JP5543681B2 - Ultrasonic diagnostic equipment - Google Patents

Description

  The present invention relates to an ultrasonic diagnostic apparatus, and in particular, a reference image having the same cross section as an image on an ultrasonic scan plane is obtained by using reference volume data created by, for example, an X-ray CT apparatus or a magnetic resonance imaging (MRI) apparatus. The present invention relates to an ultrasonic diagnostic apparatus suitable for construction in real time and displaying on a display.

  2. Description of the Related Art Ultrasonic diagnostic apparatuses that irradiate a subject with ultrasound and image the structure inside the subject using reflected echo signals are widely used because non-invasive and real-time observation is possible.

  On the other hand, medical diagnostic imaging apparatuses such as an X-ray CT apparatus and a magnetic resonance imaging (MRI) apparatus can image a wide range with high resolution, so that it is possible to easily grasp a detailed relationship between a lesion and an organ. . In particular, in recent years, contrast agents for X-ray CT apparatuses have become widespread, and for example, the detection ability for diagnosis of liver cancer or the like has been dramatically improved.

  In the ultrasonic diagnostic apparatus, a position sensor is attached to the probe to calculate an ultrasonic scan plane, and the reference volume data obtained from the medical image diagnostic apparatus is used to obtain a two-dimensional image having the same cross section as the ultrasonic scan plane. Attempts have been made to construct a reference image composed of tomographic images and display it on a display screen.

In such an attempt, for example, in Patent Document 1 below, a reference image consisting of a characteristic cross section including, for example, a blood vessel is reconstructed from reference volume data, and the same ultrasonic tomographic image is reconstructed from this reference image. It is disclosed to perform the alignment between the reference volume data and the subject by extraction.
JP 2003-130490 A

  However, both the ultrasonic tomographic image and the reference image from the volume data that are compared at the time of alignment are imaged as including blood vessels at the same location, but the coordinates of these tomographic images are completely identical. In some cases, there is a case where a deviation occurs between the ultrasonic tomogram imaged according to the position of the probe and the reference image.

  That is, each tomographic image specified at the time of alignment has a reference for a characteristic part such as the blood vessel, but the tomographic image on which the reference is displayed is not uniquely determined. The inconvenience described above occurs.

  An object of the present invention is to avoid the occurrence of a shift in the reference image with respect to the scan plane of the ultrasonic tomogram imaged according to the position of the probe, and to improve the alignment of each tomographic plane. The object is to provide an ultrasonic diagnostic apparatus.

  Of the inventions disclosed in this application, the outline of typical ones will be briefly described as follows.

(1) An ultrasonic diagnostic apparatus according to the present invention obtains a reference image corresponding to an ultrasonic tomographic image of a subject from reference volume data of the subject by a medical diagnostic imaging apparatus including an X-ray CT apparatus or a magnetic resonance imaging apparatus. An ultrasonic diagnostic apparatus for creating and displaying, wherein the ultrasonic diagnostic apparatus is an apparatus for creating and displaying an ultrasonic tomographic image obtained through a probe brought into contact with an arbitrary part of the subject. Position information detected by a position sensor provided in the probe, the position sensor detecting position information of the probe in a coordinate system of the subject lying on a bed in a certain posture It means but to create ultrasound volume data of the subject constructed by a plurality of ultrasonic tomographic images associated, the less the pre-Symbol reference volume data Means for associating a coordinate system of the reference volume data and the ultrasonic volume data based on a tomographic image at two orthogonal cross sections and a tomographic image at at least two orthogonal cross sections of the ultrasonic volume data; after the volume data is created, the under the condition that the subject is lying in the predetermined posture on the bed, on the basis of the relationship association was coordinate system, the is contact at any site of the object A reference image of a cross section corresponding to position information detected by the position sensor of the probe, and an ultrasonic tomographic image obtained through the probe abutted at an arbitrary part of the subject. And a means for displaying.

(2) An ultrasonic diagnostic apparatus according to the present invention obtains a reference image corresponding to an ultrasonic tomographic image of a subject from reference volume data of the subject by a medical diagnostic imaging apparatus including an X-ray CT apparatus or a magnetic resonance imaging apparatus. an ultrasonic diagnostic apparatus creates, displays, before Symbol ultrasonic diagnostic apparatus creates an ultrasonic tomographic image obtained through abutment been probe at any site of the subject, to the display device A position sensor that is provided in the probe, the position sensor detecting position information of the probe in the coordinate system of the subject lying on the bed in a certain body position. information means for creating ultrasonic volume data of the subject constructed by a plurality of ultrasonic tomographic images associated, before Symbol reference volume data and the ultrasonic sound Means for associating a coordinate system of the reference volume data and the ultrasound volume data based on matching of the same feature portions of each of the volume data, and after the ultrasound volume data is created, the subject under the condition that lying in the predetermined posture on the bed, on the basis of the relationship association was coordinate system, detected by the said position sensor of the probe is contact at any site of the object And a means for displaying the reference image of the cross section corresponding to the position information and an ultrasonic tomographic image obtained through the probe abutted on an arbitrary part of the subject.

  In addition, this invention is not limited to the above structure, A various change is possible in the range which does not deviate from the technical idea of this invention.

  The ultrasonic diagnostic apparatus configured in this way avoids the occurrence of a shift in the reference image with respect to the scan plane of the ultrasonic tomographic image that is imaged according to the position of the probe, and aligns each tomographic plane. Improvements can be made.

  Embodiments of an ultrasonic diagnostic apparatus according to the present invention will be described below with reference to the drawings.

  FIG. 2 is a schematic block diagram showing an embodiment of the ultrasonic diagnostic apparatus according to the present invention. In the figure, first, there is a probe 10 used in contact with a subject 200. The probe 10 includes a plurality of ultrasonic transducers arranged in parallel, and the probe 10 is provided with, for example, a position sensor 20 that will be described in detail later.

  The probe 10 transmits ultrasonic waves into the subject 200 by the transmission / reception unit 12, and the ultrasonic waves reflected from the subject 200 are received as reflected echo signals by the transmission / reception unit 12, and are amplified, analog-digital Processing such as conversion and phasing addition is performed.

  A signal from the transmission / reception unit 12 is input to an ultrasonic image creation unit 14, and the ultrasonic image creation unit 14 creates ultrasonic tomographic image data on an ultrasonic scan plane from the probe 10. It has become.

  The ultrasonic tomographic image data is stored in the image memory 16 and further input to the display 18 via the synthesizing unit 60, and the ultrasonic tomographic image is displayed on the screen. The ultrasonic tomographic image is a tomographic image on the scanning surface of the ultrasonic wave from the probe 10.

  Further, data of other images to be described later is also input to the synthesis unit 60, and these other images are displayed on the screen of the display 18 together with the ultrasonic tomographic image. ing.

  Here, as another image, so-called ultrasonic volume data is constructed, a tomographic image of an arbitrary cross section in the ultrasonic volume data, and an apparatus configured separately from the ultrasonic diagnostic apparatus according to the present invention. For example, reference volume data is input from a medical diagnostic imaging apparatus (indicated by reference numeral 100 in FIG. 2) composed of, for example, an X-ray CT apparatus or a magnetic resonance imaging (MRI) apparatus, and an arbitrary cross section in this reference volume data It is a tomographic image.

  The ultrasonic volume data can be constructed from a plurality of tomographic images (slice images) sequentially obtained by moving the probe 10 in a direction perpendicular to the ultrasonic scan plane, for example, and each of the tomographic images at this time. The image is associated with position information based on a signal from the position sensor 20 provided in the probe 10.

  The position sensor 20 includes a magnetic sensor that detects, for example, a magnetic signal generated from a source 22 attached to a bed or the like on which the subject 200 is lying, and the position information (three-dimensional) of the probe 10 in the source coordinate system. (A typical position and inclination) are detected. The position sensor 20 and the source 22 are not limited to those using a magnetic field, and may use, for example, light.

  That is, by moving the probe 10 in a direction orthogonal to the ultrasonic scan plane, for example, tomographic images on the respective scan planes are obtained from the ultrasonic image creation unit 14, and each of these tomographic images is volume data constructed. It is input to the unit 26.

  On the other hand, in the process of movement of the probe 10, signals from the position sensor 20 and the source 22 are input to the probe coordinate calculation means 56, and the position of the probe 10 is detected by the probe coordinate calculation means 56. Information is calculated, and this position information is input to the volume data construction unit 26.

  In this case, the probe coordinate calculation means 56 is driven by input of a signal through the control unit 50 in accordance with an operation indicating volume data construction on the console 58.

  In the volume data construction unit 26, the position information is associated with each of the tomographic images input from the ultrasound image creation unit 14, and ultrasound volume data with a three-dimensional coordinate axis is created.

  The ultrasonic volume data created by the volume data construction unit 26 is stored in the volume data storage unit 28, and a tomographic image of an arbitrary cross section is created from the ultrasonic volume data by the arbitrary tomographic image creation unit 30. Yes. The tomographic image of this arbitrary cross section will be apparent from later description, and is created including, for example, each tomographic image composed of three orthogonal cross sectional images.

  In the arbitrary tomographic image creating unit 30, for example, each tomographic image of a preset cross section is created in the initial stage, and each tomographic image is stored in the image memory 32, and further, the display 18 through the synthesizing unit 60. The tomographic image is displayed. In this case, the operator observes each tomographic image displayed on the screen of the display 18 and responds to a cross section that changes by moving or rotating the cross section of each tomographic image by operating the console 58, for example. The tomographic image can be changed and displayed.

  That is, a signal corresponding to the operation from the console 58 is input to the display cross section calculation means 52A via the control unit 50, and is selected by the display cross section calculation means 52A according to the operation of the console 58. Information on the cross section is calculated.

  The information of the new cross section calculated by the display cross section calculating means 52A is sent to the arbitrary tomographic image creation unit 30, and the arbitrary tomographic image creation unit 30 creates the tomographic image of the cross section. This tomographic image is stored in the image memory 32, and further input to the display 18 via the synthesizing unit 60, and a tomographic image whose cross section is changed is displayed on the screen.

  Further, the reference volume data is input from the medical image signal device 100, stored in the volume data storage unit 40, and an arbitrary tomographic image generating unit 42 generates a tomographic image of an arbitrary cross section from the volume data. It has become. This tomographic image of an arbitrary cross section will be apparent from later description, but is created including, for example, each tomographic image including three orthogonal cross-sectional images.

  In this arbitrary tomographic image creating unit 42, for example, each tomographic image of a preset cross section is created in the first stage, each of these tomographic images is stored in the image memory 44, and further, the display 18 through the synthesizing unit 60. Each tomographic image is displayed. In this case, the operator observes each tomographic image displayed on the screen of the display 18 and, for example, operates a console 58 to display a tomographic image that changes by moving or rotating the cross section of the tomographic image. It can be displayed.

  That is, a signal corresponding to the operation from the console 58 is input to the display section calculation means 52B via the control unit 50, and is selected by the display section calculation means 52B according to the operation of the console 58. Cross-section information is calculated.

  The information of the new cross section calculated by the display cross section calculating means 52B is sent to the arbitrary tomographic image creating unit 42, and the arbitrary tomographic image creating unit 42 creates the tomographic image of the cross section. This tomographic image is stored in the image memory 44 and further input to the display 18 via the synthesizing unit 60, and the tomographic image whose cross section is changed is displayed on the screen.

  On the screen of the display 18, as described above, at least the three orthogonal cross-sectional images obtained from the ultrasonic volume data and the three orthogonal cross-sectional images obtained from the reference volume data are displayed. By changing the cross section of the image, it is possible to confirm the coincidence of the cross sections of the respective tomographic images. This means that the coordinate system of the three-dimensional image of the ultrasonic volume data and the three-dimensional image of the reference volume data can be matched.

  For example, the console 58 is provided with a button, and when the operator can confirm that the cross sections of the respective tomographic images match through the screen of the display 18, the signal is transmitted via the control unit 50 by pressing the button. Are input to the alignment means 54, and the alignment means 54 is driven.

  In the alignment means 54, based on the information in the display cross section calculation means 52A and the display cross section calculation means 52B, a unique relationship between the coordinate system of the ultrasonic volume data and the coordinate system of the reference volume data is made. Is calculated as a parameter, for example. This parameter corresponds to, for example, the amount of movement of the tomographic image of the three orthogonal cross sections moved by operating the console 58. The amount of movement of the tomographic image of the three orthogonal cross sections refers to the three orthogonal cross sections calculated by the display cross section calculating means 52A and the display cross section calculating means 52B by moving the respective orthogonal three cross sectional images on the XY, YZ, and ZX planes. This is the amount of movement of the coordinates of the image. When an arbitrary cross section is specified in the ultrasonic volume data, this parameter can be used to calculate a cross section on the reference volume data at the same location as the cross section. The parameters are stored in the memory 54a in the positioning means 54.

  Thereafter, the probe 10 is brought into contact with an arbitrary part of the subject 200, a tomographic image obtained through the probe 10, and a tomographic image in the same cross section as the tomographic image, the reference volume data. And the tomographic image extracted from the image can be displayed on the screen of the display 18.

  That is, the reflected echo signal from the probe 10 is generated as tomographic image data via the transmitting / receiving unit 12 and the ultrasonic image generating unit 14, and this tomographic image data is stored in the image memory 16, the synthesizing unit 60, and the display. It is displayed as a tomographic image through the device 18.

  On the other hand, the signal from the position sensor 20 provided in the probe 10 is input to the probe coordinate calculation means 56, and the probe coordinate calculation means 56 calculates the position information of the probe 10. .

  The position information of the probe 10 is input to the display section calculation means 52B. The display section calculation means 52B obtains tomographic images in the same section as the scan plane corresponding to the position information of the probe 10 as volume data. It is extracted from the storage unit 40 and created by an arbitrary tomographic image creation unit 42.

  In this case, the three-dimensional coordinate system in the position information of the probe 10 is the same as the three-dimensional coordinate system of the ultrasonic volume data created by the volume data construction unit 26. This means that the cross section on the same reference volume data as the cross section of the tomographic image obtained by the probe 10 can be calculated from the position information of the probe 10 using the parameters.

  Therefore, the display cross section calculation means 52 generates a reference image in the same cross section as the scan plane corresponding to the position information of the probe 10 based on the parameters stored in the memory 54a in the alignment means 54. Extraction from the volume data storage unit 40 is possible.

  The reference image extracted from the volume data storage unit 40 is stored in the image memory 44, and is further input to the display 18 via the synthesis unit 60 and displayed on the screen.

  FIG. 3 is a flowchart showing an embodiment of the operation of the ultrasonic temple apparatus configured as described above. In FIG. 3, the left side shows the operation of the operator (User), and the right side shows the operation on the apparatus side.

  First, the operator sends a command to load the reference volume data of the subject 200 (step S1). As a result, the apparatus reads the reference volume data from the medical image diagnostic apparatus 100 into the volume data storage unit 40 (step S′1), and further converts each tomographic image of the orthogonal three-section image from the reference volume data to an arbitrary tomographic image. While creating by the preparation part 42, this orthogonal three cross-sectional image is displayed on the screen of the indicator 18 (step S'2).

  For each tomographic image of the three orthogonal cross-sectional images at this stage, for example, a tomographic image in a preset cross-section is created by the arbitrary tomographic image creating unit 42 and displayed on the display 18. This is because it is an orthogonal three-section image in the first stage in which the section of each tomographic image of the orthogonal three-section image can be moved or rotated by a later operation.

  The operator scans ultrasonic waves (US) with the probe 10 in contact with the subject 200, and moves the probe 10 in a direction perpendicular to the surface of the scan, for example. Is irradiated with ultrasonic waves (step S2).

  As a result, the present apparatus acquires the ultrasonic image (US image) and the position information of the probe 100 by the probe coordinate calculation means 56 by the ultrasonic image creating unit 14 (step S′3), and this position. Based on the information, the volume data construction unit 26 constructs ultrasound volume data from the tomographic images of the respective scan planes of the ultrasound obtained in the process of moving the probe 10 (step S′4). Then, each tomographic image is generated as an orthogonal three-section image from the ultrasonic volume data by the arbitrary tomographic image generating unit 30 and displayed on the display 18.

  For each tomographic image of the orthogonal three cross-sectional images at this stage, for example, a tomographic image in a preset cross-section is created by the arbitrary tomographic image creating unit 30 and displayed on the display 18. This is because it is an orthogonal three-section image in the first stage in which the section of each tomographic image of the orthogonal three-section image can be moved or rotated by a later operation.

  A detailed description of the construction of the ultrasonic volume data in step S′4 will be given later with reference to FIG.

  Here, FIG. 1 is a diagram showing one form of image display on the display 18. In FIG. 1, each tomographic image of the orthogonal three cross-sectional images from the reference volume data is displayed on the upper part thereof, and each tomographic image of the orthogonal three cross-sectional images from the ultrasonic volume data is displayed on the middle part, In the lower part, a composite image is displayed by superimposing the corresponding tomographic images of the three orthogonal cross-sectional images from the reference volume data and the three orthogonal cross-sectional images from the ultrasonic volume data.

  More specifically, reference volume data Vc and cross sections CT1, CT2, and CT3 displayed orthogonal to each other in the reference volume data Vc are displayed in the leftmost column portion in the upper stage. This is a display for clarifying the positional relationship of each tomographic image to be described later in reference volume data Vc. Then, the tomographic image at the section CT1, the tomographic image at the section CT2, and the tomographic image at the section CT3 in the reference volume data Vc are sequentially displayed in parallel from the leftmost column to the right columns. An organ including the same blood vessel VS is displayed in each of the tomographic image in the cross section CT1, the tomographic image in the cross section CT2, and the tomographic image in the cross section CT3. A traveling line LN is displayed. For example, in the tomographic image at the cross section CT1, each line LN indicates a cross line with the cross section CT2 and a cross line with the cross section CT3. This is because the positional relationship can be easily grasped from each tomographic image in each of the cross sections CT1, CT2, and CT3.

  Further, in the middle stage, similarly to the upper stage, the leftmost column portion includes the ultrasonic volume data Vu and the cross sections US1, US2, US3 displayed orthogonal to each other in the ultrasonic volume data Vu. Is displayed. Then, the tomographic image at the cross section US1, the tomographic image at the cross section US2, and the tomographic image at the cross section US3 in the ultrasonic volume data Vu are sequentially displayed in parallel from the leftmost column to the right columns. Similarly to the display in the upper stage, the lines NL that cross each other at the center of the tomographic image at the cross section US1, the tomographic image at the cross section US2, and the tomographic image at the cross section US3 are displayed.

  Such display includes a tomographic image of the cross section CT1 in the reference volume data Vc, a tomographic image of the cross section US1 in the ultrasonic volume data Vu, a tomographic image of the cross section CT2 in the reference volume data Vc, and a tomographic image of the cross section US2 in the ultrasonic volume data Vu. The tomographic image of the cross section CT3 in the image and reference volume data Vc and the tomographic image of the cross section US3 in the ultrasonic volume data Vu are arranged close to each other so that they can be easily compared.

  Further, in the lower stage, a composite image (CT1 + US1) of these tomographic images, which can be determined whether or not the tomographic image in the cross section CT1 and the tomographic image in the cross section UT1 are completely coincident with each other, are to be compared with each other. A combined image (CT2 + US2) of these tomographic images that can determine whether or not the tomographic image at the cross section CT2 and the tomographic image at the cross section UT2 are completely coincident with each other, and the tomographic image at the cross section CT3 and the tomographic image at the cross section UT3 And a combined image (CT3 + US3) of these tomographic images that can be determined whether or not they completely coincide with each other.

  Each tomographic image is displayed on the same scale. This is to facilitate comparison. The composite image is, for example, a translucent color composite of each tomographic image of the orthogonal three cross-sectional images from the reference volume data and each tomographic image of the orthogonal three cross-sectional images from the ultrasonic volume data by alpha blending or the like. Alternatively, a tomogram of one tomogram extracted and superimposed on the other is adopted. The composite image is displayed because it is convenient to grasp the degree of positional deviation between the orthogonal three-section image from the reference volume data and the orthogonal three-section image from the ultrasonic volume data.

  In addition to the above-described image display, buttons B1 and B2 such as synchronous, asynchronous, movement, and rotation are displayed on the display surface of the display 18. For example, a mouse provided on the console 58 is used to display the display surface on the display surface. It can be operated by a moving pointer. Both are buttons for matching the tomographic images of the orthogonal three cross-sectional images from the reference volume data and the tomographic images of the orthogonal three cross-sectional images from the ultrasonic volume data.

  A Registration button B3 is also displayed, and is operated when it is determined that the tomographic images of the orthogonal three cross-sectional images from the reference volume data and the tomographic images of the orthogonal three cross-sectional images from the ultrasonic volume data are matched. It is a button. That is, this Registration button B3 functions as an alignment completion button B3. In this embodiment, the Registration button B3 is provided as being displayed on the screen of the display 18. However, as another embodiment, the Registration button B3 may be provided directly on the console 58.

  In FIG. 1, the case where the three orthogonal cross-sectional images from the reference volume data and the three orthogonal cross-sectional images from the ultrasonic volume data are all matched is drawn. However, it is normal that the initial orthogonal three-section images when displayed on the display 18 in step S′2 and step S′5 in FIG. 3 do not coincide with each other.

  Therefore, returning to the description in FIG. 3, as shown in step 3, the operator moves or rotates the display surface of each tomographic image of the orthogonal three-section image through the screen of the display 18. This is for the purpose of matching the orthogonal three-section image obtained from the reference volume data with the orthogonal three-section image obtained from the ultrasonic volume data.

  The movement or rotation of the display surface of each tomographic image of the orthogonal three-section image can be performed by operating a mouse provided in the console 58, for example. The position of the cross section can be switched by moving the display surface in the front-rear direction (depth direction) on the two-dimensional image, and the cross section can be rotated by rotating the display surface about the display axis. Can do.

  In this case, a synchronization button is installed, the synchronization button is set to the synchronization mode, and the movement or rotation of the display surface in one orthogonal three-section image is synchronized with the movement or rotation of the display surface in the other orthogonal three-section image. You may make it changeable.

  The mouse operation by such an operator is performed on the apparatus side by updating the orthogonal three-section image from the reference volume data (step S′6) and updating the orthogonal three-section image from the ultrasonic volume data (step S ′). 7) is performed, and a composite image is created and displayed (step S'8).

  The update of each orthogonal three-section image and the creation and display of a composite image are performed by the operator through the display unit 18, each sectional view (reference image) of the orthogonal three-section image from the reference volume data and the orthogonal three-section from the ultrasonic volume data. The process is continued until it is determined that each cross-sectional view (US image) of the cross-sectional image is the same image (step S4).

  Then, it is determined that each cross-sectional view (reference image) of the three orthogonal cross-sectional images from the reference volume data and each cross-sectional view (US image) of the three orthogonal cross-sectional images from the ultrasound volume data are the same image. If it has been done, the operator presses a registration completion button (Registration button) B3 (step S5).

  When this alignment complete button B3 is pressed, the present apparatus aligns the display parameters in the three orthogonal cross-sectional images from the ultrasonic volume data, that is, the display parameters calculated by the display cross-section calculating means 52A at this time. The parameters are stored in the memory 54a of the positioning means 54 (step S'9). Further, the display parameters in the three orthogonal cross-sectional images from the reference volume data, that is, the display parameters calculated by the display cross-section calculating unit 52B at this time are stored in the memory 54a of the alignment unit 54 as alignment parameters. (Step S′9).

  A detailed description of each alignment parameter (display parameter) in steps S′9 and S′10 will be described later with reference to FIG.

  Here, the display parameter indicates the intersection and direction of each cross-sectional view of the orthogonal three cross-sectional images, and is specifically expressed by the following determinant (1).

[r11 r12 r13 x
r21 r22 r23 y
r31 r32 r33 z
0 0 0 1] (1)
In this determinant (1), x, y, and z are parameters representing the coordinates of the intersection of each cross-sectional image of the orthogonal three cross-sectional image, and r11 to r33 represent the direction of each cross-sectional image of the orthogonal three-sectional image. It is a parameter.

  Assuming that there is no change in the body position of the subject 200 from the acquisition of the ultrasound volume data to the present, the coordinate system of the ultrasound volume data is considered as the current coordinate system of the subject 200. be able to.

  For this reason, the current coordinate system obtained from the probe 10 of the subject is related to the coordinate system of the reference volume data. This is because the three orthogonal cross-sectional images from the reference volume data and the three orthogonal cross-sectional images from the ultrasonic volume data are matched, and their coordinate systems are matched.

  Therefore, after that, when an ultrasonic tomographic image is obtained by the probe 10, a reference image on the same tomographic plane as the ultrasonic tomographic image is created from the reference volume data based on the display parameter corresponding to the tomographic plane. This reference image is displayed on the display 18 (step S′11).

  FIG. 4 shows a process of constructing ultrasonic volume data from each tomographic image (slice image) sequentially obtained based on position information from the position sensor 20 of the probe 10 in step S′4 shown in FIG. In the explanatory diagram, the construction of the ultrasonic volume data is performed by the volume data construction unit 6 shown in FIG.

  FIG. 4A shows a source coordinate system SO, a probe coordinate system PR, and an ultrasound volume data coordinate system UV together with the subject 200. Information on the source coordinate system SO and the probe coordinate system PR is sent via the probe coordinate calculation means 56, and information on each tomographic image (slice image) is sent via the ultrasonic image creation unit 14 to volume data. It is input to the construction unit 6.

  FIG. 4B shows a coordinate system CV of reference volume data for comparison with the coordinate system UV of the ultrasonic volume data.

  The ultrasonic volume data is constructed by the following equation (2) using a transformation matrix UV2PR between the coordinate system UV and the coordinate system PR of the probe 10.

(X_vol, y_vol, z_vol)
= UV2PR · (x_2D, y_2D, 0) (2)
Here, (x_vol, y_vol, z_vol) are coordinates on the ultrasonic volume, and x_2D, y_2D are coordinates on a tomographic image (slice image) created by the probe 10.

  The conversion matrix UV2PR is expressed by the following equation (3).

UV2PR = UV2SO / SO2PR
= (SO2UV) ^-1 · SO2PR (3)
SO2PR represents a transformation matrix from the coordinate system SO of the source 22 to the coordinate system PR of the probe 10, and the output from the position sensor 20 attached to the source 22 and the probe 10 is used as the above-mentioned. It is calculated by the probe coordinate calculation means 56.

  SO2UV represents a transformation matrix from the source coordinate system SO to the coordinate system UV of the ultrasonic volume data, and is defined by the position of the probe 10 at the time when the coordinate system UV of the ultrasonic volume data is started to move. As a result, the probe coordinate calculation means 56 calculates the output from the position sensor 20 when the probe 10 starts to move.

  Therefore, by performing the above-described calculation, it is possible to construct ultrasonic volume data to which the above-described coordinate information is attached.

  FIG. 5A shows the coordinate system UV of the ultrasonic volume data created as described in FIG. 4 and the coordinate system UP of the ultrasonic tomographic image, which are related to each other. The conversion from the coordinate system UV of the sound wave volume data to the coordinate system UP of the ultrasonic tomographic image (US image) can be performed using the conversion matrix UV2UP.

  This conversion matrix UV2UP corresponds to the alignment parameter calculated in step S'9 shown in FIG. Then, the alignment parameter which is the transformation matrix UV2UP is calculated by the display section calculating means 52A in the description of FIG. 2, and thereafter stored in the memory 54a of the alignment means 54. As described above.

  In FIGS. 5A and 5B, when the coordinate system UP of the ultrasonic tomographic image and the coordinate system CP of the reference image are matched, the coordinate system of the ultrasonic volume data is used. The coordinate system CV of UV and reference volume data is designed so that a certain relationship can be established between them.

  That is, the relationship between the coordinate system UV of the ultrasonic volume data and the coordinate system CV of the reference volume data can be expressed by a transformation matrix UV2CV shown in the following equation (4).

UV2CV = UV2UP / UP2CP / CP2CV (4)
Here, the coordinate system UP of the ultrasonic tomographic image and the coordinate system CP of the reference image are determined by matching the three orthogonal cross-sectional images through the screen of the display 18 (determined by the operation of the Registration button B3). Therefore, UP2CP = 1.

  Therefore, the equation (4) can be easily expressed as shown in the following equation (5).

UV2CV = UV2UP ・ CP2CV
= UV2UP · (CV2CP) ^-1 (5)
Therefore, by using the alignment parameters UV2UP and CV2CP, the unique relationship between the coordinate system UV of the ultrasonic volume data and the coordinate system CV of the reference volume data can be expressed.

  The relationship between the coordinate system UV of the ultrasonic volume data and the coordinate system CV of the reference volume data is as follows. In the alignment means 54 shown in FIG. 2, each position consisting of the transformation matrix UV2UP and the transformation matrix CV2CP stored in the memory 54a. Calculations are made based on the alignment parameters.

  Then, after the coordinate system UV of the ultrasonic volume data and the coordinate system CV of the reference volume data are related to each other (after the operation of the Registration button B3), the coordinate system PR of the probe 10 and the reference A transformation matrix PR2CV with the coordinate system CV of volume data is calculated.

  This calculation is performed by the display section calculation means 52b shown in FIG. 2, and the calculation formula is shown by the following formula (6). The display section calculation means 52b receives the position information of the probe 19 from the probe coordinate calculation means 56 and the information of each alignment parameter stored in the memory 54a of the alignment means 54. An operation is performed based on these pieces of information.

PR2CV = PR2UV ・ UV2CV
= (UV2PR) ^-1 · UV2CV (6)
Further, the PR2CV is specifically calculated using the above-described equations (3) and (5).

  Then, the reference image of the cross section corresponding to the position information of the probe 10 can be created from the reference volume data by the following equation (7).

(X_plane, y_plane, 0)
= PR2CV (x_vol, y_vol, z_vol) (7)
That is, the display cross section calculating means 52B shown in FIG. 2 inputs the position information of the probe 19 from the probe coordinate calculating means 56, calculates information corresponding to the cross section corresponding to the position information, and uses this information. The image is sent to the arbitrary tomographic image creation unit 42. The arbitrary tomographic image creation unit 42 creates a reference image corresponding to the cross section from the reference volume data in the volume data storage unit 40, and this reference image is displayed on the display device via the image memory 44 and the synthesis unit 60. 18 will be displayed on the screen.

  As will be apparent from the above description, according to the ultrasonic diagnostic apparatus of the present invention, first, the alignment of the ultrasonic volume data with respect to the reference volume data is performed by comparing the respective tomographic images of the corresponding three orthogonal cross-sectional images. Is going.

  That is, FIG. 6A shows an ultrasonic wave of a subject created by moving the probe 10 from a certain position (x, y, z) to another position (x ′, y ′, z ′). Volume data Vu is shown, and FIG. 6B shows reference volume data Vc of the subject.

  The coincidence by comparison of the corresponding tomographic images of the orthogonal three-section images based on the ultrasonic volume data Vu and the orthogonal three-section images based on the reference volume data Vc is the coordinate system UV (coordinates of the subject) of the ultrasonic volume data Vu with respect to the source 22. System) and the coordinate system CV of the reference volume data, and this relationship is maintained in the subsequent operation of the probe 10.

  For this reason, as shown in FIG. 6A, the position coordinates corresponding to the scan plane SF of the probe (indicated by 10 ′ in the figure) at an arbitrary position are the positions provided in the probe 10 ′. A reference image on the scan plane SF ′ of the reference volume data Vc detected by the sensor 20 and corresponding to the scan plane SF can be created from the volume data Vc. In this case, even if the probe 10 'is tilted more than necessary, a reference image on the scan surface SF' of the reference volume data Vc corresponding to the scan surface SF formed in that state can be obtained.

  Therefore, it is possible to obtain a reference image that coincides with the scan plane of the ultrasonic tomographic image displayed in accordance with the position of the probe 10, and avoid the occurrence of deviation in the reference image.

  In the above-described embodiment, three orthogonal sectional views are created from each of the ultrasonic volume data and the reference volume data, and the corresponding tomographic images are taken to coincide with each other. However, it is not necessarily limited to three orthogonal cross-sectional images, and a tomographic image composed of one cross-section and another orthogonal cross-section intersecting with this one cross-section is created, and the corresponding tomographic images are taken to coincide with each other. You may make it aim at. This is because even in this case, compared to the conventional case, there is an effect of avoiding the shift of the reference image with respect to the scan plane of the ultrasonic tomographic image displayed according to the position of the probe 10.

  Further, in the above-described embodiment, the operation of aligning the tomographic image based on the ultrasonic volume data and the tomographic image based on the reference volume data is performed by an operator who visually observes the screen of the display 18 on which they are displayed. is there. However, it may be configured to perform these operations automatically.

  FIG. 7 is a schematic block diagram showing another embodiment of the ultrasonic diagnostic apparatus according to the present invention, which is the ultrasonic diagnostic apparatus configured as described above. Components having the same reference numerals as those shown in FIG. 2 have the same configuration and function.

  Hereinafter, components newly added as compared with FIG. 2 will be mainly described.

  First, the volume data from the volume data storage unit 28 in which the ultrasonic volume data is stored is input to the blood vessel extraction unit 63.

  In this case, the volume data to be stored in the volume data storage unit 28 is a so-called color mapping image in which the blood vessel portion is colored by the ultrasonic image creation unit 14 and the volume data construction unit 26 It is preferable to construct. This is because the blood vessel portion of the volume data is colored, and the blood vessel extraction portion 63 can easily extract only the blood vessel portion. However, the method is not limited to this method, and the blood vessel portion may be extracted by adopting the region growing method. The region growing method is to check whether the neighboring pixel of the start point specified by the operator satisfies the specified condition, and if it satisfies, it determines that the neighboring pixel belongs to the same area and repeats this. This is a method for extracting the entire target area. The blood vessel extraction unit 63 also performs processing for thinning the extracted blood vessel portion (skeleton structure). This is because blood vessels extracted from reference volume data, which will be described later, are also thinned, and it is easy to compare these thinned blood vessels.

  The volume data having the blood vessel portion thinned by the blood vessel extracting unit 63 is input to the blood vessel matching processing unit 62.

  On the other hand, the volume data from the volume data storage unit 40 in which the reference volume data is stored is input to the blood vessel extraction unit 61.

  In this blood vessel extraction unit 61, for example, a region growing method is employed to extract only the blood vessel portion from the volume data. Then, similarly to the blood vessel extraction unit 63 described above, a process for thinning the extracted blood vessel portion is also performed.

  The volume data having the blood vessel portion thinned by the blood vessel extracting unit 61 is input to the blood vessel matching processing unit 62.

  In the blood vessel matching processing unit 62, matching processing is performed by superimposing the thinned blood vessel portion in the ultrasound volume data and the thinned blood vessel portion in the reference volume data.

  That is, for example, as shown in FIG. 8, the blood vessel portion 80 in the ultrasonic volume data UVD and the blood vessel portion 82 in the reference volume data RVD are conceptually overlapped with each other by matching the same portions. Is made automatically. In other words, the origin of the coordinate system is matched so that the branch points of each blood vessel part correspond to each other, and the direction of the coordinate system is set so that the traveling direction of the blood vessel part is opposed, for example, the angle parameter is changed. Then, the adjustment is performed by specifying the angle at which the sum of the absolute values of the differences in the positions of the blood vessel portions is minimized.

  After the superposition of the blood vessel portions 80 and 82 as described above, the relationship between the coordinate system of the ultrasonic volume data UVD and the coordinate system of the reference volume data RVD is calculated by each coordinate related calculation unit 64. It comes to derive automatically. For example, in the case of FIG. 8, the coordinate system of the ultrasonic volume data UVD can be expressed by X′-Y′-Z ′ with respect to the space in FIG. 8, and the coordinate system of the reference volume data RVD is XYZ. Can be represented. The relationship between these coordinate systems can be expressed as an alignment parameter. This alignment parameter is obtained by, for example, applying (for example, multiplying) the alignment parameter to the coordinate system X′-Y′-Z ′ of the ultrasonic volume data UVD, thereby generating the coordinate system XY of the reference volume data RVD. It can be expressed as a relationship that −Z can be calculated.

  As described above, the alignment parameters calculated by each coordinate-related calculation unit 64 are stored in the memory of the alignment means 54, and thereafter, scanning in an ultrasonic tomographic image obtained by operating the probe 10 is performed. This is used when a reference image on the same surface as the surface is created from the reference volume data.

  In the ultrasonic diagnostic apparatus shown in FIG. 7, the relationship between the reference volume data of the subject 200 and the coordinate system of the ultrasonic volume data is based on matching of the same blood vessel portion. However, the present invention is not limited to the blood vessel part, and may be performed based on matching of other identical feature parts such as an organ. This is because the same effect can be obtained even in this case.

  Each of the embodiments described above may be used alone or in combination. This is because the effects of the respective embodiments can be achieved independently or synergistically.

It is explanatory drawing which shows one form of the image display in the indicator of the ultrasonic diagnosing device by this invention. It is a schematic block diagram which shows one Example of the ultrasonic diagnosing device by this invention. It is a flowchart which shows one Example of operation | movement of the ultrasonic diagnosing device by this invention. It is explanatory drawing which shows one Example regarding construction | assembly of the ultrasonic volume data in the ultrasonic diagnosing device by this invention. It is explanatory drawing regarding the display parameter (positioning parameter) used in one Example of the ultrasonic diagnosing device by this invention. It is explanatory drawing which shows the effect of the ultrasonic diagnosing device by this invention. It is a schematic block diagram which shows the other Example of the ultrasonic diagnosing device by this invention. It is explanatory drawing which shows notionally one of the operation | movement in the ultrasonic diagnosing device shown in FIG.

Explanation of symbols

B3: Position complete button (Registration button), Vc: Reference volume data, Vu: Ultrasound volume data, VS ... Blood vessel, CT1, CT2, CT3 ... Cross section, 10 ... Probe, 12 ... Transmission / reception unit, 14 ... Ultrasound image creation unit, 16, 32, 44 ... Image memory, 20 ... Position sensor, 22 ... Source, 26 ... Volume data construction unit, 28, 40 ... Volume data storage , 30, 42... Arbitrary tomographic image creation unit, 52A, 52B... Display cross section calculating means, 54... Positioning means, 54a. Memory, 56. , 50... Control unit, 58 .. console, 60... Composition unit, 61, 63 .. blood vessel extraction unit, 62 .. blood vessel matching processing unit, 64. Diagnostic imaging Location.

Claims (3)

An ultrasonic diagnostic apparatus that creates and displays a reference image corresponding to an ultrasonic tomographic image of a subject from reference volume data of the subject by a medical image diagnostic apparatus including an X-ray CT apparatus or a magnetic resonance imaging apparatus. ,
The ultrasonic diagnostic apparatus comprises:
An apparatus for creating and displaying an ultrasonic tomographic image obtained through a probe brought into contact with an arbitrary part of the subject,
Corresponding to position information detected by a position sensor provided in the probe, the position sensor detecting position information of the probe in the coordinate system of the subject lying on the bed in a certain posture Means for creating ultrasonic volume data of the subject constructed by a plurality of attached ultrasonic tomograms;
Based on the tomographic images in at least two orthogonal cross sections of the reference volume data and the tomographic images in at least two orthogonal cross sections of the ultrasonic volume data, the coordinate system of the reference volume data and the ultrasonic volume data is related. Means,
After the ultrasound volume data is created, the under the condition that the subject is lying in the predetermined posture on the bed, on the basis of the relationship association was coordinate system, at any site of the subject person The reference image of the cross section corresponding to the position information detected by the position sensor of the probe that is in contact, and the ultrasonic tomographic image obtained through the probe that is in contact with an arbitrary part of the subject And a means for displaying the ultrasonic diagnostic apparatus. An ultrasonic diagnostic apparatus that creates and displays a reference image corresponding to an ultrasonic tomographic image of a subject from reference volume data of the subject by a medical image diagnostic apparatus including an X-ray CT apparatus or a magnetic resonance imaging apparatus. ,
The ultrasonic diagnostic apparatus comprises:
An apparatus for creating and displaying an ultrasonic tomographic image obtained through a probe brought into contact with an arbitrary part of the subject,
Corresponding to position information detected by a position sensor provided in the probe, the position sensor detecting position information of the probe in the coordinate system of the subject lying on the bed in a certain posture Means for creating ultrasonic volume data of the subject constructed by a plurality of attached ultrasonic tomograms;
Means for associating a coordinate system of the reference volume data and the ultrasound volume data based on matching of the same feature portions of the reference volume data and the ultrasound volume data;
After the ultrasound volume data is created, the under the condition that the subject is lying in the predetermined posture on the bed, on the basis of the relationship association was coordinate system, at any site of the subject person The reference image of the cross section corresponding to the position information detected by the position sensor of the probe that is in contact, and the ultrasonic tomographic image obtained through the probe that is in contact with an arbitrary part of the subject And a means for displaying the ultrasonic diagnostic apparatus.   2. The ultrasonic wave according to claim 1, wherein the tomographic image in at least two orthogonal cross sections of the reference volume data and the tomographic image in at least two orthogonal cross sections of the ultrasonic volume data are orthogonal three cross sectional images. Diagnostic device.

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