JP2005110973A - Image diagnostic device, image display device and three-dimensional image display method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image diagnostic device, an image display device and a three-dimensional image display method capable of stable moving image display by image data for fly-through at the time of performing fly-through display on the basis of three-dimensional image data time-sequentially obtained for a testee body. <P>SOLUTION: In MPR image data generated from 3D image data of an initial time phase T0, by using the information of the view point/line-of-sight direction of an initially set virtual endoscope mode (fly-through display) and the 3D image data of the initial time phase T0 and a time phase T1, respective fly-through image data are generated, and the view point/line-of-sight direction at the time phase T1 are automatically set by calculating deviations among images in the image data. Then, the fly-through image data of the time phase T1 are generated from the view point/line-of-sight direction of the time phase T1 and the 3D image data of a reference time phase T1. In the time phase T2 and thereafter, the view point/line-of-sight direction of the time phase Tn are set from the 3D image data of the time phase Tn and the time phase Tn-1 and the view point/line-of-sight direction of the time phase Tn-1, and the fly-through image data of the time phase Tn are generated on the basis of the 3D image data of the time phase Tn and the view point/line-of-sight direction of the time phase Tn. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an image diagnosis apparatus, an image display apparatus, and a three-dimensional image display method, and more particularly to an image diagnosis apparatus, an image display apparatus, and a three-dimensional image display method capable of displaying a moving image using virtual endoscopic image data.

  Medical image diagnostic technology has made rapid progress with X-ray CT apparatuses and MRI apparatuses that have been put into practical use with the development of computer technology in the 1970s, and is indispensable in today's medical care. In particular, recent X-ray CT apparatuses and MRI apparatuses are capable of real-time display of image data along with the increase in speed and performance of biological information detection apparatuses and arithmetic processing apparatuses, and also the generation and display of three-dimensional image data. It became easy to do.

  For example, in an X-ray CT apparatus, an X-ray tube for irradiating X-rays and an X-ray detector for detecting the irradiated X-rays are arranged opposite to the periphery of the subject, and the subject is further placed on the X-ray CT. By relatively moving in the body axis direction (slice direction) with respect to the X-ray tube and the X-ray detector, X-ray projection data in a plurality of slice sections of the subject are collected, and three-dimensional based on these X-ray projection data Image data (volume data) is generated.

  In addition, the time required for generating three-dimensional image data is being further shortened by using a so-called helical scanning method in which X-ray projection data is collected while the subject is continuously moved in the body axis direction.

  On the other hand, the observer's viewpoint is virtually set in, for example, a hollow organ of the three-dimensional image data obtained by the above-described method, and the organ surface observed from this viewpoint is generated and displayed as three-dimensional image data. A virtual endoscope mode (hereinafter, “fly-through display method”) has already been put into practical use (for example, see Patent Document 1).

The development of this fly-through display method makes it possible to generate endoscopic images based on 3D image data collected from outside the body, greatly reducing the degree of invasiveness to the subject, Since it is possible to easily set the viewpoint for an arbitrary part, it has become possible to perform a highly accurate inspection safely and efficiently.
JP 2000-51207 A (page 4-5, FIG. 1-2)

  Since the conventional fly-through display method is performed based on three-dimensional image data collected in one time phase, it is difficult to display a moving image by applying this display method. The first reason that it has been difficult to display moving images by the fly-through display method is that it is difficult to generate 3D image data in real time, i.e., it is difficult to generate 3D image data in real time.

  The second reason is that the viewpoint position set in advance in a desired position in the luminal organ in the three-dimensional image data is a tube that accompanies respiratory movement or pulsatile movement of the subject, and further body movement. It moves relatively by the movement of the hollow organ, and in the worst case, it may move outside the lumen structure. For this reason, it has been difficult to perform a stable fly-through display for a luminal organ that moves and moves rapidly.

  The present invention has been made in view of the above problems, and its object is to perform fly-through display when performing fly-through display on a subject based on three-dimensional image data obtained in time series. An object of the present invention is to provide an image diagnostic apparatus, an image display apparatus, and a three-dimensional image display method that enable stable moving image display using image data.

In order to solve the above-described problem, the diagnostic imaging apparatus according to the first aspect of the present invention provides a fly-through display viewpoint and line-of-sight direction for three-dimensional image data obtained in time series for a subject. In a diagnostic imaging apparatus that generates and displays fly-through image data based on the set viewpoint and line-of-sight direction and the three-dimensional image data, the reference time phase obtained in time series and the reference time phase Detection means for detecting an inter-image shift based on the subsequent three-dimensional image data of the next time phase, the inter-image shift detected by the detection means, and the viewpoint and line-of-sight direction in a preset reference time phase Viewpoint / line-of-sight direction setting means for setting the viewpoint and line-of-sight direction in the next time phase;
Fly-through image data generating means for generating fly-through image data of the next time phase based on the viewpoint and line-of-sight direction in the next time phase; and display means for displaying the fly-through image data of the next time phase; The time phase is set as a new reference time phase, the detection unit detects an image gap, the viewpoint and line-of-sight direction setting unit sets the viewpoint and line-of-sight direction of the next time phase, and the fly-through image data generation The generation of the fly-through image data of the next time phase by the means and the display of the fly-through image data of the next time phase by the display means are repeatedly executed.

  The image display device of the present invention according to claim 7 sets the viewpoint and the line-of-sight direction for fly-through display for time-series three-dimensional image data generated by the image diagnostic device for the subject, In an image display device that generates and displays fly-through image data based on the set viewpoint and line-of-sight direction and the three-dimensional image data, a reference time phase obtained in a time series and a subsequent time following the reference time phase Detection means for detecting an inter-image shift based on time-phase three-dimensional image data, and the next time phase based on an inter-image shift detected by the detection means and a preset viewpoint and line-of-sight direction in a reference time phase Viewpoint / line-of-sight direction setting means for setting the viewpoint and line-of-sight direction in the image, and a fly-through image for generating fly-through image data of the next time phase based on the viewpoint and line-of-sight direction in the next time phase Data generating means, and display means for displaying the fly-through image data of the next time phase, setting the next time phase as a new reference time phase, detecting a shift between images by the detecting means, Setting the viewpoint and line-of-sight direction of the next time phase by the line-of-sight direction setting means, generation of the fly-through image data of the next time phase by the fly-through image data generation means, and display of fly-through image data by the display means It is characterized by being repeatedly executed.

  On the other hand, the three-dimensional image display method of the present invention according to claim 9 sets and sets the viewpoint and line-of-sight direction for fly-through display on the three-dimensional image data obtained in time series for the subject. A three-dimensional image display method for generating and displaying fly-through image data based on the viewpoint and line-of-sight direction and the three-dimensional image data, comprising: (a) a reference time phase obtained in time series and the reference Detecting a gap between images based on the three-dimensional image data of the next time phase following the time phase; and (b) based on the detected gap between images and the viewpoint and line-of-sight direction in a preset reference time phase. Setting the viewpoint and line-of-sight direction in the next time phase; (c) generating fly-through image data of the next time phase based on the viewpoint and line-of-sight direction in the next time phase; and (d) the next time Phase And displaying Raisuru image data is characterized by the step of repeatedly executing (e) the set the following time phase during phase a new reference, step (a) to step (d).

  According to the present invention, in the fly-through display performed using the three-dimensional image data obtained in time series on the subject, it is possible to display the moving image with the accurate and stable image data for fly-through display. .

  Embodiments of the present invention will be described below with reference to the drawings.

  In a first embodiment of the present invention described below, a multi-slice X-ray CT apparatus having an X-ray detector in which X-ray detection elements are two-dimensionally arranged is used for a plurality of slice surfaces of a subject. X-ray projection data (hereinafter referred to as projection data) is continuously collected. Then, three-dimensional image data is generated with respect to the obtained projection data, and further based on the viewpoint and the line-of-sight direction set in the luminal organ of the three-dimensional image data obtained continuously in time. Generation and display of luminal organ fly-through display image data (hereinafter referred to as fly-through image data) from the dimensional image data.

  Although an X-ray CT apparatus will be described as an example of the image diagnostic apparatus in the present embodiment, the present invention is not limited to the X-ray CT apparatus, and other examples such as an MRI apparatus and an ultrasonic diagnostic apparatus are available. The image diagnostic apparatus may be used.

(Configuration of diagnostic imaging equipment)
Hereinafter, the configuration of the diagnostic imaging apparatus according to the first embodiment of the present invention will be described with reference to FIG.

  FIG. 1 is a block diagram showing the overall configuration of an image diagnostic apparatus according to the present embodiment. An image diagnostic apparatus 100 using an X-ray CT apparatus as a specific example places a subject 30 around the subject 30. A couch 1 is inserted into the opening of the gantry rotating unit 2 that rotates, and a couch and gantry mechanism unit 3 that executes movement and rotation of the couch 1 and the gantry rotating unit 2, and further controls the couch / gantry mechanism unit 3. A mechanism control unit 4 that performs X-ray generation on the subject 30, and a projection data collection unit 6 that collects X-ray data transmitted through the subject 30.

  The image diagnostic apparatus 100 also includes a three-dimensional image data generation unit 7 that reconstructs the projection data collected by the projection data collection unit 6 to generate three-dimensional image data, and fly-through image data from the three-dimensional image data. A fly-through image data generation unit 8 for generating the image, a display unit 9 for displaying the generated image data, an input unit 10 for inputting various conditions and various commands, and the above-described units are centrally controlled. A system control unit 11 is provided.

  The bed 1 has a top plate that can be slid in the longitudinal direction by driving the bed / base mechanism unit 3. Normally, the body axis direction of the subject 30 substantially coincides with the longitudinal direction of the top plate. To be placed. Further, the mechanism control unit 4 controls the movement of the couch 1 in the longitudinal direction, the rotation speed of the gantry rotating unit 2, and the like by a control signal from the system control unit 11.

  On the other hand, the X-ray generator 5 includes an X-ray tube 13 that irradiates the subject 30 with X-rays, and a high-voltage generator 12 that generates a high voltage applied between the anode and the cathode of the X-ray tube 13. The X-ray diaphragm 14 for collimating the X-rays irradiated from the X-ray tube 13 and the slip ring 15 for supplying power to the X-ray tube 13 installed on the gantry rotating unit 2 are provided.

  The X-ray tube 13 is a vacuum tube that generates X-rays, and accelerates electrons by a high voltage supplied from the high-voltage generator 12 and collides with a tungsten target to generate X-rays. The X-ray diaphragm 14 is located between the X-ray tube 13 and the subject 30 and has a function of narrowing the X-ray beam emitted from the X-ray tube 13 to a predetermined image receiving size. For example, the X-ray beam emitted from the X-ray tube 13 is shaped into a cone beam (quadrangular pyramid) shape or a fan beam shape X-ray beam based on the effective field of view (FOV).

  On the other hand, the projection data collection unit 6 includes an X-ray detector 16 that detects X-rays transmitted through the subject 30, a switch group 17 that bundles signals from the X-ray detector 16 into a predetermined number of channels, and a switch group. A data acquisition circuit (hereinafter referred to as DAS (data acquisition system)) 18 that performs A / D conversion on the output signal from 17, and a data transmission circuit that supplies the output of DAS 18 to the three-dimensional image data generation unit 7 in a non-contact manner 19 is provided.

  The X-ray tube 13, the X-ray diaphragm 14, the slip ring 15, and the projection data collection unit 6 are provided in the gantry rotating unit 2 that can rotate with respect to the gantry fixing unit, and are driven by a drive control signal from the mechanism control unit 4. Then, high-speed rotation of 1 rotation / second to 2 rotations / second is performed around the rotation center axis (Z axis) substantially parallel to the body axis of the subject 30.

  Next, in the X-ray detector 16 in the projection data collection unit 6, X-ray detection elements having scintillators and photodiodes are two-dimensionally arranged. The multi-slice X-ray detector 16 is, for example, 80 elements with respect to the slice direction (Z direction) that is the body axis direction of the subject 30 and the channel direction (X direction) orthogonal to the slice direction. 24 X-ray detection elements are arranged. However, the X-ray detection elements arranged in the channel direction are actually mounted on the gantry rotating unit 2 along an arc centered on the focal point of the X-ray tube 13.

  When transferring a signal detected by the X-ray detector 16 to the DAS 18, the switch group 17 of the projection data acquisition unit 6 “binds” the received signal from the X-ray detection element in the slice direction to a predetermined number of channels. To DAS18. That is, the slice interval in the slice direction, which will be described later, is determined by this “data bundling”.

  The DAS 18 has a multi-channel receiving unit, which converts the current signal from the X-ray detector 16 into a voltage, and further converts it into a digital signal by an A / D converter (not shown) to produce projection data. Is generated.

  The data transmission circuit 19 stores the projection data output from the DAS 18 in, for example, the projection data storage circuit 20 of the three-dimensional image data generation unit 7 described later using an optical communication unit. Note that this data transmission method can be replaced with another method as long as signal transmission between the rotating body and the stationary body is possible. For example, the slip ring described above may be used. However, the X-ray detector 16 detects two-dimensional projection data during one rotation (about 1 second), and in order to realize such a huge amount of projection data transmission, the DAS 18 and data transmission The circuit 19 is required to have a high speed processing function.

  Next, the three-dimensional image data generation unit 7 includes a projection data storage circuit 20 and a reconstruction calculation circuit 21. The projection data storage circuit 20 is a storage circuit that stores projection data detected by the X-ray detector 16 and sent via the data transmission circuit 19, and is collected for a plurality of slice planes of the subject 30. The projected data is saved. The reconstruction calculation circuit 21 reads out the projection data stored in the projection data storage circuit 20 and performs data interpolation processing in the slice direction, and then performs reconstruction processing to perform a plurality of pieces of axial image data in the slice direction. Alternatively, three-dimensional image data is generated. Further, the reconstruction calculation circuit 21 performs volume rendering processing for highlighting the surface and boundary surface of the organ with respect to the reconstructed three-dimensional image data. In the following, the processed image data is referred to as three-dimensional image data.

  On the other hand, the milling-through image data generation unit 8 includes an MPR image data generation circuit 25, a viewpoint / line-of-sight direction setting circuit 23, a fly-through processing circuit 24, and an image data storage circuit 22.

  The MPR image data generation circuit 25 uses the 3D image data generated by the 3D image data generation unit 7 to generate MPR (Multi-Planar-Reconstruction) image data in a plurality of image cross sections set in a predetermined direction. . For example, MPR image data is generated on an XY plane perpendicular to the body axis direction (Z direction) of the subject 30, and an XZ plane and a YZ plane orthogonal to the XY plane.

  Next, the viewpoint and line-of-sight direction setting circuit 23 includes an arithmetic circuit and a storage circuit, and stores information on the viewpoint and line-of-sight direction for fly-through display that is initially set in the plurality of MPR image data displayed on the display unit 9. Temporarily storing in the storage circuit, and then detecting the inter-image shift in the fly-through image data between adjacent time phases obtained on the basis of the set initial setting information of the viewpoint and the line-of-sight direction. Update.

  Further, the fly-through processing circuit 24 is a three-dimensional image data of a predetermined time stored in the image data storage circuit 22, and is calculated using the three-dimensional image data, and is stored in the storage circuit of the viewpoint / gaze direction setting circuit 23. The stored fly-through display viewpoint and line-of-sight direction information is read in units of time phases, and fly-through image data is generated.

  Then, the image data storage circuit 22 includes the three-dimensional image data generated by the reconstruction calculation circuit 21 of the three-dimensional image data generation unit 7, the MPR image data generated by the MPR image data generation circuit 25, and fly-through processing. The fly-through image data generated by the circuit 24 is stored in each storage area.

  The display unit 9 includes a display data generation circuit 26, a conversion circuit 27, and a monitor 28. The display data generation circuit 26 generates display data by superimposing the MPR image data and fly-through image data stored in the image data storage circuit 22 and the accompanying information related to these image data. The display data is displayed on the monitor 28 after D / A conversion and television format conversion are performed by the conversion circuit 27. By using the monitor 28 and the input unit 10 of the display unit 9, the operator can interact with the apparatus.

  On the other hand, the input unit 10 is an interactive interface including input devices such as a display panel, a keyboard, various switches, selection buttons, and a mouse, and an operator can project through the input unit 10 before collecting projection data. Various settings such as data collection conditions, reconstruction conditions, and image display conditions are performed.

  The projection data collection conditions include an imaging region, a scanning method, a slice interval, the number of slices, a tube voltage / tube current, an imaging region size, a scan interval, a view interval, an imaging time (Tx), and the like. Note that the scan interval is an imaging time interval of a plurality of image data captured at a predetermined slice position, and the view interval is a data collection interval in the rotation direction of the X-ray tube 13 and the X-ray detector 16. is there.

  On the other hand, the reconstruction conditions include a reconstruction method, a reconstruction area size, a reconstruction matrix size, an image data interval in the slice direction, and the number of image data. As image display conditions, there are a display method of MPR image data and fly-through image data, and an image processing method necessary for displaying these image data.

  Further, the viewpoint and line-of-sight direction for fly-through display in the MPR image displayed on the display unit 9 and the input of various command signals are also performed using the input device of the input unit 10.

  The system control unit 11 includes a CPU and a storage circuit (not shown), and temporarily stores various setting conditions and various command signals sent from the input unit 10 in an internal storage circuit. Then, according to an instruction from the input unit 10, each unit such as the mechanism control unit 4, the X-ray generation unit 5, the projection data collection unit 6, the three-dimensional image data generation unit 7, the fly-through image data generation unit 8, and the display unit 9 Overall control.

(Fly-through image data generation procedure)
Next, a procedure for generating fly-through image data according to the first embodiment of the present invention will be described with reference to FIGS. FIG. 2 is a flowchart showing a procedure for generating fly-through image data in this embodiment.

  Prior to the collection of projection data, the operator of the apparatus sets the above-described projection data collection conditions, reconstruction conditions, image display conditions, and the like on the input unit 10, and the system control unit 11 sets these set conditions. The data is stored in a memory circuit (not shown).

  FIG. 3 shows a method for collecting projection data in this embodiment. In this embodiment, as already described, the projection data on the 80 slice plane with the X-ray detector 16 having 80 X-ray detection elements in the slice direction (body axis direction) and the bed 1 fixed in the slice direction. To collect. For example, by detecting the X-rays irradiated by the X-ray tube 13 while rotating the X-ray detector 16 having an X-ray detection element having an array interval of 1 mm in the slice direction around the subject 30, the slice interval is detected. Projection data is collected at slice positions Z1 to Z80 where ΔZ is 1 mm.

  When the setting of the above conditions is completed, the subject 30 is placed on the top plate of the bed 1, and the slice positions Z = Z1 to Z80 of the gantry rotating unit 2 correspond to the examination site of the subject 30. The subject 30 is moved to a desired position in the slice direction (step S1 in FIG. 2).

  Next, the operator inputs a command signal for collecting projection data and generating three-dimensional image data at the input unit 10. The system control unit 11 that has received this command signal from the input unit 10 supplies the control signal to the bed / table mechanism unit 3 via the mechanism control unit 4 so that the X-ray tube 13 and the X-ray detector 16 face each other. In the state where the mounted gantry rotating unit 2 is rotated around the subject 30 at a speed of 1 rotation / second to 2 rotations / second, X-ray irradiation and detection are repeated to collect projection data.

  When the subject 30 is irradiated with X-rays, the high-voltage generator 12 uses the power necessary for X-ray irradiation (in accordance with tube voltage and tube current setting conditions stored in a storage circuit (not shown) of the system control unit 11). (Tube voltage and tube current) are supplied to the X-ray tube 13. The X-ray tube 13 receives this power supply and irradiates the subject 30 with fan beam X-rays.

  X-rays irradiated from the X-ray tube 13 and transmitted through the subject 30 are detected by the X-ray detector 16 of the projection data collection unit 6. That is, the X-rays transmitted through the subject 30 are converted into electric charges (current) proportional to the transmitted dose in the X-ray detector 16 having 80 elements in the slice direction and 24 elements in the channel direction. Further, this current is supplied to the DAS 18 and converted into a voltage, and then A / D converted, for example, projection data for 80 slices is generated.

  This projection data is sent to the transmission unit of the data transmission circuit 19 mounted on the gantry rotating unit 2, converted into an optical signal, and received by the reception unit of the data transmission circuit 19 attached to the gantry fixing unit via the air. Received. The received projection data is stored in the projection data storage circuit 20 of the three-dimensional image data generation unit 7.

  X-ray irradiation and X-ray transmission data detection on the subject 30 are performed while the X-ray tube 13 and the X-ray detector 16 are rotated around the subject 30, for example, at a frequency of 1000 times / rotation. When 30 is irradiated with X-rays, projection data of 80,000 / second to 160000 / second is collected for 80 slices. Then, the projection data collected at each slice position (Z = Z1 to Z80) is stored in the projection data storage circuit 20, and the collection and storage of the projection data in the inspection region are finished (step S2 in FIG. 2).

  Next, the reconstruction calculation circuit 21 of the three-dimensional image data generation unit 7 reads the projection data stored in the projection data storage circuit 20 within a range of, for example, 180 degrees + fan beam angle, and slice direction as necessary. After performing the interpolation process, a reconstruction process is performed to generate three-dimensional image data.

  Further, the reconstruction calculation circuit 21 performs volume rendering processing on the three-dimensional image data based on the image processing method setting data supplied from the system control unit 11, and contours such as a body surface and an organ boundary surface. Three-dimensional image data that can be enhanced is generated. Then, the 3D image data after image processing is stored in the 3D image data storage area of the image data storage circuit 22. (Step S3 in FIG. 2).

  Next, the operator inputs display commands for MPR image data and fly-through image data from the input unit 10. FIG. 4 shows an MPR image cross section of the luminal organ 64 displayed on the monitor 28 of the display unit 9 in accordance with the initially set image display conditions. That is, the MPR image A61 on the XZ plane orthogonal to each other, the MPR image B62 on the YZ plane, and the MPR image C63 on the XY plane are displayed on the monitor 28.

  FIG. 5 shows an MPR image A61 through MPR image C63 displayed on the monitor 28, and a fly-through image 67 obtained based on viewpoints 65a through 65c and line-of-sight directions 66a through 66c set on these MPR images.

  That is, the initial images of the MPR image A61, the MPR image B62, and the MPR image C63 are displayed on the right side of the monitor 28 from above, and the viewpoints 65a to 65c and the line-of-sight directions 66a to 66c associated with each other are displayed on each image. The initial state is displayed. The initial state is set based on image display conditions stored in advance in the storage circuit of the system control unit 11.

  On the other hand, on the left side of the monitor 28, a fly-through image generated from the three-dimensional image data based on the initial states of the viewpoints 65a to 65c and the line-of-sight directions 66a to 66c set in the MPR image A61 to MPR image C63. 67 is displayed.

  Note that the viewpoint 65 described above is a virtual viewpoint position when a milling-through image is obtained, and an arrow in the line-of-sight direction 65 is the central portion of the viewpoint 65 and the fly-through image (hereinafter referred to as an attention point). 68 is a direction vector connecting 68.

  For example, by dragging the viewpoint 65a of the MPR image A61 in an arbitrary direction using the input device of the input unit 10, the MPR image B62 on the YZ plane at the new X coordinate of the viewpoint 65a MPR images C63 on the XY plane at the new Z coordinate of the viewpoint 65a are displayed.

  Similarly, by dragging the viewpoint 65b of the MPR image B62 in an arbitrary direction, the MPR image B62 and the MPR image C63 at the new Y coordinate and Z coordinate of the viewpoint 65b and the viewpoint 65c of the MPR image C63 are arbitrarily set. By dragging in the direction, the MPR image B62 and the MPR image A61 at the new X coordinate and Y coordinate of the viewpoint 65a are respectively displayed (step S4 in FIG. 2).

  Then, a fly-through image 67 generated based on the newly set position of the viewpoint 65 and the direction of the line-of-sight direction 66 is displayed.

  The operator drags the viewpoints 65a to 65c in the MPR image A61 to the MPR image C63 while observing the monitor 28 of the display unit 9 on which the three MPR images A61 to C63 and the fly-through image 67 are displayed. Thus, a desired MPR image cross section, that is, a cross section of the MPR image A61 to MPR image C63 in which the longitudinal cross section or the horizontal cross section of the luminal organ 64 is displayed, is set, and the MPR image A61 to MPR image C63 The line-of-sight directions 66a to 66c are set in the lumens of the luminal organs 64 displayed respectively.

  Then, if it is confirmed that the above-described viewpoints 65a to 65c and the line-of-sight directions 66a to 66c are optimally set based on the fly-through image data generated based on the set viewpoints 65a to 65c and the line-of-sight directions 66a to 66c. For example, the fly-through image data is stored in the fly-through image data storage area of the image data storage circuit 22 as fly-through image data of the initial time phase T0, and the viewpoint 65 and the line-of-sight direction 66 at this time are stored in the system control unit 11. Save in the circuit (step S5 in FIG. 2).

  Next, the operator inputs a milling through image data generation start command for real-time display of the fly-through image from the input unit 10. That is, in the reference time phase T1, the projection data of the slice positions Z = Z1 to Z80 of the subject 30 are collected and the three-dimensional image data is generated by the same procedure as described above (Step S6 and Step S7 in FIG. 2). Further, the first fly-through image data of the reference time phase T1 is generated from the information of the viewpoint 65 and the line-of-sight direction 66 set in the initial time phase T0 and the three-dimensional image data obtained in the reference time phase T1. The image is stored in the milling through image data storage area of the image data storage circuit 22 (step S8 in FIG. 2).

  On the other hand, the milling-through processing circuit 24 reads out the first fly-through image data of the reference time phase T1 and the milling-through image data of the initial time phase T0 stored in the image data storage circuit 22, respectively. And the line-of-sight direction 66 is updated.

  First, the update of the viewpoint 65 will be described with reference to FIGS. 6 and 7. FIG. 6 shows luminal organ images (hereinafter referred to as peripheral milling-through image data) 71A and 71B around the viewpoint 65 obtained based on the three-dimensional image data of the initial time phase T0 and the reference time phase T1. In this method, the viewpoint / gaze direction setting circuit 23 reads the information of the viewpoint 65 and the gaze direction 66 in the initial time phase T0 stored in the system control unit 11, and includes the viewpoint 65 in the gaze direction 66. Peripheral milling through image data 71A of the initial time phase T0 in or near the vertical cross section is generated from the three-dimensional image data of the initial time phase T0. However, the above-described peripheral fly-through image data may be two-dimensional image data generated from the three-dimensional image data.

  Similarly, peripheral fly-through image data 71B of the reference time phase T1 is generated from the three-dimensional image data of the reference time phase T1. Then, the amount of deviation of the peripheral fly-through image data 71B with respect to the peripheral fly-through image data 71A is calculated, and the position of the viewpoint 65 in the initial time phase T0 is updated based on the amount of deviation to set the viewpoint 65 in the reference time phase T1. To do.

  For ease of explanation, the coordinate axis Xa-Ya shown in FIG. 6 is within the cross section determined by the viewpoint 65 and the line-of-sight direction 66 of the initial time phase T0, and the origin is the initial time phase T0. The viewpoint 65 is set.

上式（１）の計算の結果、ｋ＝ｋ１、ｓ＝ｓ１においてγ_ＡＢ（ｋ、ｓ）が最大値をもつ場合には、画像データＢは画像データＡに対してｐ方向（図６のＸａ方向）にｋ１、ｑ方向（図６のＹａ方向）にｓ１だけズレていることを示す。但し、図７のグラフではｋをパラメータにした場合のみを示しているが、ｓをパラメータにした場合についても同様に求めることができる。 FIG. 7 shows an example of a method for calculating a gap between images of the above-described peripheral fly-through image data 71B (hereinafter referred to as image data B) with respect to the peripheral fly-through image data 71A (hereinafter referred to as image data A). The shift between images is calculated by obtaining the cross-correlation coefficient γAB while sequentially shifting the data A and the image data B in the image plane direction. If the signal intensity at the pixel (p, q) of the image data A is A (p, q) and the signal intensity at the pixel (p, q) of the image data B is B (p, q) in the same way, It is possible to detect a deviation in the image plane direction of the image data A and the image data B from the cross-correlation function γAB (k, s) obtained by the expression (1) shown. That is

When γ _AB (k, s) has the maximum value when k = k1 and s = s1 as a result of the calculation of the above equation (1), the image data B is in the p direction (see FIG. 6). X1 direction is shifted by k1, and q direction (Ya direction in FIG. 6) is shifted by s1. However, although the graph of FIG. 7 shows only the case where k is a parameter, the same can be obtained for the case where s is a parameter.

  Next, the setting of the line-of-sight direction in the reference time phase T1 will be described. First, by using the same method as described above, an inter-image shift is calculated by a cross-correlation process between the fly-through image data at the initial time phase T0 and the first fly-through image data at the reference time phase T1, and the reference amount is calculated from the amount of the shift. The position of the attention point 68 in the time phase T1 is obtained. Next, the line-of-sight direction 66 in the reference time phase T1 is set by connecting the viewpoint 65 in the reference time phase T1 that has already been obtained and the point of interest 68 in the reference time phase T1.

  The first fly-through image data of the reference time phase T1 is generated using the viewpoint and line-of-sight direction information set in the initial time phase T0 and the three-dimensional image data obtained in the reference time phase T1 by the above-described procedure, Next, the viewpoint and line-of-sight direction in the reference time phase T1 are set (updated) by calculating the amount of deviation of the first fly-through image data in the reference time phase T1 from the fly-through image data in the initial time phase T0 (FIG. 2). Step S9).

  Next, the fly-through processing circuit 24 generates second fly-through image data of the reference time phase T1 using the updated viewpoint and line-of-sight direction of the reference time phase T1 and the three-dimensional image data of the reference time phase T1. Then, the generated second fly-through image data of the reference time phase T1 is stored in the milling-through image data storage area of the image data storage circuit 22, and the display data generation circuit 26 of the display unit 9 is stored in the image data storage circuit 22. The stored second milling-through image data of the reference time phase T1 is read, and image data for display of the milling-through image is generated according to a predetermined display format. Then, the display image data is displayed on the monitor 28 of the display unit 9 via the conversion circuit 27. (Step S10 in FIG. 2).

  In the same manner, after the next time phase T2 (T1 + ΔT) set at the time interval ΔT, the above-described procedure, that is, the procedure from step S6 to step S10 in FIG. 4 is repeated.

  For example, in the next time phase T2, the first fly-through image in the next time phase T2 is obtained using the viewpoint and line-of-sight direction information updated in the reference time phase T1 and the three-dimensional image data obtained in the next time phase T2. Data is generated, and then the viewpoint and line-of-sight direction in the next time phase T2 are set by calculating the amount of deviation of the first fly-through image data in the next time phase T2 from the fly-through image data in the reference time phase T1. Next, second fly-through image data of the next time phase T2 is generated using the set viewpoint and line-of-sight direction of the next time phase T2 and the three-dimensional image data of the next time phase T2.

  Next, the next time phase is newly set as the reference time phase and the above procedure is repeated to generate and display fly-through image data. If the preset time phase (shooting time) Tx is reached (FIG. Step S11 of 2) The generation of the three-dimensional image data and the generation and display of the fly-through image data are finished according to the control signal supplied from the system control unit 11 (Step S12 of FIG. 2).

  When manual resetting of the viewpoint or line-of-sight direction is necessary during real-time display of fly-through image data, the operator inputs a manual setting command from the input unit 10 to thereby display the diagnostic imaging apparatus 100. The operation returns to step S5 in FIG. 2, and the operator can set the viewpoint and the line-of-sight direction again by the method described in FIG.

(Modification)
Next, a modification of the present embodiment will be described with reference to FIG. In the first embodiment described above, the movement of the viewpoint in the adjacent time phase is detected by the cross-correlation processing of the fly-through image. In this modification, a method using a bidirectional vector will be described.

  For example, as shown in FIG. 8, a plurality of bidirectional vectors c11, c12, and c13 with respect to the luminal organ surface d1 in the three-dimensional image data in the initial time phase T0 from the viewpoint a1 initially set in the initial time phase T0. And the distance from the viewpoint a1 to the luminal organ surface d1 (for example, e11 and e21 for the bidirectional vector c11) is measured in each bidirectional vector.

  Next, in the three-dimensional image data obtained at the reference time phase T1, bidirectional vectors c21, c22, and c23 are formed in the same direction from the viewpoint a1. Then, viewpoint candidate points b1, b2, and b3 are set on each bidirectional vector. In this case, for example, the viewpoint candidate point b1 of the bidirectional vector c21 is set such that the distances e31 and e41 from the viewpoint candidate point b1 to the luminal organ surface d2 are e31 / e41 = e11 / e21, and the viewpoint candidate point b2 And b3 are also set by a similar method. Next, the viewpoint a2 in the reference time phase T1 is set by obtaining the average value of the coordinates of the set viewpoint candidate points b1, b2, and b3. Hereinafter, also in setting the viewpoint in the next time phase T2 and subsequent times, the same procedure as described above is repeated based on the position of the viewpoint in the previous time phase.

  Note that the number of bidirectional vectors in the above-described modification is not limited to three. The bidirectional vector formed with reference to the viewpoint a1 may be formed three-dimensionally, but may be formed within a predetermined plane. In particular, the plane in the latter case is set in the previous time phase. A plane that is perpendicular to the viewing direction is preferred.

  According to the first embodiment and the modification described above, the viewpoint position is always set in the lumen organ when the moving image is displayed using the fly-through image data in the lumen organ generated in time series. Therefore, stable fly-through image data moving image display can be performed.

  Furthermore, in this embodiment, since the generation of three-dimensional image data and the generation of fly-through image data for the subject can be performed in parallel, the fly-through image data can be displayed in real time.

  In the flowchart of FIG. 2 showing the procedure for generating fly-through image data, after setting the viewpoint and line-of-sight direction in step S9, generation and display of fly-through image data based on the set viewpoint and line-of-sight direction (step S10). ), But when the deviation of the viewpoint or line-of-sight direction between adjacent time phases is very small, instead of displaying the fly-through image data obtained in step S10, as shown in the flowchart of FIG. The fly-through image data obtained in step S8 may be displayed.

  On the other hand, in the above-described embodiment, the real-time display of the so-called fly-through image data in which the generation of the three-dimensional image data and the generation and display of the fly-through image data are performed in parallel has been described. The fly-through image data generated using the three-dimensional image data of a plurality of time phases once stored may be displayed in time series.

  Furthermore, although the case where the MPR image data in the present embodiment is generated from three-dimensional image data has been described, it may be generated directly from data before reconstruction such as projection data. Other image processing methods such as a surface rendering method may be used as an image processing method for three-dimensional image data.

  Next, a second embodiment of the present invention will be described with reference to FIGS. The difference between this embodiment and the first embodiment is that an image display device for generating fly-through image data is provided independently of the image diagnostic device.

(Configuration of image display device)
The configuration of the image display apparatus in this embodiment will be described with reference to FIG. In the block diagram of the image display apparatus shown in FIG. 10, units having the same functions as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  The image display device 150 illustrated in FIG. 10 is generated by the fly-through image data generation unit 8 that generates fly-through image data from the three-dimensional image data of the subject 30 supplied from the separately installed image diagnostic device 50. A display unit 9 for displaying fly-through image data and the like, an input unit 41 for setting various conditions and inputting various commands, and a system control unit 42 for comprehensively controlling the above-described units.

  Then, the milling-through image data generation unit 8 uses the three-dimensional image data supplied from the image diagnostic apparatus 50, and an MPR image data generation circuit 25 that generates MPR image data in a plurality of image slices set in a predetermined direction. In addition, the viewpoint and line-of-sight direction are initially set in these MPR image data, and the amount of movement between the phases of fly-through image data generated based on the viewpoint and line-of-sight information in each time phase and three-dimensional image data is detected. Thus, a viewpoint / line-of-sight direction setting circuit 23 for updating the viewpoint and line-of-sight direction is provided.

  Further, the milling-through image data generation unit 8 includes a fly-through processing circuit 24 that generates fly-through image data based on the viewpoint and line-of-sight direction set in each time phase and the three-dimensional image data in each time phase, and image diagnosis. The image data storage circuit 22 stores the three-dimensional image data supplied from the apparatus 50, the MPR image data generated by the MPR image data generation circuit 25, and the fly-through image data generated by the fly-through processing circuit 24. I have.

  The display unit 9 superimposes and displays MPR image data and fly-through image data stored in the image data storage circuit 22 and incidental information related to these image data.

  On the other hand, the input unit 41 includes input devices such as a display panel, a keyboard, various switches, a selection button, a mouse, and the like, and setting of the viewpoint and line-of-sight direction for fly-through display in the MPR image displayed on the display unit 9, and Various command signals are input.

  The system control unit 42 includes a CPU and a storage circuit (not shown), and temporarily stores various setting conditions and various command signals sent from the input unit 41 in an internal storage circuit. And according to the instruction | indication from this input part 41, said each unit is controlled comprehensively.

(Fly-through image data generation procedure)
Next, a procedure for generating fly-through image data in the second embodiment of the present invention will be described with reference to FIGS. FIG. 11 is a flowchart showing the procedure for generating fly-through image data in this embodiment, and the same steps as those in the first embodiment shown in FIG.

  The operator inputs an MPR image display command from the input unit 41. The MPR image data generation circuit 25 that has received the command signal via the system control unit 42 is supplied in advance from the image diagnostic apparatus 50 and stored in the image data storage circuit 22 of the fly-through image data generation unit 8 in time series 3. The three-dimensional image data of the initial time phase T0 is read out from the two-dimensional image data. Then, MPR image data in a predetermined section is generated from the three-dimensional image data, and the MPR image data, the viewpoint for fly-through display, and the initial state of the line-of-sight direction are superimposed and displayed on the monitor 28 of the display unit 9 (FIG. 11 step S4).

  Then, the MPR image cross section is updated by dragging the viewpoint displayed on the MPR image in an arbitrary direction using the input device of the input unit 41, and the position of the viewpoint set on the updated MPR image is further updated. The fly-through image data generated based on the line-of-sight direction is displayed on the monitor 28.

  Next, if it is confirmed that the above-described viewpoint and line-of-sight direction are optimally set by the fly-through image generated based on the set viewpoint and line-of-sight direction, the fly-through image data is stored in the image data storage circuit 22. In addition, information on the viewpoint and line-of-sight direction at this time is stored in the storage circuit of the system control unit 42 (step S5 in FIG. 11).

  Next, the operator inputs a milling-through image data generation start command for the purpose of moving image display of fly-through image data from the input unit 41. However, since the following procedures for generating and displaying the milling-through image data for the purpose of moving image display are the same as those in the first embodiment, description thereof will be omitted.

  According to the second embodiment described above, stable real-time display or moving image display of fly-through image data is performed using three-dimensional image data in a plurality of time phases of the subject as in the first embodiment. It becomes possible.

  Furthermore, since the image display apparatus in the present embodiment can be connected to different types of image diagnostic apparatuses, generation and display of fly-through image data based on the three-dimensional image data obtained by the desired image diagnostic apparatus is performed. It can be done easily.

  As mentioned above, although the Example of this invention was described, it is not limited to said Example, You may deform | transform and implement. For example, the MPR image cross section is not limited to the three cross sections orthogonal to each other as shown in FIG. 5, and may be arbitrarily set. Further, if manual setting of the viewpoint and line-of-sight direction for fly-through display on the MPR image is completed, only fly-through image data may be displayed on the display unit.

  On the other hand, the display end timing of the fly-through image data may be in accordance with a preset shooting time (Tx), or may be based on a shooting end command input by the operator at the input unit.

  In addition, the setting of the viewpoint and the line-of-sight direction in the above-described embodiment is performed based on fly-through image data obtained from the three-dimensional image data, but the three-dimensional image data or the two-dimensional image data generated from the three-dimensional image data. May be used.

1 is a block diagram showing a configuration of an entire diagnostic imaging apparatus according to a first embodiment of the present invention. The flowchart which shows the production | generation procedure of the fly through image data in the Example. The figure which shows the collection method of the projection data in the Example. The figure which shows one example of the MPR image cross section set with respect to the luminal organ of the Example. The figure which shows the relationship between the viewpoint set to the MPR image of the Example, a gaze direction, and a fly-through image. The figure which shows the viewpoint in the initial time phase T0 of the Example, and the reference | standard time phase T1, and the luminal organ wall in the circumference | surroundings. The figure which shows the calculation method of the viewpoint moving amount | distance in the image of a different time phase of the Example. The figure which shows the calculation method of the viewpoint movement amount in the modification of the Example. The flowchart which shows the other production | generation procedure of the fly through image data in 1st Example of this invention. The block diagram which shows the structure of the image display apparatus which concerns on 2nd Example of this invention. The flowchart which shows the production | generation procedure of the fly through image data in the Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Bed 2 ... Base rotation part 3 ... Bed and base mechanism part 4 ... Mechanism control part 5 ... X-ray generation part 6 ... Projection data collection part 7 ... Three-dimensional image data generation part 8 ... Fly through image data generation part 9 ... Display unit 10 ... Input unit 11 ... System control unit 12 ... High voltage generator 13 ... X-ray tube 14 ... X-ray restrictor 15 ... Slip ring 16 ... X-ray detector 17 ... Switch group 18 ... DAS
DESCRIPTION OF SYMBOLS 19 ... Data transmission circuit 20 ... Projection data storage circuit 21 ... Reconstruction calculation circuit 22 ... Image data storage circuit 23 ... Viewpoint, gaze direction setting circuit 24 ... Fly through processing circuit 25 ... MPR image data generation circuit 26 ... Display data generation circuit 27 ... Conversion circuit 28 ... Monitor

Claims (10)

A viewpoint and line-of-sight direction for fly-through display are set for 3D image data obtained in time series for the subject, and fly-through is performed based on the set viewpoint and line-of-sight direction and the 3D image data. In an image diagnostic apparatus for generating and displaying image data,
Detecting means for detecting a shift between images based on a three-dimensional image data of a reference time phase obtained in time series and a next time phase following the reference time phase;
Viewpoint / line-of-sight direction setting means for setting the viewpoint and line-of-sight direction in the next time phase based on the gap between images detected by the detection means and the viewpoint and line-of-sight direction in the preset reference time phase;
Fly-through image data generating means for generating fly-through image data of the next time phase based on the viewpoint and line-of-sight direction in the next time phase;
Comprising display means for displaying the fly-through image data of the next time phase,
The next time phase is set as a new reference time phase, detection of an image gap by the detection unit, setting of the viewpoint and line-of-sight direction of the next time phase by the viewpoint / line-of-sight direction setting unit, and the fly-through image An image diagnostic apparatus characterized in that the generation of the next time phase fly-through image data by the data generation means and the display of the next time phase fly-through image data by the display means are repeatedly executed. A viewpoint and line-of-sight direction for fly-through display are set with respect to the three-dimensional image data obtained in time series for the subject, and fly based on the set viewpoint and line-of-sight direction and the three-dimensional image data. In an image diagnostic apparatus that generates and displays through image data,
The reference time phase fly-through image data and the next time based on the reference time phase obtained in time series, the next time phase three-dimensional image data following the reference time phase, and the viewpoint and line-of-sight direction in the reference time phase. Fly-through image data generating means for generating phase fly-through image data;
Detecting means for detecting a gap between images of the fly-through image data of the reference time phase and the fly-through image data of the next time phase;
Viewpoint / line-of-sight direction setting means for setting the viewpoint and line-of-sight direction in the next time phase based on the gap between images detected by the detection means;
Display means for displaying at least one of the fly-through image data of the reference time phase or the fly-through image data of the next time phase;
The next time phase is set as a new reference time phase, the reference time phase by the fly-through image data generation unit and generation of fly-through image data of the next time phase following the reference time phase, and the detection unit by the detection unit Detection of an inter-image shift in the fly-through image data of the reference time phase and the next time phase, setting of the viewpoint and line-of-sight direction of the next time phase by the viewpoint / gaze direction setting unit, and fly-through image data by the display unit The diagnostic imaging apparatus is characterized by repeatedly executing the display.   The image diagnostic apparatus according to claim 1 or 2, wherein the three-dimensional image data is generated based on any of X-ray CT image data, MRI image data, and ultrasonic image data.   The fly-through image data generating means converts the three-dimensional image data obtained by performing either volume rendering processing or surface rendering processing to any of X-ray CT image data, MRI image data, and ultrasonic image data. 4. The diagnostic imaging apparatus according to claim 1, wherein fly-through image data is generated. 5.   3. The image detection apparatus according to claim 1, wherein the detection unit detects a shift between images by a cross-correlation process between the fly-through image data of the reference time phase and the fly-through image data of the next time phase. Diagnostic imaging equipment.   The diagnostic imaging apparatus according to claim 1, wherein the display unit displays a moving image using fly-through image data generated by the fly-through image data generation unit. A viewpoint and line-of-sight direction for fly-through display are set for time-series three-dimensional image data generated by the image diagnostic apparatus for the subject, and based on the set viewpoint and line-of-sight direction and the three-dimensional image data. In an image display device that generates and displays fly-through image data,
Detecting means for detecting a shift between images based on a three-dimensional image data of a reference time phase obtained in time series and a next time phase following the reference time phase;
Viewpoint / line-of-sight direction setting means for setting the viewpoint and line-of-sight direction in the next time phase based on the gap between images detected by the detection means and the viewpoint and line-of-sight direction in the preset reference time phase;
Fly-through image data generating means for generating fly-through image data of the next time phase based on the viewpoint and line-of-sight direction in the next time phase;
Comprising display means for displaying the fly-through image data of the next time phase,
The next time phase is set as a new reference time phase, detection of an image gap by the detection unit, setting of the viewpoint and line-of-sight direction of the next time phase by the viewpoint / line-of-sight direction setting unit, and the fly-through image An image display apparatus characterized by repeatedly generating the next-phase fly-through image data by the data generation means and displaying the fly-through image data by the display means. The viewpoint and line-of-sight direction for fly-through display are set for the time-series three-dimensional image data generated by the image diagnostic apparatus for the subject, and the set viewpoint and line-of-sight direction and the three-dimensional image data are set. In an image display device for generating and displaying fly-through image data based on
The reference time phase fly-through image data and the next time based on the reference time phase obtained in time series, the next time phase three-dimensional image data following the reference time phase, and the viewpoint and line-of-sight direction in the reference time phase. Fly-through image data generating means for generating phase fly-through image data;
Detecting means for detecting a gap between images of the fly-through image data of the reference time phase and the fly-through image data of the next time phase;
Viewpoint / line-of-sight direction setting means for setting the viewpoint and line-of-sight direction in the next time phase based on the gap between images detected by the detection means;
Display means for displaying at least one of the fly-through image data of the reference time phase or the fly-through image data of the next time phase;
The next time phase is set as a new reference time phase, the reference time phase by the fly-through image data generation unit and generation of fly-through image data of the next time phase following the reference time phase, and the detection unit by the detection unit Detection of an inter-image shift in the fly-through image data of the reference time phase and the next time phase, setting of the viewpoint and line-of-sight direction of the next time phase by the viewpoint / gaze direction setting unit, and fly-through image data by the display unit An image display device characterized by repeatedly displaying the above. A viewpoint and line-of-sight direction for fly-through display are set for 3D image data obtained in time series for the subject, and fly-through is performed based on the set viewpoint and line-of-sight direction and the 3D image data. A three-dimensional image display method for generating and displaying image data,
(A) detecting a shift between images based on a reference time phase obtained in time series and three-dimensional image data of a next time phase subsequent to the reference time phase;
(B) setting the viewpoint and line-of-sight direction in the next time phase based on the detected image gap and the viewpoint and line-of-sight direction in a preset reference time phase;
(C) generating fly-through image data of the next time phase based on the viewpoint and line-of-sight direction in the next time phase;
(D) displaying the fly-through image data of the next time phase;
(E) A method for displaying a three-dimensional image, comprising: setting the next time phase as a new reference time phase and repeatedly executing steps (a) to (d). A viewpoint and line-of-sight direction for fly-through display are set with respect to the three-dimensional image data obtained in time series for the subject, and fly based on the set viewpoint and line-of-sight direction and the three-dimensional image data. A three-dimensional image display method for generating and displaying through image data,
(A) Reference time phase fly-through image data based on the reference time phase obtained in time series, the three-dimensional image data of the next time phase following the reference time phase, and the viewpoint and line-of-sight direction in the reference time phase And generating the next time phase fly-through image data;
(B) detecting an inter-image shift between the fly-through image data of the reference time phase and the fly-through image data of the next time phase;
(C) setting a viewpoint and a line-of-sight direction in the next time phase based on the image gap;
(D) displaying at least one of the fly-through image data of the reference time phase or the fly-through image data of the next time phase;
(E) A method for displaying a three-dimensional image, comprising: setting the next time phase as a new reference time phase and repeatedly executing steps (a) to (d).

Images