JP2007330286A - Ultrasonic diagnostic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for controlling an ultrasonic diagnostic device to display a more useful diagnostic mode on a screen, when displaying an instrument. <P>SOLUTION: A preceding first beam scanning control of an ultrasonic beam based on an ultrasonic wave transmitted/received in a living body is executed in a three-dimensional space, and the position of the instrument existing in the three-dimensional space is detected. By executing a following second beam scanning control means based on the detected positional information, a scanning control according to the position of the instrument is executed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an ultrasonic diagnostic apparatus, and more particularly to scanning control of an ultrasonic beam.

  In recent years, ultrasonic diagnostic apparatuses having a three-dimensional display function have been widely used. When the three-dimensional display function is used, the original shape of the living tissue is rendered three-dimensionally on the display with a sense of depth. For this reason, the three-dimensional display function has greatly contributed to image diagnosis, and by using this function, it has become possible to clearly depict the appearance of a fetus, a tumor in an organ, and the like.

  On the other hand, the ultrasonic diagnostic apparatus is also used as an apparatus for supporting treatment and surgery. For example, there is a method called ultrasonic guided puncture. This method is a method of inserting a puncture needle into a living tissue while observing the inside of the body using an ultrasonic diagnostic apparatus. According to this method, since puncture can be performed while observing the puncture state in the body and the tissue to be treated in real time, puncture can be performed reliably and safely.

  Japanese Patent Application Laid-Open No. 2004-228561 shows that in a three-dimensional ultrasonic diagnostic apparatus, a ROI (region of interest) is set on a stereoscopic projection image and a high-resolution stereoscopic projection image is obtained within the set range. In Patent Document 1, since ROI setting is performed at an arbitrary position, manual setting by the user is assumed.

  In Patent Document 2, in a three-dimensional display ultrasonic diagnostic apparatus, a line-of-sight direction at the time of rendering a three-dimensional image is determined based on the orientation and tip position of an instrument inserted on the image, and the three-dimensional image is It is shown to make up. In Patent Document 2, control that changes the scanning range of the ultrasonic beam based on the position of the instrument is not performed. The instrument is a means for determining the direction of rendering, and is not the purpose of drawing.

Japanese Patent Laid-Open No. 10-277030 JP 2004-215701 A

  In applying a three-dimensional display function to ultrasonic guided puncture, a control method for an ultrasonic diagnostic apparatus that displays a more useful aspect on diagnosis on the screen has not yet been realized. In particular, a three-dimensional display image is not formed in a form that focuses on an instrument such as a puncture needle, and control that focuses on a moving instrument is not performed. The same applies to instruments other than the puncture needle.

  An object of the present invention is to provide a new beam control technique in the case where an instrument is displayed as a three-dimensional image together with a living tissue on the premise of three-dimensional image formation.

  Alternatively, another object of the present invention is to provide a device that is useful for intraoperative support, for example, for a user who uses an ultrasonic diagnostic apparatus and that can be used for observation of an instrument.

  The present invention is a means for executing control for forming a three-dimensional space in a living body by two-dimensionally scanning an ultrasonic beam, and forming a first three-dimensional space and acquiring a first volume data Beam scanning control means for executing scanning control, and position information detection means for detecting position information of an instrument inserted into the living body based on the first volume data, the beam scanning control means further comprising: The second beam scanning control for acquiring the second volume data by forming a second three-dimensional space as a partial space including the instrument based on the position information is performed.

  According to the above configuration, an ultrasonic beam based on an ultrasonic wave transmitted and received in a living body is formed, and the first volume scanning control is applied to the ultrasonic beam in a three-dimensional space, whereby the first volume is set. Based on the data acquired, the position information of the instrument existing in the first three-dimensional space is detected. Since the subsequent second beam scanning control is executed based on the execution of the first beam scanning control and the position information detected by the position information detecting means, it is possible to realize the scanning control according to the position of the instrument.

  An instrument inserted into a living body generally shows a high reflectivity with respect to ultrasonic waves, so that an echo signal having a high intensity can be obtained. Therefore, the position detection of the instrument is relatively easy, and the position in the three-dimensional space can be specified with high accuracy. Here, the three-dimensional space is, for example, a three-dimensional space assumed in the living body. In the present application, it is an echo signal capturing space using an ultrasonic beam, and its three-dimensional shape is arbitrary. Specific examples of the instrument include a surgical knife, forceps, a puncture needle, and a suture instrument. The material of the instrument may be either metal or non-metal, but in particular, the instrument made of metal has a high acoustic impedance and a high reflectivity with respect to the ultrasonic wave, so that it is easy to specify the position by the ultrasonic wave.

  Further, the instrument position information detection means may detect information on the boundary position of the instrument based on the first volume data, or may detect the position of a part of the instrument. For example, in the case of a puncture needle, it is preferable to specify at least position information of the tip of the needle.

  Preferably, the beam scanning control unit forms the first three-dimensional space as an entire space when the first beam scanning control is executed, and the first three-dimensional space when the second beam scanning control is executed. Forming the second three-dimensional space included in

  According to the above configuration, when the first beam scanning control is executed, the first volume data is acquired from the entire range, and the second volume data corresponding to the position range of the instrument is specified from the range. By scanning the entire space prior to specifying the position of the instrument, the position of the instrument is specified, and settings for performing the second beam scanning control can be performed.

  Preferably, the beam scanning control means forms a first three-dimensional space as a partial space including an instrument when the first beam scanning control is executed, and the first beam scanning control is executed when the second beam scanning control is executed. Following the movement of the instrument from the time of scanning control to the time of second beam scanning control, forming a second three-dimensional space as a partial space partially overlapping with the first three-dimensional space; Features.

  According to the above configuration, when the first beam scanning control is executed, the position of the instrument is specified from the partial space including the instrument. Even when the instrument moves after the first beam scanning control, the beam scanning according to the position of the instrument is performed by the second beam scanning control. Therefore, even if the instrument moves, the position can be specified following the movement.

  If the entire three-dimensional space is scanned in the first beam scanning control, the position of the instrument that was initially unknown can be specified. In addition, in the second beam scanning control, a partial space including the instrument is specified based on the position specified by the first beam scanning control. Thereafter, when the third beam scanning control is further executed, it is possible to specify the partial space following the movement of the instrument based on the position specified by the previous second beam scanning control. Since the partial space is specified using two volume data that are temporally related to each other, the second volume by the second beam scanning control is used as the data processing when the third beam scanning control is performed. The data is used as the new first volume data, and the third volume data by the next beam scanning control is used as the new second volume data, so that the new first volume data and the new second volume data are used. The partial space can be specified using the volume data.

  That is, by repeating the execution of the first beam scanning control and the second beam scanning control as described above, it is possible to update the specific operation of the partial space including the instrument as needed. Scan control that follows the instrument can be performed without losing sight.

  Incidentally, it is desirable to execute the first beam scanning control for performing the entire scanning in the first scanning, but once the position of the instrument is specified, it is not incorporated into the beam scanning sequence. It is not always necessary, and scanning control following the instrument is possible by repeating the first and second beam scanning controls that form a partial space including the instrument.

  Preferably, the position information of the instrument is information representing an instrument existing range in at least one of the first scan direction and the second scan direction, and the beam scanning control means includes the instrument present range. A beam scanning range for forming the second three-dimensional space is set by adding a margin.

  According to the above configuration, the second three-dimensional space is set relatively or adaptively to the instrument by adding a margin to the range where the instrument exists. Accordingly, a margin can be provided by enlarging the presence range of the instrument with respect to at least one of the first scanning direction and the second scanning direction, so that the volume can be adjusted even when the instrument moves. As the data is updated, the movement of the instrument in the entire three-dimensional space can be tracked.

  When a margin is added to the existence range of the instrument in either one of the first scanning direction and the second scanning direction, for example, an existence range sandwiched between two surfaces facing the instrument may be set. It becomes possible. In addition, in the first scanning direction and the second scanning direction, when a margin is added to the existence range of the instrument, an enclosed space that surrounds the instrument with four surfaces (for example, two parallel parallel surfaces) It is possible to set an enclosing space using two sets.

  The margin is an area located in the vicinity of the existence range (existing space) of the instrument. For example, in a three-dimensional space, for example, for a blade, a marginal space that is described as a portion of a sheath that houses the blade. To do. However, the adjacent space is not limited by the concept of having a substantially uniform distance from the surface of the instrument, and the space with a margin set may be a rectangular parallelepiped or a square pyramid shape. In many cases, the margin setting space can be arbitrarily set according to the embodiment of the beam scanning control.

  The margin to be set may be on one side or the other side with respect to the region where the instrument is present when focusing on a certain direction. Desirably, it may be set on both sides. In some cases, if the movement direction of the instrument can be recognized, a large margin may be set in the movement direction. Furthermore, as long as the moving direction and moving speed of the appliance can be recognized, the set amount of the margin may be made variable according to the moving direction and moving speed.

  Desirably, the position information of the instrument is information indicating the existence range of the instrument in each of the first scanning direction, the second scanning direction, and the depth direction, and the beam scanning control means includes the first scanning direction and the first scanning direction. In the second scanning direction, a beam scanning range for forming the second three-dimensional space is set by adding a margin to the existing range of the instrument, and the beam scanning control means is configured to detect the presence of the instrument in the depth direction. The diagnostic depth is set based on the range.

  According to the above configuration, since the existence range of the instrument can be specified in the depth direction in addition to the first scanning direction and the second scanning direction, the existence of the instrument in the three-dimensional space that scans the whole. The range can be narrowed down to the range that needs scanning.

  The diagnostic depth is the depth of field that can be diagnosed by transmitting and receiving ultrasonic waves. Specifically, it is the length specified as the distance from the probe according to the pulse repetition frequency of the ultrasonic waves. is there. Therefore, in the depth direction, when the position of the instrument is close to the ultrasonic probe (for example, when the instrument is shallow from the body surface), a shallow diagnostic depth sufficient to identify the instrument is set. It becomes possible to set. Conversely, when the position of the instrument is far from the ultrasound probe (for example, when the instrument is deep from the body surface), the diagnostic depth can be set deep to identify the instrument.

  Preferably, the beam scanning control unit executes beam scanning control according to a beam scanning sequence in which the first beam scanning control and the second beam scanning control are combined.

  According to the above configuration, it is possible to configure a beam scanning sequence in which the first volume data acquired by the first beam scanning control and the second volume data acquired by the second beam scanning control are combined. Depending on the setting of the beam scanning sequence, the number of updates of the second volume data can be increased, so that the movement of the instrument can be easily captured.

  Preferably, based on the positional relationship between the first and second three-dimensional spaces, a synthesis unit that synthesizes the first volume data and the second volume data, and a synthesis volume data generated by the synthesis unit. And 3D image forming means for forming a 3D display image.

  According to the above configuration, since the synthesized volume data including the information of the first volume data and the second volume data is formed, the three-dimensional image based on the synthesized volume data is the position of the instrument in the three-dimensional space and It is generated as an image whose form can be easily grasped. That is, it is possible to provide an unprecedented three-dimensional image function focusing on the instrument.

  As described above, according to the present invention, it is possible to provide a beam control technique in a mode in which attention is paid to an instrument in three-dimensional display.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the drawings.

  FIG. 1 is a functional block diagram showing a configuration of an ultrasonic diagnostic apparatus according to the present invention. This ultrasonic diagnostic apparatus is a device for displaying a three-dimensional image for displaying a tissue in a living body and confirming the position of a body insertion instrument such as a puncture needle or a scalpel.

  The system control unit 32 includes a CPU that integrally controls each unit in the ultrasonic diagnostic apparatus, a DSP as a peripheral device of the CPU, a memory, and the like. The system control unit 32 stores setting values input from the input unit 34.

  The input unit 34 is configured by an operation panel having a keyboard and a trackball, and a user can make necessary settings for the system control unit 32 using the input unit 34. In the present embodiment, for example, a threshold value used when detecting an appliance can be set using the input unit 34.

  The system control unit 32 includes a beam scanning control unit 36, and the beam scanning control unit 36 controls the transmission beam former 38 and the reception beam former 42. In the present embodiment, the beam scanning control unit 36 performs timing control for radiating the ultrasonic beam, and at the same time, determines the scanning range of the ultrasonic beam. That is, the first beam scanning control for acquiring the first volume data by forming the first three-dimensional space, and the second beam scanning control for acquiring the second volume data by forming the second three-dimensional space. Any of these beam scanning controls is performed based on a command from the beam scanning control unit 36.

  In the present embodiment, the beam scanning control unit 36 exists as one function of the system control unit 32, but it may exist as an independent module. The substance of the beam scanning control unit 36 may be configured by hardware or software.

  The transmission beam former 38 has a voltage amplification unit for radiating ultrasonic waves from the transducer in the probe, and forms the ultrasonic beam 41 by performing delay setting for each vibration element. Specifically, under the control of the beam scanning control unit 36, the transmission beam former 38 generates a plurality of transmission signals having voltages for ultrasonic transmission. These transmission signals are output to a vibrating element in the probe 40 after timing control of each of the transmission signals.

  The probe 40 in the present embodiment is a 2D array transducer including a plurality of vibration elements. The transmission signal from the transmission beam former 38 is output to a plurality of vibration elements in the probe 40 after timing is controlled. The ultrasonic beam 41 is formed by operating a plurality of vibration elements in a coordinated manner. The transmission beam former 38 appropriately specifies the aperture size of the vibration element, the azimuth angle and the focal length of the ultrasonic beam 41, and the ultrasonic beam 41 is scanned in the direction of the scanning angle θ. By scanning the ultrasonic beam 41, the first scanning direction is determined, and a two-dimensional scanning surface is formed. A three-dimensional scanning space 43 is formed by spatially scanning the scanning surface. An echo signal obtained from the three-dimensional scanning space 43 is output to the reception beam former 42.

  In the present embodiment, the probe 40 is in contact with the body surface, and the target tissue 45 in the body is displayed as a diagnosis target in FIG. A puncture adapter 39 is attached to the probe 40, and a puncture needle 37 is attached to the puncture adapter 39. The puncture needle 37 is punctured into the living body by the puncture adapter 39 while the direction of the insertion path is determined.

  The reception beam former 42 includes an A / D conversion circuit and a phasing addition unit. The plurality of reception signals input to the reception beam former 42 are converted into digital signals to form a reception beam electronically, and then subjected to phasing addition by a phasing addition unit. The reception beamformer receives echo signals at the time of beam scanning of the preceding beam scanning control (first beam scanning control) and the subsequent beam scanning control (second beam scanning control), and these are temporally related. The signals are input to the reception beam former 42 at different timings. The preceding beam scanning control is, for example, scanning control performed on the entire scanable range. The signal acquired by the preceding beam scanning control is input to the reception beam former 42 as an echo signal having information on the entire space. The trailing beam scanning control is, for example, scanning control performed by narrowing the scanning range with respect to the instrument. The signal acquired by the trailing beam scanning control is input to the reception beam former 42 as an echo signal having information on the partial space of the instrument. The received signal after the phasing addition is output to the subsequent signal processing unit 44 as an echo signal for distinguishing each of the received signals.

  The signal processing unit 44 processes the echo signal output from the reception beam former 42. The signal processing unit 44 includes a circuit for performing logarithmic compression processing and dynamic range setting processing. The logarithmic compression processing circuit performs processing for uniformly averaging the amplitudes of a wide range of reflected ultrasonic signals from an object by logarithmic amplification. In the signal processing unit 44, basically, common signal processing is performed for each echo signal regardless of preceding or following beam scanning control. Each processed echo signal is sent as volume data to the position information detector 46 at the next stage.

  The position information detection unit 46 has detection means for specifying the position information of the instrument based on the volume data. The position information of the instrument is detected by the following method, for example.

  In general, since the reflected signal of an instrument inserted into the body has a high intensity, data indicating high luminance is processed as corresponding to the position where the instrument is present. A numerical value input from the input unit 34 or a numerical value recorded in advance in the system control unit 32 may be used as the threshold value serving as a luminance determination criterion.

  The volume data input to the position information detection unit is composed of a plurality of frame data, and each frame data is composed of a plurality of beam data. It is possible to determine at which scanning position and azimuth angle each piece of beam data is acquired because all the beam data is managed. Therefore, data having the position information of the instrument can be obtained by specifying high-luminance data on the beam data by threshold determination. Note that a histogram process may be used as a method for determining the luminance in addition to the threshold process.

  Information regarding the position of the instrument detected by the position information detection unit 46 is fed back to the beam scanning control unit 36. Based on the position information, the scanning range of the beam scanning control to be performed in the next scanning can be determined. That is, when the position of the instrument is specified by beam scanning and position detection, the beam scanning can be performed while paying attention to the position. The volume data used for detecting the position information is output from the position information detection unit 46 and input to the three-dimensional image forming unit 48.

  The three-dimensional image forming unit 48 has a memory for storing data for image formation. In the three-dimensional image forming unit 48, processing for converting original data obtained as volume data in a three-dimensional space into a voxel data set is performed using a memory. This data reconstruction process is a three-dimensional coordinate conversion process, and an aggregate of voxel data that does not depend on the scanning method of the probe's three-dimensional space is formed by this process. Furthermore, a known volume rendering process is performed using a collection of voxel data. By this processing, a three-dimensional display image is formed as if a set of voxel data is projected through the watermark, and the image is sent to the display unit 50.

  The display unit 50 includes a display processor and a display. The display processor has an image composition function, a color composition function, and the like. A CRT or LCD is used as the display. The data of the 3D display image sent to the display unit 50 is subjected to signal processing such as video signal processing, and the data is displayed as a visual image on the display device.

  As described in the above-described series of flows, the entire volume data is acquired by the command of the beam scanning control unit 36, and the position of the instrument is detected by the position information detection unit 46. Since the detected position information is fed back to the beam scanning control unit, beam scanning control corresponding to the position of the instrument is performed.

  The upper part of FIG. 2 shows a conceptual diagram of a three-dimensional spatial data capturing space when a 2D array probe is used. The puncture route is set by the puncture adapter, and the figure shows a state in which the puncture needle is inserted from the upper right side direction. In the upper part of FIG. 2, the vibration element surface 10 of the 2D array transducer and the volume data capturing space are schematically shown. An ultrasonic wave is transmitted from a plurality of vibration elements forming the vibration element surface 10 of the 2D array probe in accordance with an oscillation command signal subjected to time phase control from the transmission beam former 38. The ultrasonic waves transmitted from the plurality of vibration elements are formed as one ultrasonic beam 41 in the three-dimensional space. By scanning the ultrasonic beam 41 with a predetermined azimuth angle, a scanning space 43 having a quadrangular pyramid shape as shown in FIG. 2 is formed. The puncture needle 37 attached to the puncture adapter is inserted into the scanning space 43 from obliquely above.

  2 shows projection data 14 obtained by projecting a three-dimensional stereoscopic scanning space from above. The volume data corresponding to the partial area where the puncture needle 37 exists shows high luminance. Therefore, a partial area 16 corresponding to the portion where the puncture needle is present is specified on the projection data 14. The partial region 16 can specify a range from the X direction and the Y direction on the XY plane. In FIG. 2, the partial region 16 is shown as a region specified between x1 and x2 in the X direction, and is shown as a region specified between 0 and y1 in the Y direction. A margin can be provided so as to surround the rectangular partial region 16. In FIG. 2, a concave portion surrounding the partial region 16 is shown as a margin region 18.

  FIG. 3 is a diagram conceptually showing a state in which the ellipsoidal instrument 20 passes through the three-dimensional space 22. The volume rendering viewpoint 24 is set right above the three-dimensional space 22. In FIG. 3, the object of observation by ultrasonic waves is an ellipsoidal instrument 20 made of metal. Projection data observed from the viewpoint 24 obtained using the three-dimensional space 22 will be described with reference to FIG.

  FIG. 4 is an explanatory diagram showing the relationship between an instrument that accompanies movement and projection data that is the basis of a three-dimensional display image. Each of the four rectangular frames from (a) to (d) shown in FIG. 4 indicates projection data onto a plane when the three-dimensional space 22 is observed from the viewpoint direction described with reference to FIG. These projection data are conceptually similar to the projection data 14 shown in FIG. In terms of time, there is a change over time from the first acquired projection data (a) to the last acquired projection data (d). They are shown side by side over time. Each projection data shown in FIG. 4 captures how the instrument 20 moves in the ultrasonic three-dimensional scanning space.

  The projection data shown in FIG. 4A shows a state when the ellipsoidal component moving in the positive direction of the Y axis enters the three-dimensional scanning space. This projection data is obtained by the following operation. First, the entire beam data of the three-dimensional space 22 is acquired by executing the first beam scanning control. The position of the instrument 20 is detected by analyzing the volume data. In FIG. 4A, the detected position information is indicated as between x1 and x2 in the X direction, and is indicated by 0 (zero) to y1 in the Y direction. In FIG. 4A, the region including the instrument 20 is indicated by a rectangular region 26. Based on the position information, a margin is added in two directions of the XY directions. In FIG. 4A, margins of widths Δx1, Δx2, and Δy1 are set so as to surround the periphery of the instrument.

  Next, the operation of the second beam scanning control will be described. Since the second beam scanning control is scanning of a partial space corresponding to the instrument 20, the range of the scanning space is reduced as compared with the entire three-dimensional space 22. However, the range is set by expanding the margin not only to the portion corresponding to the instrument 20 but also to the range including the space. That is, for the scanning range in the X direction, (x1−Δx1) is set with the margin widened in the negative direction of the X axis. In addition, (x2 + Δx2) is set with a wider margin in the positive direction of the X axis. For the scanning range in the Y direction, (y1 + Δy1) is set with the margin widened in the positive direction of the Y axis. The area to which the margin is added is shown as a rectangular margin setting area 28a in the drawing. On the XY plane, the second beam scanning control is executed for this margin setting area 28a.

  The projection data shown in FIG. 4B is projection data obtained by the Nth beam scanning control. The projection data (b) shows a state in which the instrument 20 is further moved in the + Y direction. During the period from (a) to (b), the second to Nth beam scanning controls are executed. Even if the instrument 20 moves by executing the beam scanning control a plurality of times, the position information is updated every time the beam scanning control is executed, and projection data is generated accordingly. Even when the movement of the instrument 20 is fast, the position of the instrument can be specified by executing beam scanning control that scans the entire three-dimensional space 22, and based on the position information obtained therefrom. The projection data shown in (b) can be acquired.

  The projection data shown in FIG. 4C is projection data after the projection data (b) is acquired, and indicates the projection data acquired by executing the (N + M) -th beam scanning control (provided that N And M is an integer of 2 or more). Even if the instrument 20 moves, it is updated each time the beam scanning control is executed, so that projection data that follows the movement of the instrument 20 is created.

  The projection data shown in FIG. 4D shows projection data (d) obtained by the (N + M + 1) -th beam scanning control. From the state shown in the projection data (c), a state where the instrument 20 has moved slightly is shown. That is, the instrument 20 shown in the (N + M + 1) th projection data (d) has moved only within a range that falls within the margin setting area 28c set by the projection data (c). Since all the instruments 20 are within the margin setting area 28c, in the projection data (d), the position of the instrument 20 can be specified by scanning the partial space based on the margin setting area 28c. The margin setting area 28d can be set by updating the margin setting area.

  As described above, when the instrument 20 moves, the position information detection unit 46 analyzes either the volume data of the entire three-dimensional space or the volume data corresponding to the component space with a margin added. Thus, the position of the instrument 20 is specified, and beam scanning control corresponding to the position of the instrument 20 can be performed. Thereby, the appliance 20 can be automatically followed to perform three-dimensional display. Furthermore, the accuracy of real-time display can also be improved by improving the volume rate of data focused on the instrument 20. It is desirable to use a metal instrument that can perform such processing for a high-reflecting material and obtain high-luminance data in response to a reflected wave having a strong amplitude as an observation target.

  FIG. 5 is an explanatory diagram of image composition performed in the three-dimensional image composition unit. The image composition process shown in FIG. 5 is, for example, a process executed in the three-dimensional image forming unit 48 shown in FIG.

  FIG. 5A shows the entire three-dimensional space 52 for acquiring the entire volume data. That is, FIG. 5A schematically shows a first three-dimensional space which is a volume data capturing space by the Nth beam scanning control. FIG. 5B shows a three-dimensional space 54 of a part from which the volume data of the part is acquired. That is, FIG. 5B schematically shows a second three-dimensional space which is a partial volume data capturing space by the (N + 1) -th beam scanning control. Volume data acquired in each space is aligned and image-synthesized. In FIG. 5, volume data synthesizing means is indicated by reference numeral 56. Thereafter, the data is reconstructed as three-dimensional spatial data and converted into a collection of voxel data.

  FIG. 5C shows the converted voxel data aggregate 58. One viewpoint 60 for performing the volume rendering process is determined. Based on the viewpoint 60, a three-dimensional display image is formed as projection data obtained by projecting an aggregate of voxel data. By having the volume data synthesizing means in this way, it is possible to obtain a projection image paying attention to the position of the instrument.

  Here, the partial space of the instrument is also limited in the Z direction, and is set to be shallower than the entire three-dimensional space. That is, FIG. 5C shows that the depth z2 of the partial space of the instrument is smaller than the overall depth z1 of the three-dimensional space. This setting determines the diagnostic depth for imaging with attention to the instrument. By reducing the diagnostic depth, the amount of volume data in the portion including the instrument is reduced. As a result, it is possible to acquire volume data of an appropriate amount of a portion that is not excessive or insufficient for imaging the device. In addition, it is possible to reduce the data processing load required for the rendering process. A margin may also be provided in the depth direction Z.

  FIG. 6 is an explanatory diagram of a beam scanning sequence for data acquisition. The total volume data A shown in FIG. 6 is volume data acquired in the entire three-dimensional space 52 shown in FIG. The partial volume data B is volume data acquired in the three-dimensional space 54 corresponding to the appliance shown in FIG. 5 or volume data with a margin added thereto. In the beam scanning control unit, usually, a certain scanning pattern is repeatedly executed. A beam scanning sequence is formed by repeating the scanning pattern. FIG. 6 illustrates three specific scanning sequences (1), (2), and (3). These three beam scanning sequences are repetitions of unique scanning patterns.

  FIG. 6 (1) shows one of the repeated patterns, which is a beam scanning sequence in which partial volume data B is acquired with priority. In this beam scanning sequence, first, the entire volume data A as the entire scanning range is acquired once. Then, the position of the appliance is specified based on the entire volume data A. Based on the data, scanning of the partial volume data B is started next. The scanning of the partial volume data B is repeated 5 times continuously. After obtaining the entire volume data A once and obtaining the partial volume data B five times, beam scanning control is performed by repeating the scanning pattern. According to such scanning, since the entire volume data A is acquired intermittently, it is possible to grasp the position of the instrument without losing its position regardless of the position of the instrument. The data B can be followed intensively. That is, there is an effect that a high-quality instrument can be acquired.

  FIG. 6 (2) shows an example of a scanning sequence in which the entire volume data A and the partial volume data B are alternately and repeatedly acquired. That is, the entire volume data A is acquired once, and the partial volume data B is acquired by specifying the position of the instrument there. In this scanning method, the number of acquisitions of both volume data is equal. Therefore, even when the position of the tool is difficult to identify with a fast-moving instrument, or when the contact angle of the probe is unstable and it moves, the entire scanning will be over. Is repeated, the position of the instrument can be accurately specified. Alternatively, there is an effect that a clear image can be obtained when the biological tissue moves quickly, for example, when an instrument is displayed together with a heart valve.

  FIG. 6 (3) shows a beam scanning sequence in which the entire volume data A is acquired once, and thereafter, the partial volume data B mainly including the instrument is continuously acquired. In this beam scanning sequence, after the initial position of the instrument is specified based on the entire volume data A, a three-dimensional display image is formed mainly in the partial space of the instrument. Since the image of the living tissue is formed only by the first scan, it is effective when the living tissue hardly moves. That is, in contrast to the case where the living tissue depicted in the entire space hardly moves, the beam scanning sequence is effective when the instrument grasped in the partial space moves relatively quickly. Since the image that captures the device is updated as needed based on the latest partial volume data B, it is possible to accurately capture the fast-moving device on the image and display the device clearly with high-accuracy images. You can also. There is an effect that the movement of the instrument can be accurately captured for a living tissue with little movement.

  The three illustrated beam scanning sequences each have unique advantages. It is desirable to select an optimal beam scanning sequence as appropriate according to the size of the object and the characteristics of the movement. In the three beam scanning sequences, the volume data A, the volume data B, the switching order, and the number of updates of the volume data are specifically shown only as an example, and the number of updates may be changed as appropriate. However, it is also possible to combine the respective sequences.

  In this way, by executing the beam scanning sequence based on the position of the instrument, as described below, the number of 3D images updated per second (volume rate) is improved with respect to the instrument to be displayed in three dimensions. There is an advantage that the image quality can be improved.

  That is, when displaying the living body tissue in the body on the ultrasonic image, first, the whole image of the target living tissue is displayed. For example, even when puncturing is performed, after a wide display range is set and the whole is confirmed, puncturing is performed after specifying the puncture site of the living tissue. Here, when the puncture target is a large biological tissue such as the uterus, placenta, or liver, it is necessary to widen the scanning space in order to display the whole. Therefore, when trying to acquire volume data by displaying a large living tissue for puncture, the number of scanning lines of the ultrasonic beam decreases, the frame interval becomes rough, and the image quality deteriorates or is updated every second. This reduces the number of three-dimensional images (volume rate). However, as described above, by performing the beam scanning control based on the position of the instrument and executing the optimum beam scanning sequence, the volume rate related to the instrument is improved and the image quality of the instrument can be improved. Furthermore, the data processing time required for imaging the biological tissue can be greatly reduced.

It is a functional block diagram which shows the structure of the ultrasonic diagnosing device which concerns on this invention. It is a conceptual diagram of the data taking-in space in a three-dimensional space at the time of using a 2D array probe. FIG. 3 is a diagram conceptually illustrating a state in which an elliptical instrument 20 passes through a three-dimensional space 22. It is explanatory drawing which shows the relationship between the apparatus with a motion, and the projection data used as the basis of a three-dimensional display image. It is explanatory drawing of the image composition performed in a three-dimensional image composition part. It is an explanatory diagram of a beam scanning sequence for data capture.

Explanation of symbols

10 vibration element plane, 14 projection data, 16 partial area, 18 margin area, 20 instrument, 22 three-dimensional space, 24 viewpoints, 26 area, 28a, 28b, 28c, 28d margin setting area, 32 system control section, 34 input section 36 beam scanning control unit, 37 puncture needle, 38 transmitting beam former, 39 puncturing adapter, 40 probe, 41 ultrasonic beam, 42 receiving beam former, 43 scanning space, 44 signal processing unit, 45 tissue of interest, 46 position information detection unit, 48 three-dimensional image forming unit, 50 display unit, 52, 54 three-dimensional space, 56 data synthesis means, 58 voxel data aggregate, 60 viewpoints.

Claims (7)

A means for executing a control for forming a three-dimensional space in a living body by two-dimensionally scanning an ultrasonic beam, and executing a first beam scanning control for obtaining a first volume data by forming a first three-dimensional space. Beam scanning control means,
Position information detecting means for detecting position information of the instrument inserted into the living body based on the first volume data;
Including
The beam scanning control means further executes second beam scanning control for acquiring second volume data by forming a second three-dimensional space as a partial space including the instrument based on the position information.
An ultrasonic diagnostic apparatus. The ultrasonic diagnostic apparatus according to claim 1,
The beam scanning control means includes
When the first beam scanning control is executed, the first three-dimensional space as an entire space is formed,
When the second beam scanning control is executed, the second three-dimensional space included in the first three-dimensional space is formed.
An ultrasonic diagnostic apparatus. The ultrasonic diagnostic apparatus according to claim 1,
The beam scanning control means includes
When the first beam scanning control is performed, a first three-dimensional space is formed as a partial space including the instrument,
When the second beam scanning control is executed, a partial space that partially overlaps the first three-dimensional space following the movement of the instrument from the first beam scanning control to the second beam scanning control. Forming a second three-dimensional space as
An ultrasonic diagnostic apparatus. The ultrasonic diagnostic apparatus according to claim 1,
The instrument position information is information representing an instrument presence range in at least one of the first scanning direction and the second scanning direction,
The beam scanning control means sets a beam scanning range for forming the second three-dimensional space by adding a margin to the instrument existing range.
An ultrasonic diagnostic apparatus. The ultrasonic diagnostic apparatus according to claim 4,
The position information of the instrument is information representing the existence range of the instrument in each of the first scanning direction, the second scanning direction, and the depth direction,
The beam scanning control means sets a beam scanning range for forming the second three-dimensional space by adding a margin to the existing range of the instrument in the first scanning direction and the second scanning direction,
The beam scanning control means sets the diagnostic depth based on the presence range of the instrument in the depth direction.
An ultrasonic diagnostic apparatus. The ultrasonic diagnostic apparatus according to claim 1,
The beam scanning control unit executes beam scanning control according to a beam scanning sequence in which the first beam scanning control and the second beam scanning control are combined.
An ultrasonic diagnostic apparatus. The ultrasonic diagnostic apparatus according to claim 1,
Combining means for combining the first volume data and the second volume data based on the positional relationship between the first and second three-dimensional spaces;
3D image forming means for forming a 3D display image based on the combined volume data generated by the combining means;
An ultrasonic diagnostic apparatus comprising:

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