JP5420360B2 - Radiography management system - Google Patents

Description

  The present invention relates to a radiography management system and method for managing the exposure dose to a patient during radiography.

  Conventionally, the inside of a human body is diagnosed with a radiographic image by performing radiography using chest X-ray imaging, a mammography apparatus, a CT apparatus, or the like. Since this radiography exposes the human body with a small amount of radiation, it is necessary to manage the radiation exposure in consideration of the safety of the human body. In order to manage the exposure dose, it is necessary to measure the exposure dose, and various methods for measuring the exposure dose have been proposed (see, for example, Patent Documents 1 and 2).

  Patent Document 1 discloses that a dosimeter is arranged at the irradiation unit or the detection unit for the irradiation X-ray dose, and the exposure dose is measured based on the radiation dose measured by the dosimeter. Is disclosed, for example, in DICOM or the like to calculate an irradiation dose associated with image data.

JP 2008-284294 A JP 2006-218139 A

  However, in Patent Document 1, a dosimeter is required separately, and it is necessary to attach a dosimeter to every radiation imaging apparatus, and since the dosimeter is exposed every time radiography is performed, the cost of maintenance, etc. There is a problem that it takes. In addition, as in Patent Document 2, when management is performed based on the radiation dose associated with the image data, there is a case where the estimation accuracy of the recorded radiation dose itself is lowered due to the influence of sensitivity fluctuation or the like due to deterioration over time. There is a problem that the radiation dose cannot be accurately controlled.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a radiography management system and method capable of managing a radiography apparatus based on an exposure dose accurately detected with respect to a radiation dose exposed to a patient. Is.

  The radiation imaging management system of the present invention is an exposure by a radiation imaging apparatus that detects radiation transmitted through a subject when the subject is irradiated with radiation from a radiation source that irradiates the subject with a radiation detector and acquires a radiation image. A radiography management system for managing an amount, comprising: an exposure amount detection unit that detects an exposure amount based on a pixel value of a radiographic image when radiography is performed; and an exposure detected by the exposure amount detection unit. The present invention is characterized by comprising a management means for managing the shooting amount by distinguishing between shooting based on shooting conditions under which a predetermined calibration is performed and shooting based on other shooting conditions.

  The radiography management method of the present invention is an exposure by a radiography apparatus that detects radiation transmitted through a subject when the subject is irradiated with radiation from a radiation source that irradiates the subject with a radiation detector and acquires a radiation image. A radiography management method for managing an amount, wherein an exposure amount is detected based on a pixel value of a radiographic image when the radiography is performed, and the detected exposure amount is subjected to a predetermined calibration. It is characterized in that it is managed by distinguishing between shooting based on the above and shooting based on other shooting conditions.

  Here, the radiation imaging apparatus may be anything as long as it detects a radiographic image by detecting radiation that has passed through the subject. For example, it may be a chest X-ray imaging apparatus, a mammography apparatus, a dental apparatus, or an internal organ. It may be a CT apparatus for observation.

  Further, the exposure amount detection means is provided on the radiation imaging apparatus side, and the management means is provided on the exposure amount management apparatus connected to a plurality of radiation imaging apparatuses via a network so that data transmission is possible. The exposure dose management means may manage the exposure doses of a plurality of radiation imaging apparatuses, or the management means may be built in the radiation imaging apparatus.

  Note that the management unit may have a function of determining whether or not the number of shootings based on shooting conditions other than the shooting conditions for which the predetermined calibration is performed is greater than or equal to the specified number. And it may be provided with a warning output means for outputting a warning when the management means determines that the number of times of photographing is equal to or greater than the prescribed number. Furthermore, the management means may have a function of determining whether or not the total exposure dose is equal to or greater than a set threshold value. And it may be provided with a warning output means for outputting a warning when the management means determines that the number of times of photographing is equal to or greater than the prescribed number.

  Furthermore, when the number of imaging is equal to or more than the specified number, the management unit may control the radiation imaging apparatus so as to prohibit the radiation imaging.

  According to the radiography management system and method of the present invention, radiography that acquires radiation images by detecting radiation transmitted through a subject when the subject is irradiated with radiation from a radiation source that irradiates the subject with a radiation detector. The exposure amount is managed by the device. The exposure amount is detected based on the pixel value of the radiographic image when the radiographing is performed, and the radiographing is performed under a predetermined calibration condition. By managing the exposure dose in distinction to imaging under the imaging conditions, maintenance management of the radiation imaging apparatus based on the exposure dose with guaranteed accuracy can be performed.

  The management means has a function of determining whether or not the total exposure amount is greater than or equal to the set threshold value, and when the exposure means is determined to be greater than or equal to the set threshold value in the management means, When a warning output means for outputting a warning is further provided, a warning such as a request for maintenance can be output in consideration of the accuracy of the aggregated exposure dose. Maintenance management of the radiation imaging apparatus can be performed.

  Further, the management means has a function of determining whether or not the number of times of photographing under the photographing condition other than the photographing condition for which the predetermined calibration is performed is equal to or greater than the prescribed number, and the number of photographing is equal to or greater than the prescribed number of times. If it is determined that the system is equipped with a warning output means for outputting a warning, the total exposure dose accuracy exceeds the specified number of times that would cause a maintenance problem. In this case, since maintenance warnings can be output in consideration of the accuracy of the total exposure dose, maintenance management of the radiation imaging equipment based on the exposure dose guaranteeing the accuracy of the estimated value should be performed. Can do.

  In addition, if the management means controls the radiation imaging apparatus to prohibit radiation imaging when the number of imaging is greater than or equal to the specified number of times, a decrease in accuracy of the total exposure dose due to exceeding the specified number of times is suppressed. be able to.

  The exposure dose detection means is provided on the radiation imaging apparatus side, and the management means is provided on the exposure dose management apparatus connected to a plurality of radiation imaging apparatuses via a network so that data transmission is possible. If the exposure dose management apparatus manages the exposure doses of a plurality of radiation imaging apparatuses, it is possible to efficiently manage a plurality of radiation imaging apparatuses using a single exposure dose management apparatus. .

Schematic which shows preferable embodiment of the radiography management system of this invention. 1 is a system diagram showing an example of a radiation imaging apparatus connected to the radiation imaging management system of FIG. The schematic diagram which shows an example of the radiography apparatus connected to the radiography management system of FIG. The flowchart which shows preferable embodiment of the radiography management method of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic view showing a preferred embodiment of the radiation imaging management system of the present invention. The radiation imaging management system 1 manages the exposure dose by the radiation imaging apparatus 10 installed in each hospital or the like for each patient, and a plurality of radiation imaging apparatuses 10 and the exposure dose management apparatus 20 are networked. 2 is connected so that data transmission is possible.

  FIG. 2 is a system diagram illustrating an example of the radiation imaging apparatus 10, and FIG. 3 is a schematic diagram illustrating an example of the radiation imaging apparatus 10. The radiation imaging apparatus 10 in FIGS. 2 and 3 is a saddle type radiation imaging apparatus, and includes a radiation source 11 and a radiation detector 12. Then, radiation is emitted from the radiation source 11 to the subject S, and the radiation transmitted through the subject S is detected as a radiation image by the radiation detector 12. The radiation source 11 and the radiation detector 12 are controlled by the imaging control means 13.

  The radiation detector 12 may be a so-called TFT method or an optical readout method. The TFT radiation detector 12 is configured, for example, by laminating a photoelectric conversion layer that absorbs radiation X and converts it into charges on a TFT active matrix substrate. The photoelectric conversion layer is made of amorphous a-Se (amorphous selenium) containing, for example, selenium as a main component (for example, a content rate of 50% or more), and when irradiated with radiation X, a charge corresponding to the amount of irradiated radiation. By generating a certain amount of charge (electron-hole pairs) internally, the irradiated radiation X is converted into a charge.

  On the other hand, the optical readout type radiation detector 12 uses a phosphor material and a photoelectric conversion element (photodiode) instead of the radiation-to-charge conversion material that directly converts the radiation X such as amorphous selenium into charges. Used to convert to charge indirectly. As phosphor materials, gadolinium sulfate (GOS) and cesium iodide (CsI) are well known. In this case, radiation X-light conversion is performed by a fluorescent material, and light-charge conversion is performed by a photodiode of a photoelectric conversion element.

  The imaging control unit 13 includes an imaging condition setting unit 14, an exposure amount detection unit 15, and a warning output unit 16. The imaging condition setting unit 14 sets imaging conditions when performing radiation imaging. In particular, the shooting condition setting unit 14 stores a plurality of set shooting conditions RCref that are shooting conditions under which a predetermined calibration is performed, and the operator can select one set shooting condition from among the plurality of set shooting conditions RCref. RCref is selected via the input means 17. Then, the imaging control unit 13 performs control so as to perform radiation imaging using the selected set imaging condition RCref. The plurality of set imaging conditions RCref are quality-controlled by periodically calibrating, and the correspondence between the radiation exposure amount and the pixel value of the radiation image is kept high.

  On the other hand, in the radiographing condition setting means 14, in consideration of reasons such as the physicist's physique of the patient S, a pregnant woman, an infant, an implant, and a standard positioning (imaging position) cannot be taken, other than the radiographing conditions RCref described above In addition, it has a function of freely setting imaging conditions in accordance with the input from the input means 17 by the radiologist. For example, as described above, after setting one set shooting condition RCref, the operator changes the shooting condition according to the subject, and sets the changed shooting condition CRC. The imaging control means 13 performs radiography using the changed imaging condition CRC after the change. Note that the imaging condition setting means 14 is changed so that the exposure dose to the patient S such as mAs value (product of tube current (mA) and time (sec)) is different from the setting imaging condition RCref. Is recognized as the changed shooting condition CRC. In other words, when the set imaging condition RCref is changed without changing the mAs value, the imaging condition setting unit 14 recognizes that the radiography is performed under the set imaging condition RCref.

  The exposure amount detection means 15 detects the exposure amount irradiated to the subject S during radiation imaging based on the pixel values of the radiation image. A known method can be used for the estimation of the exposure amount. For example, the exposure amount may be measured from the density of the unexposed portion of the radiation image, or a pixel of a specific part such as a bone portion. The exposure dose may be measured from the value.

  The warning output means 16 in FIG. 3 outputs a warning for alerting the radiation technician to the patient's exposure amount, and outputs a warning, for example, as a display unit or sound.

  The exposure dose management apparatus 20 shown in FIG. 1 manages the exposure doses in a plurality of radiation imaging apparatuses 10 connected to a network. The exposure dose totaling means 21, the frequency measurement means 22, and the apparatus management means 23 are used. It has. The exposure amount totaling means 21 acquires and totals the exposure amount for each radiography measured by the exposure amount detection means 15 via the network 2. Here, the exposure dose totalizing means 21 totals the total exposure dose when radiography is performed under the set imaging condition RCref and the changed imaging condition CRC. Note that the exposure dose totalization unit 21 may reset the total exposure dose every time the radiographic imaging apparatus 10 is regularly maintained, and may start calculating a new total exposure dose.

  The number-of-times measuring means 22 measures the number of times of exposure exposure for radiation imaging under the changed imaging condition CRC. For example, the exposure amount detection unit 15 adds a flag to the exposure amount detected when radiation imaging is performed under the changed imaging condition CRC and transmits the data to the number measurement unit 22. On the other hand, the exposure amount detection means 15 transmits the exposure amount detected when radiation imaging is performed under the set imaging condition RCref to the number counting means 22 without adding a flag to the data. The number-of-times measuring means 22 measures the number of radiation imaging using the changed imaging condition CRC, that is, the total amount of radiation totaled in the exposure amount totaling means 21 by measuring the number of exposure amount data to which the flag is given. The number of times of radiographic imaging under the modified imaging condition CRC included in is measured. Note that the number measuring unit 22 may reset the number of times of imaging every time the radiographic apparatus 10 is regularly maintained, and may newly start counting the number of times of measurement.

  The apparatus management unit 23 manages the exposure amount detected by the exposure amount detection unit 15 by distinguishing between shooting under shooting conditions under which predetermined calibration is performed and shooting under other shooting conditions. Specifically, the apparatus management unit 23 has a function of managing the radiation imaging apparatus 10 by using the total exposure amount calculated by the exposure amount totaling unit 21 and the number of imaging times measured by the number-of-times measurement unit 22. doing. The apparatus management unit 23 determines whether or not the exposure amount totaled by the exposure amount totaling unit 21 is greater than or equal to a set threshold value. When it is determined that the number of times of photographing is equal to or greater than the prescribed number, the apparatus management unit 23 performs control so that a warning is output from the warning output unit 16. In addition, the device management unit 23 determines whether or not the number of photographing is equal to or more than the specified number. And when it determines with the frequency | count of imaging | photography being more than regulation number, the apparatus management means 23 is controlled so that a warning is output from a warning output means.

  As a warning output from the warning output means 16, for example, a message indicating that maintenance / inspection is recommended may be output, or a message indicating that shooting with the set shooting condition RCref is recommended may be output. Good. Alternatively, when the plurality of changed shooting conditions CRC are substantially the same shooting conditions, the modified shooting condition CRC is set as the set shooting condition RCref, and it is output that it is recommended to be a calibration target at the time of maintenance. Good.

  Note that when the apparatus management unit 23 outputs a warning, the radiation imaging apparatus 10 may be controlled to prohibit radiation imaging. The radiation imaging apparatus 10 may restart radiation imaging after determining based on the input of the input means 17 that the operator has confirmed the warning from the warning output means 16. Thereby, the effect of alerting the operator can be enhanced.

  In this way, by managing the radiation imaging apparatus 10 using the total exposure amount and the number of times of imaging of the changed imaging condition CRC in the radiation imaging apparatus 10, it is based on the exposure amount accurately estimated from the pixel value of the radiation image. Maintenance management can be performed. In other words, when the performance management of the device is performed based on the exposure dose estimated from the pixel value of the radiographic image, etc. In some cases, the accuracy of the estimation may decrease, and the accuracy of the estimated value may not be objectively guaranteed. On the other hand, the exposure amount detected when set to the set imaging condition RCref whose performance is regularly guaranteed by calibration or the like has high estimation accuracy, and the exposure detected when set to the changed imaging condition CRC. The estimation accuracy of the amount is lower than that in the case of the set photographing condition RCref.

  Focusing on this point, if the number of times of imaging under the changed imaging condition CRC is less than the specified number of times, the radiation imaging apparatus 10 based on the total amount of radiation is considered to be an allowable error even if the accuracy of the total amount of radiation deteriorates. Perform performance management. On the other hand, when the number of times of radiation imaging other than the set imaging condition RCref exceeds the specified number, a warning that the accuracy of the total exposure dose is reduced is issued and maintenance is urged. Maintenance management of the radiation imaging apparatus 10 based on the exposure amount estimated with accuracy can be performed.

  FIG. 4 is a flowchart showing a preferred embodiment of the radiography management method of the present invention. The radiography management method will be described with reference to FIGS. First, imaging conditions are set for the radiation imaging apparatus 10 according to the subject S (step ST1). Specifically, one set imaging condition RCref is selected from a plurality of setting imaging conditions RCref according to the observation site and patient, or the changed imaging condition CRC is arbitrarily changed according to the subject S. Is set.

  Here, the photographing control means 13 determines whether or not the photographing condition input from the input means 17 is the set photographing condition RCref (step ST2). When the imaging condition is the set imaging condition RCref, a radiographic image is detected by performing radiation imaging using the set imaging condition RCref (step ST3). Then, the exposure dose is measured by the exposure dose detection means 15 based on the pixel value of the radiation image (step ST4).

  On the other hand, when the shooting condition is the changed shooting condition CRC other than the set shooting condition RCref, the number of shootings by the changed shooting condition CRC is counted in the number counting unit 22 (step ST11). Thereafter, it is determined in the apparatus management means 23 whether or not the number of times of photographing under the changed photographing condition CRC is equal to or greater than the prescribed number of times (step ST12). If the number of times of imaging under the changed imaging condition CRC is equal to or greater than the specified number, a warning is output from the warning output means 16, or radiation imaging is prohibited together with the warning (step ST7). On the other hand, when the number of times of imaging is less than the specified number of times, the radiography and the exposure amount are detected under the changed imaging condition CRC as described above (steps ST3 and ST4).

  Thereafter, the exposure dose detected by the exposure dose detection means 15 is transmitted to the exposure dose management apparatus 20 via the network 2, and the total exposure dose is counted for each radiation imaging apparatus 10 by the exposure dose counting means 21. (Step ST5). Then, it is determined whether or not the total exposure amount is equal to or greater than the set threshold value in the device management means 23 (step ST6). Is output (step ST7).

  According to the radiation imaging management system and method of the present invention, when the subject is irradiated with radiation from the radiation source 11 that irradiates the subject S, the radiation transmitted through the subject is detected by the radiation detector 12 to obtain a radiation image. The exposure amount by the radiation imaging apparatus 10 is managed, the exposure amount is detected based on the pixel value of the radiation image when the radiation imaging is performed, and the detected exposure amount is subjected to a predetermined calibration. By managing the imaging under the imaging conditions that are different from the imaging conditions under the other imaging conditions, it is possible to perform maintenance management of the radiation imaging apparatus based on the exposure amount with guaranteed accuracy.

  Further, the apparatus management means 23 has a function of determining whether or not the total exposure amount is equal to or greater than a set threshold value, and the apparatus management means 23 determines that the exposure amount is equal to or greater than the set threshold value. If the warning output means 16 for outputting a warning is further provided, a warning such as a request for maintenance can be output in consideration of the accuracy of the total exposure dose. It is possible to perform maintenance management of the radiation imaging apparatus based on the exposure amount that guarantees the above.

  Further, the device management means 23 has a function of determining whether or not the number of times of photographing under the photographing conditions other than the photographing conditions for which the predetermined calibration is performed is greater than or equal to the prescribed number. When it is determined that the number of times is equal to or greater than the specified number of times, and the warning output means 16 that outputs a warning is provided, the accuracy of the total amount of exposure exceeds the specified number of times that causes a maintenance management failure. When shooting is being performed, warnings such as requests for maintenance can be output in consideration of the accuracy of the total exposure amount, so exposure that guarantees the accuracy of the estimated value of exposure amount Maintenance management of the radiation imaging apparatus 10 based on the quantity can be performed.

  Further, if the apparatus management unit 23 controls the radiation imaging apparatus 10 to prohibit radiation imaging when the number of imaging is equal to or more than the specified number, the accuracy of the total exposure amount due to exceeding the specified number of times can be improved. The decrease can be suppressed.

  The imaging condition setting means 14 and the exposure dose detection means 15 are provided on the radiation imaging apparatus side, and the exposure dose counting means 21, the frequency measurement means 22 and the device management means 23 are connected to a plurality of radiation imaging apparatuses. If the exposure dose management device 20 manages the exposure doses of the plurality of radiation imaging devices 10, one unit is provided. A plurality of radiation imaging apparatuses can be efficiently managed using the exposure dose management apparatus 20.

  The embodiment of the present invention is not limited to the above embodiment. For example, FIG. 2 and FIG. 3 illustrate the case of a supine type radiography apparatus, but the present invention can also be applied to radiography apparatuses such as a chest X-ray apparatus, a mammography apparatus, a CT apparatus, and a dental X-ray apparatus. Can do.

  1 illustrates the case where the radiation imaging apparatus 10 and the exposure dose management apparatus 20 are connected via a network so that data transmission is possible. However, the exposure dose management apparatus 20 is connected to the radiation imaging apparatus 10. The radiation amount may be managed in each radiation imaging apparatus 10.

  Further, in the apparatus management unit 23 of FIG. 1, the case where the accuracy of the total exposure amount is guaranteed based on the number of times of the changed imaging condition CRC is illustrated, but the total exposure amount of the exposure amount based on the changed imaging condition CRC is illustrated. When the ratio of the number to the threshold is equal to or greater than the set threshold value, it may have a function of determining that the accuracy has deteriorated and outputting a warning.

DESCRIPTION OF SYMBOLS 1 Radiation imaging management system 2 Network 10 Radiography apparatus 11 Radiation source 12 Radiation detector 13 Imaging control means 14 Imaging condition setting means 15 Exposure amount detection means 16 Warning output means 17 Input means 20 Exposure amount management apparatus 21 Exposure amount Counting means 22 Counting means 23 Device management means CRC Changed shooting condition RCref Setting shooting condition S Subject

Claims (5)

Radiography management for managing the exposure dose by a radiography apparatus that detects radiation transmitted through the subject by a radiation detector when the subject is irradiated with radiation from a radiation source that irradiates the subject. A system,
An exposure amount detecting means for detecting an exposure amount based on a pixel value of the radiographic image when performing radiography,
Management means for managing the exposure amount detected by the exposure amount detection means separately for imaging under imaging conditions under which a predetermined calibration is performed and imaging under other imaging conditions. Radiography management system. The management means has a function of determining whether or not the total exposure amount of the shooting under the shooting conditions under which the predetermined calibration is performed and the shooting under the other shooting conditions is greater than or equal to a set threshold value,
If the total exposure dose is determined to be less than the set threshold value before Symbol management means, radiation according to claim 1, characterized in that with further warning output means for outputting a warning Shooting management system. It said management means has a function determining whether a by that shooting number prescribed number of times or more in the image capturing condition of the other shooting conditions prescribed calibration is being performed,
If the number of shots is determined to be the prescribed number of times or more before Symbol management means, radiography management according to claim 1, wherein characterized in that further comprising an alarm output means for outputting a warning system.   The management means controls the radiation imaging apparatus so as to prohibit radiation imaging when the number of imaging times based on imaging conditions other than the imaging conditions under which a predetermined calibration is performed is equal to or greater than a predetermined number. The radiation imaging management system according to claim 3. The exposure dose detection means is provided on the radiation imaging apparatus side, and the management means is provided in an exposure dose management apparatus connected to the plurality of radiation imaging apparatuses via a network so that data transmission is possible. And
The radiation imaging management system according to any one of claims 1 to 4, wherein the exposure dose management device manages exposure doses of the plurality of radiation imaging devices.

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