CN114376590A

CN114376590A - CT device and light path abnormity detection method thereof

Info

Publication number: CN114376590A
Application number: CN202111619406.4A
Authority: CN
Inventors: 李兵; 江一峰
Original assignee: Shanghai United Imaging Healthcare Co Ltd
Current assignee: Shanghai United Imaging Healthcare Co Ltd
Priority date: 2015-12-30
Filing date: 2015-12-30
Publication date: 2022-04-22
Also published as: CN106923852A; CN106923852B

Abstract

The invention relates to a method for detecting the abnormal light path of a CT device, wherein the CT device comprises a ray source for generating rays; and a detector for detecting radiation, the method comprising the steps of: performing detection scanning along an optical path of the CT device to obtain detection scanning data, wherein the optical path is a path which the ray passes from the ray source to the detector during scanning; establishing a state characteristic index of the light path according to the detection scanned data; and analyzing the state characteristic index to judge whether the optical path is abnormal. According to the invention, the CT equipment is used for detecting and scanning, and the obtained detection scanning data is analyzed to judge whether the light path component is in a normal state. Compared with the prior art, the invention does not need manual inspection or auxiliary equipment, and is more convenient.

Description

CT device and light path abnormity detection method thereof

The application is a divisional application, the application number of the original application is 201511024391.1, the application date is 2015, 12 and 30, and the name is CT equipment and a method for detecting the optical path abnormality.

Technical Field

The present invention relates to a CT apparatus, and more particularly, to a CT apparatus and a method for detecting an optical path abnormality thereof.

Background

Computed Tomography (CT) scans a certain thickness of a human body with X-ray beams, gamma rays, ultrasonic waves, etc., receives the X-ray beams, gamma rays, ultrasonic waves transmitted through the surface by a detector, converts the X-ray beams, gamma rays, and ultrasonic waves into visible light, converts the visible light into electrical signals by photoelectric conversion, converts the electrical signals into Digital signals by an Analog/Digital Converter (ADC), and inputs the Digital signals into a computer for processing.

The optical path part in the CT apparatus includes a filter, a collimator, a detector, etc., and the normal operation of these optical path parts has an important influence on the CT image quality. Before the CT apparatus starts to work, it is often necessary to check whether these optical path components are normal, for example, whether there is a defect or a foreign object, and whether they are tilted or shaken, in order to ensure that these optical path components are in a desired good condition. However, some inspections require extra work of the operator, such as inspecting the filter and the probe for defects or foreign objects, which requires considerable attention by the operator. In addition, some inspections, such as checking the shake of the filter and the tilt of the collimator, require additional equipment.

Accordingly, it is desirable to provide a method and apparatus for optical path component detection of a CT apparatus that does not require operator deep intervention.

Disclosure of Invention

The technical problem to be solved by the invention is to provide a CT device and a method for detecting the optical path abnormality thereof, which can implement detection by the automatic operation of the CT device.

The present invention adopts a technical solution to solve the above technical problems, and provides a method for detecting an abnormal light path of a CT apparatus, the CT apparatus including a radiation source for generating a radiation, a detector for detecting the radiation, and a light path member located between the radiation source and the detector, the method including the steps of:

performing detection scanning along an optical path of the CT device to obtain detection scanning data, wherein the optical path is a path which the ray passes from the ray source to the detector during scanning;

establishing a state characteristic index of the light path component according to the detection and scanning data; and

analyzing the state characteristic index to judge whether the state of the light path component is abnormal or not;

when the optical path component is a collimator, the state of the collimator includes whether the slice is inclined, and the state characteristic index is an attenuation coefficient of the collimator.

Optionally, analyzing the status feature indicator comprises: comparing the state characteristic index with a standard characteristic index, and determining whether the state of the optical path component is abnormal or not according to the compared deviation degree; when the light path component is the collimator, the standard characteristic index is a standard attenuation coefficient; and/or, the step of analyzing the state characteristic index to judge whether the state of the optical path component is abnormal further comprises: judging whether the ray source and the detector are abnormal or not, or judging whether a path among the ray source, the detector and a light path component positioned between the ray source and the detector is abnormal or not; and/or judging whether the abnormity among the ray source, the detector and the light path component between the ray source and the detector includes whether foreign matters exist or not.

Optionally, the detection scan is a stationary detection scan or a rotational detection scan; and/or the detection scan is a single focus or multi-focus detection scan; and/or the number of detection scans is multiple, and the scanning conditions of the multiple detection scans are the same or different, and the scanning conditions comprise at least one of the following conditions: focal position, energy, object; the rotation speed of the rotational scan; the position of the source of the radiation.

Optionally, when the number of times of the detection scanning is multiple, establishing the state characteristic index according to a difference value of data scanned multiple times; and/or the object is air or a phantom.

Optionally, the optical path component is a filter, the state of the filter further includes whether there is a defect and whether there is a foreign object, the method includes:

enabling the CT device to carry out one or more detection scans along the optical path of the CT device under the condition that the filter is contained in the optical path, and obtaining first detection scan data;

establishing a state characteristic curved surface of the filter according to the first detection scanning data; and

and comparing the state characteristic curved surface with a standard characteristic curved surface to determine whether the filter is defective or not and whether foreign matters exist or not.

Optionally, the method further includes performing one or more detection scans by the CT apparatus without including the filter in the optical path, obtaining second detection scan data, and establishing a state characteristic curve of the filter according to a difference value between the first detection scan data and the second detection scan data.

Optionally, the detector is abnormal or not including defect or not and foreign matter or not, and the method includes:

causing the CT apparatus to perform one or more detection scans along the optical path of the CT apparatus with the detector included in the optical path;

establishing a state characteristic curved surface of the detector according to the detection scanning data; and

and comparing the state characteristic curved surface with a standard characteristic curved surface to determine whether the detector is defective or not and whether foreign matters exist or not.

Optionally, the number of detection scans is multiple, the multiple detection scans are obtained under different scanning conditions, and the state characteristic curved surface is established according to difference values of data of the multiple detection scans.

Optionally, the method of establishing the attenuation coefficient of the collimator includes:

enabling the CT equipment to carry out one or more detection scans along the light path of the CT equipment under the condition that the collimator is contained in the light path and the edge of a detector is just not shielded, and obtaining first detection scan data;

and establishing the attenuation coefficient of the collimator according to the data of the detection scanning.

Optionally, the method further includes performing one or more rotation detection scans by the CT apparatus under the condition that the collimator is not included in the optical path and does not completely block the edge of the detector, obtaining second detection scan data, and establishing an attenuation coefficient of the collimator according to a difference value between the first detection scan data and the second detection scan data.

By adopting the technical scheme, the invention can judge whether the light path component is in a normal state by detecting and scanning the CT equipment and analyzing the obtained detection and scanning data. Compared with the prior art, the invention does not need manual inspection or auxiliary equipment, and is more convenient.

Drawings

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below, wherein:

fig. 1 is a schematic view of an overall structure of a Computed Tomography (CT) apparatus.

Fig. 2 is a schematic diagram of the internal structure of a chamber of a Computed Tomography (CT) apparatus.

Fig. 3 is a flowchart of a method for detecting an optical path abnormality of a CT apparatus according to an embodiment of the present invention.

Fig. 4 is a view showing an example of the detection of a defect in a filter and a foreign object in the CT apparatus of the present invention.

Fig. 5 is experimental data of a filter defect and foreign object detection example of the CT apparatus of the present invention.

Fig. 6 is a filter shake detection example of the CT apparatus of the present invention.

Fig. 7 is experimental data of a filter shaking detection example of the CT apparatus of the present invention.

Fig. 8 is an example of detector defect and foreign object detection of the CT apparatus of the present invention.

Fig. 9 is an example of collimator tilt detection of a CT apparatus of the present invention.

Fig. 10 is a circuit block diagram of a Computed Tomography (CT) apparatus.

Detailed Description

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, but the present invention may be practiced in other ways than those specifically described herein, and thus the present invention is not limited to the specific embodiments disclosed below.

Embodiments of the present invention describe a method and apparatus for detecting an optical path member of a Computed Tomography (CT) apparatus by operating the CT apparatus to perform detection of an abnormal state such as a defect, a foreign object, shaking, or inclination on the optical path member thereof.

Fig. 1 is a schematic structural diagram of a CT apparatus, and as shown in fig. 1, a CT apparatus 100 includes a gantry 110, a couch 120, a radiation source 131 for generating radiation, and a detector 132 for detecting the radiation. For example, the gantry 110 has a rotatable portion 130 that rotates about the axis S of the apparatus. The rotatable part 130 has a radiation system consisting of a radiation source 131 and a detector 132 arranged opposite. The radiation used by the radiation source 131 is X-rays. The rotatable portion 130 has a scanning chamber 135 in the center, and the couch 120 is movable into and out of the scanning chamber 135.

While performing an examination, a subject on the couch 120 may be pushed into the scanning volume 135 along the Z-axis. The source 131 is rotated about the S-axis and the detector 132 is moved together with respect to the source 131 to acquire projection measurement data, which are then used to reconstruct an image. A helical scan may also be performed during which the source 131 generates a helical trajectory relative to the subject by continuous motion of the subject along the S-axis and simultaneous rotation of the source 131.

The CT device 100 may also include a controller 140 and a processor 142. The controller 140 is used to control the various components of the CT apparatus 100 during a scan according to a particular scan protocol. The processor 142 is used to reconstruct an image from the raw data acquired by the detector 132. Fig. 2 is a schematic diagram of the internal structure of a chamber of a Computed Tomography (CT) apparatus. As shown in fig. 2, a radiation source 131, a detector 132, a filter 133 and a collimator 134 are disposed on the rotatable portion 130 of the CT apparatus 100. The radiation source 131 and the detector 132 are respectively disposed at opposite ends of the rotatable portion 130. The filter 133 and the collimator 134 are sequentially arranged on the rotatable portion 130 and between the radiation source 131 and the subject 200. In operation, the radiation source 131 emits radiation R for detecting the subject 200. The detector 132 is operable to receive the radiation R that has passed through the subject 200 and convert the detected radiation R into data required for subsequent image reconstruction.

A Collimator (collimater) 134 is used to control the irradiation range of the radiation R, thereby controlling the slice thickness of the portion of the subject 200 to be scanned. The collimator 134 includes a plurality of slices whose positions can be controlled. The filter 133 is located between the source 131 and the collimator 134, and absorbs the low-energy radiation R, and can control the irradiation intensity distribution of the radiation R.

During operation of the CT apparatus, X-rays emitted from the source 131 pass through the filter 133, the collimator 134, and the like, and finally reach the detector 132. The path that the radiation passes from the source 131 to the detector 132 during this scan is called the optical path. If an abnormality occurs in the optical path, such as a defect in the detector 132 or the filter 133 or a foreign object on the detector, shaking of the filter 133 or inclination of the collimator 134, or a foreign object in the area between these components, the performance of the apparatus may be affected. Advantageously, an abnormality of the optical path, for example, an abnormal state of the detector 132, the filter 133 and the collimator 134 or the region therebetween is reflected in the data received by the detector 132 during the scanning, and thus by analyzing the data, it is possible to judge whether an abnormal state exists in the detector 132, the filter 133 and the collimator 134 or the region therebetween. For example, a status characteristic index is established for the status of whether the detector 132 and the filter 133 are defective or not or whether foreign matters exist, and the status characteristic index is represented by a characteristic curved surface; or establishing a state characteristic index for the shaking state of the filter 133, which is characterized by a gravity center parameter; or establishing a state characteristic index for the state of whether the collimator 134 is tilted, which is characterized by an attenuation coefficient; or to establish a status signature for the area between the filter 133, the collimator 134 and the detector 132. By analyzing the status indicators of the detector 132, the filter 133, and the collimator 134, and the area therebetween, it is possible to determine whether there is an abnormality in these components.

Of course, the embodiments of the present invention are not limited to determining these components, but may be other components in the optical path of the CT apparatus as long as their states can be reflected in the scan data. Accordingly, the status characteristic index can be established according to the characteristics of the optical path member.

Referring to fig. 3, the method includes the steps of:

in step 301, a detection scan is performed along an optical path of the CT apparatus to obtain detection scan data.

When scanning, the optical path component needs to be included in the optical path, which means that the optical path component affects the scanning data. In the case of the filter 133 of fig. 2, the filter 133 is included in the optical path, i.e., the radiation will pass through the filter 133 to the subject 200, so that the signal sensed at the detector 132 will exhibit the effect of the filter 133, which will be transferred to the scan data converted from the sensed signal. In the case of the detector 132 of fig. 2, the detector 132 would be included in the optical path since it is the component required to sense the signal. In the case of the collimator 134 of fig. 2, the collimator 134 is included in the light path as long as the rays are blocked by at least one slice of the collimator 134.

Here, the number of scans may be one or more. For the case of multiple scans, the conditions of the scans may be the same or different. The conditions of the scanning are, for example, focus position, energy, object; the rotation speed of the rotational scan; source location, etc. In one aspect, the number of times may be determined based on reliability requirements. For example, the result of multiple scans under the same scanning condition is considered comprehensively, so that the reliability of the scanning data is improved, and accidental interference is reduced. On the other hand, the number of times can be determined according to the accuracy requirement. For example, combining the results of multiple scans under different scanning conditions can help to improve the accuracy or sensitivity of the scan data. For example, conventionally, only a single focus position is needed for scanning, and the scanning data obtained at different focus positions are compared with each other, so that the accuracy or sensitivity of the scanning data can be improved. To obtain different focus position data, a multi-focus scan may be performed, and a flying focus scan may also be introduced. The energy is the energy of radiation radiated by the radiation source 131. The subject may be air (i.e., without placing a phantom on the table of fig. 1) or a phantom. During multiple scanning, a state characteristic index can be established according to the difference value of data of multiple scanning, so that the detection sensitivity is improved.

Here, the scanning manner may be stationary scanning or rotational scanning, which may be determined according to the characteristics of the state detection of the optical path member. For example, for foreign object, defect, or tilt detection, both stationary and rotational scanning are applicable. In step 302, a status characteristic index of the optical path is established according to the data of the detection scanning.

The state characteristic index characterizes a certain aspect of the light path component, such as a state of a defect, a foreign object, shaking, or tilting. Characteristic surfaces established for the probe 132 and the filter 133, for example, indicate the condition of whether these components are defective or foreign; or whether the component is sloshing or not is characterized by a center of gravity parameter established for the pass filter 133; or the attenuation coefficient characteristic established for the collimator 134 characterizes whether this component is tilted.

In step 303, the status characteristic indicator is analyzed to determine whether the optical path is abnormal.

Since the condition characteristic indicator is capable of characterizing the condition of its associated optical circuit component, by analyzing this indicator the condition of the optical circuit component in the relevant respect can be determined. The state of the optical path member includes, for example, whether there is a defect, whether there is a foreign substance, whether there is a shake, and whether there is a tilt.

Alternatively, according to an embodiment of the present invention, the standard state characteristic index is previously established for the normal state of the detector 132, the filter 133, and the collimator 134. For example, a standard state characteristic index is established for the state of the detector 132 and the filter 133 without defects and foreign objects, which is characterized by a standard characteristic curved surface; or a standard state characteristic index is established for the shake-free state of the filter 133, which is characterized by a relatively stable gravity center parameter; or a standard state characteristic index is established for the state of no tilt of the collimator 134, which is characterized by a reasonable attenuation coefficient. By comparing the state characteristic indexes of the detector 132, the filter 133 and the collimator 134 with the standard state characteristic indexes and measuring the deviation degrees thereof, it is possible to determine whether there is an abnormality in these components.

Since the condition characteristic indicator is also capable of characterising the condition of the region between its associated lightpath components, analysis of this indicator allows the condition of the lightpath in the relevant respect to be determined. For example, the area between the optical path members is free from foreign matter.

Fig. 4 is a view showing an example of the detection of a defect in a filter and a foreign object in the CT apparatus of the present invention. Referring to fig. 4, in this example, the detection method is embodied as the following steps:

in step 401, one or more scout scans are performed along the optical path of the CT apparatus to obtain first scout scan data.

Specifically, the air-targeted detection scan with the filter may be performed first, and the air-targeted detection scan without the filter may be performed again. The scan data of the two detection scans is taken as first detection scan data.

In step 402, a state feature surface of the filter is established according to the first detection scanning data.

Specifically, the scanning data of the two detection scans obtained in step 401 may be divided to obtain the state characteristic curved surface L1 of the filter. In step 403, the status characteristic surface is compared with a standard characteristic surface to determine whether the filter is defective and whether there is a foreign object.

Specifically, the state characteristic curved surface L1 may be subjected to a smoothing operation to obtain L1_ smooth, and L1_ smooth may be used as the standard characteristic curved surface. Whether the filter is defective or foreign can be judged by judging whether L1_ smooth-L1 exceeds a certain threshold.

In step 401, the detection scan mode may be a stationary detection scan or a rotating detection scan. In order to eliminate errors, different detection scanning data can be obtained by means of multiple detection scanning under different conditions, and the detection scanning data are comprehensively considered. For example, in step 401, the CT apparatus may be caused to perform one or more detection scans without including a filter in the optical path, and second detection scan data may be obtained. Then, in step 402, a state feature curved surface can be established according to the difference value between the first detected scan data and the second detected scan data. Other scanning conditions may be selected by those skilled in the art to obtain different detection scan data. Here, the difference value may be calculated by subtracting the two pieces of detected scan data or by dividing the two pieces of detected scan data.

In step 403, comparing the state characteristic curved surface with the standard characteristic curved surface, namely comparing each point on the state characteristic curved surface with each point on the standard characteristic curved surface, judging whether the difference value of each point exceeds a threshold value, and if so, determining whether the filter has defects or foreign matters.

In step 403, the standard feature surface may also be obtained and saved in advance. The

steps

401 and 402 are performed in advance, for example, in a state where the defect and foreign matter of the strainer are secured, and the obtained characteristic curved surface is set as a standard characteristic curved surface.

Fig. 5 is a state characteristic curved surface obtained by a filter defect and foreign matter detection example of the CT apparatus, the abscissa of fig. 5(a) represents each channel (channel) of the detector, the ordinate represents data obtained by dividing scan data of two detection scans, 51 is a state characteristic curved surface L1 obtained by the detection scans, and 52 is a standard characteristic curved surface L1_ smooth; the ordinate of FIG. 5(b) represents the value of L1_ smooth-L1. As shown in fig. 5, the state feature curved surface L1 is an image appearing at the middle compared with the standard feature curved surface L1_ smooth, and if the value of the abrupt change (i.e., L1_ smooth-L1) exceeds a certain threshold, it is determined whether the filter is defective or foreign matter.

Fig. 6 is a filter shake detection example of the CT apparatus of the present invention. In this example, the detection method is embodied as the following steps:

in step 601, one or more detection scans are performed along the optical path of the CT device to obtain first detection scan data.

In step 602, a state feature curved surface of the filter is established according to the first detection scanning data.

In this embodiment, further details of step 601 and step 602 are the same as those of step 401 and step 402 of the previous embodiment, and are not described here. It is to be noted that the inspection scan performed in the present embodiment must be a scan of the rotating gantry. In step 603, the gravity center parameter of the filter is obtained according to the state characteristic curved surface.

Specifically, the barycentric parameter is obtained by calculating the geometric center of the filter in the Channel and Slice directions at each view angle of the rotation detection scan.

At step 604, the barycentric parameters are analyzed to determine whether the filter is sloshing.

Fig. 7 is a filter gravity center parameter obtained in a filter shake detection example of a CT apparatus, referring to fig. 7, in which the abscissa represents different view angle (view) directions and the ordinate represents a gravity center position. In the case of no shaking of the filter, the position of the center of gravity in these different view (view) directions should be fixed, i.e. should be a straight line parallel to the horizontal axis; if the filter is shaken, the centers of gravity of the filter in the respective viewing directions do not coincide, and a curve such as that shown in fig. 7 appears. Therefore, if the maximum deviation value or the average deviation value of the gravity center of the filter in each view angle direction exceeds a certain threshold value, the filter is judged to shake; if the deviation value of the gravity center of the filter in each view angle direction does not exceed the threshold value, the filter is judged not to shake.

Fig. 8 is an example of detector defect and foreign object detection of the CT apparatus of the present invention. Referring to fig. 8, in this example, the detection method is embodied as the following steps:

in step 801, a CT apparatus is caused to perform one or more scout scans along an optical path of the CT apparatus with a detector included in the optical path.

In step 802, a state feature surface of the probe is established based on the data of the inspection scan.

In step 803, the status characteristic surface is compared with a standard characteristic surface to determine whether the detector is defective and whether there is a foreign object.

In step 801, the detection scan mode may be a stationary detection scan or a rotating detection scan. In the rotational detection scanning method, detection scan data in each view (view) direction is averaged.

In order to improve the precision, different detection scanning data can be obtained by a mode of multiple detection scanning under different conditions, and the detection scanning data are comprehensively considered. For example, in step 801, two detection scans may be performed at two focal points to obtain detector data at two focal points, and then a state feature curved surface is established according to a difference value between the two detection scans. Or scanning under the flying focus to obtain data of two focus positions, and then establishing a state characteristic curved surface according to a difference value of two times of detection scanning data. For another example, the air may be detected and scanned once, the mold body may be detected and scanned once again to obtain two detection scanning data, and then the state characteristic curved surface may be established according to a difference value between the two detection scanning data. The mold body is preferably a thicker, homogeneous mold body to increase the beam hardness. For another example, two detection scans may be performed at different energies to obtain two detection scan data, and then the state characteristic curved surface is established according to a difference value between the two detection scan data. Of course, other scanning conditions can be selected by those skilled in the art to obtain different detection scan data. Here, the difference value may be calculated by subtracting the two pieces of detected scan data or by dividing the two pieces of detected scan data.

In step 803, the state feature curved surface is compared with the standard feature curved surface by comparing each point on the state feature curved surface with each point on the standard feature curved surface, and determining whether a difference between the points exceeds a threshold, and if so, determining whether the detector has a defect or a foreign object.

In step 803, the standard feature surface may be obtained and saved in advance.

Steps

801 and 802 are performed in advance, for example, in a state where the probe is ensured to be free of defects and foreign matter, and the resulting characteristic curved surface is taken as a standard characteristic curved surface. Alternatively, the standard feature surface may be obtained by performing a smoothing operation on the state feature surface immediately after step 802.

Fig. 9 is an example of collimator tilt detection of a CT apparatus of the present invention. Referring to fig. 9, in this example, the detection method is embodied as the following steps:

in step 901, a CT apparatus is caused to perform one or more detection scans along an optical path of the CT apparatus with a collimator included in the optical path and without just blocking edges of a detector.

In step 902, the attenuation coefficient of the collimator is established from the data of the detection scan.

In step 903, the attenuation coefficient is compared to a standard attenuation coefficient to determine if the collimator slice is tilted.

In step 901, the scanning mode may be a stationary detection scan or a rotational detection scan. The collimator is arranged just not to shield the edge of the detector, so that the collimator does not shield one line of the edge of the detector

In order to eliminate errors, different detection scanning data can be obtained by means of multiple detection scanning under different conditions, and the detection scanning data are comprehensively considered. For example, in step 901, the CT apparatus may also perform one or more rotation detection scans without including a collimator in the optical path and completely blocking one line of the detector edge, and obtain second detection scan data. The attenuation coefficient of the collimator can then be established at step 902 based on the difference between the first detected scan data and the second detected scan data. Other scanning conditions may be selected by those skilled in the art to obtain different detection scan data. Here, the difference value may be calculated by subtracting the two pieces of detected scan data or by dividing the two pieces of detected scan data.

In step 903, whether the collimator slice is tilted is determined by comparing the attenuation coefficient with the standard attenuation coefficient and determining whether the attenuation coefficient exceeds the standard attenuation coefficient by a threshold value.

Fig. 10 is a circuit block diagram of a Computed Tomography (CT) apparatus. Referring to FIG. 10, the circuitry includes the aforementioned source 131 and detector 132, as well as a controller 140, processor 142, and display 146. The radiation source 131 is used for generating radiation and is provided to a rotatable portion of the CT apparatus. The detector 132 is for detecting radiation and is arranged at the rotatable part opposite to the radiation source 131. The radiation source 131 and the detector 132 constitute an image scanner for acquiring projection measurement data of a subject. The processor 142 is connected to the detector 132 to obtain projection measurement data of the subject for subsequent processing. The controller 140 is connected to the radiation source 131 to control the scanning process. The display 146 is used to present interfaces, data and images to the user. The controller 140 is connected to the radiation source 131 to control the scanning process. The controller 140 is also coupled to the processor 142 and the display 146 to control the operation of these two components.

According to the present embodiment, the controller 140 is configured to perform a detection scan along the optical path of the CT apparatus. The processor 142 is operatively configured to obtain the inspection scan data, establish a status characteristic indicator of the optical path based on the inspection scan data, and analyze the status characteristic indicator to determine whether the optical path is abnormal.

According to the previous embodiments, the controller 140 and the processor 142 may perform specific detection operations according to different anomaly detections. For example, if the detector 132 and the filter 133 are defective or foreign, the operations shown in fig. 4 and 8 are performed. If it is detected whether the filter 133 is shaken, the operation shown in fig. 6 is performed. If it is detected whether the collimator 134 is tilted, the operation as shown in fig. 9 is performed. The details of these operations, as well as other details of the operation of the CT apparatus, have been described in detail in the foregoing embodiments and will not be further described herein.

The method for detecting the optical path component of the CT apparatus according to the above embodiment of the present invention can be implemented in a computer readable medium, such as computer software, hardware, or a combination of computer software and hardware. For a hardware implementation, the embodiments described herein may be implemented within one or more Application Specific Integrated Circuits (ASICs), Digital Signal Processors (DSPs), digital signal processing devices (DAPDs), Programmable Logic Devices (PLDs), Field Programmable Gate Arrays (FPGAs), processors, controllers, micro-controllers, microprocessors, other electronic devices designed to perform the functions described herein, or a selected combination thereof. In some cases, such embodiments may be implemented by a controller.

Although the present invention has been described with respect to the preferred embodiments, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. An optical path abnormality detection method of a CT apparatus including a radiation source for generating radiation, a detector for detecting the radiation, and an optical path member between the radiation source and the detector, characterized by comprising the steps of:

2. The method of claim 1, wherein analyzing the status signature indicators comprises: comparing the state characteristic index with a standard characteristic index, and determining whether the state of the optical path component is abnormal or not according to the compared deviation degree; when the light path component is the collimator, the standard characteristic index is a standard attenuation coefficient; and/or, the step of analyzing the state characteristic index to judge whether the state of the optical path component is abnormal further comprises: judging whether the ray source and the detector are abnormal or not, or judging whether a path among the ray source, the detector and a light path component positioned between the ray source and the detector is abnormal or not; and/or judging whether the abnormity among the ray source, the detector and the light path component between the ray source and the detector includes whether foreign matters exist or not.

3. The method of claim 1, wherein the detection scan is a stationary detection scan or a rotating detection scan; and/or the detection scan is a single focus or multi-focus detection scan; and/or the number of detection scans is multiple, and the scanning conditions of the multiple detection scans are the same or different, and the scanning conditions comprise at least one of the following conditions: focal position, energy, object; the rotation speed of the rotational scan; the position of the source of the radiation.

4. The method according to claim 3, wherein when the number of the detection scans is multiple, the status feature index is established according to a difference value of data of the multiple scans; and/or the object is air or a phantom.

5. The method of claim 2, wherein the optical path component is a filter, the condition of the filter further including whether there is a defect and whether there is a foreign object, the method comprising:

6. The method of claim 5, further comprising causing the CT apparatus to perform one or more inspection scans without including the filter in the optical path, obtaining second inspection scan data, and establishing a state characteristic curve of the filter based on a difference value between the first inspection scan data and the second inspection scan data.

7. The method of claim 3, wherein the detector abnormality includes a defect and a foreign object, the method comprising:

8. The method according to claim 7, wherein the number of the detection scans is a plurality of times, the plurality of detection scans are obtained under different scanning conditions, and the state feature curved surface is established according to difference values of data of the plurality of detection scans.

9. The method of claim 1, wherein establishing an attenuation coefficient of the collimator comprises:

10. The method of claim 9, further comprising causing the CT apparatus to perform one or more rotational scout scans without including the collimator in the optical path and without completely obscuring detector edges, obtaining second scout scan data, and establishing an attenuation coefficient of the collimator from a difference value of the first scout scan data and the second scout scan data.