JP2002253549A - Ultrasonic image pickup device and method, and probe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ultrasonic image pickup method, etc., capable providing a wide-range image in vi-vo without deteriorating a special resolution of the image. SOLUTION: A probe is separated into a sending probe 31 and a receiving probe 41, ultrasonic wave is sent to a subject by using the sending probe 31, an echo is received by the receiving probe 41 having a plurality of transducers disposed into a two-dimensional array, signals received by the transducers of the receiving probe 41 are amplified, and waveform data 18a of the subject is provided based on the signals. In this case, the relative positions of the both probes are detected using magnetic sensors 33 and 43. The waveform data is processed referring to the relative positions so as to provide image data, the image data is processed, and the echo is three-dimensionally imaged.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic imaging method and an ultrasonic imaging apparatus capable of obtaining organ and blood flow information in a living body. In particular, the present invention relates to an ultrasonic imaging method and an ultrasonic imaging apparatus capable of acquiring an image of a wide range in a body without deteriorating the spatial resolution of the image.

[0002]

2. Description of the Related Art An ultrasonic diagnostic apparatus for performing so-called ultrasonic echo observation or the like includes an ultrasonic sensor unit (probe) provided with a PZT.
Generally, a piezoelectric material represented by (lead zirconate titanate) is used. FIG. 4 is a diagram schematically showing the structure of a general probe currently used. FIG. 2A is an overall perspective view, and FIG. 2B is an enlarged perspective view showing an arrayed vibrator. The probe 301 in this figure has a thin box shape as a whole, and has an elongated rectangular probe surface 302.
The probe 302 is applied to the human body to emit ultrasonic waves, and receives ultrasonic echoes returned from the back of the human body. Probe 3
A cable 307 for transmitting an ultrasonic transmission / reception signal is connected to the upper side of FIG.

[0003] A comb-shaped arrayed oscillator 303 serving as an ultrasonic oscillator and a transducer is housed in a probe surface 302. The arrayed oscillator 303 is thin (for example, a thickness of 0.2 to
0.3mm) A number of slits 306 are formed in a PZT strip.
(For example, 0.1 mm in width) and a comb-shaped individual vibrator 3
05 (for example, 0.2 mm in width and 20 mm in length) are arranged in a large number (for example, 256 pieces). Note that such an ultrasonic probe and an ultrasonic diagnostic apparatus are described in detail in Toyo Shuppan “Ultrasonic Observation and Diagnosis Method” and in Medical and Dental Medicine “Basic Ultrasonic Medicine”.

[0004] In the field of ultrasonic diagnosis, collection of three-dimensional data is desired in order to obtain more detailed in-vivo information of a subject. In order to realize this, it is required that the ultrasonic detection unit (sensor) be formed into a two-dimensional array.

[0005] ULTRASONIC IMAGING 20, 1-15 (1998) states that "Progress in Two-
Dimensional Arrays for Real-Time Volumetric Imagin
g ". In this sentence, PZ
A probe having a two-dimensional array of T ultrasonic sensors (two-dimensional probe) is disclosed.

[0006]

At the time of actual diagnosis, the ultrasonic waves are strongly scattered so as to avoid bones and the like which are noise sources.
It is necessary to navigate the probe on the body surface. However, when the probe is made two-dimensional as described above, the size of the probe becomes large, and the position of the human body to which the probe is applied is easily restricted. In particular, when imaging the heart, it is a usual practice to touch the probe to the gap between the ribs. However, if the probe is large, it becomes more difficult to image the space between the ribs. On the other hand, if the number of elements is reduced to reduce the aperture of the two-dimensional probe for easy navigation, the spatial resolution of the image will be degraded, and the diagnostic performance will be reduced.

The present invention has been made in view of such a problem, and an ultrasonic imaging method and an ultrasonic imaging apparatus capable of acquiring an image of a wide range in a body without deteriorating the spatial resolution of the image. The purpose is to provide.

[0008]

In order to solve the above problems, an ultrasonic imaging apparatus according to the present invention comprises: a transmitting probe having a plurality of transducers for transmitting ultrasonic waves to a subject; A receiving probe having a plurality of transducers arranged in a two-dimensional array, which receives echoes generated by ultrasonic waves being reflected by the tissue of the subject,
Driving means for driving the transducer of the transmitting probe, and waveform processing means for amplifying a signal received by the transducer of the receiving probe and obtaining waveform data of the subject based on the signal. The transmitting probe and the receiving probe are separated from each other, and the apparatus further comprises means for detecting a relative positional relationship between the two probes.

By separating the probes, the size of the transmitting probe can be reduced. Therefore, by imaging a relatively small transmission probe by navigating, it is possible to image a wide area in the body. As a result, it is possible to perform imaging in the vicinity of the intercostal space, which has been conventionally difficult. Further, by providing a means for detecting the position of the probe, the relative position can be grasped even when the probe is separated into two parts.

[0010] In the ultrasonic imaging apparatus, it is preferable that the size of the opening of the receiving surface of the receiving probe (the surface to be applied to a human body) is about 100 mm x 100 mm or more. By increasing the opening of the receiving probe, more transducers can be arranged on the receiving probe, and the spatial resolution of the image can be improved.

In the ultrasonic imaging apparatus, it is preferable that a sensor is provided for each of the probes as a means for detecting a relative position of the probe, and the sensor is a magnetic sensor. By providing the probe with the sensor, the relative position can be grasped even when the probe is separated into two parts.

[0012] The ultrasonic imaging apparatus preferably includes image processing means for processing the waveform data with reference to the relative position to obtain image data. By combining a plurality of images having different transmission directions obtained by navigating the transmission probe, speckle can be reduced.

In the ultrasonic imaging apparatus, the transmitting probe is composed of a relatively small number of transducers, and a wide range of measurement can be performed by directing ultrasonic waves emitted from the transducers to a wide field of view. Can be.

In the ultrasonic imaging apparatus, the image data is processed to convert the echo into a three-dimensional image.
It is preferable to include a two-dimensional image forming unit. This makes it possible to convert the echo into a three-dimensional image.

In the ultrasonic imaging method of the present invention, an ultrasonic wave is transmitted to a subject, an echo generated by the transmitted ultrasonic wave being reflected on the tissue of the subject is received by a probe, and the received signal is An ultrasonic imaging method for obtaining image information of the subject based on the transmission probe, wherein the probe is separated into a transmission probe and a reception probe, and the transmission probe includes a plurality of transducers. Transmitting the ultrasonic wave to the subject using a probe, receiving the echo with a receiving probe having a plurality of transducers arranged in a two-dimensional array,
Amplify the signal received by the transducer of the receiving probe, obtain the waveform data of the subject based on the signal, detect the relative position of the two probes, refer to the relative position, The method is characterized in that the waveform data is processed to obtain image data, the image data is processed, and the echo is converted into a three-dimensional image.

A probe according to the present invention is a probe that transmits an ultrasonic wave to a subject and receives an echo generated when the transmitted ultrasonic wave is reflected by the tissue of the subject. A transmitting probe having a plurality of transducers for transmitting ultrasonic waves to the subject, and receiving an echo generated by reflecting the transmitted ultrasonic waves on the tissue of the subject;
And a receiving probe having a plurality of transducers arranged in a two-dimensional array. The two probes are provided with means for detecting a relative positional relationship between the two probes. It is characterized by the following.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. First, the transmission probe according to the embodiment of the present invention will be described in detail. FIG. 2 is a perspective view showing a schematic configuration of the transmission probe according to the embodiment of the present invention. The transmission probe 31 shown in FIG. 2 has a thin box shape as a whole, and has an elongated rectangular probe surface 34. The ultrasonic wave is radiated by applying the probe surface 34 to the human body. A cable 35 for transmitting an ultrasonic drive signal is connected to the upper side of the probe 31 in the drawing.

A comb-like arrayed oscillator 36, which is an ultrasonic oscillator, is housed in the probe surface 34. Array vibrator 3
Reference numeral 6 denotes a comb-shaped ultrasonic transducer 32 (for example, having a width of 0.1 mm) formed by inserting a number of slits 37 (for example, 0.1 mm in width) in a thin (for example, 0.2 to 0.3 mm thick) PZT strip. For example, 16 pieces (2 mm, length 20 mm) are arranged. In this embodiment, the number of the ultrasonic transducers 32 provided on the transmission probe 31 is very small, such as 16. However, by directing the ultrasonic beam from here to a wide field of view, a wide range of measurement is possible. Become.

Although not shown, electrodes are formed on each of the ultrasonic transducers 32 and signal lines are connected thereto. Although not shown in the drawing, an acoustic lens layer or a matching layer made of a resin material (including rubber) is attached to the front surface (the lower surface in the figure) of the ultrasonic transducer 32, and is attached to the back surface. Has a backing material attached. The acoustic lens layer improves the convergence of the oscillating ultrasonic waves. The matching layer increases the oscillation efficiency of the ultrasonic wave. The backing material has a function of holding the vibrator and ends vibration of the vibrator quickly.

The transmitting probe 31 is provided with a magnetic sensor 33 used for measuring the position of the probe. As the magnetic sensor 33, a hexagonal coil wound in a cube shape can be used. A signal line (not shown) is connected to the magnetic sensor 33, and a detection signal of a magnetic field is detected by the detection unit 5.
3 (see FIG. 1).

Next, the receiving probe according to the embodiment of the present invention will be described in detail. FIG. 3 is a perspective view showing a schematic configuration of the receiving probe according to the embodiment of the present invention. The receiving probe 41 shown in FIG. 3 has a substantially cubic box shape, and has a substantially square probe surface 44. The ultrasonic wave is received by contacting the probe surface 44 with the groin of the human body. The size of the opening of the probe surface 44 is 100 mm × 100
mm or more. A cable 45 for transmitting an ultrasonic reception signal is connected to the upper side of the probe 41 in the drawing.

In the probe surface 44, for example, a plurality of columnar ultrasonic transducers 42 are incorporated two-dimensionally. Although not shown in the figure, the ultrasonic transducer 42 has, for example, 256 lengths × 256 widths and a total of 655.
36 are arranged. Each ultrasonic transducer 42
, An electrode (not shown) is formed, and a signal line for transmitting a drive signal and received data is connected to the electrode. Although not shown, the ultrasonic transducer 4
An acoustic lens layer or a matching layer made of a resin-based material (including rubber) is adhered to the tip (the lower surface in the figure) of the second member, and a backing material is adhered to the electrode side. The acoustic lens layer improves the convergence of the oscillating ultrasonic waves. The matching layer increases the oscillation efficiency of the ultrasonic wave. The backing material has a function of holding the vibrator and ends vibration of the vibrator quickly.

The receiving probe 41 is provided with a magnetic sensor 43 used for measuring the position of the probe. As the magnetic sensor 43, a hexagonal coil wound in a cube shape can be used. A signal line (not shown) is connected to the magnetic sensor 43, and transmits a drive signal of the magnetic sensor from the drive circuit 52 (see FIG. 1) to the magnetic sensor 43.

Next, an ultrasonic imaging apparatus according to an embodiment of the present invention will be described. FIG. 1 is a system diagram showing a main configuration of an ultrasonic imaging apparatus according to an embodiment of the present invention. The ultrasonic imaging apparatus is used, for example, as an ultrasonic diagnostic apparatus for examining a human body or the like or an industrial flaw detector.

The ultrasonic imaging apparatus shown in FIG. 1 comprises the following main parts. (1) A small transmitting probe 31 (see FIG. 2) (2) A relatively large receiving probe 41 (see FIG. 3) (3) A system control unit that controls the entire system of the ultrasonic imaging apparatus 14 (4) Waveform processing unit 1 for processing the waveform of the received ultrasonic wave
8 (5) Coordinate measuring unit 51 for calculating the position of the probe from the sensor of the probe (6) Image processing unit 23 for performing image processing of waveform-processed data from the ultrasonic data and the position of the probe

The transmission probe 31 is relatively small.
Navigation between the ribs on the body surface of the subject is facilitated. The transmission probe 31 is provided with an ultrasonic transducer 32 having an ultrasonic transmission function. As the ultrasonic transducer 32, for example, a piezoelectric element made of PZT or PVDF can be used.
The transmission probe 31 is provided with a magnetic sensor 33 used for measuring the probe position.

The plurality of ultrasonic transducers 32 are driven and vibrated by drive signals input from a corresponding plurality of pulse generating circuits (pulsars) 12, and transmit ultrasonic pulses to the subject. The plurality of pulsars 12 excite based on the output signals of the corresponding plurality of digital delay devices 13 and output drive signals. As these pulsers, high-speed pulsers that can output drive signals at a high repetition cycle are preferable.

A system control unit 14 for controlling the entire system of the ultrasonic imaging apparatus controls delay times in the plurality of digital delay units 13. With this control, ultrasonic pulses having a phase difference corresponding to the time difference between these drive signals are transmitted from the plurality of ultrasonic transducers 32 to the subject, and a sound ray formed by combining these ultrasonic pulses is desired. In this direction.

The receiving probe 41 is relatively large.
It is placed on the groin, etc. on the body surface of the subject. The receiving probe 41 is provided with a plurality of two-dimensionally assembled ultrasonic transducers 42 having an ultrasonic receiving function. As the ultrasonic transducer 42, for example, a piezoelectric element made of PZT or PVDF, or an optical sensor can be used. Receiving probe 4
1 also includes a magnetic sensor 43 used for measuring the probe position.

The receiving probe 41 receives an ultrasonic pulse echo in which the ultrasonic wave emitted from the transmitting probe 31 is reflected by the subject. When the receiving probe 41 receives an ultrasonic pulse from the subject, detection signals are output from the plurality of ultrasonic transducers 42. This detection signal is input to the waveform processing unit 18.

A plurality of preamplifiers 15 corresponding to a plurality of ultrasonic transducers 42 and a TG
A C (Time Gain Compensation) amplifier 16 and an A / D converter 17 are arranged. The detection signals output from the plurality of ultrasonic transducers 42 correspond to the plurality of preamplifiers 1 corresponding thereto.
5 and the TGC amplifier 16 perform analog processing. By this analog processing, the levels of these detection signals are matched with the input signal levels of the A / D converter 17. Analog signals output from the plurality of TGC amplifiers 16 are digitized by the plurality of A / D converters 17 under the control of the system control unit 14. The waveform data 18a output from the waveform processing unit 18 is stored in the memory 24 arranged in the image processing unit 23.

The magnetic sensor 33 of the transmitting probe 31 and the magnetic sensor 43 of the receiving probe 41 are connected to a coordinate measuring unit 51. The coordinate measuring unit 51 includes a magnetic sensor 43.
Is provided with a drive circuit 52 for transmitting a drive signal, and is connected to the magnetic sensor 43 of the receiving probe 41. The coordinate measuring unit 51 is also provided with a detecting unit 53 that detects magnetism from the magnetic sensor 33, and is connected to the magnetic sensor 33 of the transmission probe 31. The drive circuit 52 and the detection unit 53 are connected to a position calculation unit 54 that calculates a relative position of the probe.

Here, a method for detecting the relative position of the probe will be described. First, when a drive signal is transmitted from the drive circuit 52, a uniform magnetic field is generated from the magnetic sensor 43. At this time, the magnetic sensor 43 functions as a magnetic source. When a magnetic field is generated, this magnetic field is
To detect. At this time, the magnetic sensor 33 functions as a magnetic sensing unit. The position calculator 54 calculates the relative position coordinates (x, y, z) and the relative inclination angles (azimuth angle ψ, elevation angle θ, rollover angle φ) of the detected magnetic field. The position data 51a output from the coordinate measuring unit 51 is stored in the memory 24 arranged in the image processing unit 23.

When the waveform data 18a and the position data 51a are stored in the memory 24 at the time of imaging, the image processing unit 2
In 3, the image processing is performed by synchronizing the two as follows.

The waveform data 18a output from the plurality of A / D converters 17 is input in parallel to a digital beamformer arranged in the data processing unit 25. The digital beamformer is provided with a plurality of phase adjusters corresponding to each of the plurality of ultrasonic transducers. Each phase adjuster gives a desired delay to the waveform data 18a while synchronizing with the position data 51a by a shift register delay line, a digital minute delay, software, or a combination thereof. The outputs of these phase adjustment units are digitally added by a digital adder, so that a plurality of waveform data 1 obtained using a series of ultrasonic transducers 42 included in the probe 41 are obtained.
The phase matching at 8a is performed. Data processing unit 25
In, detection of a detected waveform, conversion into image data, and predetermined image processing are performed. Through these processes, tomographic data of the subject is obtained, and the data is stored in the memory 24 as needed.

Further, DSC (Digital Scan Converto)
The image data in the sound ray data space is converted into image data in the physical space by performing a scan format conversion in the (r: digital scan converter) 26. still,
When displaying a three-dimensional image, the memory 24 and the DSC
26, a three-dimensional image forming unit 27 may be incorporated. The three-dimensional image forming unit 27 generates voxel data, which is data on a certain volume, from a plurality of pieces of tomographic data stored in the memory 24. DSC
The image data whose scanning format has been converted by 26 is converted into an analog signal by a D / A converter 28 and displayed on an image display unit 29.

The ultrasonic imaging method according to the embodiment of the present invention has been described with reference to FIGS.
The present invention is not limited to this, and various modifications can be made.

[0038]

As is apparent from the above description, according to the present invention, an image of a wide range in the body can be obtained without deteriorating the spatial resolution of the image.

[Brief description of the drawings]

FIG. 1 is a system diagram showing a main configuration of an ultrasonic imaging apparatus according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing a schematic configuration of a transmission probe according to the embodiment of the present invention.

FIG. 3 is a perspective view showing a schematic configuration of a receiving probe according to the embodiment of the present invention.

FIG. 4 is a diagram schematically showing the structure of a general probe currently used. FIG. 2A is an overall perspective view, and FIG. 2B is an enlarged perspective view showing an arrayed vibrator.

[Explanation of symbols]

 Reference Signs List 12 pulse generating circuit 13 digital delay unit 14 system control unit 15 amplifier 16 TGC amplifier 17 A / D converter 18 waveform processing unit 18a waveform data 23 image processing unit 24 memory 25 data processing unit 26 DSC 28 D / A converter 29 image Display unit 31 Transmitting probe 32 Ultrasonic transducer 33 Magnetic sensor 41 Receiving probe 42 Ultrasonic transducer 43 Magnetic sensor 51 Coordinate measuring unit 51a Position data 52 Drive circuit 53 Detecting unit 54 Position calculating unit

Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat II (reference) H04N 7/18 F term (reference) 4C301 AA03 AA04 BB23 EE02 EE09 GB04 GB09 GD02 GD16 KK16 5C024 AX09 EX06 EX22 EX45 HX57 5C054 CA08 FD01 GA04 GB01 HA12 5J083 AA02 AB17 AC28 AC31 AD04 AE10 BC02 BE49 CA02 CA12 CA20 CA24 CB03 EA18

Claims (8)

[Claims] A transmitting probe having a plurality of transducers for transmitting ultrasonic waves to a subject; and a two-dimensional array for receiving an echo generated by reflecting the transmitted ultrasonic waves on the tissue of the subject. A receiving probe having a plurality of transducers arranged in a shape, driving means for driving the transducer of the transmitting probe, amplifying a signal received by the transducer of the receiving probe, and Waveform processing means for obtaining waveform data of a subject based on the transmission probe and the reception probe are separated, and a means for detecting a relative positional relationship between the two probes An ultrasonic imaging apparatus, further comprising: 2. The ultrasonic imaging apparatus according to claim 1, wherein the size of the opening of the receiving surface of the receiving probe (surface applied to a human body) is about 100 mm × 100 mm or more. . 3. A sensor is provided for each of the probes as a means for detecting the relative position of the probe, and the sensors are magnetic sensors.
An ultrasonic imaging apparatus according to claim 1. 4. The image processing apparatus according to claim 1, further comprising image processing means for processing the waveform data with reference to the relative position to obtain image data. Ultrasonic imaging device. 5. The transmission probe comprises a relatively small number of transducers, and measures a wide range by directing ultrasonic waves emitted from the transducers to a wide field of view. The ultrasonic imaging apparatus according to any one of claims 1 to 4. 6. The apparatus according to claim 1, further comprising a three-dimensional image forming unit that processes the image data and converts the echo into a three-dimensional image.
Item 7. The ultrasonic imaging apparatus according to Item 1. 7. An ultrasonic wave is transmitted to a subject, an echo generated when the transmitted ultrasonic wave is reflected by the tissue of the subject is received by a probe, and an image of the subject is formed based on the received signal. An ultrasonic imaging method for obtaining information, wherein the probe is separated into a transmission probe and a reception probe, and the ultrasonic wave is transmitted using a transmission probe having a plurality of transducers. To the subject, receiving the echo with a receiving probe having a plurality of transducers arranged in a two-dimensional array, amplifying a signal received by the transducer of the receiving probe, Obtaining waveform data of the subject based on the signal, detecting a relative position of the two probes, referring to the relative position, processing the waveform data, obtaining image data, and processing the image data. And the three-dimensional image An ultrasonic imaging method characterized by characterized by reduction. 8. A probe that transmits an ultrasonic wave to a subject and receives an echo generated when the transmitted ultrasonic wave is reflected on the tissue of the subject, wherein the probe transmits the ultrasonic wave to the subject. A transmitting probe having a plurality of transducers for transmitting to the subject, and a plurality of transducers arranged in a two-dimensional array for receiving echoes generated by reflecting the transmitted ultrasonic waves on the tissue of the subject And a receiving probe having: (a) a means for detecting a relative positional relationship between the two probes;