WO2018182317A1 - X-ray ct scanning apparatus and scanning method thereof - Google Patents

Abstract

Disclosed is an X-ray CT scanning apparatus that is capable of acquiring X-ray scanning data necessary for CT image reconstruction in a shorter time without increasing, beyond an existing rotation speed, the rotation speed of a scanning unit of the X-ray CT scanning apparatus. The X-ray CT scanning apparatus according to the present invention comprises: a first scanning unit having a first generator for irradiating a first X-ray beam and a first detector which is disposed opposite the first generator, with a region to be scanned and a rotation axis therebetween, and receives the first X-ray beam; and a second scanning unit having a second generator for irradiating a second X-ray beam and a second detector which is disposed opposite the second generator, with the region to be scanned and the rotation axis therebetween, and receives the second X-ray beam, wherein when performing a scanning sequence, the first scanning unit and the second scanning unit are driven to rotate simultaneously about the rotation axis.

Description

X-ray CT scanner and its method

The present invention relates to an X-ray CT imaging apparatus and an imaging method thereof, and more particularly, to an apparatus configuration and an imaging method for shortening the X-ray imaging data acquisition time for X-ray CT image acquisition.

In the medical field, an X-ray imaging apparatus refers to a device that transmits a predetermined amount of X-rays to a body part to be photographed, detects the transmitted X-rays with an X-ray sensor, and forms an X-ray image based on the detected electrical signal. X-rays are attenuated and transmitted at different attenuation rates depending on the material on the path of progress, and are converted into electrical signals by the photoelectric effect when they reach the X-ray sensor. The X-ray imaging apparatus provides information about the inside of the photographing object as an X-ray image by using an electrical signal reflecting an accumulated attenuation amount according to the X-ray progress path.

In dental practice, X-ray CT images can accurately and clearly display tomographic images of the user's desired location and orientation, as well as three-dimensional X-ray images of teeth, jaw joints, or head areas of interest in the patient's body. As a result, it is utilized in fields requiring high precision such as implant procedures. An X-ray computed tomography (CT) imaging apparatus reconstructs X-ray imaging data photographed from various angles of an object to provide tomography images and 3D X-ray images of the object. To this end, the X-ray CT photographing apparatus supports an X-ray generator that generates and irradiates X-rays, an X-ray detector disposed opposite to the X-ray generator with the subject interposed therebetween, and supporting the X-ray generator and the X-ray detector. It includes a rotation support for rotating the X-ray generator and the X-ray detector around the axis of rotation between, and an image reconstruction unit for implementing a CT image through the detection result of the X-ray detector.

For X-ray CT imaging, the X-ray generator and the X-ray detector rotate opposite to each other in a predetermined angle range about a rotation axis passing through the object, and transmit X-rays to the subject area of the subject, that is, the field of view (FOV) at various angles. Get the data. In general X-ray CT imaging, the X-ray generator and the X-ray detector rotate the center axis of the photographing area as its rotation axis, and irradiate and receive X-rays passing through the entire area of the photographing area in various directions of the photographing area. The X-ray photographing data is reconstructed through an image reconstruction unit, and as a result, a 3D X-ray image of a voxel unit for a photographing target area is obtained.

The present invention has been proposed to solve the above-mentioned problems. More specifically, the X-ray CT imaging apparatus acquires X-ray imaging data necessary for reconstructing the CT image in a relatively short time without rotating the imaging unit at an excessively high speed. An object of the present invention is to provide an X-ray CT imaging apparatus and an imaging method thereof.

In order to solve the above-mentioned problems, the X-ray CT imaging apparatus according to the present invention, the first generator for irradiating the first X-ray beam, and the first generator is disposed opposite to the first generator with the shooting target region and the rotation axis between the first generator A first photographing unit having a first detector for receiving an X-ray beam; And a second detector for irradiating a second X-ray beam, and a second detector disposed to face the second generator with the photographing target area and the rotation axis interposed therebetween to receive the second X-ray beam. ; The first photographing unit and the second photographing unit are driven to rotate about the rotation axis simultaneously.

The first and second X-ray beams may face each other or cross each other with respect to the rotation axis. In this case, each of the first and second X-ray beams may transmit the entirety or less in half or more of the region to be photographed.

The X-ray CT photographing apparatus may further include an image reconstructing unit configured to reconstruct a 3D X-ray image of the photographing target region from the X-ray photographing data received by the first and second detectors.

At least one of the first and second photographing units may be configured to be movable along a traveling direction of the X-ray beam such that a distance between the generator and the detector with respect to the rotation axis is variable.

The first and second X-ray beams may be configured to pass through upper and lower portions of the photographing target area, respectively.

The first and second X-ray beams may have different energy levels.

The X-ray CT imaging apparatus may include a rotation drive system that controls rotation of the first and second photographing units; A controller for controlling the first and second photographing units; And a readout circuit for reading out the electrical signals of the first and second detectors in units of frames. In this case, the controller may control the first and second generators to irradiate the first and second X-ray beams at different timings.

According to the configuration of the present invention, an X-ray CT imaging apparatus and an imaging method thereof, which enable the imaging unit of the X-ray CT imaging apparatus to acquire X-ray imaging data necessary for CT image reconstruction within a relatively short time without rotating at an excessively high speed. This is provided.

As a result, it is possible to finish the shooting in less than half of the conventional time, for example, within about 2 seconds, while reducing the psychological burden of the subject due to the rapid rotational movement of the photographing unit, and obtaining a safer and more accurate CT image. There is.

1 is a schematic view showing a photographing unit according to an embodiment of the present invention seen in a direction of a rotation axis thereof.

FIG. 2 conceptually shows a configuration of a photographing unit in the embodiment of FIG. 1.

3 is a schematic view of a photographing unit viewed in a direction of a rotation axis thereof according to an embodiment of the present invention.

4 is a schematic view of a photographing unit viewed in a direction of a rotation axis thereof according to an embodiment of the present invention.

5 is a schematic view of a photographing unit viewed in a direction of a rotation axis thereof according to an embodiment of the present invention.

6 is a schematic view of a photographing unit viewed in a direction of a rotation axis thereof according to an embodiment of the present invention.

7 is a schematic view of a photographing unit viewed in a direction perpendicular to a rotation axis thereof according to an embodiment of the present invention.

Hereinafter, various embodiments of the present invention will be described with reference to the drawings. Through the embodiments will be understood the technical spirit of the present invention more clearly. The present invention is not limited to the embodiments described below. Like reference numerals denote elements of the same nature, and a description of a component having the same reference numeral as a component described in one drawing may be omitted in the description of another drawing.

1 is a schematic view showing a photographing unit according to an embodiment of the present invention seen in a direction of a rotation axis thereof.

In the photographing unit 100 according to the present exemplary embodiment, the first generator 111, which is an X-ray generator, is disposed on either side with the photographing target area F interposed therebetween, and the first detector 112, which is an X-ray detector, on the opposite side thereof. The first photographing unit 110 and the second generator 121, which is another X-ray generator, are disposed with the photographing target region F interposed therebetween, and the second detector 122, which is another X-ray detector, on the opposite side thereof. The second photographing unit 120 is disposed. For example, the first photographing unit 110 and the second photographing unit 120 may be disposed opposite to each other.

Each of the first imaging unit 110 and the second imaging unit 120 includes a first X-ray beam 11B and a second X-ray beam 21B, which are emitted and received by each imaging unit, respectively. It can be arranged to cover more than half in the width direction. Referring to the direction shown in the drawings, for example, the first X-ray beam 11B transmits at least one half of the upper left side of the photographing area F in one direction, and the second X-ray beam 21B is at the lower right side thereof. It may be arranged to transmit more than half in the opposite direction. Each of the first X-ray beam 11B and the second X-ray beam 21B may be an asymmetric half-beam. However, the present invention is not limited to the half beam, and may be a narrow full-beam having a width that can transmit at least half of the width of the photographing target area F. In any case, the first X-ray beam 11B and the second X-ray beam 21B are configured to be in contact with or slightly overlap with each other at the position of the rotation axis C.

The above-described components of the first photographing unit 110 and the second photographing unit 120 are structurally connected by the rotation arm 130. The photographing unit 100 is configured to include a rotation drive system (not shown) for rotating the rotary arm 130 with respect to the ground fixed structure about its rotation axis (C). The rotation drive system may include a motor, a gear, and the like. On the other hand, the rotation axis (C) also coincides with the longitudinal axis, which is the center of the photographing target area (C), as shown, but does not necessarily follow such restrictions.

The photographing unit 100 configured as described above may acquire X-ray photographing data necessary for reconstructing the X-ray CT image by performing a series of photographing sequences while rotating 180 degrees or more about the rotation axis C. FIG. In the case of a conventional CT imaging apparatus having a half-beam size X-ray detector, for example, the rotational arm should be rotated 360 degrees or more, and the photographing sequence should be performed. will be. This shortens the shooting time. Assuming that the rotation speed and frame rate of the conventional device and the rotational arm are the same, the imaging sequence for the CT image acquisition can be completed in half the time, for example, within about 2 seconds.

On the other hand, the photographing unit 100 may be configured such that its center of gravity is located on the rotation axis (C). In general, an X-ray generator using a hot electron X-ray source is relatively heavier than an X-ray detector. As described above, the first imaging unit 110 and the second imaging unit 120 are symmetric about the rotation axis C. By arranging with, the center of gravity of the rotating body coincides with the rotating shaft, and as a result, mechanical vibration during rotation can be suppressed.

FIG. 2 conceptually shows a configuration of a photographing unit in the embodiment of FIG. 1.

The second photographing unit 120 having the first photographing unit 110 having the first generator 111 and the first detector 112, the second generator 121, and the second detector 122 in the photographing unit 100. ) Is a control unit 133 that controls rotation of the first and second imaging units 110 and 120, X-ray imaging of the first and second imaging units 110 and 120, and the first and second detectors. The readout circuit 135 that reads out the electrical signals 112 and 122 in units of frames may be configured to share each other. The controller 133 controls the operation of the first and second generators 111 and 121, the first and second detectors 112 and 122, and the rotation drive system 131. The readout circuit 135 receives and collects electrical signals according to X-ray reception from the first and second detectors 112 and 122 in units of frames to generate multiple frames of X-ray photographing data, and includes one or more integrated circuits. It may be provided in the form of a printed circuit board (PCB). The printed circuit board having the control unit 133 and the lead-out circuit 135 may be installed in the above-described rotating arm, and may be installed in a structure fixed to the ground by being connected through a cable or a flexible printed circuit (FPC). May be

In the X-ray CT imaging apparatus according to the present embodiment, since the rotation range of the rotation arm is only about 180 degrees, the first and second generators 111 and 121, such as the controller 133, the lead-out circuit 135, and the like, are described. ) And the first and second detectors 112 and 122 may be connected to each other using a cable or the like to reduce the risk of trouble caused by cable twisting.

The controller 133 may divide and drive the first generator 111 and the second generator 121 in time. By driving the frame timings of the first imaging unit 110 and the second imaging unit 120 at different timings so as not to overlap each other, mutual interference between the first X-ray beam and the second X-ray beam may be prevented, X-ray exposure can also be maintained at the same level as the conventional method.

3 is a schematic view of a photographing unit viewed in a direction of a rotation axis thereof according to an embodiment of the present invention.

In the case of the photographing unit 101 according to the present exemplary embodiment, energy levels of the first X-ray beam 12B emitted from the first generator 111 and the second X-ray beam 22B emitted from the second generator 121 may be determined. You can do it differently. Compared to the conventional X-ray CT imaging apparatus, by implementing so-called multi-energy X-ray imaging without increasing the rotation range, CT images with improved gray levels can be obtained even in soft tissues.

For example, assuming that the first X-ray beam 12B emitted from the first generator 111 has a high energy level and the second X-ray beam 22B emitted from the second generator 121 has a low energy level. X-ray imaging data collected through the detector 112 may obtain a relatively strong tissue, that is, an image with emphasis on bones, etc. X-ray imaging data collected through the second detector 122 may be relatively weak tissue, Soft tissues and other images can be obtained. It is also possible to obtain an image with emphasis on other tissues by applying appropriate weights to these two images.

4 is a schematic view of a photographing unit viewed in a direction of a rotation axis thereof according to an embodiment of the present invention.

The photographing unit 102 according to the present embodiment includes a first photographing unit 110 and a second generator including a first generator 111 and a first detector 112 as described above with reference to FIG. 1. A third including a third generator 141 and a third detector 142 having a second photographing unit 120 including a second detector 122 and a second detector 122, and arranged in a direction perpendicular to the second photographing unit 120. The fourth photographing unit 150 includes a photographing unit 140, a fourth generator 151, and a fourth detector 152. As shown, the X-ray beam 11B of the first imaging unit 110 and the X-ray beam 15B of the third imaging unit 140 are disposed in a direction perpendicular to each other, and the X-ray of the second imaging unit 120 is disposed. The beam 21B and the X-ray beam 25B of the fourth imaging unit 150 may be arranged in a direction perpendicular to each other.

Through such a configuration, X-ray imaging data sufficient for CT image reconstruction may be obtained by only photographing while rotating the photographing unit 102 by 90 degrees or more.

5 is a schematic view of a photographing unit viewed in a direction of a rotation axis thereof according to an embodiment of the present invention.

The imaging unit 200 of the X-ray CT imaging apparatus according to the present exemplary embodiment may include a first imaging unit 210 and a second generator 221 including a first generator 211 and a first detector 212 disposed to cross each other. ) And a second photographing unit 220 including a second detector 222. They differ from the above-described embodiment of FIG. 1 in that they have a first detector 212 and a second detector 222, each of which is a full-beam size X-ray detector. In addition, the first photographing units 211 and 212 may be configured to have a first rotating arm 231, and the second photographing units 221 and 222 may have a second rotating arm 232.

In the photographing unit 200 according to the present exemplary embodiment, the X-ray beam 13B of the first photographing unit and the X-ray beam 23B of the second photographing unit are disposed at a predetermined angle, for example, perpendicular to each other, while maintaining a relative angle. When rotating, the photographing unit 200 may finish the photographing sequence for acquiring the CT image by simply rotating the photographing unit 200 by 90 degrees or more.

Meanwhile, according to the present embodiment, the first rotary arm 231 and the second rotary arm 232 rotate about a common rotation axis C, and at least one of them extends in the longitudinal direction (the X-ray beam). It can be installed so that it can move in parallel with the direction of travel). As a result, X-ray imaging data of different magnifications can be obtained for the same subject. In addition, they may be configured such that the relative angle αα between the first rotary arm 231 and the second rotary arm 232 is variable. As a result, different amounts of X-ray imaging data may be obtained for the same subject.

6 is a schematic view of a photographing unit viewed in a direction of a rotation axis thereof according to an embodiment of the present invention.

The imaging unit 202 according to the present exemplary embodiment includes first to third imaging units disposed at angular intervals of 120 degrees from each other, and each of the first to third X-ray detectors 212, 222, and 232 of the full beam size, and a matching agent corresponding thereto. The first to third X-ray generators 211, 221, and 231 to irradiate the first to third X-ray beams 16B, 17B, and 18B, respectively. In this case, the photographing unit 202 may finish the photographing sequence necessary for reconstructing the CT image through rotation of 60 degrees or more.

As seen through the above embodiments, the number of imaging units having each of the X-ray generators and the X-ray detectors is not limited, and as the number of imaging units increases, the rotation angle required to perform the imaging sequence decreases accordingly. As a result, the time required for shooting is also reduced.

7 is a schematic view of a photographing unit viewed in a direction perpendicular to a rotation axis thereof according to an embodiment of the present invention.

On the other hand, the plurality of photographing units may be arranged with different heights from each other. As shown, a first imaging unit having a first generator 311 and a first detector 312 installed in one rotary arm 330, and a second generator 321 and a second detector 322 In the second photographing unit, when viewed in a direction perpendicular to the rotation axis C, each of the X-ray beams, that is, the first X-ray beam 14B and the second X-ray beam 24B, are at different heights. It can be arranged to transmit. In this case, the trajectory of the first X-ray beam 14B and the trajectory of the second X-ray beam 24B may ideally overlap each other and may overlap each other in a narrow range. Through the above configuration, even with a limited size detector, an X-ray CT image of a shooting target area F having a height higher than that of an individual detector can be taken.

The present invention relates to an X-ray CT imaging apparatus and a photographing method thereof, and may be used in a dental X-ray CT imaging apparatus.

Claims (9)

A first photographing unit having a first generator for irradiating a first X-ray beam and a first detector disposed opposite to the first generator with an image capturing region and a rotation axis therebetween to receive the first X-ray beam; And, A second imaging unit having a second generator for irradiating a second X-ray beam and a second detector disposed opposite to the second generator with the recording target area and the rotation axis therebetween to receive the second X-ray beam; Including, When the scan sequence is performed, the first photographing unit and the second photographing unit are driven to rotate simultaneously about the rotation axis. X-ray CT imaging device. The method of claim 1, The 1, 2 X-ray beams are opposite to each other or intersecting with respect to the axis of rotation, X-ray CT imaging apparatus. The method of claim 2, And the first and second X-ray beams respectively transmit less than half of the first and second X-ray beams at least half of the region to be photographed. The method of claim 1, And an image reconstructing unit configured to reconstruct a 3D X-ray image of the photographing target region from the X-ray photographing data received by the first and second detectors. The method of claim 1, At least one of the first and second imaging units, X-ray CT imaging apparatus is movable in the direction of travel of the X-ray beam so that the distance between the generator and the detector with respect to the rotation axis is variable. The method of claim 1, The X-ray CT imaging apparatus, wherein the first and second X-ray beams respectively penetrate the upper and lower portions of the photographing target area. The method of claim 1, The first and second X-ray beams have different energy levels, X-ray CT imaging apparatus. The method of claim 1, A rotation drive system for controlling rotation of the first and second photographing units; A controller for controlling the first and second photographing units; And And a readout circuit for reading out the electrical signals of the first and second detectors in units of frames. The method of claim 8, The controller controls the first and second generators to irradiate the first and second X-ray beams at different timings.

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