JP2015154815A - Subject information acquisition apparatus and method of controlling the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a subject information acquisition apparatus capable of performing aperture synthesis with high accuracy even when the number of channels of a transmission/reception circuit is small.

SOLUTION: A subject information acquisition apparatus 1 comprises: a probe 2 which sends an acoustic wave to a subject E by an opening composed of a plurality of elements, and performs electronic scan by receiving a reflection wave of the acoustic wave within the subject and outputting a reception signal; a processing unit 5 which acquires characteristic information within the subject E by using the reception signal; and a scanning unit 60 which moves the position of the probe 2 with respect to the object E in a first direction and a second direction crossing the first direction. The probe 2 performs the electronic scan while moving in the first direction. The scanning unit 60 moves the probe 2 in the same direction as the first direction plural times. The processing unit 5 acquires the characteristic information by aperture synthesis using the reception signal obtained by the electronic scan in the plurality of movements in the same direction.

COPYRIGHT: (C)2015,JPO&INPIT

Description

  The present invention relates to a subject information acquisition apparatus and a control method thereof.

  2. Description of the Related Art Conventionally, an ultrasonic echo diagnostic apparatus that acquires information inside a subject such as a living body by transmitting and receiving acoustic waves has been proposed. Patent Document 1 discloses a medical imaging apparatus that acquires a B-mode image by scanning a probe in a state in which a subject is compressed with two compression plates. Further, Patent Document 2 discloses a medical imaging apparatus that acquires a B-mode image by widening an opening with a small-sized transmission / reception circuit.

JP 2009-028366 A JP 2003-319938 A

  In the mechanical imaging method disclosed in Patent Document 1, the resolution of the B-mode image is limited to the number of channels of the transmission / reception circuit. Patent Document 2 discloses a technique for improving the resolution of a B-mode image by aperture synthesis even when the number of channels of a transmission / reception circuit is small. However, there is a problem that it is difficult to align the apertures during aperture synthesis.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a subject information acquisition apparatus that can perform aperture synthesis with high accuracy even when the number of channels of a transmission / reception circuit is small.

The present invention employs the following configuration. That is,
A probe that transmits an acoustic wave to an object through an opening formed of a plurality of elements, receives a reflected wave of the acoustic wave in the object, outputs a reception signal, and performs electronic scanning;
A processing unit for acquiring characteristic information in the subject using the received signal;
A scanning unit that moves a position of the probe with respect to the subject in a first direction and a second direction that intersects the first direction;
Have
The probe performs the electronic scanning while moving in the first direction;
The scanning unit moves the probe a plurality of times in the same direction in the first direction,
The processing unit is an object information acquisition apparatus that acquires the characteristic information by aperture synthesis using a reception signal obtained by the electronic scanning in the plurality of movements in the same direction.

The present invention also employs the following configuration. That is,
A probe that transmits an acoustic wave to an object through an opening formed of a plurality of elements, receives a reflected wave of the acoustic wave in the object, outputs a reception signal, and performs electronic scanning;
A processing unit for acquiring characteristic information in the subject using the received signal;
A scanning unit that moves a position of the probe with respect to the subject in a first direction and a second direction that intersects the first direction;
A method for controlling a subject information acquisition apparatus comprising:
The probe performing the electronic scanning while moving in the first direction;
The scanning unit moving the probe a plurality of times in the same direction in the first direction;
The processing unit obtains the characteristic information by aperture synthesis using the received signal obtained by the electronic scanning in a plurality of movements in the same direction;
A control method for a subject information acquiring apparatus.

  According to the subject information acquiring apparatus according to the present invention, aperture synthesis can be performed with high accuracy even when the number of channels of the transmission / reception circuit is small.

The figure which shows the structure of the subject information acquisition apparatus. The figure which shows the imaging condition of a probe. The figure which shows an ultrasonic scanning line in the case of scanning while a probe moves. The figure which shows opening synthetic | combination operation | movement. FIG. 4 is another diagram showing an aperture synthesis operation. FIG. 4 is another diagram showing an aperture synthesis operation. FIG. 4 is another diagram showing an aperture synthesis operation. FIG. 4 is another diagram showing an aperture synthesis operation. The figure which shows the movement of the probe for opening synthetic | combination operation | movement. The figure which shows the ultrasonic beam used for opening synthetic | combination operation | movement. The figure which shows the movement of the probe for opening synthetic | combination operation | movement. The figure which shows the position of the element in opening synthetic | combination operation | movement. The figure which shows the movement of the probe for opening synthetic | combination operation | movement. The figure which shows the position of the element in opening synthetic | combination operation | movement. FIG. 10 is a diagram illustrating movement of a probe for aperture synthesis operation according to the second embodiment. FIG. 10 is a diagram illustrating movement of a probe for aperture synthesis operation according to the third embodiment. FIG. 9 is a diagram showing an ultrasonic beam used for aperture synthesis operation according to the third embodiment. The figure which shows opening synthetic | combination operation | movement according to the number of elements. FIG. 6 is another diagram showing an aperture synthesis operation according to the number of elements. FIG. 6 is another diagram showing an aperture synthesis operation according to the number of elements.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. However, the dimensions, materials, shapes, and relative arrangements of the components described below should be changed as appropriate according to the configuration of the apparatus to which the invention is applied and various conditions. It is not intended to limit the following description.

  The subject information acquisition / reception device of the present invention includes an ultrasound imaging device that transmits an acoustic wave such as an ultrasonic wave to the subject and receives a reflected wave (ultrasonic echo) reflected and propagated inside the subject. The subject information acquisition apparatus acquires characteristic information in the subject using the ultrasonic echo described above. The characteristic information is information that reflects the difference in acoustic impedance of the tissue inside the subject.

  In the following description, an imaging apparatus that generates and displays image data based on the acquired characteristic information will be described. However, the apparatus according to the present invention is not necessarily required to display the characteristic information, and may be stored as usable data.

The ultrasonic wave referred to in the present invention is a typical acoustic wave, and the wavelength and the like are not particularly limited. The ultrasonic wave in the following description includes elastic waves called sound waves and acoustic waves. An analog electric signal converted from an acoustic wave by a probe or a digital electric signal after AD conversion is also called an acoustic signal.

  Hereinafter, the present invention will be described in detail with reference to the drawings. The present invention can also be understood as an operation method and a control method of a subject information acquisition apparatus. The present invention can also be understood as a program for causing an information processing apparatus or the like to execute an operation method or a control method.

<First Embodiment>
FIG. 1 shows a configuration of a subject information acquisition apparatus 1 according to the first embodiment.
The subject information acquisition apparatus 1 in FIG. 1 includes a probe (probe) 2, a signal processing unit 5, an image display unit 7, a control CPU 10, an ultrasonic transmission unit 11, and a mechanical scanning mechanism 60 as a scanning unit. The signal processing unit 5 may be built in the probe 2.

The ultrasonic transmission unit 11 generates an ultrasonic waveform to be transmitted to the subject E under the control of the control CPU 10 or the like. The ultrasonic transmission unit 11 includes a memory that stores ultrasonic transmission waveform data according to the control of the control CPU 10 and the like, a waveform data reading circuit that reads waveform data from the memory, and a pulser that outputs an electric transmission waveform based on the waveform data Etc. (not shown).
The probe 2 includes a plurality of ultrasonic elements (also simply referred to as elements). Then, the plurality of ultrasonic elements provided in the probe 2 receive the reflected ultrasonic waves transmitted to the subject E and convert them into analog electrical signals.

  Next, in the signal processing unit 5, the analog electric signal output from the ultrasonic element is converted into a digital electric signal by an AD converter (not shown) in the signal processing unit 5. Then, the signal processing unit 5 performs processing such as phasing addition, filter processing, logarithmic compression, envelope detection, and the like on the digital electric signal. Next, the signal processing unit 5 performs processing necessary for image generation on the reception signal that has been subjected to the above processing, and generates ultrasonic image data.

Note that the order of signal processing performed by the signal processing unit 5 is not limited to the order of this embodiment. For example, digital conversion can be performed after analog processing such as phasing addition, filter processing, logarithmic compression, envelope detection, and the like. In addition, a series of processing such as phasing addition, filter processing, logarithmic compression, and envelope detection may be performed first using an analog signal and may be performed using data obtained by digital conversion from a certain processing.
The signal processing unit 5 is configured by a CPU, GPU, DSP, and other hardware, and a phasing addition process or an arbitrary algorithm can be applied. As an algorithm other than the phasing addition, for example, a back projection method in a time domain or a Fourier domain usually used in the tomography technique can be cited.

An ultrasonic image is displayed on the image display unit 7 based on the image data generated by the signal processing unit 5.
The control CPU 10 supplies data and control signals necessary for controlling each block.

  FIG. 2A shows an imaging state of the probe 112 for acquiring ultrasound in the subject information acquiring apparatus of the present invention. The ultrasound acquisition probe 112 moves in the vicinity of the holding plate 101 </ b> A that holds the subject 100 in the X direction and the Y direction that intersects (typically orthogonal) the X direction and propagates from the subject 100. Acquire ultrasonic waves at each moved position.

A specific operation will be described. First, the ultrasonic wave acquisition probe 112 receives ultrasonic waves while moving the row A portion on the holding plate 101A in the Y direction (main scanning direction). This ultrasonic wave is reflected inside the subject after being transmitted by the probe. At this time, if the width of the probe in the element arrangement direction is equal to or larger than the width of the column A, the reception signal can be acquired from the region of the column A by one scan. On the other hand, if the width of the probe is smaller than the width of the region, aperture synthesis is preferable.

The Y direction corresponds to the first direction of the present invention, and the X direction corresponds to the second direction of the present invention. Here, the direction includes two directions that can be formed on a substantially straight line. That is, the first direction includes a first direction and a second direction opposite to the first direction. The region on the subject is divided in the X direction (second direction) to form a plurality of rows.
In addition, when the subject information acquisition apparatus of the present invention has a function of receiving the photoacoustic wave generated by the photoacoustic effect and acquiring the optical characteristic information, in parallel with the reception of the ultrasonic echo, the light irradiation Receive photoacoustic waves.

  Subsequently, the probe 112 for acquiring ultrasound moves to the row B by moving in the X direction (sub-scanning direction) on the holding plate 101A. Then, ultrasonic waves are received while scanning row B. By repeating such an operation, all the rows A, B, C, and D are imaged.

  As a result of imaging, 3D volume image data of the holding plates 101A and 101B and the subject 101 is obtained with respect to the ultrasonic waves. When the object information acquisition apparatus also serves as a photoacoustic apparatus, 3D volume image data for photoacoustic waves is also obtained. As a result, the user (examiner such as a doctor) can check the 3D volume image data in an arbitrary cross section. In FIG. 2A, four rows are shown, but the number of rows can be changed as appropriate depending on the size of the probe 112, the size of the holding plate 101A, and the area to be imaged.

  FIG. 2A shows the state where the probe 112 for acquiring ultrasound moves in both the X and Y directions, but it does not necessarily need to move in both the X and Y directions. Even if the probe 112 for acquiring ultrasonic waves can move in both XY directions, it may move only in the Y direction. Alternatively, there may be only a moving means in one axial direction in the first place.

  FIG. 2B is a view for explaining electronic scanning by the ultrasonic probe 112 according to the embodiment of the present invention. In FIG. 2, the X axis is in the array direction (the direction in which the elements are arranged), the Z axis is in the ultrasonic beam transmission / reception direction (the depth direction of the ultrasonic scanning line), and the Y axis is in the direction perpendicular to the XZ plane. Stipulate. N lines extending from the ultrasonic element along the Z axis represent the ultrasonic beam 11. In addition, a surface on which electronic scanning is actually performed (a surface surrounded by a broken line (YZ plane) in FIG. 2B) is defined as an electronic scanning surface 12.

  The ultrasonic probe performs electronic scanning by transmitting and receiving an ultrasonic beam while sequentially changing from 1 to N. When the transmission / reception of the Nth ultrasonic beam is completed, the transmission / reception of the ultrasonic beam is repeated again from the first to the Nth. That is, transmission / reception of an ultrasonic beam is performed in order from one end of the ultrasonic probe to the other end. However, the transmission / reception of the ultrasonic beam is not necessarily performed in order from one end of the ultrasonic probe to the other end, and may be appropriately changed (not shown). The transmission aperture and the reception aperture are configured by at least a part of the ultrasonic element included in the probe. In the following example, the transmission aperture and the reception aperture match to constitute a transmission / reception aperture.

  The signal processing unit 5 generates multi-section tomographic image data based on an ultrasonic reception signal obtained by transmitting and receiving an ultrasonic beam. If necessary, rendering is performed on a set of multi-sectional tomographic image data, and various pseudo three-dimensional image data such as a maximum value projection image and a surface (surface) image are generated.

FIG. 3A shows the position of the ultrasound scanning line when the ultrasound probe 112 scans the main scanning direction to the right in a certain XY plane. FIG. 3B shows the position of the ultrasonic scanning line when the ultrasonic probe 112 scans leftward.
As shown in FIGS. 3A and 3B, the ultrasound probe 112 moves in a direction (Y axis) orthogonal to the array direction (X axis). The circles shown in FIGS. 3A and 3B indicate the ultrasonic scanning lines 13. The position of the ultrasonic scanning line 13 corresponds to the position of the ultrasonic scanning line signal related to the ultrasonic scanning line 13.

In the present invention, when a wide range is imaged by mechanical scanning, electronic scanning is performed while continuously moving the probe. Accordingly, the line connecting the positions of the ultrasonic beams when acquiring one tomographic image (the line connecting 1 to N in the figure) does not coincide with the arrangement direction of the elements, and mechanical scanning and electrical scanning are performed. It has a slope according to the speed. When one electronic scan is completed, the next electronic scan is performed again from the original position (the reference numeral 1 side of the probe). As is apparent from the figure, if the mechanical scanning is at a constant speed and the electronic scanning starts from the same side (1 in this figure), the inclination angle becomes a line target in the forward path and the backward path.
In the following description, the case where the mechanical scanning speed in the main scanning direction is constant will be considered. However, the present invention can be applied even when the speed fluctuates.

  4A to 4E are views for explaining the aperture synthesis processing of the present invention. Here, an example in which two openings with the number of elements (L / 2) are combined to form an opening with the number of elements L in the linear array is taken as an example, but the number of openings to be combined may be three or more. The type of array is not limited to a linear array or a one-dimensional array. Furthermore, it is not necessary that the number of elements of the apertures to be combined is the same.

  FIG. 4A shows an ultrasonic transmission operation of one of the two openings that perform aperture synthesis. In the ultrasonic transmission unit 11, pulsars 11-1 to 11- (L / 2) exist. Therefore, the number of channels for ultrasonic transmission is (L / 2). In one ultrasonic transmission, (L / 2) elements are selected from the ultrasonic elements 20 of the probe 2 and connected to each pulser. For example, in FIG. 4A, the ultrasonic elements 20-K to 20- (K + L / 2-1) are selected.

  When each pulser outputs a transmission waveform, the ultrasonic element of the probe (probe) 2 connected to each pulser transmits the ultrasonic wave toward the subject E. At this time, by sequentially changing the delay shape, different ultrasonic scanning lines are formed. The pulsars 11-1 to 11- (L / 2) in the ultrasonic transmission unit 11 may be replaced with an arbitrary waveform generator so that an arbitrary waveform can be output.

  FIG. 4B shows an ultrasonic reception operation of one of the two openings that perform aperture synthesis. The reflected wave from the subject E of the ultrasonic wave transmitted in FIG. 4A is received by the ultrasonic elements 20-K to 20- (K + L / 2-1) of the probe (probe) 2 and converted into an electric signal. Is done. The electric signal is converted into digital data by the AD converters 27-1 to 27-(L / 2) in the signal processing unit 5.

  The received signal converted into digital data by the AD converters 27-1 to 27-(L / 2) in the signal processing unit 5 is phased in the signal processing unit 5 based on delay information corresponding to one of the openings. The phasing addition data A is generated by the addition. In this case, the obtained scanning line is the scanning line 17-A-B (A is 1) formed between the ultrasonic element 20- (K + L / 2-1) and the ultrasonic element 20- (K + L / 2). -J and B shall be 1-N).

  FIG. 4C shows an ultrasonic transmission operation of the other opening of the two openings that perform aperture synthesis. The pulsars 11-1 to 11- (L / 2) in the ultrasonic transmitter 11 are connected to the ultrasonic elements 20- (K + L / 2) to 20- (K + L-1). Each element to which a transmission waveform is input from each pulser transmits an ultrasonic wave toward the subject E.

  FIG. 4D shows an ultrasonic wave reception operation of the other opening of the two openings that perform aperture synthesis. The reflected wave from the subject E of the ultrasonic wave transmitted in FIG. 4C is received by the ultrasonic elements 20- (K + L / 2) to 20- (K + L-1) and converted into electric signals. The electric signal is converted into digital data by AD converters 27-1 to 27-(L / 2) in the signal processing unit 5.

  The received signal converted into digital data by the AD converters 27-1 to 27-(L / 2) in the signal processing unit 5 is adjusted in the signal processing unit 5 based on delay information corresponding to the other opening. Phase addition is performed, and phasing addition data B is generated. In this case, the obtained scanning line is a scanning line 18-A-B (A is 1) formed between the ultrasonic element 20- (K + L / 2-1) and the ultrasonic element 20- (K + L / 2). -J and B shall be 1-N).

  Finally, the phasing addition data A corresponding to the scanning line 17-A-B and the phasing addition data B corresponding to the scanning line 18-A-B are added in the signal processing unit 5. Then, the phasing addition data which transmitted / received by the opening for L element of ultrasonic element 20-K-20- (K + L-1) virtually is obtained like FIG. 4E. In this case, the obtained scanning line is the scanning line 19 formed between the ultrasonic element 20- (K + L / 2-1) and the ultrasonic element 20- (K + L / 2).

  In the above description, the number of channels of the pulser and the AD converter is small with respect to the elements, and element selection and connection change are performed. However, in actual aperture synthesis, it is only necessary to have data obtained by ultrasonic beam formation at different positions. For example, the probe may be moved to each opening, and data may be obtained using the same element group at each opening position.

FIG. 5 to FIG. 10 are diagrams for explaining an operation mode in which aperture synthesis processing is performed by mechanically scanning a probe in the subject information acquiring apparatus of the present invention.
FIG. 5 is a schematic diagram for obtaining image data (characteristic information) of one column by performing aperture synthesis based on the results of two scans. When acquiring data for one opening (first time) and when acquiring data for the other opening (second time), scanning is performed in the same direction. Note that the number of scans may be a plurality of movements of three times or more instead of two.

  FIG. 6A shows the first scanning in the same direction, and FIG. 6B shows the second scanning. As shown here, the positions of the ultrasonic scanning lines are aligned between one opening and the other opening. For example, the position of the scanning line 17-1-1 when acquiring data for one aperture and the position of the scanning line 18-1-1 when acquiring data for the other aperture are the same. Thus, the scanning lines 17-A-B (A is 1 to J, B is 1 to N) and the scanning lines 18-A-B (A is 1 to J, B is 1 to N) are aligned and opened. Since data can be acquired, aperture synthesis processing can be performed with high accuracy.

  According to the object information acquiring apparatus according to the present embodiment, the position of acquiring the data for aperture synthesis is controlled by the mechanical scanning mechanism 60. Therefore, a plurality of aperture positions, that is, the positions of the scanning lines obtained at the respective apertures can be set to desired positions with high accuracy, and aperture synthesis processing with high accuracy is possible. The direction of mechanical scanning is not necessarily limited to the direction in which the Y-axis value increases, but may be the direction in which the Y-axis value decreases.

  There may also be variations in the arrangement of element arrays during imaging for aperture synthesis. First, as shown in FIG. 7, the number of elements of the element array 201 is 2 in addition to the imaging width of one column corresponding to the number of elements F, and the number of arrays (L / 2) of one aperture of the aperture synthesis. This is the case of double, that is, {F + 2 × (L / 2)}.

FIG. 8A shows the position of the element array 201 with respect to the imaging range of one column in the first scanning in the same direction. FIG. 8B shows the position of the element array 201 with respect to the imaging range of one column in the second scanning. In this case, as shown in FIGS. 8A and 8B, the position of the element array 201 may be the same as the imaging width in the first time and the second time.

  Another variation is that, as shown in FIG. 9, in addition to the imaging width of one column corresponding to the number of elements F, the number of elements in the element array 201 is the number of arrays of one aperture in the aperture synthesis (L / 2). That is, the case of (F + L / 2).

  FIG. 10A shows the position of the element array 201 with respect to the imaging range of one column in the first scanning in the same direction. FIG. 10B shows a position with respect to the imaging range of one column of the element array 201 in the second scanning. In this case, as shown in FIGS. 10A and 10B, the number of elements F can be increased by changing the physical position of the element array 201 in the first and second scans in the same direction. It is possible to acquire a data group of scanning lines necessary for aperture synthesis of the corresponding imaging width of one column. Therefore, in order to perform aperture synthesis of this embodiment, it is desirable that the number of elements in the element array 201 is at least (F + L / 2).

The number of elements in the element array 201 may be less than (F + L / 2). However, in that case, the scanning line data acquired at the end of the array is transmitted and received with fewer elements than N, and the scanning line data is deteriorated.
The number of elements in the element array 201 may be larger than {F + (2 × L / 2)}. In that case, the physical position of the element array 201 and the position of the scanning line to be acquired may be appropriately adjusted so that desired aperture synthesis can be performed.

  As described above, according to the subject information acquiring apparatus according to the present embodiment, the scanning line positions at the time of acquiring a plurality of aperture data can be aligned by using the mechanical scanning of the probe in the aperture synthesis process. As a result, the accuracy of aperture synthesis processing is improved, so that the image quality (for example, resolution) of an ultrasonic image such as a B-mode image can be improved even when the number of channels of the transmission / reception circuit is small.

<Second Embodiment>
Next, a probe moving method when the probe is mechanically scanned over a wide range using the same object information acquiring apparatus as that of the first embodiment will be described.

  As shown in FIG. 2A, when the probe 112 performs imaging along the holding plate 101A that holds the subject 100, it is necessary to perform imaging for a plurality of existing columns. Even in such a case, the image quality of the ultrasonic image can be improved by applying aperture synthesis. However, in order to align the scanning line positions of the apertures that perform aperture synthesis, it is necessary to make the mechanical scanning directions the same when performing the imaging operation of each aperture in each column.

  First, as shown in FIG. 11A, after acquiring data of one opening by mechanical scanning in a direction (first direction) in which a value in the Y-axis direction (first direction) increases in a certain column, Return to the data acquisition start position of the same column. Then, mechanical scanning is performed again in the same direction, and data on the other opening is acquired. Then, the data acquired by the two mechanical scans in the same direction in the Y-axis direction are added to perform aperture synthesis. In this case, the order of scanning directions does not change between adjacent columns.

  For example, in the row A of FIG. 11A, the probe 112 is mechanically scanned from the point A-1 to the point A-2 to acquire data of one opening, and the data of the scanning line group as shown in FIG. To get. Then, the probe 112 is once moved from the point A-2 to the point A-1, and then the probe 112 is mechanically scanned again from the point A-1 to the point A-2 to acquire data of the other opening. To obtain data of the scanning line group as shown in FIG. After that, the signal processing unit 5 adds the acquired data having the same scanning line position to obtain phasing addition data by aperture synthesis.

That is, in the signal processing unit 5, the scanning lines 17-A-B (A is 1 to J, B is 1 to N) and the scanning lines 18-A-B (A is 1 to J, B is 1 to N) Are added, and appropriate signal processing is added to generate ultrasonic tomographic image data of column A by aperture synthesis.
As soon as imaging of the column A is completed, it moves to the point B-1 of the column B, and data acquisition in the column B is performed. A movement path from one row to another can be arbitrarily set. Such data acquisition operation is repeated to acquire ultrasonic tomographic image data by aperture synthesis for all columns A, B, C, and D.

  Further, the direction of mechanical scanning may be different for each column. For example, column A performs mechanical scanning twice in the positive direction of the Y axis, and column B performs mechanical scanning twice in the negative direction of the Y axis. In FIG. 11A, data acquisition is performed in the order of columns A, B, C, and D, but this order is not necessarily required. The probe 112 may be moved so that data of the target imaging range can be acquired. In addition, the number of movements in each row a plurality of times is not limited to twice.

  Further, as shown in FIGS. 7 to 10, depending on the number of elements in the element array, it is necessary to perform imaging by appropriately changing the physical position of the element array at the imaging start point. Therefore, as long as aperture synthesis can be performed without contradiction, the imaging start point of the probe 112 may be appropriately changed according to the number of elements in the element array.

  As described above, according to the subject information acquiring apparatus according to the present embodiment, the scanning line position at the time of acquiring the aperture data a plurality of times can be aligned by adjusting the direction and position of the mechanical scanning of the probe in the aperture synthesis process. . In addition, the imaging range can be expanded. As a result, it is possible to improve the accuracy of aperture synthesis processing and improve the image quality of ultrasonic images captured over a wide range even when the number of channels of the transmission / reception circuit is small.

<Third Embodiment>
Next, a probe moving method capable of reducing the probe moving distance when the probe is mechanically scanned over a wide range using the same object information acquiring apparatus as in the first and second embodiments will be described.

An imaging operation of the subject information acquiring apparatus according to the third embodiment of the present invention will be described with reference to FIG. 11B. In FIG. 11B, the width of the probe 112 is shown to be the same as the width of the rows A to D (corresponding to the number of elements F), but in reality, the number of elements of the probe 112 is {F + (2 × L / 2)} and is not physically the same as the width of columns A to D.
First, in the row A of FIG. 11B, the probe 112 is mechanically scanned from the point A-1 to the point A-2 to acquire data of one opening in the row A, and the scanning line as shown in FIG. Get group data.

  Next, it moves to point B-2 in row B by sub-scanning. In the case of sub-scanning, data acquisition is not performed and only the probe 112 needs to be moved. Then, the probe 112 is mechanically scanned from the point B-2 to the point B-1 in the row B to acquire data of one opening in the row B, and the data of the scanning line group as shown in FIG. get. Comparing the data acquisition of FIG. 12 with FIG. 6, the probe movement axis is the same, but the orientation changes. In addition, the order of ultrasonic beam formation during electronic scanning is the same. Therefore, the inclinations of the electronic scanning plane with respect to the mechanical scanning direction are different from each other.

  Then, it moves to point A-1 in row A by sub-scanning. Next, the probe 112 is mechanically scanned from the point A-1 to the point A-2 to acquire data of the other aperture in the row A, and acquire data of the scanning line group as shown in FIG. .

  Furthermore, it moves to the point B-2 in the row B by sub-scanning. Then, the probe 112 is mechanically scanned from the point B-2 to the point B-1 in the row B, the data of the other opening in the row B is acquired, and the scanning line group as shown in FIG. Get the data. At this point, the data group necessary for aperture synthesis is ready for the two columns A and B. Column A corresponds to the first column of the present invention, and column B corresponds to the second column of the present invention. In this example, both columns are adjacent to each other, but this is not a limitation.

Further, it moves to the point C-1 in the row C by sub-scanning. In the column C of FIG. 11B, the probe 112 is mechanically scanned from the point C-1 to the point C-2 to acquire data of one opening in the column C, and the scanning line group as shown in FIG. Get the data.
Next, it moves to point D-2 in row D by sub-scanning. Then, the probe 112 is mechanically scanned from the point D-2 to the point D-1 in the row D to acquire data of one opening in the row D, and the data of the scanning line group as shown in FIG. get.

Thereafter, the sub-scan moves to the point C-1 in the row C. Next, the probe 112 is mechanically scanned from the point C-1 to the point C-2, and the data of the other opening in the row C is acquired, and the data of the scanning line group as shown in FIG. 6B is acquired. .
Further, it moves to the point D-2 in the row D by sub-scanning. Then, the probe 112 is mechanically scanned from the point D-2 to the point D-1 in the row D, the data of the other opening in the row D is acquired, and the scanning line group as shown in FIG. Get the data. At this point, the data groups necessary for aperture synthesis have been prepared for the two columns C and D.

  In this way, by mechanically scanning the probe 112 with a combination of main scanning and sub-scanning, imaging can be performed over a wide range along the holding plate 101A that holds the subject 100. In the case of this embodiment, the order of scanning directions changes between adjacent columns.

  In the mechanical scanning at the time of imaging by the subject information acquisition apparatus according to the third embodiment of the present invention, when moving in the Y-axis direction having a long distance, data acquisition is performed on separate columns for the forward path and the backward path. For this reason, there is no time required to move in the Y-axis direction without performing data acquisition (return time to the data acquisition start position), and a wide range of data can be acquired in a short time. As a result, there may occur a situation in which the main scanning direction is different for each column, such as the imaging in the first direction in the column A and the imaging in the second direction in the column B. However, since the main scanning directions for electronic scanning are the same in one column, aperture synthesis can be performed without contradiction.

In FIG. 11B, the imaging of the column D is performed from the point A-1 when the imaging of the column A is performed, the imaging of the column D is performed from the point B-2 when the imaging of the column B is performed, and when the imaging of the column C is performed. Is performed, the mechanical scanning in the main scanning direction of the probe 112 is performed from the point D-2. In FIG. 11B, the width of the probe 112 is larger than the width of the rows A to D (corresponding to the number of elements F) because the number of elements of the probe 112 is larger than {F + (2 × L / 2)}. In the rows A to D, the physical position of the probe 112 at the point where imaging is started can be made the same. Even if the physical position of the probe 112 at the point where imaging starts is the same, the number of elements of the probe 112 is larger than {F + (2 × L / 2)}.
This is because it is possible to perform imaging by aperture synthesis for the rows.

  However, as shown in FIGS. 7 to 10, depending on the number of elements in the element array, it is necessary to perform imaging by appropriately changing the physical position of the element array at the imaging start point. Therefore, as long as aperture synthesis can be performed without contradiction, the imaging start point of the probe 112 may be appropriately changed according to the number of elements in the element array. In that case, the moving distance of the mechanical scanning in the sub-scanning direction is also appropriately changed according to the number of elements in the element array.

For example, in FIGS. 13A to 13C, the number of elements in the element array 201 is 1 corresponding to the number of elements F.
In addition to the imaging width of the column, the mechanical scanning procedure at the time of imaging in the case of the number of arrays of one aperture of aperture synthesis (L / 2), that is, (F + L / 2) is shown.

In STEP 1 shown in FIG. 13A, at the time of imaging of the row A, the probe 112 is mechanically scanned in the main scanning direction from the point A-1-1, and data of one opening in the row A is acquired. Next, in STEP2, the probe 112 is moved to the point B-2-2 in the sub scanning direction. At this time, data acquisition is not performed.
In STEP 3 also shown in FIG. 13B, the probe 112 is mechanically scanned in the main scanning direction from the point B-2-2 to the point B-1-2, and data of one opening in the row B is acquired.

In STEP 4, the probe 112 is moved from the point B-1-1 to the point A-1-2 in the sub-scanning direction. In STEP 5, when the image of the row A is picked up, the probe 112 is mechanically scanned in the main scanning direction from the point A-1-2 to the point A-2-2, and data of the other aperture in the row A is acquired.
In STEP 6 shown in FIG. 13C, the probe 112 is moved from the point A-2-2 to the point B-2-2 in the sub-scanning direction.

  In STEP 7, when the image of the row B is picked up, the probe 112 is mechanically scanned in the main scanning direction from the point B-2-2 to the point B-1-2, and data of the other aperture in the row B is acquired. At the time of STEP 7, the data group necessary for aperture synthesis has been prepared for the two columns A and B.

Further, in STEP 8, the probe 112 is moved from the point B-1-2 to the point C-1-1 in the sub-scanning direction, and is changed into two columns C and D by the procedure shown in STEP 1 to STEP 7. On the other hand, a data group necessary for aperture synthesis is acquired.
Thus, by mechanically scanning the probe 112 with a combination of main scanning and sub-scanning, imaging can be performed over a wide range along the holding plate 101A that holds the subject 100.

  As described above, according to the subject information acquiring apparatus according to the present embodiment, the scanning line positions at the time of acquiring a plurality of aperture data can be aligned by using the mechanical scanning of the probe in the aperture synthesis process. In addition, the imaging range can be expanded. As a result, it is possible to improve the accuracy of aperture synthesis processing and improve the image quality of ultrasonic images captured over a wide range even when the number of channels of the transmission / reception circuit is small. In addition, the imaging time can be shortened.

In all the embodiments of the present invention, the imaged electronic scanning surface 12 is inclined with respect to the XZ plane due to the influence of mechanical scanning in the main scanning direction. Therefore, an image subjected to coordinate conversion may be displayed on the image display unit 7 in consideration of the inclination of the electronic scanning surface 12.
In all the embodiments of the present invention, mechanical scanning may be repeated, imaging data may be acquired by changing the transmission / reception direction, and processing that combines aperture synthesis and spatial compound processing may be performed (not shown).

In all the embodiments of the present invention, it is also possible to repeat the mechanical scanning, change the transmission focus, acquire the imaging data, and perform a process of combining aperture synthesis and multi-stage focus (not shown).
As mentioned above, although embodiment of this invention was described, embodiment mentioned above is only a mere illustration in all the points, and does not limit the scope of the present invention.

  1: object information acquisition device, 2: probe, 5: signal processing unit, 11: transmission unit, 60: mechanical scanning mechanism

Claims (10)

A probe that transmits an acoustic wave to an object through an opening formed of a plurality of elements, receives a reflected wave of the acoustic wave in the object, outputs a reception signal, and performs electronic scanning;
A processing unit for acquiring characteristic information in the subject using the received signal;
A scanning unit that moves a position of the probe with respect to the subject in a first direction and a second direction that intersects the first direction;
Have
The probe performs the electronic scanning while moving in the first direction;
The scanning unit moves the probe a plurality of times in the same direction in the first direction,
The object information acquisition apparatus, wherein the processing unit acquires the characteristic information by aperture synthesis using a reception signal obtained by the electronic scanning in the plurality of movements in the same direction. When the subject is divided into a plurality of columns in the second direction, the probe moves in the same direction in the first direction when acquiring characteristic information of one column. The subject information acquiring apparatus according to claim 1, wherein the electronic scanning is performed. The probe performs the electronic scanning while moving in the first direction in the first direction, and then in the second direction opposite to the first direction in the first direction, The object information acquiring apparatus according to claim 2, wherein the object information acquiring apparatus moves without performing electronic scanning. The probe performs movement in the first direction in the first direction and characteristics of a second column different from the first column, which are performed to acquire characteristic information of the first column. 3. The object information acquisition according to claim 2, wherein movement in a second direction opposite to the first direction in the first direction is performed in order to acquire information. apparatus. The subject information acquiring apparatus according to claim 4, wherein the second column is adjacent to the first column. The object information acquiring apparatus according to claim 2, wherein the position of the opening of the probe changes in the plurality of movements in the same direction. The object information acquiring apparatus according to claim 2, wherein the probe includes at least the plurality of elements arranged in the second direction. The object information acquiring apparatus according to claim 7, wherein the position of the opening of the probe changes in accordance with the number of the plurality of elements in the second direction and the width of the column. . The subject information acquisition apparatus according to claim 1, further comprising a display unit that displays an image in the subject based on the characteristic information. A probe that transmits an acoustic wave to an object through an opening formed of a plurality of elements, receives a reflected wave of the acoustic wave in the object, outputs a reception signal, and performs electronic scanning;
A processing unit for acquiring characteristic information in the subject using the received signal;
A scanning unit that moves a position of the probe with respect to the subject in a first direction and a second direction that intersects the first direction;
A method for controlling a subject information acquisition apparatus comprising:
The probe performing the electronic scanning while moving in the first direction;
The scanning unit moving the probe a plurality of times in the same direction in the first direction;
The processing unit obtains the characteristic information by aperture synthesis using the received signal obtained by the electronic scanning in a plurality of movements in the same direction;
A method for controlling a subject information acquiring apparatus, comprising:

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