linear scanning method is not suitable, the scanning method can be easily changed without replacing the ultrasonic probe. Of course, the same applies when the scanning method is returned from the current sector scanning method to the linear scanning method.

As described above, after the completion of the tomographic image acquisition according to each scanning method, the operator displays the composite image of the linear tomographic image TL and the sector tomographic image TS obtained by the operator through the selection circuit 8. If you give an instruction to
Under the control of the system control circuit 7, the scan converter 11 creates and displays the composite tomographic image ILS of the linear tomographic image TL and the sector tomographic image TS shown in FIG. The method of combining the linear tomographic image TL and the sector tomographic image TS is, for example,
The sector tomographic image TS is given priority, and the linear tomographic image TL is added to the sector tomographic image TS in order to supplement the part that cannot be displayed in the sector tomographic image TS with the linear tomographic image TL. By observing the composite tomographic image ILS, the operator can make a diagnosis with a wide field of view from a shallow portion to a deep portion near the body surface.

Next, a second embodiment will be described. The present embodiment relates to an ultrasonic probe having a good adaptability to the device of the first embodiment. Therefore, here, only the ultrasonic probe and a circuit whose function is changed to some extent in accordance with the change of the ultrasonic probe will be described, and description of other circuits will be omitted because they have already been described.
FIG. 6 is a diagram showing a transducer array of this ultrasonic probe. Here, the transducers compatible with the sector scanning method are generally set to have a smaller pitch than the transducers compatible with the linear scanning method. This is because in the case of the sector scanning method, the influence of the grating lobe increases with the deflection of the ultrasonic beam, and as a result, artifacts may increase, but by setting the array pitch of the transducers small, This is to increase the angle at which the lobe occurs, reduce its level, and reduce its effect. In view of this, the ultrasonic probe according to the present embodiment, as shown in FIG. 6, has a transducer group E to be driven when the sector scanning method is selected.
The pitch of each vibrator K1 to K12 of 1
The pitch is different from 1 to T4 and T11 to T14. Specifically, here, the pitch of the vibrators K1 to K11 is set to approximately 1 of the pitches P0 of the other vibrators T1 to T4 and T11 to T14.
/ 2. As a result, when the sector scanning method is selected, depending on the miniaturization of the pitch of the vibrators K1 to K12,
Artifacts caused by the influence of the grating lobe can be reduced. The oscillators K1 to K12
In accordance with the miniaturization of the pitch, the delay time information for each transducer of the transmission delay circuit 3 and the reception delay circuit 6, the aperture range information of the transducer switching circuit 2 and the storage position information of the digital scan converter 11 are set to the first value. Although different from the case of the first embodiment, if the changed data is provided in the system control circuit 7 in advance, it can be easily dealt with.

On the other hand, when the linear scanning method is selected, a predetermined number of miniaturized vibrators K1 to K12 are commonly connected according to the pitches of the other vibrators T1 to T4 and T11 to T14. The resonators connected in common shall operate in common. Here, since the pitches of the vibrators K1 to K12 are set to approximately half the pitch P0 of the other vibrators T1 to T4 and T11 to T14, the two adjacent vibrators K1 to K12 are Connect the oscillator, K1 and K2, K3 and K4, etc. in common. If the pitch ratio of both vibrators is set to about 1/3, the three adjacent vibrators will be commonly connected. With this common connection, even if the linear scanning method is selected, the ultrasonic beam width in the same tomographic image does not differ, and a linear tomographic image with a uniform scanning line width is obtained as in the case of the first embodiment. Can be obtained. In addition,
As means for achieving this common connection, a switch for turning on / off the connection relationship between the adjacent transducers that are commonly connected is provided in the ultrasonic probe, and the transducer switching circuit 2 uses the system control circuit 7 to set the linear scanning method. The switch is turned on to make a common connection when an instruction to the effect that the sector scanning method is applied is made, and the switch is turned off when an instruction to the effect that the sector scanning method is applied is set, and each transducer K1 to K12 is Each can be driven individually.

By connecting the ultrasonic probe as described above to the apparatus of the first embodiment, a high-quality sector tomographic image with few artifacts can be easily obtained, and scanning can be performed even when the linear scanning method is selected. A linear tomographic image with a uniform line width can be obtained. The ultrasonic probe according to the present embodiment is a linear probe in which a plurality of transducers are arranged side by side, but a convex probe as shown in FIG. 7 without changing the arrangement of the transducers, That is, a plurality of vibrators may be arranged side by side in an arc shape. This makes it possible to obtain the convex tomographic image IC shown in FIG. 8 in which the field width in the deep portion is expanded from the linear tomographic image, and the convex tomographic image IC and the sector shown in FIG. 9 obtained by switching the convex scanning to the sector scanning. The tomographic image Is can be combined in the same manner as in the first embodiment to obtain the combined tomographic image ICS. The specifications of the plurality of transducer arrays are not limited to the linear type and the convex type, and for example, as shown in FIG. 11, a transducer group with a small pitch to be driven in the sector scanning is provided. The central portion E3 is linear and both end portions E4 and E5 are convex, so that the shape can be appropriately changed.

Next, a third embodiment will be described. In the present embodiment, even when the opening is restricted by the diagnosis site, without changing the scanning method as in the above embodiment,
The present invention relates to an ultrasonic probe and an ultrasonic diagnostic apparatus main body for obtaining a tomographic image having a wide field of view from a shallow portion to a deep portion. FIG. 12 is a diagram showing a transducer array of the ultrasonic probe, and FIG. 13 is a diagram showing a tomographic image display range obtained by the ultrasonic probe. The configuration of the ultrasonic diagnostic apparatus main body according to the present embodiment is substantially the same as that of a normal ultrasonic diagnostic apparatus main body, and therefore is not illustrated and the functional differences will be described.

As shown in FIG. 12, the ultrasonic probe 15 has an opposite arrangement relationship between the ultrasonic probe 12 shown in FIG. 7 and a transducer group having a different pitch. That is, in the transducer array of the ultrasonic probe 15, a plurality of transducers T1 to T6 that always perform convex scanning are arrayed in the central portion E6, and both side portions E7 and E8 of the central portion E6 are selected. A plurality of transducers K1 to K8 and K9 to K16 for performing sector scanning are arranged. Pitch of vibrators T1 to T6 and vibrators K1 to K8
, K9 to K16, the pitches of the vibrators T1 to T6 are the pitch P0, and the pitches of the vibrators K1 to K8 and K9 are the same as in the second embodiment.
K16 is approximately 1/2 of the pitch P0. As a result, when sector scanning is performed on both side portions E7 and E8, it is possible to reduce the artifacts caused by the influence of the grating lobe, as in the second embodiment.
When the operator selects the convex scanning method, both side portions E7 and E7 are used as in the case of the second embodiment.
Two oscillators K1 to K8 and K9 to K16 are connected in common, and the pitch is the same as that of the oscillators T1 to T6 in the central portion E6, and all the oscillators K1 to K8, K9 to K16 and T1.
Using -T6, a convex tomographic image is obtained within the aperture range. Further, when the operator selects the sector scanning method, unlike the second embodiment, the vibrators to be driven during the convex scanning do not operate, and all the vibrators are driven. This is because when the sector scanning method is selected, sector scanning and convex scanning are used together. That is, when sector scanning is selected, convex scanning is performed in the central portion E6 and sector scanning is performed in both side portions E7 and E8.
This is because one convex tomographic image and two sector tomographic images obtained at each portion are combined to obtain a combined tomographic image. Note that the control operation for the transducer switching circuit 2, the transmission delay circuit 3, the reception delay circuit 6 and the digital scan converter 11 of the system control circuit 7 is different due to the combined use of the sector scanning and the convex scanning. The control operation will be described together with the following operation explanation.

The operation of the apparatus of this embodiment relating to the ultrasonic beam scanning method accompanying the creation of an ultrasonic tomographic image using the ultrasonic probe 15 according to this embodiment will be described. Regarding the operation when the convex scanning method is selected,
Since it is the same as the case of the second embodiment, its explanation is omitted.
Only the operation of the sector scanning method that uses both the sector scanning and the convex scanning after switching from the convex scanning method to the sector scanning method will be described.

The sector scanning system in this embodiment uses both sector scanning and convex scanning as described above. In the scanning order, the transducers K1 to K8 are driven in the end portion E7 while giving a predetermined delay time to scan the ultrasonic beam in a fan shape to obtain the first sector tomographic image IS1 shown in FIG. obtain.
At this time, the oscillator switching circuit 2 is controlled by the system control circuit 7 to turn only the oscillators K1 to K8 included in the one end portion E7 into the drive target, that is, the electrical connection relationship with the main body side. The obtained first sector tomographic image IS1 is stored in the digital scan converter 11 which is controlled by the system control circuit 7 and controls the storage position according to the ultrasonic scanning method.

When this sector scanning is completed, convex scanning is performed while moving the ultrasonic beam using the transducers T1 to T6 included in the central portion E6.
The convex tomographic image IL shown in FIG. 3 is obtained and stored in the digital scan converter 11 like the first sector tomographic image IS1. At this time, the oscillator switching circuit 2 receives the control of the system control circuit 7 and changes the oscillator group to be driven from the oscillators K1 to K8 included in the one end portion E7 to the oscillators T1 to T6 included in the central portion E6. In addition, the transmission delay circuit 3 and the reception delay circuit 6 also change the delay time according to the scanning method under the control thereof, and the convex scanning is performed while moving a predetermined number of simultaneous driving vibrators as in the normal convex scanning. To do. Under the control of the digital scan converter 11, the storage order is also changed according to the scanning method, and the convex tomographic image IL is stored next to the first sector tomographic image IS1 obtained previously.

Further, when this convex scanning is completed, the ultrasonic beams are driven by driving the transducers K9 to K16 in the other end portion E8 while giving the same delay time as in the sector scanning using the previous one end portion E7. The second sector tomographic image IS2 shown in FIG. 13 is obtained by scanning in a fan shape. At this time, the vibrator switching circuit 2 is controlled by the system control circuit 7 to turn on only the vibrators K9 to K16 included in the one end portion E8 as an object to be driven, that is, the electrical connection with the main body side. The obtained second sector tomographic image IS2
Is stored next to the convex tomographic image IL in the digital scan converter 11 under the control of the storage position according to the ultrasonic scanning system from the system control circuit 7, and a synthetic tomographic image ISCS is obtained. This synthetic tomographic image ISCS is
After being D / A converted on the monitor 12, it is provided for display. As described above, according to the present invention, it is possible to obtain a tomographic image having a wide field of view from a shallow portion to a deep portion even when the aperture restriction is unavoidable.

The present invention is not limited to the above embodiment, but can be modified in various ways. For example, the pitch of the transducer group that is the target of the sector scan is linear or approximately 1/2 of the pitch of the transducer group that is the target of the convex scan, but the ratio is not limited to approximately 1/2. Other ratios, for example, approximately 1/3 may be used. In this case,
The number of transducers commonly connected during linear or convex scanning may be changed according to the ratio. For example, when the ratio is approximately 1/3, three adjacent transducers may be commonly connected.

[0032]

As described above, according to the present invention, it is possible to obtain a tomographic image having a wide field of view from a shallow portion to a deep portion near the body surface, and when high Doppler mode sensitivity is required or acoustic It is possible to provide an ultrasonic probe that can immediately cope with the case where the opening width is limited.

[Brief description of drawings]

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

FIG. 2 is a diagram showing a transducer array of the ultrasonic probe shown in FIG.

FIG. 3 is a diagram showing a display range of a linear tomographic image obtained by the linear scanning when the selection circuit shown in FIG. 1 is operated to select the linear scanning.

FIG. 4 is a diagram showing a display range of a sector tomographic image obtained by the sector scanning when the selection circuit shown in FIG. 1 is operated to select the sector scanning.

5 is a diagram showing a display range of a combined tomographic image obtained by combining the tomographic images shown in FIGS. 3 and 4. FIG.

FIG. 6 is a diagram showing a transducer array in which the pitch of transducer groups of the ultrasonic probe used in the ultrasonic diagnostic apparatus according to the second embodiment is not constant.

7 is a diagram showing a transducer array when the transducer array of the ultrasonic probe shown in FIG. 6 is applied to a convex probe.

8 is a diagram showing a display range of a convex tomographic image obtained by the convex scanning when the convex scanning is selected using the convex probe shown in FIG.

9 is a diagram showing a display range of a sector tomographic image obtained by sector scanning when sector scanning is selected using the convex probe shown in FIG.

10 is a diagram showing a display range of a combined tomographic image obtained by combining the tomographic images shown in FIGS. 8 and 9. FIG.

FIG. 11 is a diagram showing a transducer array of another example of the ultrasonic probe used in the ultrasonic diagnostic apparatus according to the second embodiment.

FIG. 12 is a diagram showing an array of transducers of an ultrasonic probe used in the ultrasonic diagnostic apparatus according to the third embodiment.

FIG. 13 is a diagram showing a display range of a composite tomographic image obtained by the ultrasonic diagnostic apparatus according to the third embodiment.

[Explanation of symbols]

1 ... Ultrasonic probe, 2 ... Transducer, 3 ... Transmission delay circuit,
4 ... Oscillator, 5 ... Amplifier, 6 ... Reception delay circuit, 7 ... System control circuit, 8 ... Selection circuit, 9 ... Addition circuit, 10 ... Detection circuit, 11 ... Digital scan converter, 1
2 ... Monitor.

Claims (1)

[Claims] 1. An ultrasonic probe having a plurality of transducers provided side by side, a means for transmitting and receiving ultrasonic waves by driving each transducer of the ultrasonic probe according to a predetermined driving method, and transmission and reception of the transmitting and receiving means. An ultrasonic diagnostic apparatus comprising: a means for obtaining a tomographic image using a reception signal obtained by; and a means for instructing the transmitting / receiving means to change the predetermined driving method to another driving method. ..