JP2009034538A - Ultrasonic diagnostic apparatus and imaging method in ultrasonic diagnostic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide ultrasonic images having intended frame rates by varying scanning ranges of a probe. <P>SOLUTION: This ultrasonic diagnostic apparatus 1 includes: an electronic scanning type radial probe 10 formed by disposing a plurality of transducers for transmitting and receiving ultrasonic waves toward a subject, on the circumferential face of a cylindrical distal end; a probe control section 12 for drivingly scanning the plurality of transducers of the probe along the circumferential direction; an image processing section 14 for receiving reflected echo signals from the subject, processing the signals and generating a circular radial image; and a display section 16 for displaying the radial image. This apparatus further includes a scanning range setting section for setting a part of the range of the circular radial image as a scanning range, wherein the probe control section drivingly scans transducers corresponding to the set scanning range. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an ultrasonic diagnostic apparatus suitable for obtaining an ultrasonic image having a desired frame rate by variably setting a scanning range of a probe.

  The ultrasonic diagnostic apparatus transmits an ultrasonic wave to a subject through a probe having a plurality of transducers, receives an echo signal generated from the subject, and performs an image based on the echo signal. Is known to obtain a diagnostic image of a region of interest.

  In such an ultrasonic diagnostic apparatus, for example, when diagnosing a body cavity such as the stomach or lower digestive organ, an ultrasonic endoscope is often used. An ultrasound endoscope has a probe in which an optical endoscope and an ultrasound probe are integrated, and the probe is inserted into the stomach or the like from the mouth to observe the stomach wall or the like. It is.

  In general, a mechanical scanning radial probe is widely used as a probe for this ultrasonic endoscope. A mechanical scanning radial probe is a device in which a single transducer is attached to the tip of a shaft, and the shaft is mechanically rotated to rotate the transducer 360 degrees from the scanning start line to the scanning end line. An image inside the body cavity is obtained. One frame of the obtained image is displayed as, for example, a circular image in which the scanning start line and the scanning end line are adjacent (see, for example, Non-Patent Document 1).

Japan Electronic Machinery Manufacturers Association "Revised Medical Ultrasound Handbook" Corona, January 20, 1997, p. 112

  By the way, when the inside of a body cavity accompanied by body movement is observed using a mechanical scanning type radial probe, there is a case where the image is displaced and the diagnosis cannot be performed accurately. For example, when gallbladder is observed, a mechanical scanning radial probe is inserted into a body cavity, and then the probe shaft is mechanically rotated. At this time, it takes time to rotate the shaft once. If the gallbladder moves within this time, a so-called shift occurs in the image by the amount of the gallbladder movement at the adjacent portion between the scan start line and the scan end line. If the region of interest to be observed overlaps the location where the image is shifted, accurate diagnosis may not be performed.

  Therefore, it is necessary to adjust the rotational position of the mechanical scanning radial probe so that the position where the image is misaligned and the region of interest do not overlap. That is, it is necessary to rotate the probe shaft so as to move the adjacent portion so that the position where the image is shifted, that is, the adjacent portion between the scanning start line and the end line is located outside the region of interest.

  However, it is difficult to freely adjust the rotational position of the mechanical scanning radial probe. For example, when scanning the gallbladder, the rotation axis of the probe is in the body cavity, for example, in the duodenum. Therefore, when the axis is rotated, a load that impedes rotation in the duodenum may be applied to the axis. When a load is applied to the shaft, it is difficult to accurately adjust the scan range, for example, the position of the scan start line.

  Further, in the case of observing an observation site accompanied by body movement, for example, an organ or the like, the mechanical scanning radial probe cannot obtain an image following the body movement of the organ, and the image may flicker. In other words, for example, when observing the gallbladder, it may be desired to increase the frame rate of the image in order to obtain an image that follows the movement of the part. However, with a mechanical scanning radial probe, the frame rate of an image is determined only by the rotational speed of the axis, and even if the region of interest is limited to a specific part, the scanning range cannot be limited to that part. . Thus, there are cases where the frame rate cannot be improved and an image following the movement of the gall bladder cannot be obtained.

  On the other hand, instead of the mechanical scanning radial probe, an electronic scanning radial probe is conceivable in which a plurality of transducers are arranged on the peripheral surface of the tip of a cylindrical probe to perform electronic scanning. In this case as well, for example, a B-mode image is captured by driving and scanning the full-width transducer, and therefore, a point in which the image is misaligned at a portion adjacent to the scanning start line and the end line and a specific region of interest are observed. It is the same that the frame rate cannot be improved.

  On the other hand, not only a radial probe for observing the inside of a body cavity, but also a convex type probe, for example, a B-mode image is taken by driving and scanning a full-width transducer, so a specific region of interest is observed. The same applies to the point that the frame rate cannot be improved.

  An object of the present invention is to obtain an ultrasonic image having a desired frame rate by changing a scanning range of a probe.

  In order to achieve the above object, an ultrasonic diagnostic apparatus of the present invention includes a transmitter that drives a probe and transmits ultrasonic waves to a subject, and receives a reflected echo signal from the subject and processes the signal. An image processing unit for generating an ultrasonic image and a display unit for displaying the generated ultrasonic image, and a means for variably setting the scanning range of the probe, and corresponding to the variably set scanning range. And a control means for driving and scanning the probe.

  That is, by setting the scanning range corresponding to the region of interest, the control unit drives and scans only a specific transducer corresponding to the set scanning range, so that compared with a case where a full-width transducer is driven. The scanning time can be shortened. As a result, the frame rate can be improved, and for example, a good image following the body movement can be obtained.

  Further, if the position of the first transducer to be driven at the start of scanning is changed and set so that the region of interest does not overlap the adjacent portion that causes the image misalignment, that is, the connecting portion between the scan start line and the scan end line, the scan start line Can be shifted out of the region of interest. Accordingly, since it is possible to avoid the region of interest from overlapping the adjacent portion in the display image, it is possible to reliably prevent the image of the region of interest from being displaced as compared with the case where the scan start line cannot be arbitrarily set. .

  In this case, a variable setting means for setting the scanning range with a marker displayed on the display unit is preferable. Thereby, if an observer, for example, a doctor moves a marker that is easy to grasp visually to set a scanning range, for example, compared to a case where a scanning start line is intuitively set on a screen on which no marker is displayed. The setting operation is easy.

  It is desirable to set the marker along the shape of the probe. For example, obtained by a probe in which a plurality of transducers are arranged in a linear shape, a curved shape, a planar shape, or a curved shape, or a radial probe in which a plurality of transducers are arranged along the circumference. It is preferable to set the marker along the shape of the image. Thus, the viewer can visually set the scanning range along the displayed ultrasonic image while referring to the displayed ultrasonic image, and can easily set the scanning range.

  According to the present invention, an ultrasonic image having a desired frame rate can be obtained by changing the scanning range of the probe.

  Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a configuration example of an ultrasonic diagnostic apparatus to which the present invention is applied. As shown in the figure, the ultrasonic diagnostic apparatus 1 includes a probe unit 10 that transmits and receives ultrasonic waves to and from a subject, and a probe control unit 12 that issues a scanning control command to the probe unit 10. An image processing unit 14 that converts an echo signal of a region of interest acquired by the probe unit 10 into a display signal and a display unit 16 that displays an image from the image processing unit 14 are provided.

  The probe unit 10 is configured by driving an electronic scanning radial probe that performs electronic scanning by arranging a plurality of transducers around the tip of a cylindrical probe, and driving the radial probe. A transmitting unit that transmits ultrasonic waves to the subject and a receiving unit that receives echo signals generated from the subject via a vibrator are provided.

  A console 18 for inputting a command for changing the scanning range of the region of interest is provided, and control for driving and scanning the transducer of the probe unit 10 based on the scanning range input by the console 18 is provided. A signal command unit 20 that transmits a signal to the probe control unit 12 and displays a marker that always indicates the scanning start line of the scanning range on the display unit 16 is provided.

  The operation of the ultrasonic diagnostic apparatus configured as described above will be described. An electronic scanning radial probe is inserted into the body cavity of the subject, and ultrasonic waves are transmitted from the transmitting unit to the observation site of the subject via the radial probe based on the command of the probe control unit 12 To do. Thereby, the echo signal generated from the observation site is received by the receiving unit via the radial probe. The received echo signal is converted into an image signal by the image processing unit 14 and displayed on the display unit 16.

  Conventionally, when observing the inside of a body cavity such as the stomach, a mechanical scanning radial probe is inserted into the stomach, and the inserted radial probe is mechanically rotated to acquire an image of the stomach wall. . Here, the mechanical scanning type radial probe means that a single transducer is attached to the tip of a shaft and the shaft is mechanically rotated so that the transducer is rotated 360 degrees from the scanning start line to the scanning end line. The image in the body cavity is obtained by rotating.

  At this time, if the stomach moves while rotating the mechanical scanning type radial probe, the image is moved by the amount of stomach movement at the adjacent portion of the acquired radial image, that is, at the connection portion between the scanning start line and the scanning end line. Misalignment may occur. In addition, since the rotational speed of the shaft is mechanically limited in the mechanical scanning type radial probe, the frame rate of the image is also limited, and an image that follows the movement of the fast-moving observation site can be obtained. In some cases, the screen may flicker.

  Therefore, in this embodiment, the scanning range is arbitrarily set by using an electronic scanning radial probe that performs electronic scanning by arranging a plurality of transducers on the peripheral surface of the tip of the cylindrical probe. Thus, the region of interest, for example, a polyp in the stomach is adjusted so as not to overlap an adjacent portion where a radial image shift occurs, and the frame rate of the display image is increased.

  Here, the characteristic part of this invention is demonstrated using FIG. FIG. 2 is a flowchart showing an example of the processing procedure of the signal command unit 20 according to the present invention.

  Step 100: The scanning range setting process is started. That is, a process of designating a scanning range corresponding to the region of interest and transmitting a signal for driving and scanning the transducer corresponding to the range from the signal command unit 20 to the probe control unit 12 is started.

  Step 101: Wait for input from a user interface provided on the console 18, such as an input key, a pointing device, or a dedicated device.

  Step 102: It is determined whether or not there is a command to rotate the image. For example, when a command for rotating the image in the circumferential direction is input from the console 18 about the center of the circular radial image, the rotation angle is calculated based on the command (step 102a). Then, the calculated rotation angle is temporarily stored in the memory for use in the processing of step 109.

  Step 104: It is determined whether or not there is a command for changing the monochrome image display area of the image. For example, when a command for limiting the display range to the region of interest is input from the console 18 in the circular radial image, the monochrome display region is calculated based on the command (step 104a). The calculated black and white area is temporarily stored in the memory for use in the processing of step 109.

  Step 106: It is determined whether or not there is a command for changing the color image display area of the image. For example, in a radial image in which a black-and-white image is overlaid with a color image, for example, an image in which the blood flow velocity is colored and the blood flow is visible, a command for limiting the display range of the color image to the region of interest from the console 18. When input, the color image display area is calculated based on the command (step 106a), and the black and white display area is recalculated in alignment with the calculated color display area (step 106b). The calculated color image display area and monochrome image display area are temporarily stored in the memory for use in the processing of step 109.

  Step 108: It is determined whether or not there is a command to change the position of the display image. For example, when a command for moving the marker displayed on the console 18 along the circumference of the radial image is input, the display position, particularly the display start position is calculated based on the command (step 108a). The calculated display position is temporarily stored in the memory for use in the processing of step 109.

  Step 109: A scanning range for driving and scanning the vibrator is calculated. That is, the scanning range is calculated based on the calculated values temporarily stored in the memory, for example, the rotation angle in step 102a, the monochrome display area in step 104a, the color display area in step 106a and the monochrome display area in step 106b, and the display position in step 108a. Then, the transducer control unit 12 drives and scans the transducer in accordance with the calculated scanning range.

  Step 110: The scanning range setting process is terminated.

  As described above, according to the present embodiment, the probe control unit 12 specifies the scanning range of the electronic scanning radial probe as the region of interest and sets the scanning range corresponding to the region of interest. Since only a specific transducer corresponding to the set scanning range is driven and scanned among the plurality of transducers, the scanning time can be shortened as compared with the case where the full-width transducer is driven. As a result, the frame rate can be improved.

  Also, if the drive range is set by changing the position of the transducer to be driven at the start of scanning so that the adjacent part of the scan start line and the scan end line does not overlap the region of interest, the scan start line is moved out of the region of interest. Can be shifted. Therefore, since it is possible to avoid the region of interest overlapping the adjacent portion in the display image, it is possible to avoid the occurrence of a shift in the image of the region of interest as compared to the case where the scan start line cannot be arbitrarily set.

  A specific example in which the scanning range of the radial probe is made variable using the above embodiment will be described with reference to FIGS. FIG. 3 shows an embodiment in the case of moving the connection part. As shown in the figure, the circular radial image 31, the connecting line 32 indicating the adjacent portion of the scanning start line and the scanning end line of the radial image, and the scanning start position are always located near the circumference of the radial image. A pointing marker 33 is displayed. Then, two images 34a and 35a of the region of interest are displayed on the left and right with the connecting line 32 interposed therebetween, and a blood flow image 34b in which the blood flow velocity is visualized by coloring the blood flow velocity in the images 34a and 35a, 35b is displayed.

  FIG. 3A shows an example in which the image 34a and the image 35a of the region of interest are displayed shifted from each other. That is, for example, when the stomach moves during the time when the mechanical scanning type radial probe is axially rotated from the scanning start position to the scanning end position, the image 34a and the image 35a are displayed with a shift corresponding to the stomach movement. Further, since the blood flow velocity changes between the blood flow image 34b and the blood flow image 35b due to the time difference between the scanning start line and the scanning end line, the blood flow image 34 and the blood flow image 35b are displayed in different colors.

  FIG. 3B shows an embodiment in which the connecting line 32 is moved manually. For example, by operating the pointing device of the console 18, the marker 33 of the display unit 16 is rotated and moved along the circumference of the radial image 31 via the signal command unit 20. Based on the amount of movement of the moved marker 33, the signal command unit 20 transmits a command to change the transducer driven at the start of scanning to another transducer to the probe control unit 12 (step 102). The transducer is driven and scanned by the probe controller 12 in accordance with the received command. Therefore, the connecting line 32 can be shifted from the region of interest. Thereby, since the time difference between the acquisition times of the image 34a and the image 35a can be removed, the image 34a and the image 35a are displayed in alignment, so that the observation site can be diagnosed accurately. Moreover, since the blood flow image 34b and the blood flow image 34b are displayed in the same color, an accurate blood flow velocity can be recognized.

  FIG. 4 shows another embodiment in which the connecting line 32 is moved. FIG. 4A shows an example of an image in which the connection line 32 and the region of interest overlap as in FIG. 3A. On the other hand, FIG. 4B shows an embodiment in which the connecting line 32 is moved semi-automatically at an angle of 90 degrees. For example, in response to a command from the console 18, the signal command unit 20 transmits a command to the probe control unit 12 to rotate the connecting line 32 around a circle center at a preset angle, for example, 90 ° ( Step 102), the transducer control unit 12 is driven to scan the transducer in accordance with the transmitted command. As described above, if the connection line 32 is semi-automatically moved by a predetermined angle each time the input key of the console 18 is pressed, the operation burden is reduced as compared with the case of manually moving while visually observing the scanning start line. Can be reduced. Note that the preset rotation angle can be set to a desired angle.

  FIG. 5 shows another embodiment for moving the connecting portion. FIG. 5A shows an example in which the connection line 32 and the region of interest are displayed so as to overlap each other as in FIG. 3A. On the other hand, FIG. 4B shows an embodiment in which the connecting line 32 is automatically moved. That is, the signal command unit 20 transmits a command for moving the connecting line 32 for each line to the probe control unit 12 every time one frame of the radial image 31 that is a complete image is acquired, and based on the command. The probe control unit 12 drives the transducer. By performing this control at a high speed, the connection line 32 is automatically displayed so as to move one line at a time, so that the operator is not aware of the presence of the connection line 32. Therefore, compared with the case where the operator's connection part 32 is moved manually or semi-automatically, the operation burden can be reduced. Since the number of lines for moving the connecting line 32 can be arbitrarily set every time one frame of the image is acquired, the connecting line 32 can be moved on the screen at a desired speed.

  FIG. 6 shows an embodiment for improving the frame rate of a display image in a monochrome image. 6A shows a circular monochrome image 31a, FIG. 6B shows a semicircular monochrome image 31b, and FIG. 6C shows a fan-shaped monochrome image 31c. At this time, since the black and white image 31a having a wide observable range has a large number of scanning lines, the frame rate of the image is low. On the other hand, the black and white image 31c having a narrow observable range has a small number of scanning lines and therefore the frame rate of the image is high. .

  In this case, it is preferable to adjust the frame rate by controlling the observation range according to the property of the observation region in the region of interest. For example, when observing an observation site with fast movement, a high frame rate is required to obtain an image following the movement. Therefore, a command for specifying the observation range only for the observation region is input from the console 18, and the signal command unit 20 transmits a command for limiting the scanning range to the probe control unit 12 based on the command (step 104). . In accordance with the command, the transducer control unit 12 is driven to scan the transducer. Thus, by specifying and limiting the scanning range, the number of scanning lines of the probe unit 10 can be reduced, so that the frame rate of the image can be improved. As a result, an image following the body movement can be obtained, and an accurate diagnosis can be performed based on the image.

  FIG. 7 shows an embodiment in which the frame rate of an image in which a color image is superimposed and displayed on a black and white image is improved. In FIG. 7A, a circular monochrome image 31a is displayed, and a color image 40a is superimposed on the monochrome image 31a. In FIG. 7B, a semicircular color image 40b is superimposed and displayed on the black and white image 31a, and in FIG. 7C, a fan-shaped color image 40c is superimposed and displayed on the black and white image 31a. At this time, as in FIG. 6, the color image 40a having a wide observable range in the color mode has a large number of scanning lines for the color mode, so the frame rate of the entire image is low, while the observable range in the color mode is large. Since the narrow color image 40c has a small number of scanning lines for the color mode, the frame rate of the entire image is high.

  In such a color display mode, for example, when the blood flow velocity at the observation site is measured by the pulse Doppler method, a high frame rate is often required to ensure the real-time property of the measurement result. Therefore, the console 18 inputs a command for specifying the observation range in the color mode only to the observation region, and based on the command, the signal command unit 20 transmits a command to drive and scan the transducer to the probe control unit 12. The vibrator is driven in accordance with the transmitted command. Thereby, the scanning range for color display can be limited to a specific part (step 105). As a result, the number of scanning lines for color display can be reduced, so that the frame rate of the entire image can be improved.

  FIG. 8 shows an embodiment in which the observation site is changed while maintaining the scanning range. As shown in the figure, a circular radial image 60 and a region of interest 70 in which the display range of the radial image 60 is limited to a fan shape are displayed. A blood flow image 72 of the blood vessel 71 is displayed in the region of interest 70.

  In this case, a command for moving the region of interest 70 is input from the console 18 while the range of the region of interest 70 is maintained, and the signal command unit 20 causes the probe control unit 12 to drive the transducer based on the command. A command is transmitted (step 108). As a result, the observation site can be changed while maintaining a high frame rate of the display image, so that it becomes easy to track the blood vessel running in blood flow observation, for example.

  As mentioned above, although this invention was demonstrated based on embodiment, the ultrasonic device 1 which concerns on this invention is not restricted to this. For example, instead of the electronic scanning radial probe used in the present embodiment, it can be applied to a convex probe in which a plurality of transducers are arranged in an arc. In short, the present invention can be applied not only to a radial probe but also to any type of probe as long as it is an electronic scanning probe having a plurality of transducers.

  In the present embodiment, as shown in FIG. 1, the case where the probe control unit 12 and the signal command unit 20 are configured by different devices has been described. However, the probe control unit 12 and the signal command unit 20 are not described. The unit 20 may be integrated, or the console 18 and the signal command unit 20 may be integrated.

  In addition, the shape of the marker indicating the scanning start line on the diagnostic image may be an arbitrary shape. In particular, a form having protrusions in the movement direction so as to indicate the movement direction of the marker is preferable. Thereby, the viewer can visually grasp the moving direction or the rotating direction.

  Furthermore, in this embodiment, the case where the stomach is observed is described as an example, but the present invention is not limited to this. For example, the ultrasonic diagnostic apparatus according to the present invention can be applied when gallbladder is observed.

It is a block diagram which shows the structural example of the ultrasonic diagnosing device to which this invention is applied. It is a flowchart which shows an example of the process sequence of the signal instruction | command part which concerns on this invention. The Example in the case of moving a connection part is shown. The other Example which moves a connection part is shown. The embodiment which improves the frame rate of the display image in a monochrome image is shown. The embodiment which improves the frame rate of the display image in a monochrome image is shown. An embodiment is shown in which the frame rate of an image in which a color image is superimposed and displayed on a black and white image is improved. The Example which changes the display position of an observation site | part is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Probe part 12 Probe control part 14 Image processing part 16 Display part 18 Operation console 20 Signal command part 32 Connection part 33 Marker 31 Radial image

Claims (12)

An electronic scanning radial probe in which a plurality of transducers for transmitting and receiving ultrasonic waves to and from the subject are arranged on the peripheral surface of a cylindrical tip, and the plurality of transducers of the probe in the circumferential direction A probe control unit that drives and scans along the line, an image processing unit that receives a reflected echo signal from the subject and processes the signal to generate a circular radial image, and a display that displays the radial image An ultrasonic diagnostic apparatus comprising:
A scanning range setting unit that sets a partial range of the circular radial image as a scanning range;
The ultrasonic diagnostic apparatus, wherein the probe control unit drives and scans a transducer corresponding to the set scanning range.   The ultrasonic diagnostic apparatus according to claim 1, wherein the scanning range is set corresponding to a region of interest of the subject.   The ultrasonic diagnostic apparatus according to claim 1, wherein the scanning range setting unit sets the scanning range based on a viewer's operation of a pointing device.   The ultrasonic diagnostic apparatus according to claim 1, wherein the scanning range setting unit moves the scanning range by a preset angle for each input operation of a viewer.   The ultrasonic diagnostic apparatus according to claim 1, wherein the scan range setting unit moves the scan range by one scan line every time one frame of an image corresponding to the set scan range is acquired. . When the circular radial image is an image generated by superimposing a color image on a black and white image,
The ultrasonic diagnostic apparatus according to claim 1, wherein the scanning range setting unit sets the scanning range of the color image so as to be limited to a partial range of the circular radial image.   The ultrasonic diagnostic apparatus according to claim 6, wherein the color image is an image generated by a pulse Doppler method.   The ultrasonic diagnostic apparatus according to claim 1, wherein the scan range setting unit moves the scan range in a circumferential direction of the radial image while maintaining the scan range.   The scanning range setting unit sets the scanning range based on a position of a marker displayed on the display unit and moving along a circumference of the radial image, and the shape of the marker indicates a moving direction of the marker The ultrasonic diagnostic apparatus according to claim 1, wherein the ultrasonic diagnostic apparatus is formed with a protrusion.   The ultrasonic diagnostic apparatus according to claim 1, wherein the probe is an in-vivo probe having an observation site in the body cavity of the subject. Drives and scans a plurality of transducers of an electronic scanning radial probe in which a plurality of transducers for transmitting and receiving ultrasonic waves to and from the subject are arranged on the circumferential surface of a cylindrical tip along the circumferential direction. An imaging method of an ultrasonic diagnostic apparatus that generates a circular radial image based on a received reflected echo signal of the subject and displays the image on a display unit,
Setting a partial range of the circular radial image as a scanning range;
Driving and scanning a transducer corresponding to the set scanning range;
An imaging method in an ultrasonic diagnostic apparatus comprising:   The imaging method in the ultrasonic diagnostic apparatus according to claim 11, wherein the scanning range is set corresponding to a region of interest of the subject.

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