CN111882510A - Projection method, image processing method and device for CTA three-dimensional reconstruction mirror data - Google Patents

Abstract

The invention discloses a projection method, an image processing method and a device for CTA three-dimensional reconstruction mirror data which can be accurately fused with angiography. The projection method includes the following steps: obtaining CTA three-dimensional reconstructed mirror data; setting the image projection mode of the CTA three-dimensional reconstructed mirror data to the perspective projection mode; correcting the distance from the projection center of the perspective projection of the CTA three-dimensional reconstructed mirror data to the DSA display screen as The distance from the X-ray tube to the detector; and the distance from the projection center of the perspective projection of the CTA three-dimensional reconstruction mirror data to the target organ is corrected to the distance from the X-ray tube to the catheter bed; The center of the screen overlaps the center of the DSA contrast image. The invention can not only realize the precise fusion of the three-dimensional image reconstructed by CTA and coronary angiography, but also help the coronary intervention operator to quickly establish the three-dimensional perception of the coronary angiography, significantly improve the level of the coronary intervention operator, reduce the difficulty of the interventional operation, and significantly reduce the difficulty of the interventional operation. Improve patient outcomes.

Description

Projection method, image processing method and device for CTA three-dimensional reconstruction mirror data

technical field

The invention relates to a projection method, an image processing method and a device for CTA three-dimensional reconstruction mirror data which can be accurately integrated with angiography, and belong to the technical field of medical image processing.

Background technique

Digital Subtraction Angiography (DSA) machine is an angiography X-ray machine with digital subtraction function and pulse fluoroscopy function. It is mainly used for angiographic diagnosis and interventional treatment of the heart, cerebral blood vessels and peripheral blood vessels. Real-time shooting and playback of images, as well as pathological indications of lesions can be performed. The DSA machine includes a rotatable frame (including C-arm and P-arm), a catheter bed that can move horizontally/vertically/up and down, a high-voltage generator, an X-ray tube, an image intensifier, a camera system (detector), and image digital Processing system, DSA display and external data storage system. It can reduce the radiation of X-rays to patients and surgeons, and its use has become increasingly popular in recent years.

During percutaneous coronary intervention (PCI) procedures, doctors have always relied on fluoroscopy to guide the procedure. However, since fluoroscopy is limited to two-dimensional projections, and doctors understand the treatment primarily through intuition and tactile feedback, the accuracy of this procedure cannot be guaranteed. It is well known that CT angiography (CTA) can clearly visualize the coronary arteries and their branches. CTA three-dimensional reconstruction can not only reconstruct the coronary arteries, but also the aorta, atrium and ventricle, allowing doctors to intuitively understand the three-dimensional contours and adjacent structures of the coronary arteries. The resolution is much higher than the images obtained by coronary angiography (CAG) performed by DSA machines. In order to make up for the deficiency of two-dimensional X-ray projection in coronary intervention, the method of realizing CTA and CAG fusion registration has become a research hotspot.

As shown in Figure 1, the current fusion registration methods such as Innova HeartVision or Navigation directly overlap the CTA reconstructed 3D image in the CT workstation on the CAG image, and take the position of the doctor's eyes or the detector as the viewpoint. This method of image fusion is inaccurate, and can only be fused when the C-arm rotates left and right. It cannot be applied to the application scenario where the left and right and cephalopod positions of the DSA gantry rotate at the same time in coronary intervention. Therefore, it can only be used for Interventional arterial surgery.

In the Chinese utility model patent with the patent number of ZL 200820123994.6, the position of the C-arm in the operation is used to match the preoperative CT three-dimensional reconstruction image and DSA angiography image. In the Chinese patent application with the application number of 201610201387.6, the CTA image and DSA image of coronary blood vessels are matched with the center line of the CTA image and the center line of the DSA image (the frame of DSA image with the highest similarity with the CTA image). to obtain a fused image. Since only centerline fusion is required, the fused images lack depth information. This fusion registration method will greatly reduce the stereo perception of coronary intervention (PCI) operators, while the stereo perception of DSA images is extremely important for PCI operators. . Furthermore, these methods do not explore the essential difference between CAG and CTA from the perspective of the PCI operator. The resulting fusion image is the superposition of various complex algorithms, the operation process is complicated, and the precision is low, which is difficult to be understood and accepted by PCI operators.

SUMMARY OF THE INVENTION

The primary technical problem to be solved by the present invention is to provide a projection method for CTA three-dimensional reconstruction mirror data.

Another technical problem to be solved by the present invention is to provide an image processing method for CTA three-dimensional reconstructed mirror data.

Another technical problem to be solved by the present invention is to provide a projection device for CTA three-dimensional reconstruction mirror data.

In order to realize the above-mentioned purpose of the invention, the present invention adopts the following technical scheme:

According to a first aspect of the embodiments of the present invention, there is provided a projection method for CTA three-dimensional reconstruction mirror data, the angiography is obtained by using a DSA machine, and the DSA machine has an X-ray tube, a catheter bed, a detector and a DSA display, including the following steps:

Obtain CTA 3D reconstruction image data;

Setting the image projection mode of the CTA three-dimensional reconstruction mirror data to a perspective projection mode;

Correcting the distance from the projection center of the perspective projection of the CTA three-dimensional reconstruction mirror data to the DSA display screen as the distance from the X-ray tube to the detector; and converting the perspective projection of the CTA three-dimensional reconstruction mirror data The distance from the projection center to the target organ is corrected as the distance from the X-ray tube to the catheter bed;

The screen center of the perspective projection of the CTA three-dimensional reconstruction mirror data is overlapped with the center of the DSA contrast image.

Preferably, the target organ is the spine.

Preferably, the distance from the X-ray tube bulb of the DSA machine to the catheter bed, and the distance from the X-ray tube bulb to the catheter bed are the distances of the DSA machine in the upright state.

According to a second aspect of the embodiments of the present invention, an image processing method for CTA three-dimensional reconstructed mirror data is provided for precise fusion with angiography obtained by using a DSA machine, the DSA machine has an X-ray tube Ball, catheter bed, and DSA display, including the following steps:

Obtain CTA 3D reconstruction image data;

Setting the image projection mode of the CTA three-dimensional reconstruction mirror data to a perspective projection mode;

Correcting the distance from the projection center of the perspective projection of the CTA three-dimensional reconstruction mirror data to the DSA display screen as the distance from the X-ray tube to the detector; and converting the projection of the perspective projection of the CTA three-dimensional reconstruction mirror data The distance from the center to the target organ is corrected as the distance from the X-ray tube to the catheter bed;

The perspective projection of the adjusted CTA three-dimensional reconstruction mirror data is displayed on the DSA display screen of the fusion device;

Accurate fusion of the X-ray projection of the spine in the DSA angiography image and the perspective projection of the spine in the CT 3D reconstruction mirror data;

rotating the perspective projection of the reconstructed mirror data according to the rotation angle of the gantry of the DSA machine;

Obtain and output the fused image.

Preferably, according to the distance between the X-ray tube and the catheter bed in the current state of the DSA machine, the distance from the projection center to the lesion is adjusted to make the two equal; and the CTA image is adjusted according to the distance from the X-ray tube to the detector. The distance from the projection center to the screen, so that the two are equal.

Preferably, the center of the screen of the perspective projection of the CTA three-dimensional reconstructed mirror data is overlapped with the center of the DSA angiography image.

Preferably, the perspective projection image of the CTA three-dimensional reconstruction mirror data has an X-axis and a Z-axis,

When the perspective projection image of the three-dimensionally reconstructed mirror data of the CTA is in the front view, the X axis is rotated according to the C-arm angle of the DSA machine in the current state, and then the Z axis is rotated according to the P-arm angle.

According to a third aspect of the embodiments of the present invention, there is provided a projection device for CTA three-dimensional reconstruction mirror data, the device is connected to a DSA machine to realize the projection of CTA three-dimensional reconstruction mirror data, and the DSA machine includes a C arm, a detector, and a catheter bed. , X-ray tube and DSA display, including:

The projection of the CTA three-dimensional reconstruction mirror data is a perspective projection mode; the distance from the projection center of the perspective projection of the CTA three-dimensional reconstruction mirror data to the human target organ is equal to the distance from the X-ray tube to the catheter bed; the The distance from the projection center of the perspective projection of the CTA three-dimensional reconstruction mirror data to the DSA display screen is the distance from the X-ray tube to the detector.

Preferably, the perspective projection of the CTA three-dimensional reconstructed mirror data is displayed on the projection device, and the display position is such that the center of the screen of the perspective projection of the CTA three-dimensional reconstructed mirror data is the same as the DSA contrast image. center overlap.

Preferably, when the perspective projection image of the CTA three-dimensional reconstructed mirror data is in front view, the X axis is rotated according to the C-arm angle of the DSA machine in the current state, and then the Z axis is rotated according to the P-arm angle.

Using the method provided by the present invention, the three-dimensionally reconstructed CTA image and the DSA image can be accurately fused, with correct registration, consistent viewpoints, correct spatial relationship, and no image distortion. It can not only realize the precise fusion of CTA three-dimensional reconstruction images and DSA angiography, but also help the operators of interventional operations to quickly establish the stereoscopic perception of DSA angiography, significantly improve the level of interventional operators, facilitate the formulation of treatment plans, reduce the difficulty of interventional operations, and significantly improve the patient prognosis.

Description of drawings

Fig. 1 is in the prior art, the fusion effect diagram of angiography image and CTA three-dimensional reconstruction data image;

Fig. 2 is a schematic diagram of the influence of rotation order on image fusion effect;

3A to FIG. 3E are schematic diagrams illustrating the influence of the rotation order of the stereoscopic image on the image fusion effect according to an embodiment of the present invention;

4A to 4B are flowcharts of a method for processing images of CTA 3D reconstruction data that can be accurately fused with DSA angiography in an embodiment of the present invention;

5A to 5G are simulation effect diagrams of processed images after CTA three-dimensional reconstruction data that can be accurately fused with angiography according to an embodiment of the present invention;

FIG. 6 is an actual effect diagram of a processed image after CTA three-dimensional reconstruction data that can be accurately fused with angiography in the present invention.

Detailed ways

The technical content of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

In order to clearly illustrate the technical content of the present invention, the cause of the fusion error between the CTA image and the CAG image and its influence on the CAG stereoscopic perception of the operator of coronary intervention are firstly introduced. However, the present invention only takes the CTA image as an example, and is not limited to coronary intervention. As long as it is an image obtained by a DSA machine and an image obtained by a CT machine, the method provided by the present invention can be applied to achieve fusion. For example, the images of the skeletal system, the digestive system, the reproductive system, the urinary system, etc. obtained by a CT machine and a DSA machine, respectively, are used to fuse the images of the same parts captured by the two devices, and the projection method of the present invention can be used, and An image processing method based on this projection method.

Moreover, as long as the image generated by the fluoroscopic imaging device (eg, DSA machine) is fused with the image generated by the parallel projection imaging device (eg, CT machine), the method provided by the present invention can be used.

X-ray imaging is equivalent to the perspective projection with the tube ball as the projection center. It is a proportional enlargement of the perspective view. Therefore, the X-ray imaging fully conforms to the principle of perspective, which is essentially the same as the perspective view, which is also obtained by two-dimensional X-ray imaging. The theoretical basis of three-dimensional sense.

Corresponding to perspective projection, another projection method for displaying three-dimensional objects on a two-dimensional screen is called parallel projection. The so-called parallel projection means that when the projection center is moved to infinity from the object, all the projection lines are parallel to each other. A projection method in which the projection lines are parallel to each other is called parallel projection. Almost all CT workstations use parallel projection to display 3D CT reconstruction data.

The X-ray imaging of the DSA machine is equivalent to the perspective projection with the tube as the projection center (viewpoint), and the X-ray imaging completely conforms to the perspective principle. Since coronary angiography (X-ray fluoroscopy) belongs to perspective projection, it cannot be directly fused with the parallel projection of the CT workstation, and the current mainstream view adopted in image fusion, such as the InnovaHeartVision system of General Technology Group Healthcare Co., Ltd. Or the viewing angle of the detector is used as the viewpoint of coronary angiography image. Due to the wrong viewpoint selection, the post-processing image of CTA obtained by perspective projection is exactly the opposite of that of coronary angiography, which will further lead to the lack of stereoscopic perception of coronary angiography.

In order to correct this error, the present invention first proposes to convert CTA three-dimensional reconstructed mirror image data from parallel projection to perspective projection to obtain a stereoscopic image that is fully integrated with coronary angiography. As a result, precise fusion can be achieved, and at the same time, by directly displaying the stereoscopic image in front of the doctor, it can help the doctor to quickly establish a three-dimensional sense of coronary angiography.

Since the rotation of the C-arm will lead to the transformation of the angiographic image, it will cause an error in the fusion with the CT image. To do this, it is necessary to understand how the 3D stereoscopic image is rotated on the display screen. In order to facilitate understanding and simply study the rotation axis, the following uses a 16 cube Rubik's cube as an example to illustrate. As shown in Figure 2, the 16 cube Rubik's Cube is placed on the DSA machine platform, and the cross vertical lines of the X, Y, and Z axes of the Rubik's Cube can be clearly seen under the X-ray (Fig. 2A shows that the DSA frame is positive The X-ray image of the Rubik's Cube at the time of digitization), collect the x-ray images of the Rubik's Cube under different DSA gantry angles, and use UG NX11.0 to build the digital model of the Rubik's Cube (Fig. axis). According to the angle of the DSA rack, the digital model of the Rubik's Cube can be rotated in two ways to obtain the effect after rotation as shown in Figure 2C (the effect of DSA image rotation of the Rubik's Cube) and Figure 2D (the effect of rotation of the digital model). : The first method is to first rotate the Z axis at the P-arm angle in the front view shown in Figure 2B, and then rotate the X axis at the C-arm angle (resulting in the effect shown in Figure 2E). The second method is to first rotate the X-axis at the C-arm angle in the front view, and then rotate the Z-axis at the P-arm angle (resulting in the effect shown in Figure 2F). In Figure 2F, it is found that the X, Y, and Z axes in the digital model of the Rubik's Cube and the X, Y, and Z axes in the Rubik's Cube DSA image are completely coincident in the second method (as shown in Figure 2F, the perspective of the Rubik's Cube represented by light gray) The figure overlaps with the digital model map represented by dark colors); the renderings obtained in the first method do not overlap (as shown in Figure 2E, the perspective map of the Rubik's cube represented by light gray does not overlap with the digital model map represented by dark colors). Since the X-axis in the front view of the Rubik's cube digital model is parallel to the upper and lower edges of the screen, the Z-axis after the X-axis is rotated is at an angle with the left and right edges of the display screen (the angle is equal to the X-axis rotation angle), and the DSA contrast image can be obtained. The rotation axis of the C arm is parallel to the upper and lower edges of the display screen, while the rotation axis of the P arm responsible for left and right rotation and the left and right edges of the display screen form an angle with the angle of the head and foot position. equal.

The following describes the corresponding positional relationship between the rotation of the DSA machine during the operation and the DSA image displayed on the DSA display screen 4 in detail. As shown in Figure 3A, when the C-arm of the DSA machine is in the positive position (not rotated), the detector 2 is located directly above the catheter bed 3, and the X-ray tube 5 is located directly under the catheter bed 3, which is aligned with the detector 2 up and down . With the rotation of the C arm 1, the DSA image can be rotated around the rotation axis of the head and foot, and with the rotation of the P arm, the DSA image can also be rotated around the left and right rotation axes.

Since the image displayed on the DSA display screen 4 used in conjunction with the DSA machine is the image of the detection range of the detector 2 , the edge of the detector 2 of the DSA machine is the same as the edge of the DSA display screen 4 . As shown in FIG. 3A , the detection range of the detector 2 and the DSA display screen 4 are both rectangular, with left edge, right edge, upper edge and lower edge. The upper/lower edges are equal and perpendicular to the left/right edges. As shown in FIG. 3A , the left edge of the detector 2 will be displayed on the left edge of the DSA display screen 4 ; the right edge of the detector 2 will be displayed on the right edge of the DSA display screen 4 .

Determination of the rotation axis of the head and foot: Since the detector is fixed on the C arm responsible for the rotation of the head and foot, the rotation axis of the C arm is always parallel to the upper and lower edges of the detector, so the rotation axis of the head and foot of the DSA image is always parallel to the DSA display screen 4 , regardless of how the angle of the P-arm changes.

Determination of the left and right rotation axes: When the C-arm responsible for the rotation of the head and feet rotates, the C-arm moves relative to the P-arm responsible for the left-right rotation of the DSA image. Therefore, the detector fixed on the C-arm is also relative to the P-arm rotation axis produce relative movement. Further, as shown in Figure 3B, the normal angle between the position of the detector in the positive position (the position marked 2 in the figure) and its position when the foot is 30 degrees (the position marked 2' in the figure) is C Arm rotation angle θ. The included angle γ between the plane where the detector 2 is located (the plane perpendicular to the normal line of the aforementioned detector) and the rotation axis of the P arm is equal to the head-foot rotation angle θ by using geometric knowledge. The results obtained that the left and right rotation axes of the DSA image and the left and right edges of the DSA display screen formed an angle with the change of the angle of the C-arm cephalopod, and the angle formed was equal to the angle of the C-arm cephalopod.

As shown in Figure 3C. Correspondingly, during DSA angiography, the rotation axis of the DSA image head and foot is always parallel to the upper and lower edges of the DSA display screen 4 no matter what, and the angle between the left and right rotation axes and the plane where the upper and lower edges of the DSA display screen 4 are located is the same as the rotation axis of the C arm. changes with the rotation angle.

As we all know, 3D fusion technology is to coordinate two dissimilar volume acquisitions using DSA 3D rotation technology and CTA three-dimensional reconstruction technology. 3D fusion technology needs to accurately select multiple anatomical points with anatomical landmarks on the 3D image (X-ray angiography image) of DSA angiography, and then find the corresponding anatomical points on the pre-obtained CTA three-dimensional projection image of the same patient. fusion. This technology replaces the rotation of the C-arm by the three-dimensional rotation function of the computer, which reduces the radiation dose and is easy to operate.

Based on the analysis of the rotation mode of the Rubik's cube and the digital model, the embodiment of the present invention provides a projection method of a CTA three-dimensional reconstruction data image that can be accurately integrated with angiography, and an image processing method based on the projection method. As shown in FIGS. 4A and 4B , the CTA three-dimensional projection method provided by the present invention that can be accurately integrated with angiography includes the following steps:

S1: Obtain 3D reconstruction mirror data

Import the 3D reconstruction image data obtained by CT scan, such as CTA 3D data, into UG NX11.0 or other 3D software. Thereby, the three-dimensional CTA data of the spine and the three-dimensional CTA data of the location of the lesion can be obtained. CTA 3D data of spine, thoracic vertebrae, ribs, etc., are used as a reference position for the location of CTA 3D data of lesions, but the spine is given priority. In other words, the relative position of the lesion (relative to the spine) is the key positional information for reconstruction. Here, the lesion may be the heart, the kidney, or the like.

S2: Set the image projection mode of the CTA 3D reconstruction mirror data to perspective projection mode

As mentioned above, through the configuration of professional software, the CTA three-dimensional reconstruction mirror data is set to perspective projection, so that the CTA image and the DSA angiography image have the same projection mode (perspective mode).

S3: Correct the distance from the projection center of the perspective projection of the CTA three-dimensional reconstruction mirror data to the spine as the distance from the X-ray tube to the catheter bed.

Since the spine is in close contact with the catheter bed during DSA, the two positions can be considered the same. The distance from the projection center of the perspective projection of the CTA 3D reconstruction mirror data to the spine can be regarded as the distance from the projection center of the perspective projection of the CTA 3D reconstruction mirror data to the catheter bed (more precisely, the distance from the projection center to the surface of the catheter bed) .

S4: Correct the distance from the projection center of the perspective projection of the CTA three-dimensional reconstructed mirror data to the DSA display screen as the distance from the X-ray tube to the detector.

By modifying the parameter configuration of the professional software, the distance from the projection center to the lesion can be adjusted to make it equal to the distance from the X-ray tube to the detector in the DSA angiography image. Adjusting the two distances to be equal can ensure that the size of the lesions in the two images is the same. Here, the distance from the X-ray tube bulb of the DSA machine to the catheter bed, and the distance from the X-ray tube bulb to the catheter bed are the distances of the DSA machine in the upright state.

S5: Overlap the screen center of the perspective projection of the CTA three-dimensional reconstructed mirror data adjusted by the above steps and the screen center of the DSA angiography image.

The center of the DSA display screen 4 in the embodiment of the present invention is the position of the coordinate origin when the DSA contrast image is displayed. The screen center of the perspective projection of the CTA three-dimensional reconstruction mirror data is the screen center of the DSA display screen 4 . By overlapping the screen centers of the two, the relative position of the projection of the CTA three-dimensional reconstruction mirror data and the DSA angiography image can be fixed, so that the two images have a common coordinate origin.

Here, the center of the screen of the DSA angiography image is the center point of the screen displaying the DSA angiography image; the center of the screen of the perspective projection of the CTA 3D reconstruction mirror data is the center point of the screen displaying the projection. If the two screens are in the same, then this step can be omitted.

After steps S1-S5, the perspective projection of the CTA three-dimensional reconstruction mirror data is completed.

S6: Integrate the X-ray projection of the spine in the DSA angiography image with the perspective projection of the CT three-dimensional reconstruction mirror data of the spine to complete the basic registration (to ensure that the patient's position and posture during the operation are consistent with the position and posture of the CT).

Here, by moving the patient's body, the X-ray projection of the spine in the DSA angiography image and the perspective projection of the CTA three-dimensional reconstruction mirror data of the spine can be overlapped. Of course, if the patient poses the same, the perspective projection of the mirror data can be reconstructed 3D by moving the CTA so that its spine overlaps that in the DSA angiography image.

After the adjustment of the aforementioned steps S2-S6, the perspective projection of the mirror data of the three-dimensional reconstruction of the CTA has the same projection mode (perspective mode), the same viewpoint and the same position and posture as the DSA angiography image, and has the conditions for accurate fusion, complete. The basic registration of CTA 3D reconstruction mirror data.

After the aforementioned basic registration, as shown in FIG. 4B , the image processing method in DSA angiography is as follows.

S7: During the operation, adjust the parameters according to the distance from the X-ray tube of the DSA machine to the catheter bed and the distance from the tube to the detector

During surgery, the doctor will adjust the relative position of the catheter bed and the detector or the relative position of the catheter bed and the X-ray tube based on the location of the lesion and other reasons. Therefore, after adjusting the position of the catheter bed, the doctor needs to call the parameters in the professional software, and adjust the distance from the projection center to the lesion according to the distance from the X-ray tube of the DSA machine to the catheter bed to make the two equal; The distance from the ball to the detector, adjust the distance from the projection center of the CTA image to the screen, so that the two are equal. Of course, if the catheter bed is not adjusted in position, this step can be omitted.

Here, the distance from the X-ray tube bulb of the DSA machine to the catheter bed, and the distance from the X-ray tube bulb to the catheter bed are the distances of the DSA machine in the current state.

S8: Rotate the CTA 3D image according to the rotation angle of the DSA gantry

The doctor can rotate the perspective projection of the CTA 3D reconstruction mirror data according to the rotation angle of the DSA gantry, and rotate the same angle so that it overlaps the DSA angiography image.

In the perspective projection of the CTA 3D reconstructed mirror data, the X axis is rotated at the corresponding C-arm angle in the front view. Then rotate the Z axis according to the P arm angle. After the 3D image of the CTA 3D data is rotated in the order of the X axis and then the Z axis, the reconstructed 3D image of the CTA 3D data and the DSA angiography image are precisely aligned.

S9: According to the attitude transformation of the DSA machine, adjust the image position in real time

During the operation, the operator needs to adjust the position of the perspective projection of the CTA three-dimensional reconstruction mirror data on the DSA display screen 4 in real time, so that the CT three-dimensional reconstruction image always overlaps the DSA image.

S10: Obtain and output the fused image

Using steps S7-S10, the perspective projection of the CTA three-dimensional reconstructed mirror image data is overlapped with the angiography image to form a fusion image, and a stereoscopic image that is completely consistent with the X-ray angiography image in the interventional operation is obtained.

Hereinafter, the technical effect of the image processing method using the CTA three-dimensional reconstruction mirror data that can be accurately fused with angiography provided by the present invention will be introduced.

As shown in Figures 5A-5C, the UG NX11.0 was used to simulate the influence of the common movements of the DSA gantry during PCI on the two-dimensional X-ray images. Since the scale of the projected image of the model is uniform, parallel projection (as shown in Figure 5A), or X-ray (perspective) projection, the detector (screen) is raised and lowered, the image does not change (as shown in Figure 5B); The lines all come from the tiny focal point (viewpoint) of the X-ray tube. The closer the tube or viewpoint is to the heart model (such as lowering the catheter bed of the DSA machine), the more uneven the scaling of the projected image, and the more obvious the distortion of the image, and vice versa. (shown in Figure 5C). In addition, when the position of the DSA image on the screen is changed by translating the catheter bed, the X-ray from the tube focus to the object is angled (not parallel) to the X-ray from the tube focus to the object before moving, causing the surgical platform ( The X-ray image rotates automatically when the catheter bed) moves horizontally (Fig. 5D); when the object is in the center of the ISO of the DSA machine, regardless of the angle of the C-arm, the X-ray from the X-ray tube (viewpoint) to the object always points to the detection The X-ray image of the model can maintain its position on the screen no matter how the DSA gantry angle changes (Fig. 5E); when the object is below the ISO center of the DSA machine, after the DSA gantry is rotated, the The position of the X-ray from the tube ball (viewpoint) to the object pointing to the detector will change. As a result, the rotation angle of the X-ray image (angle 2) will be greater than the rotation angle of the C-arm (angle 3), which is similar to the mechanism in Figure 5D. consistent. After the DSA gantry is rotated, the surgical platform can be moved horizontally to make the X-ray projection return to its position on the screen before rotation, and the obtained image rotation angle is equal to the DSA gantry rotation angle (Figure 5F, Figure 5G). It can be seen from this that the transformation of the projection image is completely determined by the relative spatial relationship between the X-ray tube and the target object, the distance from the tube to the catheter bed, and the position of the DSA target image on the screen, that is, the center of the DSA display screen. (The center of the screen is the projection of the center of the tube on the detector), and the relative position of the DSA rack, the combination of these three can get the relative spatial relationship between the tube and the target object. The distance from the tube to the detector determines the scale of the projected image. Also, since the DSA gantry rotation changes the position of the DSA image on the screen of the DSA display screen, it also affects the contrast image.

As shown in FIG. 6 , by using the CTA three-dimensional image processing method provided by the present invention that can be accurately fused with angiography, the obtained fused image is of high quality. As can be seen from Figure 6, the perspective projection of the CTA 3D reconstruction mirror data and the angiography image are accurately fused in multiple angiography positions (four positions A-D such as foot position 27.7 degrees). In the fused image, the registration is correct, the viewpoints are consistent, the spatial relationship is correct, and the image is not distorted.

The data model processed according to the above steps can not only realize the accurate fusion of the 3D data image reconstructed by CTA and coronary angiography, but also provide the depth information of the vascular anatomy, which can help coronary interventionists quickly establish three-dimensional perception of coronary angiography , significantly improve the level of coronary interventionists, facilitate the formulation of treatment plans, reduce the difficulty of interventional operations, and significantly improve the prognosis of patients.

The present invention also provides a projection device for three-dimensional reconstruction of mirror data using CTA using the above method. The projection device is connected to the DSA machine to realize the projection of the mirror data of the three-dimensional reconstruction of the CTA. Among them, the DSA machine includes C-arm, detector, catheter bed, X-ray tube, DSA display screen, and image digital processing system. When the image digital processing system rotates the CTA three-dimensional reconstructed mirror data, it first rotates the X-axis of the reconstructed three-dimensional image in the upright position according to the C-arm angle, and then rotates the Z-axis of the reconstructed three-dimensional image according to the P-arm angle.

Using the projection device for CTA three-dimensional reconstruction of mirror data provided by the present invention, in the displayed three-dimensional image, the cephalopod rotation axis is parallel to the upper and lower edges of the screen, and the left and right rotation axes form an angle with the left and right edges of the screen, and the angle formed is the cephalopod angle. . The reconstructed or integrated image displayed on the DSA display screen of the projection device for CTA 3D reconstructed mirror data has the following characteristics:

1. CTA 3D data is mirror data, and the image projection mode is perspective projection mode;

2. The distance from the projection center of the CTA 3D image to the human target organ (such as the spine) is equal to the distance from the X-ray tube to the catheter bed;

3. The distance from the projection center of the perspective projection of the CTA 3D reconstruction mirror data to the screen is the distance from the X-ray tube to the detector;

4. The screen center of the perspective projection of the CTA 3D reconstruction mirror data overlaps with the center of the DSA machine screen.

5. The cephalopod rotation axis of the DSA image is parallel to the upper and lower edges of the DSA display screen or view plane, while the left and right rotation axes form an angle with the left and right edges of the DSA screen or view plane, and the angle is equal to the cephalopod rotation angle. These characteristics are different from the display characteristics of the CTA 3D reconstruction data in the CT workstation.

The projection method, image processing method and apparatus for CTA three-dimensional reconstruction mirror data provided by the present invention have been described in detail above. For those of ordinary skill in the art, any obvious changes made to the present invention without departing from the essential content of the present invention will constitute an infringement of the patent right of the present invention, and will bear corresponding legal responsibilities.

Claims (13)

1. A method of projecting CTA three-dimensional reconstructed mirror data, the angiogram being acquired using a DSA machine having an X-ray tube, a catheter bed, a detector, and a DSA display screen, comprising the steps of:

CTA three-dimensional reconstruction mirror image data is obtained;

setting an image projection mode of the CTA three-dimensional reconstruction mirror image data to a perspective projection mode;

correcting the distance from the projection center of the perspective projection of the CTA three-dimensional reconstruction mirror image data to the DSA display screen to be the distance from the X-ray tube ball to the detector; and correcting the distance from the projection center of the perspective projection of the CTA three-dimensional reconstructed mirror image data to the target organ to the distance from the X-ray tube ball to the catheter bed;

the screen center of the perspective projection of the CTA three-dimensional reconstruction mirror data is overlapped with the center of the DSA contrast image.

2. The projection method of claim 1, wherein:

the target organ is the spine.

3. The projection method of claim 1 or 2, characterized by:

the distance from the X-ray tube ball of the DSA machine to the guide tube bed and the distance from the X-ray tube ball to the guide tube bed are the distances of the DSA machine in a normal state.

4. The projection method of claim 1 or 2, characterized by:

the head and foot rotation axes of the perspective projected image of the CTA three-dimensional reconstruction mirror image data are parallel to the upper and lower edges of the view plane of the projection device or parallel to the upper and lower edges of the DSA display screen;

the left and right rotational axes of the image of the perspective projection of the CTA three-dimensional reconstructed mirror image data are angled from the left and right edges of the DSA display screen or from the left and right edges of the view plane of the projection device and are equal to the cephalopod rotation angle.

5. An image processing method of CTA three-dimensional reconstruction mirror image data, used for precise fusion with angiography obtained using a DSA machine having an X-ray tube, a catheter bed and a DSA display screen, characterized by comprising the steps of:

CTA three-dimensional reconstruction mirror image data is obtained;

setting an image projection mode of the CTA three-dimensional reconstruction mirror image data to a perspective projection mode;

correcting the distance from the projection center of the perspective projection of the CTA three-dimensional reconstruction mirror image data to a DSA display screen to be the distance from the X-ray tube ball to the detector; and correcting the distance from the projection center of the perspective projection of the CTA three-dimensional reconstructed mirror image data to the target organ to the distance from the X-ray tube ball to the catheter bed;

displaying the perspective projection of the adjusted CTA three-dimensional reconstruction mirror image data on a DSA display screen of the fusion device;

enabling the X-ray projection of the spine in the DSA contrast image and the perspective projection of the spine in CT three-dimensional reconstruction mirror image data to be accurately fused;

rotating the perspective projection of the reconstructed mirror image data according to a rotation angle of a gantry of the DSA machine;

a fused image is obtained and output.

6. The image processing method according to claim 5, further comprising:

adjusting the distance from the projection center to the focus according to the distance from the X-ray tube ball to the catheter bed in the current state of the DSA machine to ensure that the distance from the projection center to the focus is equal to the distance from the X-ray tube ball to the catheter bed in the current state of the DSA machine; and according to the distance from the X-ray tube ball to the detector, the distance from the projection center of the CTA image to the screen is adjusted to be equal.

7. The image processing method according to claim 5, further comprising:

the screen center of the perspective projection of the CTA three-dimensional reconstruction mirror data is overlapped with the center of the DSA contrast image.

8. The image processing method according to claim 5 or 6, characterized by:

the CTA three-dimensionally reconstructs a perspective projected image of the mirrored data, having X and Z axes,

when the image of the perspective projection of the CTA three-dimensional reconstruction mirror image data is in a front view, the C-arm angle of the DSA machine rotates the X-axis in the current state, and then the Z-axis rotates according to the P-arm angle.

9. The projection method of claim 5 or 6, wherein:

the head and foot rotation axes of the perspective projected image of the CTA three-dimensional reconstruction mirror image data are parallel to the upper and lower edges of the view plane of the projection device or parallel to the upper and lower edges of the DSA display screen;

the left and right rotational axes of the image of the perspective projection of the CTA three-dimensional reconstructed mirror image data are angled from the left and right edges of the DSA display screen or from the left and right edges of the view plane of the projection device and are equal to the cephalopod rotation angle.

10. A projection arrangement for CTA three-dimensional reconstructed mirror data connected to a DSA machine for projection of the CTA three-dimensional reconstructed mirror data, the DSA machine comprising a C-arm, a detector, a catheter bed, an X-ray tube and a DSA display screen, wherein:

the projection mode of the CTA three-dimensional reconstruction mirror image data is a perspective projection mode; the distance from the projection center of the perspective projection of the CTA three-dimensional reconstruction mirror image data to the human target organ is equal to the distance from the X-ray tube bulb to the catheter bed; the distance from the projection center of the perspective projection of the CTA three-dimensional reconstruction mirror image data to the DSA display screen is the distance from the X-ray tube ball to the detector.

11. A projection device as claimed in claim 10, wherein:

a perspective projection of the CTA three-dimensional reconstructed mirror image data is displayed on the projection device, and the display position is such that a screen center of the perspective projection of the CTA three-dimensional reconstructed mirror image data overlaps a center of the DSA contrast image.

12. A projection device as claimed in claim 11, wherein:

when the image of the perspective projection of the CTA three-dimensional reconstruction mirror image data is in a front view, the X axis is rotated by the angle of the C arm of the DSA machine in the current state, and then the Z axis is rotated according to the angle of the P arm.

13. A projection device as claimed in claim 12, wherein:

the head and foot rotation axes of the perspective projected image of the CTA three-dimensional reconstruction mirror image data are parallel to the upper and lower edges of the view plane of the projection device or parallel to the upper and lower edges of the DSA display screen;

the left and right rotational axes of the image of the perspective projection of the CTA three-dimensional reconstructed mirror image data are angled from the left and right edges of the DSA display screen or from the left and right edges of the view plane of the projection device and are equal to the cephalopod rotation angle.

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