CN115299973A - Wide temperature correction method of CT detector module and CT adopting wide temperature correction method - Google Patents
Wide temperature correction method of CT detector module and CT adopting wide temperature correction method Download PDFInfo
- Publication number
- CN115299973A CN115299973A CN202210906887.5A CN202210906887A CN115299973A CN 115299973 A CN115299973 A CN 115299973A CN 202210906887 A CN202210906887 A CN 202210906887A CN 115299973 A CN115299973 A CN 115299973A
- Authority
- CN
- China
- Prior art keywords
- temperature
- detector module
- detector
- signal intensity
- correction
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000012937 correction Methods 0.000 title claims abstract description 115
- 238000000034 method Methods 0.000 title claims abstract description 34
- 230000035945 sensitivity Effects 0.000 claims abstract description 11
- 230000008569 process Effects 0.000 claims abstract description 7
- 238000010606 normalization Methods 0.000 claims description 9
- 238000001514 detection method Methods 0.000 claims description 6
- 239000000758 substrate Substances 0.000 claims description 6
- 238000012545 processing Methods 0.000 claims description 5
- 230000002277 temperature effect Effects 0.000 claims description 4
- 238000003384 imaging method Methods 0.000 abstract description 10
- 238000002591 computed tomography Methods 0.000 abstract description 3
- 230000006978 adaptation Effects 0.000 abstract description 2
- 230000007613 environmental effect Effects 0.000 description 4
- 230000008859 change Effects 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000000969 carrier Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 230000017525 heat dissipation Effects 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000004806 packaging method and process Methods 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
Images
Classifications
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
- A61B6/58—Testing, adjusting or calibrating thereof
- A61B6/582—Calibration
- A61B6/585—Calibration of detector units
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
- A61B6/02—Arrangements for diagnosis sequentially in different planes; Stereoscopic radiation diagnosis
- A61B6/03—Computed tomography [CT]
- A61B6/032—Transmission computed tomography [CT]
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
- A61B6/02—Arrangements for diagnosis sequentially in different planes; Stereoscopic radiation diagnosis
- A61B6/03—Computed tomography [CT]
- A61B6/032—Transmission computed tomography [CT]
- A61B6/035—Mechanical aspects of CT
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
- A61B6/42—Arrangements for detecting radiation specially adapted for radiation diagnosis
- A61B6/4266—Arrangements for detecting radiation specially adapted for radiation diagnosis characterised by using a plurality of detector units
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
- A61B6/54—Control of apparatus or devices for radiation diagnosis
Landscapes
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Medical Informatics (AREA)
- Radiology & Medical Imaging (AREA)
- Molecular Biology (AREA)
- Biophysics (AREA)
- Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
- Optics & Photonics (AREA)
- Pathology (AREA)
- Physics & Mathematics (AREA)
- Biomedical Technology (AREA)
- Heart & Thoracic Surgery (AREA)
- High Energy & Nuclear Physics (AREA)
- Surgery (AREA)
- Animal Behavior & Ethology (AREA)
- General Health & Medical Sciences (AREA)
- Public Health (AREA)
- Veterinary Medicine (AREA)
- Pulmonology (AREA)
- Theoretical Computer Science (AREA)
- Measurement Of Radiation (AREA)
- Apparatus For Radiation Diagnosis (AREA)
Abstract
The invention is applicable to the technical field of computed tomography, and provides a wide temperature correction method of a CT detector module and a CT adopting the same. According to the CT, the corresponding temperature sensor is added on each detector module, the detector sensitivity at different temperatures is collected to establish a temperature-sensitivity correction table, and then projection data output in the actual imaging process are corrected based on the correction table, so that the ring-shaped artifact of a tomographic image is effectively eliminated, and the environment adaptation capability of an imaging system is enhanced.
Description
Technical Field
The invention belongs to the technical field of computed tomography, and particularly relates to a wide temperature correction method of a CT detector module and a CT adopting the same.
Background
The CT detector system mainly comprises a collimator, a detector module, a data acquisition module, a control panel, a fan, a mechanical structure for packaging and fixing the components and the like. Each detector module corresponds to a data acquisition module. Various chips are welded on the data acquisition module, and when the detector system works, the chips can generate a large amount of heat, so that the internal temperature of the detector is continuously increased.
In the case of a photodiode in a detector module, carriers in the photodiode are mainly excited by thermal motion, and the energy distribution follows a boltzmann distribution, and the carrier concentration increases due to the temperature increase. The carrier concentration increases by several tens of times with an increase in temperature. In order to prevent asynchronous changes of the sensitivity of each module of the detector caused by temperature changes, the CT whole machine is generally placed in a constant temperature environment, or the position of a high-power consumption chip (AD chip or FPGA chip) on the data acquisition module is adjusted, so that the CT whole machine can be directly blown by strong airflow generated by a rear fan, and the temperature change of the CT whole machine is ensured to be small by improving the heat dissipation efficiency.
However, the former needs an additional heating device, which results in increased system power consumption, increased power and complex structure, and is not favorable for miniaturization of the imaging system and the CT machine. Although the latter is beneficial to the miniaturization of the imaging system, because the positions of the detector modules in the detector system are different, the phenomenon that the temperature changes of the detector modules are asynchronous still occurs when the detector modules are used in an environment with a severe change of the ambient temperature, and therefore ring artifacts are caused. The prior art has the defects.
Disclosure of Invention
The invention aims to provide a wide temperature correction method of a CT detector module, which aims to establish a correction table of the sensitivity of each detector at different temperatures and avoid the problem of ring artifacts of a tomographic image during imaging in a wide temperature environment through correction.
In one aspect, the present invention provides a method for wide temperature correction of a CT detector module, the method comprising the steps of:
F1. acquiring the output signal intensity of each detector module in the CT at different temperatures, calculating corresponding temperature-sensitivity correction coefficients, and establishing a temperature-sensitivity correction table;
F2. and correcting the projection data of each detector module based on the temperature-sensitivity correction table in the actual environment.
Further, the step F1 includes the steps of:
s1, shutting down the CT, namely, calibrating a corresponding temperature sensor of each detector module when the CT is in an environment with a preset temperature;
s2, starting up the CT, and recording the dark current of each detector module before exposure; carrying out air exposure; recording the current of an X-ray source tube, the intensity of output signals of the detector modules and the corresponding ambient temperature during exposure;
s3, raising the ambient temperature and continuing air exposure; recording the output signal intensity and dark current of each detector module at different temperatures and the corresponding X-ray source tube current;
and S4, after data acquisition in the working temperature range is completed, performing table building processing on the data, and building a temperature-sensitivity correction table.
Further, the step F2 includes the steps of:
t1, collecting the actual environment temperature of each detector module to calculate the average environment temperature;
t2, converting the temperature-sensitivity correction table by taking the average ambient temperature as the reference temperature;
and T3, correcting the projection data of each detector module at the actual ambient temperature by using the transformed temperature-sensitivity correction table.
On the other hand, the invention also provides a CT working in a wide environment temperature range, which comprises a turntable, and an X-ray source and a detection system which are respectively fixed at two ends of the turntable and correspondingly arranged, wherein the wide temperature correction method of the CT detector module is adopted.
Further, the detection system comprises a plurality of detector modules; the detector modules are arranged in a circular arc shape, and the center of the circular arc is the focus of the X-ray source;
the detector module is sequentially provided with a scintillator, a photodiode, a substrate and a connector in the X-ray direction; the substrate is provided with a temperature sensor on a face facing the X-ray source.
Furthermore, the working temperature range of the temperature sensor is-50 ℃ to 100 ℃, and the precision is more than 0.5 ℃.
The invention provides a temperature-sensitivity correction table establishment scheme and is particularly applied to projection data correction of CT. Firstly, the actual working temperature of each detector module can be accurately detected under different environmental temperatures by adding the corresponding temperature sensor on each detector module on hardware, and then a correction table is established on the relationship between the temperature and the sensitivity based on the output of the detector modules. Finally, the projection data of each detector module is respectively corrected based on the correction table in the actual imaging process, so that when the CT is used in a wider temperature environment, all the detector modules can output the projection data based on a standard temperature, the ring artifact of the tomographic image is effectively eliminated, and the environment-adapting capability of the imaging system is enhanced.
Drawings
FIG. 1 is a flowchart illustrating an implementation of a wide temperature correction method for a CT detector module according to an embodiment of the present invention;
FIG. 2 is a flowchart illustrating an implementation of constructing a correction table in a method for wide temperature correction of a CT detector module according to an embodiment of the present invention;
FIG. 3 is a flowchart illustrating an implementation of a correction table in a wide temperature correction method for a CT detector module according to an embodiment of the present invention;
fig. 4 is a schematic structural diagram of a detector module of a CT according to a second embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
The following detailed description of specific implementations of the present invention is provided in conjunction with specific embodiments:
the first embodiment is as follows:
fig. 1 shows a flow of implementing a wide temperature correction method for a CT detector module according to an embodiment of the present invention, and for convenience of description, only the parts related to the embodiment of the present invention are shown, which is detailed as follows:
the invention provides a wide temperature correction method of a CT detector module, which comprises the following steps:
F1. acquiring the output signal intensity of each detector module in the CT at different temperatures, calculating corresponding temperature-sensitivity correction coefficients, and establishing a temperature-sensitivity correction table;
F2. and correcting the projection data of each detector module based on the temperature-sensitivity correction table in the actual environment.
As shown in fig. 2, step F1 includes the steps of:
s1, shutting down the CT, namely, calibrating a corresponding temperature sensor of each detector module when the CT is in an environment with a preset temperature;
s2, starting up the CT, and recording the dark current of each detector module before exposure; carrying out air exposure; recording the current of an X-ray source tube, the output signal intensity of each detector module and the corresponding ambient temperature during exposure;
s3, raising the ambient temperature and continuing air exposure; recording the output signal intensity and dark current of each detector module at different temperatures and the corresponding X-ray source tube current;
and S4, after data acquisition in the working temperature range is completed, performing table building processing on the data, and building a temperature-sensitivity correction table.
Further, step S4 includes the steps of:
s41, deducting dark currents of the output signal intensity of each detector module at different preset temperatures to obtain net signal intensity:
d k,n ＝D k,n -B k,n ；
wherein D is net signal intensity, D is output signal intensity, B is dark current, k is preset temperature, and n is detector module number;
s42, carrying out normalization correction on the tube current of the X-ray source at each preset temperature to obtain a correction coefficient of the tube current:
wherein a is a correction coefficient of tube current; i is tube current; k is a preset temperature; i is 1 Is a standard current;
s43, carrying out normalization correction on the net signal intensity of each detector module at each temperature by using the correction coefficient of the tube current, and eliminating the influence of tube current fluctuation on the sensitivity of the detector:
wherein, a k Is the correction coefficient of tube current at temperature k, C is the signal intensity output by the detector when the tube current is normalized to the standard current, C k,n The signal intensity of the nth detector module is exposed when the net signal intensity is at a preset temperature k;
and S44, selecting one preset temperature from the plurality of preset temperatures as a reference temperature, and carrying out normalization processing on the sensitivity of each detector module at each preset temperature to construct a temperature-sensitivity correction table.
Further, the normalization process in step S44 is:
wherein kB is a reference temperature selected from the preset temperatures, and f is a temperature-sensitivity correction coefficient of the detector module. The temperature-sensitivity correction coefficient table constructed by the correction coefficients of different temperatures can be used for conveniently carrying out reference temperature conversion (namely when new temperature needs to be adjusted to serve as reference temperature, all the correction coefficients in the table can be converted by dividing the coefficients corresponding to the temperature at the same time, namely, the correction coefficients corresponding to the new reference temperature are 1.) and further applied to the actual temperature environment in a wide temperature range.
In a preferred embodiment, in executing step F1, in the case where the detector module is in a suitably low temperature environment without generating a dark current, step S4 constructs a temperature-sensitivity correction table using, as a temperature-sensitivity correction coefficient of the detector module, a ratio of an output signal intensity to a signal intensity output by the detector when the tube current is normalized to a standard current.
The method specifically comprises the following steps:
thus, the speed of constructing the temperature-sensitivity correction table can be effectively improved.
Further, the step interval of the temperature rise in step S3 is 1 ℃.
As shown in fig. 3, step F2 includes the steps of:
t1, collecting the actual environment temperature of each detector module to calculate the average environment temperature;
t2, converting the temperature-sensitivity correction table by taking the average ambient temperature as a reference temperature;
and T3, correcting the projection data of each detector module at the actual ambient temperature by using the transformed temperature-sensitivity correction table.
Further, step T3 includes the steps of:
t31, calculating the net signal intensity output by each detector module at the actual environment temperature;
and T32, based on the correction of the converted temperature-sensitivity correction table, multiplying the net signal intensity output under the actual environment temperature by the ratio of the correction coefficient at the average temperature to the correction coefficient at the actual environment temperature to obtain the projection data after the temperature effect correction of the corresponding detector module:
wherein f is kB,n A correction coefficient in which the temperature in the temperature-sensitivity correction table is the reference temperature after the average ambient temperature is used as the reference temperature;
f kT,n a correction coefficient of the measured temperature T of the detector module n in the converted temperature-sensitivity correction table is obtained;
d kT,n the net signal strength output by the detector module n when the temperature T is actually measured;
E n the corrected projection data is subjected to temperature effect.
In a preferred embodiment, the average temperature of each detector module in the ambient temperature in which the CT operates is exactly the same as the reference temperature for constructing the temperature-sensitivity correction table, and the transformation step of the correction table can be skipped and used directly to correct the projection data of each detector module. The output of each detector module in the same CT is unified at a temperature, and ring artifacts are avoided.
The following table is a temperature-sensitivity correction table established with 25 degrees celsius as a reference temperature in practical implementation. The specific table is as follows:
| module 1 | Module 2 | …… | Module N | |
| Temperature 1 | f 1,1 | f 1,2 | f 1,N | |
| Temperature 2 | f 2,1 | f 2,2 | f 2,N | |
| …… | ||||
| 25 deg.C | 1 | 1 | 1 | 1 |
| …… | ||||
| Temperature K | f K,1 | f K,2 | f K,N |
If the step interval of the temperature increase in step S3 is 1 degree celsius, all the detector modules (1, 2 … N) in the CT in the table are stepped up to the temperature K with the temperature 1 as the starting point and 1 degree celsius as the step, and the correction coefficient corresponding to the reference temperature of 25 degrees celsius is recorded.
In a specific implementation, it is assumed that the temperatures of the detector modules inside the CT cannot be consistent in a short time due to a large change in the ambient temperature. For example, the temperature of module 1 is 22 degrees Celsius, and the net signal strength output is d 22℃，1 The temperature of module 2 is 24 degrees Celsius and the net signal strength output is d 24℃，2 … … Module N temperature is 28 degrees Celsius, net signal strength output is d 28℃，N And so on.
Considering that the operating temperatures of all the detector modules are distributed around 25 ℃, the output of each detector module is corrected by using a temperature-sensitivity correction table with 25 ℃ as a reference temperature. Here, the average temperature of all the detector modules may also be calculated to obtain the reference temperature.
Specifically, according to the formula:
and correcting the net signal intensity of each detector module to obtain projection data with a uniform temperature standard:
module 1:
and (3) module 2:
……
and a module N:
finally, all detector modules in the CT are corrected to the same temperature to ensure the uniformity of output dataAnd ring artifacts of the tomographic image are avoided.
In the embodiment, the correction coefficient of the tube current is used for carrying out normalization correction on the net signal intensity of each detector module at each temperature to obtain the correction coefficient of the net signal intensity, and then the sensitivity of each detector module at other temperatures is normalized based on the correction coefficient of the net signal intensity to obtain the correction coefficient of the detector module. And determining the reference temperature to construct a temperature-sensitivity correction table.
Because the correction coefficient is a ratio, the reference temperature of the correction table and the correction coefficients of other temperatures corresponding to the reference temperature can be conveniently transformed according to the average temperature of each detector module of CT in the actual environment temperature through multiplication. The temperature-sensitivity correction table can be used for correcting the acquired projection data at different environmental temperatures in the actual imaging process, effectively eliminates the ring artifacts of the tomographic image and enhances the environment adaptation capability of the imaging system.
When temperature variation is inevitable, the computer tomography correction method in the prior art generally obtains a first air correction table corresponding to a first temperature of the detector; when the detector is at a second temperature, performing air scanning, and obtaining a second air correction table based on the air scanning and the first air correction table; the image obtained at the second temperature is corrected using a second air correction table.
In this case, the CT detector must be in a steady state at the second temperature, that is, the temperature of each detector module is the same at the second temperature state twice. This is easily achieved for large CT in ambient temperature stable CT rooms. However, for mobile CT in complex and variable outdoor environments, because the temperature fields of the detector modules are different in a new ambient temperature, it takes a long time to reach a stable temperature distribution by heat transfer, which is contrary to the requirement that the mobile CT needs to scan the map quickly in the field. It can be seen that the prior art solutions do not meet the practical requirements.
The temperature-sensitivity correction table of the present invention builds a cubic rule to quickly and efficiently correct the detector gain when the temperature of the detector is not at the first temperature, to generate a second air correction table at the second temperature. According to the correction table corresponding to the actual temperature, it is possible to operate at various open ambient temperatures, for example, a wide temperature range from-20 degrees (northeast winter) to 40 degrees (southern summer).
Example two:
fig. 4 shows a CT operating in a wide ambient temperature range according to a second embodiment of the present invention, which includes a rotating disk, and an X-ray source and a detection system respectively fixed at two ends of the rotating disk, and employs the wide temperature correction method of the CT detector module as described in any one of the above embodiments.
Further, the detection system includes a plurality of detector modules; the detector modules are arranged in a circular arc shape, and the center of the circular arc is the focus of the X-ray source;
the detector module is sequentially provided with a scintillator, a photodiode, a substrate and a connector in the direction of X rays; the substrate is provided with a temperature sensor on a face facing the X-ray source.
Furthermore, the working temperature range of the temperature sensor is-50 ℃ to 100 ℃, and the precision is more than 0.5 ℃.
Because the accumulated error is likely to be larger when the operating environment temperature is larger from the reference temperature of the temperature-sensitivity correction table in the actual measurement process. For this purpose, the temperature of the individual detector modules of the detector system is ascertained using the rule of proximity when using the correction tables, i.e. the average temperature of the individual detector modules is calculated and used as the basis for the conversion of the correction tables.
Meanwhile, the invention can directly acquire the real-time temperature of each detector module in the environment by arranging the corresponding temperature sensor for each detector module on the surface facing the X-ray source, can conveniently carry out the sensitivity correction of the detector modules through the lookup table according to the converted temperature-sensitivity correction table, then directly reconstructs the tomographic image and rapidly maps.
According to the embodiment of the invention, the temperature sensor is additionally arranged on each detector module to acquire the detector sensitivity at different temperatures, and the temperature influence correction table corresponding to the temperature is established for correcting and applying the acquired projection data in the actual imaging process, so that the ring-shaped artifact of the tomographic image caused by the influence of the environmental temperature is eliminated. The environment adaptability of the mobile CT is enhanced, and the mobile CT can be used in various environmental temperatures, unlike the current clinical CT which needs to be used in the CT in a constant temperature environment.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.
Claims (10)
1. A method for wide temperature correction of a CT detector module, the method comprising the steps of:
F1. acquiring the output signal intensity of each detector module in the CT at different temperatures, calculating corresponding temperature-sensitivity correction coefficients, and establishing a temperature-sensitivity correction table;
F2. and correcting the projection data of each detector module based on the temperature-sensitivity correction table in the actual environment.
2. The method according to claim 1, wherein said step F1 comprises the steps of:
s1, shutting down the CT, namely, calibrating a corresponding temperature sensor of each detector module when the CT is in an environment with a preset temperature;
s2, starting up the CT, and recording the dark current of each detector module before exposure; carrying out air exposure; recording the current of an X-ray source tube, the intensity of output signals of the detector modules and the corresponding ambient temperature during exposure;
s3, raising the ambient temperature and continuing air exposure; recording the output signal intensity and dark current of each detector module at different temperatures and the corresponding X-ray source tube current;
and S4, after data acquisition in the working temperature range is completed, performing table building processing on the data, and building a temperature-sensitivity correction table.
3. The method of claim 2, wherein the step S4 comprises the steps of:
s41, deducting dark currents of the output signal intensity of each detector module at different preset temperatures to obtain net signal intensity:
d k,n ＝D k,n -B k,n ；
wherein D is net signal intensity, D is output signal intensity, B is dark current, k is preset temperature, and n is detector module number;
s42, carrying out normalization correction on the tube current of the X-ray source at each preset temperature to obtain a correction coefficient of the tube current:
wherein a is a correction coefficient of the tube current; i is tube current; k is a preset temperature; i is 1 Is a standard current;
s43, carrying out normalization correction on the net signal intensity of each detector module at each temperature by using the correction coefficient of the tube current, and eliminating the influence of tube current fluctuation on the sensitivity of the detector:
wherein, a k Is the correction coefficient of tube current at temperature k, C is the signal intensity output by the detector when the tube current is normalized to the standard current, C k,n The signal intensity of the nth detector module is exposed when the net signal intensity is at a preset temperature k;
and S44, selecting one preset temperature from the plurality of preset temperatures as a reference temperature, and carrying out normalization processing on the sensitivity of each detector module at each preset temperature to construct a temperature-sensitivity correction table.
4. The method according to claim 3, wherein the normalization process in step S44 is:
wherein kB is a reference temperature selected from the preset temperatures, and f is a temperature-sensitivity correction coefficient of the detector module.
5. A method according to claim 3, wherein the step interval of the temperature increase in step S3 is 1 degree celsius.
6. The method of claim 5, wherein said step F2 comprises the steps of:
t1, collecting the actual environment temperature of each detector module to calculate the average environment temperature;
t2, converting the temperature-sensitivity correction table by taking the average ambient temperature as the reference temperature;
and T3, correcting the projection data of each detector module at the actual ambient temperature by using the transformed temperature-sensitivity correction table.
7. The method of claim 6, wherein said step T3 comprises the steps of:
t31, calculating the net signal intensity output by each detector module at the actual ambient temperature;
and T32, based on the correction of the converted temperature-sensitivity correction table, multiplying the net signal intensity output under the actual environment temperature by the ratio of the correction coefficient at the average temperature to the correction coefficient at the actual environment temperature to obtain the projection data after the temperature effect correction of the corresponding detector module:
wherein, f kB,n A correction coefficient in which the temperature in the temperature-sensitivity correction table is the reference temperature after the average ambient temperature is used as the reference temperature;
f kT,n a correction coefficient of the measured temperature T of the detector module n in the converted temperature-sensitivity correction table is obtained;
d kT,n the net signal strength output by the detector module n when the temperature T is actually measured;
E n the corrected projection data is subjected to temperature effect.
8. A CT operating in a wide ambient temperature range, comprising a rotating disk and an X-ray source and a detection system respectively fixed at two ends of the rotating disk, wherein a wide temperature correction method of the CT detector module according to any one of claims 1 to 7 is adopted.
9. The CT of claim 8, wherein the detection system comprises a plurality of detector modules; the detector modules are arranged in a circular arc shape, and the center of the circular arc is the focus of the X-ray source;
the detector module is sequentially provided with a scintillator, a photodiode, a substrate and a connector in the X-ray direction; the substrate is provided with a temperature sensor on a face facing the X-ray source.
10. The CT of claim 9, wherein the temperature sensor operates in a temperature range of-50 degrees celsius to 100 degrees celsius to an accuracy greater than 0.5 degrees celsius.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210906887.5A CN115299973A (en) | 2022-07-29 | 2022-07-29 | Wide temperature correction method of CT detector module and CT adopting wide temperature correction method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210906887.5A CN115299973A (en) | 2022-07-29 | 2022-07-29 | Wide temperature correction method of CT detector module and CT adopting wide temperature correction method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115299973A true CN115299973A (en) | 2022-11-08 |
Family
ID=83858415
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210906887.5A Pending CN115299973A (en) | 2022-07-29 | 2022-07-29 | Wide temperature correction method of CT detector module and CT adopting wide temperature correction method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115299973A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117297634A (en) * | 2023-11-30 | 2023-12-29 | 苏州波影医疗技术有限公司 | CT system air calibration compensation method |
-
2022
- 2022-07-29 CN CN202210906887.5A patent/CN115299973A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117297634A (en) * | 2023-11-30 | 2023-12-29 | 苏州波影医疗技术有限公司 | CT system air calibration compensation method |
| CN117297634B (en) * | 2023-11-30 | 2024-02-09 | 苏州波影医疗技术有限公司 | CT system air calibration compensation method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103323870B (en) | Data acquisition | |
| CN115299973A (en) | Wide temperature correction method of CT detector module and CT adopting wide temperature correction method | |
| CN101975965A (en) | Flat panel detector and temperature calibration method and image correction method thereof | |
| CN111965691B (en) | Time migration correction method in PET | |
| JP2012081108A (en) | Medical image processor, x-ray computed tomographic apparatus, medical image processing method, and medical image processing program | |
| CN109323851B (en) | Terahertz focal plane response rate and response rate nonuniformity test system and method | |
| CN103006248B (en) | Digital X-ray imaging device and system nonuniformity correcting method thereof | |
| US7455454B2 (en) | X-ray detector methods and apparatus | |
| JP2019140784A (en) | Solar cell module characteristic measurement device, solar cell module temperature estimation method and solar cell module | |
| Sheikh et al. | RADCAM—a radiation camera system combining foil bolometers, AXUV diodes, and filtered soft x-ray diodes | |
| CN112882085B (en) | Temperature-adaptive PET detector energy correction method and system | |
| US20170192112A1 (en) | Solid state photomultiplier with wide temperature range of operation | |
| CN210294543U (en) | SiPM-based digital radiation detection module | |
| US8705688B2 (en) | Medical image processing apparatus, X-ray computed tomography apparatus, and medical image processing method | |
| Short | Gamma-camera systems | |
| CN211534463U (en) | Gain control device based on SiPM detection system | |
| Wang et al. | Developing a single-phase liquid argon detector with SiPM readout | |
| JP5344595B2 (en) | Solar cell evaluation apparatus, evaluation method, and solar cell manufacturing method | |
| TW202132816A (en) | Operation method for imaging system | |
| CN108703769A (en) | Bearing calibration, device, system and the computer readable storage medium of TOF data | |
| CN216628563U (en) | Detector and imaging system | |
| Job et al. | A comparison of quantum limited dose and noise equivalent dose | |
| CN109601011A (en) | With the photon counting detector for reducing power consumption | |
| CN113847992B (en) | Method, device, equipment and storage medium for improving temperature measurement precision of far small target | |
| WO2024002309A1 (en) | Methods and systems for controlling an imaging device, and detecting parameters of a detector |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |