JP2007007481A - Three-dimensional ultrasonic system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a system which presents the display directions of a three-dimensional image readably according to the three-dimensionally scanned volume areas. <P>SOLUTION: The three-dimensional ultrasonic diagnostic apparatus collects three-dimensionally a two-dimensional ultrasonic image data to form the three-dimensional ultrasonic image data to display, wherein the system displays a three-dimensional indicator on the same picture as the three-dimensionally displayed image data, the indicator forming readably the top, bottom, left, right, and the collection directions of the two-dimensional ultrasonic image data; and the system changes the display direction of the indicator in association with the three-dimensionally displayed image data. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  According to the present invention, two-dimensional ultrasonic image data collected by an ultrasonic diagnostic apparatus is taken into an external computer unit for three-dimensional image processing, and a three-dimensional image is generated and displayed in the computer unit for three-dimensional image processing. The present invention relates to a three-dimensional ultrasonic system.

  A conventional ultrasonic diagnostic apparatus generally scans an ultrasonic beam in one plane, and thus has a system for displaying a cross-sectional image. In recent years, there have been many attempts to collect a plurality of images with different scanning planes while moving an ultrasonic probe that is an ultrasonic transmission / reception unit of an ultrasonic diagnostic apparatus, and reconstruct a three-dimensional image from the plurality of images. Therefore, the display of a three-dimensional image in the ultrasonic diagnostic apparatus is expected to have a new possibility of diagnosis.

  In fact, research is being carried out by manually or mechanically moving the convex probe or linear array probe for the abdomen, or using a multi-plane probe for transesophageal that has a mechanism for rotating the electronic sector probe. .

  Here, in the conventional 3D ultrasound system, a 2D ultrasound image collected on the ultrasound diagnostic apparatus side is converted into a video signal, and the video signal is sent to an external computer unit for 3D image processing. Since the image is captured via the video capture board, the computer unit for 3D image processing has a fixed frame rate of 30 frames per second regardless of the number of frames (frame rate) of the ultrasonic image. It was supposed to be taken in.

  For this reason, in the captured image, there has been a situation in which a partial composite image in which the preceding and following frames are joined together or several consecutive images are the same. In addition, when an ultrasound image is captured from the ultrasound diagnostic apparatus into the computer unit for three-dimensional image processing, the position data of the probe during each scan is captured from a position sensor attached to the probe. The three-dimensional image processing computer unit synchronizes the acquisition of the image from the ultrasonic diagnostic apparatus and the acquisition of the position data from the position sensor, thereby matching the ultrasonic image and the position data of the probe corresponding to the image. However, this method has a problem that it cannot be applied when transferring 2D image data off-line from the ultrasonic diagnostic apparatus to the computer unit for 3D image processing.

  In addition, when the ultrasonic probe is manually moved from an appropriate position, a plurality of two-dimensional image data having different scanning planes necessary for the reconstruction of the three-dimensional image are collected. There is a problem that it is difficult to move the ultrasonic probe in accordance with the collection time and the collection time.

  Furthermore, in an ultrasonic diagnostic apparatus, there are cases where a B-mode image representing a tomographic image of a tissue and a blood flow image by color Doppler are combined and displayed, but in this case, the blood flow image is displayed as a B-mode image. Overwriting, that is, a composition in which B-mode image information is dropped and only blood flow information is assigned to a portion where blood flow exists, is used for 3D image processing as a video signal of this composite image Since the image is sent to the computer unit, the B-mode image and the blood flow image cannot be completely separated by the computer unit for 3D image processing. However, there is a strong demand to simultaneously acquire a B-mode image and a blood flow image of an ultrasonic diagnostic apparatus and reconstruct each separately as a three-dimensional image, and there is an example in which a separation method or a display method is actually proposed. Even in such a case, a three-dimensional display expression means for sufficiently observing the mutual positional relationship and individual three-dimensional shape by three-dimensional display of the ultrasonic B-mode image and blood flow image. It was not enough.

  Furthermore, when displaying an ultrasound image in three dimensions, unlike other diagnostic imaging devices such as X-ray CT and MRI, the display area of the collected image is small, and there are many display shapes depending on the scanning method of the ultrasound probe. The direction and shape of the 3D image created by reconstructing the image also has a variety of directions and shapes, and the user is oriented to the displayed 3D image, that is, the top and bottom, left and right of the image, and also the display direction (looking at the part There was a problem that it was easy to lose sight.

An object of the present invention is to provide a three-dimensional ultrasound system that can easily present a display direction of a three-dimensional image with reference to a volume region obtained by three-dimensional scanning.
Another object of the present invention is to provide a 3D super image that can be separated from a composite image into a B-mode image and a color Doppler blood flow image on the side of a 3D image processing computer unit externally attached to the ultrasonic diagnostic apparatus. To provide a sonic system.

A first aspect of the present invention provides a three-dimensional ultrasonic diagnostic apparatus that three-dimensionally collects two-dimensional ultrasonic image data, generates three-dimensional ultrasonic image data, and displays the same. A three-dimensional indicator configured to be able to determine the top, bottom, left, and right of the two-dimensional ultrasound image data and the collection direction is displayed on the screen, and the display direction of the indicator is interlocked with the display direction of the three-dimensional display image data. This is a three-dimensional ultrasonic system characterized by changing the frequency.
According to a second aspect of the present invention, in the three-dimensional ultrasonic system that separately collects and displays ultrasonic B-mode image data of the same site and blood flow image data by color Doppler as three-dimensional volume data, the ultrasonic B A first mode in which the three-dimensional image data of the mode image data and the three-dimensional image data of the blood flow image data are displayed as a single composite image, and a second mode in which the image is individually displayed in parallel on one screen. A three-dimensional ultrasound system characterized by having a switching function.

According to the first aspect of the present invention, the display direction of a three-dimensional image can be presented in an easy-to-understand manner with reference to a three-dimensionally scanned volume area.
According to the second aspect of the present invention, the B-mode image and the color Doppler blood flow image can be separated from the synthesized image on the side of the three-dimensional image processing computer unit externally attached to the ultrasonic diagnostic apparatus.

  Hereinafter, a preferred embodiment of a three-dimensional ultrasound system according to the present invention will be described with reference to the drawings. FIG. 1 shows a configuration of a three-dimensional ultrasound system according to a preferred embodiment of the present invention, and FIG. 2 shows a block diagram thereof. The three-dimensional ultrasound system of this embodiment includes an ultrasonic diagnostic apparatus 1 that collects two-dimensional image data such as B-mode image data and blood flow image data by color Doppler, and a general-purpose that can be externally attached to the ultrasonic diagnostic apparatus 1. Type of computer unit, which takes in two-dimensional image data output from the ultrasonic diagnostic apparatus 1 via the image memory 6 into the image memories 7a and 7b via the image input unit 12 and uses the three-dimensional image creation unit 8 The computer unit 4 for 3D image processing that reconstructs 3D image data.

  The ultrasonic diagnostic apparatus 1 scans the subject via the ultrasonic probe 2 and records a plurality of two-dimensional image data in the image memory 6 in the ultrasonic diagnostic apparatus 1. This image memory 6 is equipped with two systems, one of which is used for storing B-mode image data and the other 6b is used for storing blood flow image data by color Doppler. As described above, the B-mode image and the blood flow image are stored in different memories so that they can be separately transferred to the image memories 7a and 7b of the computer unit 4 for 3D image processing. The three-dimensional image processing computer unit 4 separately reconstructs the three-dimensional image of the B-mode image and the three-dimensional image of the blood flow image, and synthesizes the B-mode image and the blood flow image on the three-dimensional image. Alternatively, parallel display is possible.

  Each of the image memories 6a and 6b has a capacity for storing a plurality of two-dimensional image data, and the ultrasonic image creation unit 10 continues until a collection end (Freeze) command is sent from the host CPU 9 of the diagnostic apparatus 1. The created image data is recorded continuously. In this storage, a so-called loop method is adopted, that is, when the number of images exceeds the capacity of the image memory 6, the old image is erased and a new image is written on it (overwriting). The latest plural pieces of image data are stored.

  The number of two-dimensional ultrasound images required for reconstructing a three-dimensional image with the capacity of the image memory 6 as an upper limit is freely designated by the operator. A time obtained by multiplying the generation speed per one sonic image is defined as a three-dimensional image acquisition time.

  Position data is sequentially sent from the position sensor 3 attached to the ultrasonic probe 2 to the computer unit 4, and is stored in the position data memory 5 of the computer unit 4 at the same interval or shorter than the collection interval of the two-dimensional image data. It will be recorded.

  The operator can input an image collection start command and an image collection end command (freeze command) via the console (user interface) of the ultrasonic diagnostic apparatus 1 or the computer unit 4. In the figure, these commands are input from the console of the computer unit 4.

  When receiving the image collection start command, the three-dimensional unit CPU 11 of the computer unit 4 causes the position data collection unit 5 to start recording the position data from the position sensor 3 into the position data memory 5.

  Further, when the three-dimensional unit CPU 11 of the computer unit 4 inputs this image collection end command, the position data collection unit 5 terminates the recording of the position data from the position sensor 3 into the position data memory 5 and this image. A collection end command is transferred to the host CPU 9 of the ultrasonic diagnostic apparatus 1. When the host CPU 9 receives an image acquisition start command, the host CPU 9 is triggered by the command and prompts the ultrasonic image creation unit 10 to finish the ultrasonic scanning and finish the creation of the two-dimensional ultrasonic image. As described above, when a command to end image collection is input from one of the computer unit 4 and the ultrasonic diagnostic apparatus 1, it is transferred to the other of the computer unit 4 and the ultrasonic diagnostic apparatus 1, thereby enabling two-dimensional The collection of the image data and the collection of the position data can be finished synchronously.

  In addition, when an image collection start and end command is input from one of the computer unit 4 and the ultrasonic diagnostic apparatus 1, it is transferred to the other of the computer unit 4 and the ultrasonic diagnostic apparatus 1. The acquisition of two-dimensional ultrasonic image data and the acquisition of position data are synchronized and finished. The acquisition of two-dimensional image data and the acquisition of position data can be synchronized. However, as shown in FIG. 1 and a data acquisition timing signal generator 21 shared by the computer unit 4 for three-dimensional image processing are provided, and commands for starting and ending image acquisition generated from the data acquisition timing signal generator 21 are the ultrasonic diagnostic apparatus 1. The image data may be sent in parallel to the host CPU 9 and the three-dimensional unit CPU 11 of the three-dimensional image processing computer unit 4.

  After the collection of the two-dimensional image data and the collection of the position data is completed, the image memory 6a of the ultrasonic diagnostic apparatus 1 transfers the image data 7a and 7b of the computer unit 4 for three-dimensional image processing via the image input unit 12. Dimensional ultrasound image data is transferred.

  From the image memories 7a and 7b, the last-collected two-dimensional ultrasound image data is read out one frame at a time, and in synchronization with this, the position data memory 5 also reads out the last collected position data in order. Both are combined by the addition processor 13 and sent to the three-dimensional image creation unit 8. At this time, the two-dimensional ultrasonic image data and the position data are completely matched. This is because the collection of the two-dimensional ultrasound image data and the collection of the position data are finished synchronously, and reading is performed in order from the last collected data.

  The three-dimensional image creation unit 8 uses, for example, surface display or MIP (maximum value projection) used in three-dimensional display of X-ray CT or MRI from a plurality of frames of two-dimensional ultrasonic image data and position data thereof. 3D volume data relating to the region of interest is reconstructed using a general 3D reconstruction method such as MinIP (minimum value projection), integral projection, volume rendering, MPR image, or the like.

  In the present embodiment, the B-mode image and the Doppler blood flow image are separately stored in the image memories 6a and 6b of the ultrasonic diagnostic apparatus 1, and are separately stored in the image memories 7a and 7b of the computer unit 4 for three-dimensional image processing. , The three-dimensional volume data of the B-mode image and the three-dimensional volume data of the blood flow image can be individually reconstructed. However, as shown in FIG. By synthesizing the Doppler blood flow image with the ultrasound diagnostic apparatus 1, the computer unit 4 for 3D image processing separates the B mode image and the Doppler blood flow image from the synthesized image without missing information, The three-dimensional volume data of the B mode image and the three-dimensional volume data of the blood flow image may be individually reconstructed.

  As shown in FIG. 5, the B-mode image and the Doppler blood flow image are synthesized by the synthesized image creating unit 15 of the ultrasonic diagnostic apparatus 1, and the separation is performed by the image separation of the computer unit 4 for 3D image processing. This is done in part 18. In this case, the ultrasonic diagnostic apparatus 1 does not need to separately provide the image memories 6a and 6b for the B-mode image and the blood flow image, but one system is sufficient. Conventionally, when displaying a blood flow image by color Doppler such as CFM, the display image of the ultrasonic diagnostic apparatus 1 is displayed by overwriting a color blood flow image on a B-mode image. For this reason, when this image is transferred as it is to the image memory 7 of the computer unit 4 for 3D image processing and the B mode image and the 3D image of the blood flow image are reconstructed, the B mode of the portion where the blood flow image is overwritten The image is missing. In addition, the color blood flow image is also surrounded by the B-mode image and becomes a three-dimensional image that is difficult to see.

  Thus, when the B-mode image and the color blood flow image are combined by the composite image creation unit 15 of the ultrasound diagnostic apparatus 1, the black-and-white information of the B-mode image and the color information of the color blood flow image are In order to prevent any information from being lost at all, the information is synthesized not by conventional overwrite synthesis but by addition processing described later. On the other hand, the computer unit 4 for three-dimensional image processing collects the composite image data displayed on the ultrasonic diagnostic apparatus 1 and performs the B-mode image and color blood flow in the reverse procedure of the synthesis performed in the ultrasonic diagnostic apparatus 1. The images are separated, each image is allocated to the image memories 7a and 7b and recorded, and a three-dimensional image is individually reconstructed. In this way, both the B-mode image and the color blood flow image can be simultaneously collected and displayed three-dimensionally without omission.

  Here, an example of synthesis and separation of the B-mode image and the color blood flow image will be described. The B-mode image is a black and white image, and when separated into RGB color components, the R signal, G signal, and B signal have the same value. On the other hand, when the color blood flow image has a red gradation and a blue gradation, the value of the G signal is always zero. Using this feature, synthesis is performed as follows. The pixel value of the B-mode image is represented by (Rb, Gb, Gb), and the pixel value of the color blood flow image is represented by (Rc, Gc, Bc).

  At this time, the pixel value (Rs, Gs, Bs) of the composite image is calculated as Rs = (Rb + Rc) / 2Gs = (Gb + Gc) / 2Bs = (Bb + Bc) / 2 when Gc is not 0.

  When Gc is 0, Rs = RbGs = GbBs = Bb.

  On the contrary, the composite image is separated when Rs, Gs, and Bs are not equal. Rb = Gs × 2Gb = Gs × 2Bb = Gs × 2Rc = (Rs−Gs) × 2Gc = 0Bc = (Bs−Gs) × 2 is required.

  Further, when Rs, Gs, and Bs are equal, Rb = RsGb = GsBb = BsRc = 0 Gc = 0Bc = 0.

  The three-dimensional image of the B-mode image and the three-dimensional image of the color blood flow image that are separately reconstructed in this way are displayed on the display device 17. As this display method, as shown in FIG. 6 (a), a combined display method in which a three-dimensional image of a B-mode image and a three-dimensional image of a color blood flow image are aligned and combined into one image and displayed. In addition, as shown in FIG. 6B, two types of parallel display methods are provided, in which a three-dimensional image of a B-mode image and a three-dimensional image of a color blood flow image are arranged side by side and displayed separately. Can be switched freely. Further, as a synthesis method, a simple addition process, a semi-transparent addition process, a synthesis method in which hidden surface removal is performed in consideration of a three-dimensional depth, and the like are not particularly limited.

  In the composite display example shown in FIG. 6A, the B-mode image is MinIP (minimum value projection) and the color blood flow image is MIP (maximum value projection). An image is displayed in the center of the screen, and an operation panel on which buttons for changing the display method of each image are displayed on the left side of the image. By switching this button, each display method of the composite image can be changed. The image can be rotated, moved, and enlarged / reduced by a trackball operation or a mouse operation. At this time, the B-mode and color three-dimensional images are always rotated, moved, and enlarged / reduced.

  A button for switching the display method from composite display to parallel display is arranged on the operation panel. When the operator presses this button, the display can be switched to the parallel display shown in FIG. In the parallel display, B mode and color three-dimensional images are displayed on the left and right, respectively. The display method displayed at this time is the display method at the time of composite display before switching to parallel display. An operation panel having buttons for changing the image display direction is displayed at the bottom of the display image. In addition, the image can be rotated, moved, and enlarged / reduced by trackball operation and mouse operation.

  At this time, the left and right images can be rotated, moved, and enlarged / reduced, and only the B-mode image and only the color blood flow image can be rotated / moved / enlarged / reduced. This switching of the operation target is performed by selecting / deselecting a [Sync] (synchronization) button arranged on the operation panel. Also, on this operation panel, a button for returning the display format to the composite display is arranged, and by pressing this button, it is possible to display a composite image synthesized by the display method at the time of parallel display.

  Further, as shown in FIG. 7 (a), a B-mode image of one cross section is synthesized with a three-dimensional image of a color blood flow image, and the outer peripheral surface of the B-mode image at a portion far from the cross-sectional position is hidden. Alternatively, as shown in FIG. 7B, the B-mode image of one cross section is synthesized with the three-dimensional image of the color blood flow image, and the outer peripheral surface of the B-mode image at a portion far from the cross-sectional position is displayed. You may make it do. Furthermore, by displaying both the B-mode image of one cross section shown in FIGS. 7A and 7B and the three-dimensional image of the color blood flow image or only one of them in a translucent manner, a portion far from the cross section is displayed. You may make it easy to see the positional relationship of a B-mode image and a color blood flow image. Further, the adjustment of the transparency in the semi-transparent display may be changed by synchronizing both images or separately.

  In the three-dimensional display as described above, the relationship with the volume area obtained by scanning the subject with ultrasonic waves, that is, the direction of the currently displayed three-dimensional image with respect to the volume area (the direction of the line of sight in FIG. 9). ) It is troublesome to figure out whether the image is viewed from. In the present embodiment, an indicator generation unit 16 is provided to solve this problem.

  As shown in FIG. 8A, the indicator generation unit 16 deforms a volume area that moves a two-dimensional scanning plane and approximates its outer shape, for example, a quadrangular pyramid shape, a shape obtained by deleting the apex portion of the quadrangular pyramid. , A shape obtained by cutting a part from the center of the sphere to the surface, or a shape obtained by deleting the center point of the part of the sphere, and the collection direction (Z in FIG. A three-dimensional image that can be discriminated in the direction is generated as position indicator data. In other words, this position indicator is color-coded in different colors such as blue and red in half along the collection direction in which the scanning plane moves, as shown in FIG. Then, a schematic three-dimensional shape and a wire frame indicating the entire shape of the volume data are synthesized. The 0 ° (front) position of this position indicator represents the first acquired image (volume region scanning start surface), and the 180 ° (rear) position represents the end of the acquired image (volume region scanning final surface). Represents. Of course, the display direction of the position indicator is changed in conjunction with the display direction of the three-dimensional image such as the B-mode image. That is, when the three-dimensional image such as the B-mode image is rotated up and down and left and right, it follows it. It is designed to be rotated up and down and left and right.

  By displaying this position indicator together with a three-dimensional image such as a B-mode image on the display device 17, it is possible to easily grasp the positional relationship between the display direction of the three-dimensional image and the volume region actually scanned in three dimensions. become.

  Next, a technique for supporting the operator's three-dimensional scanning operation will be described. In many cases, the three-dimensional scanning is simply performed by the operator holding the ultrasonic probe 2 and moving the body surface of the subject, or moving it like a swing. On the other hand, it is possible to freely set how many two-dimensional ultrasonic images the three-dimensional image is reconstructed by the three-dimensional image processing computer unit 4. If a three-dimensional image is reconstructed from n two-dimensional ultrasound images, one cycle of three-dimensional image reconstruction is “n” at the reciprocal of the frame rate of image collection, that is, the collection time of one frame. Is given as the time multiplied by. It is preferable to move the ultrasonic probe 2 so as to scan the entire volume region including the region of interest in one cycle time.

  A collection indicator for assisting it is generated by the indicator generator 16 and displayed on the display device 17 so that the operator can preferably move the ultrasonic probe 2. An example of this collection indicator is shown in FIG. In this example, it is a pie chart, but it may be a bar chart. The display form of this collection indicator is changed with a cycle of one cycle time. For example, the display color of a pie chart changes with time in the circumferential direction, and the display color of the bar graph changes in the major axis direction. Changes over time. The operator can preferably move the ultrasonic probe 2 by referring to such a collection indicator.

  When two-dimensional ultrasonic image data for a plurality of frames is transferred from the image memory 6 of the ultrasonic diagnostic apparatus 1 to the image memory 7 of the computer unit 4 for three-dimensional image processing, an indicator is generated to indicate the progress of the transfer. A transfer indicator generated in the unit 16, for example, a transfer indicator that displays the remaining as a bar graph and percentage as shown in FIG. 10B may be displayed on the display device 8.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the components without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

1 is a schematic diagram of a three-dimensional ultrasound system according to a preferred embodiment of the present invention. The functional block diagram of FIG. The other functional block diagram of FIG. FIG. 6 is a principle diagram of another image separation method according to the present embodiment. FIG. 5 is a functional block diagram of a three-dimensional ultrasound system corresponding to the image separation method in FIG. 4. The halftone image displayed on the display apparatus of FIG. The halftone image displayed on the display apparatus of FIG. The figure which shows an example of the position indicator produced with an indicator generation | occurrence | production part. The figure which shows three directions of three-dimensional scanning. The figure which shows an example of the collection indicator and transfer indicator which are produced in an indicator generation part.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Ultrasonic diagnostic apparatus, 2 ... Ultrasonic probe, 3 ... Position sensor, 4 ... 3D image processing computer unit, 5 ... Position data memory, 6 ... Image memory, 7 ... Image memory, 8 ... 3D image creation Department.

Claims (7)

In a three-dimensional ultrasonic diagnostic apparatus that three-dimensionally collects two-dimensional ultrasonic image data and generates and displays three-dimensional ultrasonic image data, the two-dimensional ultrasonic wave is displayed on the same screen as the three-dimensional display image data. A three-dimensional indicator configured to be able to determine the top, bottom, left, and right of the image data and the collection direction is displayed, and the display direction of the indicator is changed in conjunction with the display direction of the three-dimensional display image data. 3D ultrasound system. The indicator is a quadrangular pyramid shape that approximates the outer shape of the three-dimensional acquisition region of the two-dimensional ultrasound image data, a shape that is obtained by deleting the apex portion of the quadrangular pyramid, a shape that is cut out from the center of the sphere to the surface, The three-dimensional ultrasonic system according to claim 1, wherein the shape is a shape obtained by deleting a central point portion of a partial shape of the sphere. The three-dimensional ultrasound system according to claim 1 or 2, wherein the indicator is displayed in different colors in half or in several stages along the collection direction. The three-dimensional ultrasound system according to claim 1, 2 or 3, wherein the indicator is displayed in a shape obtained by synthesizing a schematic three-dimensional shape and a wire frame indicating the entire shape of volume data. In a three-dimensional ultrasonic system that collects and displays ultrasonic B-mode image data of the same part and blood flow image data by color Doppler separately as three-dimensional volume data, the three-dimensional image data of the ultrasonic B-mode image data And a function of switching between a first mode in which the three-dimensional image data of the blood flow image data is displayed as a single composite image and a second mode in which the blood flow image data is individually displayed in parallel on one screen. 3D ultrasound system. 6. In the second mode, the three-dimensional image data of the ultrasonic B-mode image data and the three-dimensional image data of the blood flow image data are displayed at the same scale and in the same display direction. The three-dimensional ultrasound system described. In the second mode, when at least one of a display scale, a position, and a display direction is changed between the three-dimensional image data of the ultrasonic B-mode image data and the three-dimensional image data of the blood flow image data. 6. The three-dimensional ultrasonic system according to claim 5, wherein the other is also changed in conjunction with the other.

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