JP5317616B2 - Radiography system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To eliminate the need of obtaining a tube voltage for energy subtraction radiographing through a trial and error process and to substantially shorten the time required for the energy subtraction radiographing. <P>SOLUTION: This radiographing system includes: a result value information table in which a result value for each radiographing part of the tube voltage supplied to a radiation source in normal radiographing is registered; a tube voltage calculation part 72 for reading the result of the same radiographing part as the radiographing part in the energy subtraction radiographing from the result value information table and calculating a first tube voltage V1 to be supplied to the radiation source in the energy subtraction radiographing on the basis of the read result value; and a radiation source control part 17 for irradiating an object with radiation on the basis of the result value (second tube voltage V2) read in the tube voltage calculation part 72 and the calculated first tube voltage V1. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention obtains at least two types of radiation image information by irradiating a subject with radiation having energy distribution for normal imaging and radiation having energy distribution for energy subtraction imaging. The present invention relates to a radiation imaging system that obtains a normal captured image and an extracted image of a specific object by performing a subtraction process after weighting with.

In general, the setting of the tube voltage in normal imaging (imaging in which the tube voltage of the radiation source is one type) varies depending on the imaging region as follows.
Chest: 120kV
Lumbar spine: 80 kV
Limb: 50kV

  On the other hand, the setting of tube voltage in energy subtraction imaging (imaging with two types of tube voltages of the radiation source) is determined from the following conditions.

Condition (1): A plurality of tube voltages (high voltage and low voltage) are required.
Condition (2): Either the high voltage or the low voltage is the same as the tube voltage for normal imaging for the purpose of interpretation.
Condition (3): When the voltage difference between the high voltage and the low voltage is large, the bone image (bone image) and the soft tissue image (soft image) are clear (separation is good). I want to make it bigger. However, since the bone part image and the soft part image can be made clear by the image processing, the priority is lower than the conditions (1) and (2). Further, the high voltage has an upper limit due to the limitation of the voltage that can be supplied to the radiation source.

From these conditions (1) to (3), the tube voltage in energy subtraction imaging is as follows.
Chest: 60kV, 120kV
Lumbar spine: 80 kV, 120 kV
Limbs: 50 kV, 120 kV

  Of these, 120 kV for the chest, 80 kV for the lumbar spine, and 50 kV for the limbs are determined from condition (2). Further, 60 kV for the chest, 120 kV for the lumbar spine, and 120 kV for the limbs are determined from the condition (3).

  Radiation images obtained by energy subtraction imaging are the following two types of images, and the doctor makes a diagnosis by looking at both.

  (A) Radiographic image taken at the same voltage as normal imaging: Bone and soft tissue are seen.

  (B) Bone part image or soft part image after performing weighted subtraction processing: Diagnosing by observing the bone part or soft tissue intensively.

  The above-described examples of the tube voltage are merely average voltages, and actually vary depending on each facility / each engineer / each doctor (including an interpreting doctor) / each radiation source. This is due to the fact that the optimum voltage varies depending on the image preference of the doctor or engineer, the characteristics of the radiation source or radiation detector, and the like.

  At present, normal photography is widely performed and has a track record, so the optimum value of the tube voltage is set by an engineer. However, since energy subtraction imaging is not performed as much as normal imaging, there are few achievements, and there is a problem that an engineer must search for an optimum value of the tube voltage. The method for finding the optimum value is, for example, using a phantom (an artificial object that simulates a subject such as a human body) as the subject, changing the tube voltage, performing many test shots, and finding the optimum value through trial and error. It takes a lot of time and becomes an impediment to the spread of energy subtraction photography.

  Conventionally, as disclosed in Patent Document 1, as for tube voltage at the time of energy subtraction imaging, in high energy imaging, switching is performed while changing the tube voltage over a plurality of stages, and in imaging with low energy, the tube voltage is only once. The voltage is set to irradiate.

JP 2007-22211 A

  However, the technique described in Patent Document 1 is preferable because the radiographic image obtained by energy subtraction imaging has high image quality. However, as a compensation, the radiographic image obtained by normal imaging is not suitable for interpretation, and the necessary medical care is required. There is a problem that information cannot be obtained.

  The present invention has been made in consideration of such problems, it is not necessary to determine the tube voltage for energy subtraction imaging by trial and error, and can greatly reduce the time required for energy subtraction imaging, Moreover, it is an object to provide a radiographic system that can improve the image quality of the radiographic image obtained by normal imaging and the radiographic image obtained by energy subtraction imaging to the same level and obtain necessary medical information. To do.

  The radiation imaging system according to the present invention obtains at least two types of radiation image information by irradiating a subject with radiation having energy distribution for normal imaging and radiation having energy distribution for energy subtraction imaging. A radiographic system that obtains a normal captured image and an extracted image of a specific object by performing a subtraction process after weighting between each radiographic image information, and for each imaging portion of the tube voltage supplied to the radiation source during normal imaging The actual value of the same imaging region as the imaging region in the energy subtraction imaging is read out from the storage unit storing the actual value of the imaging region and the actual value for each imaging region, and the energy is based on the read actual value. A tube voltage calculator for calculating a tube voltage supplied to the radiation source during subtraction imaging, and the tube voltage calculator Said actual value Desa are viewed, and having a radiation source control unit for irradiation with respect to the subject based on the calculated the tube voltage.

  As described above, the radiation imaging system according to the present invention does not need to obtain the tube voltage for energy subtraction imaging by trial and error, and can greatly reduce the time required for energy subtraction imaging. Moreover, the image quality of the radiographic image obtained by normal imaging and the radiographic image obtained by energy subtraction imaging can be increased to the same level, and necessary medical information can be obtained.

  Hereinafter, an embodiment of a radiation imaging system according to the present invention will be described with reference to FIGS. In order to simplify the explanation, examples of the imaging region include “chest”, “lumbar vertebra”, and “limbs”, but are not limited thereto.

  As shown in FIG. 1, a radiation imaging system 10 according to the present embodiment includes a radiation source 14 that irradiates a subject 12 with radiation X, and a tube that sets a tube voltage in normal imaging and energy subtraction imaging (energy sub imaging). A voltage setting unit 16, a radiation source control unit 17 that controls the radiation source 14 based on imaging conditions such as a set tube voltage, tube current, and irradiation time, and radiation X that has passed through the subject 12 is converted into charge information. The radiation detection device 20 having the radiation detector 18 to be the radiation image information, the image processing unit 22 that performs image processing on the radiation image information detected by the radiation detector 18, and the image processing unit 22 A display control unit 26 for displaying radiation image information on the monitor 24; an input device 28 having a coordinate input device such as a mouse and a touch panel; a keyboard; And a console 30 for controlling these units.

  For example, as shown in FIG. 2, the radiation detector 18 includes a sensor substrate 38, a gate line driving circuit 44, a signal reading circuit 46, and a timing control circuit 48 that controls the gate line driving circuit 44 and the signal reading circuit 46. Is provided.

  In the sensor substrate 38, a photoelectric conversion layer 51 made of a substance such as amorphous selenium (a-Se) that senses radiation X and generates charges is disposed on an array of thin film transistors (TFTs) 52. After the generated charge is stored in the storage capacitor 53, the TFT 52 is sequentially turned on for each row, and the charge is read out as an image signal. In FIG. 2, only the connection relationship between one pixel 50 including the photoelectric conversion layer 51 and the storage capacitor 53 and one TFT 52 is shown, and the configuration of the other pixels 50 is omitted. Amorphous selenium must be used within a predetermined temperature range because its structure changes and its function decreases at high temperatures. A gate line 54 extending parallel to the row direction and a signal line 56 extending parallel to the column direction are connected to the TFT 52 connected to each pixel 50. Each gate line 54 is connected to the gate line drive circuit 44, and each signal line 56 is connected to the signal readout circuit 46.

As shown in FIGS. 3A and 3B, the radiation source control unit 17 applies radiation X to the subject 12 at different times (first and second times) with respect to the subject 12 at different times. 1 radiation Xa and 2nd radiation Xb) are irradiated. Here, the energy of the first radiation Xa <the energy of the second radiation Xb. In this case, the radiation detection apparatus 20 converts the first first radiation Xa (low energy) transmitted through the subject 12 into charge information to obtain first radiation image information S ₁ (see FIG. 3A), and Second radiation Xb (high energy) transmitted through the subject 12 is converted into charge information to obtain second radiation image information S ₂ (see FIG. 3B).

The first radiation image information S ₁ and the second radiation image information S ₂ described above are transferred (transmitted) from the radiation detection apparatus 20 to the image processing unit 22 wirelessly or via a cable.

The image processing unit 22 has at least a first image memory 60 which the radiation image information S ₁ and the second radiation image information S ₂ is recorded, the second radiation image information S ₂ according to the second radiation Xb high energy normal shooting A normal image display unit 62 displayed on the monitor 24 as a radiographic image (normal image), and a weighted subtraction process between the first radiographic image information S ₁ and the second radiographic image information S ₂ , to perform a radiographic image (energy subimage) A weighted subtraction processing unit 64 for obtaining Sd) and an energy sub image display unit 66 for displaying the obtained energy sub image Sd on the monitor 24 are provided.

  And the tube voltage setting part 16 has the data memory 70, the tube voltage calculation part 72, and the tube voltage output part 74, as shown in FIG.

  In the data memory 70, an actual value table 80 in which actual values for each imaging region of the tube voltage supplied to the radiation source 14 in normal imaging performed so far are registered, and a default in which default values for each imaging region are registered. A table 82, a voltage difference table 84 in which a voltage difference for each imaging region is registered, and a priority table 86 in which priorities are set are stored.

  The tube voltage calculation unit 72 reads the actual value of the same imaging region as the imaging region in energy sub imaging from the actual value table 80, and calculates the tube voltage supplied to the radiation source 14 at the time of energy sub imaging based on the read actual value. .

  Here, the types and details of the result value table 80 and the details of the default table 82, the voltage difference table 84, and the priority table 86 will be described with reference to FIGS.

  First, the actual value table 80 includes a tube-specific actual value table 80A (see FIG. 6), a patient-specific actual value table 80B (see FIG. 7), a technician-specific actual value table 80C (see FIG. 8), and a doctor-specific actual value table 80D. (See FIG. 9).

  As shown in FIG. 6, the tube-by-tube actual value table 80A is prepared for each imaging region. The tube-by-tube actual value table 80Aa, the lumbar tube-by-tube actual value table 80Ab, and the limb-by-tube actual value table 80Ac. Each tube result value table 80Aa to 80Ac has a number of records corresponding to the type of the radiation source 14 used, and each record has an identification code Da1, Da2,. , Identification codes Db1, Db2,... For identifying one or more radiation detectors 18 used in normal imaging with the radiation source 14, and tubes when normal imaging is performed for each radiation detector 18. The voltage (actual value) and the number of times (frequency) are registered. The same applies to the lumbar-by-tube actual value table 80Ab and the limb-by-tube actual value table 80Ac.

  As shown in FIG. 7, a patient-specific actual value table 80B is also prepared for each imaging region. The patient-specific actual value table 80Ba for the chest, the patient-specific actual value table 80Bb for the lumbar spine, and the patient-specific actual value table for the limbs 80Bc. Each patient result value table 80Ba-80Bc has a number of records corresponding to the number of patients who have performed normal imaging, and each record includes identification codes Dc1, Dc2,. Identification codes Da1, Da2,... That specify 14 and identification codes Db1, Db2,... That specify one or more radiation detectors 18 used in normal imaging with the radiation source 14. For each detector 18, the tube voltage (actual value) when normal photographing is performed is registered. The same applies to the patient-specific results value table 80Ba for lumbar vertebrae and the patient-specific results value table 80Bc for limbs.

  The engineer result value table 80C also has the same breakdown as the patient result value table 80B described above, and is different from the identification codes Dc1, Dc2,. , Dd2,... Are registered, and the tube voltage (actual value) when normal imaging is performed is registered for each radiation detector 18.

  The doctor-specific result value table 80D has the same breakdown as the patient-specific result value table 80B described above, and is different from the identification codes Dc1, Dc2,. , De2,... Are registered, and the tube voltage (actual value) when normal imaging is performed is registered for each radiation detector 18.

  On the other hand, in the default table 82, as shown in FIG. 10, the default value when the imaging region is unknown, the default value for the chest, the default value for the lumbar spine, and the default value for the limbs are registered according to the imaging region. Yes.

  As shown in FIG. 11, the voltage difference table 84 registers the voltage difference when the imaging region is unknown, the voltage difference for the chest, the voltage difference for the lumbar spine, and the voltage difference for the limbs according to the imaging region. .

  In the priority table 86, as shown in FIG. 12, when two or more actual values are listed as actual values, information indicating which one to select is registered. From the highest priority order, For example, doctors, technicians, patients, radiation sources, and radiation detectors.

  Here, the second tube voltage V2 for normal imaging according to various modes of processing in the tube voltage calculation unit 72, in particular, designation of doctor (interpretation doctor), technician, patient, radiation source, and radiation detector. And the calculation process of the 1st tube voltage V1 for energy sub imaging | photography is demonstrated.

  First, designation of a patient, the radiation source 14 and the radiation detector 18 is performed with reference to patient information and imaging conditions registered in the console 30 in advance. For example, if the engineer is designated as a routine in advance, the engineer is designated by referring to the photographing conditions. However, if the photographing is temporary, the engineer himself or the operator designates it through the input device 28, RFID, barcode reader, or the like. If the doctor is determined in advance as a routine, the procedure is performed with reference to the imaging conditions. However, for temporary imaging, the doctor himself or the operator designates it through the input device, RFID, barcode reader, or the like. Of course, when a situation in which the radiation source 14 and the radiation detector 18 have to be changed suddenly occurs, an engineer or an operator designates the radiation source 14 and the radiation detector 18 through an input device, an RFID, a barcode reader, or the like.

  These designations are performed, for example, by displaying a designation screen on the monitor 24 connected to the console 30. Normally, as shown in FIG. 13, all necessary items (identification codes (ID)) are specified based on patient information and imaging conditions registered in the console 30 in advance. As shown in FIG. 14, for example, “*” is added to the undesignated item and the designated change item, as shown in FIG. Is displayed, and a message further prompting the designation is displayed.

  Normally, as shown in FIG. 13, since all items are specified, all the actual value tables 80 (80A to 80D) are referred to, but the processing time becomes long. In the present embodiment, the following processing is performed.

[Normal processing]
First, with reference to the priority table 86, it is determined first which actual value table is to be referred to. In this example, since “doctor” has the highest priority, the doctor-specific result value table 80D is referred to. At this time, the corresponding actual value is read out from the already registered imaging region, information on the radiation source 14 (identification code) and information on the radiation detector 18 (identification code).

  Of course, a designated doctor may use a new radiation detector 18 or a newly installed radiation source 14. In this case, since the identification code of the radiation source 14 and the identification code of the radiation detector 18 are not registered in the doctor-specific result value table 80D, the following processing is performed.

[Exception handling 1]
First, the corresponding actual value is read from the identification code of the radiation source 14 and the identification code of the radiation detector 18 with reference to the actual value table 80A for each tube.

[Exception handling 2]
If the identification code of the radiation detector 18 to be used this time is not registered in the tube-specific actual value table 80A, the corresponding record is extracted from the identification code of the radiation source 14, and the highest frequency (number of times) is extracted from the record. Read the actual value.

[Exception handling 3]
If the identification code of the radiation source 14 used this time is not registered in the tube-by-tube actual value table 80A, the default value of the corresponding imaging region is read from the default table 82 as the actual value.

  Thereafter, the actual value read as described above is registered in the data memory 70 as the second tube voltage V2 for normal photographing.

  Thereafter, the voltage difference corresponding to the current imaging region is read from the voltage difference table 84, and the first tube voltage V1 for energy sub imaging is calculated by subtracting the voltage difference from the registered second tube voltage V2 for normal imaging. The calculated first tube voltage V1 for energy sub imaging is registered in the data memory 70.

  Then, the second tube voltage V2 for normal photographing and the first tube voltage V1 for energy sub photographing registered in the data memory 70 are displayed on the monitor 24 as shown in FIG. Is displayed. The first tube voltage V1 and the second tube voltage V2 are determined by a doctor, an engineer, or an operator operating the confirmation button 88 (for example, left-clicking the pointer with the position of the confirmation button 88). It becomes.

  On the other hand, in the above-described example, the information related to “engineer” is specified, and if the information related to “doctor” is not specified, the information on “technologist” having the next highest priority is stored on the priority table 86. Then, the same processing as [Normal processing] described above is performed. That is, with reference to the engineer result value table 80C, the corresponding result value is read out from the already registered information (identification code) of the radiation source 14 and the information (identification code) of the radiation detector 18. Of course, if necessary, processing similar to [Exception processing 1] to [Exception processing 3] described above is also performed.

  Thereafter, in the same manner as described above, the read actual value is registered in the data memory 70 as the second tube voltage V2 for normal imaging, and further, the voltage difference corresponding to the current imaging region is read from the voltage difference table 84 and registered. The first tube voltage V1 for energy sub imaging is calculated by subtracting the voltage difference from the second tube voltage V2 for normal imaging, and is registered in the data memory 70. Thereafter, the second tube voltage V2 for normal photographing and the first tube voltage V1 for energy sub photographing registered in the data memory 70 are displayed on the monitor 24 as shown in FIG. For example, “*” mark indicating waiting for designation is displayed near the displayed tube voltage until high information is designated, for example, until information about the doctor is designated. A message prompting you to specify such as “Please” is displayed.

  After that, when the information related to the doctor is designated, the above-mentioned [normal processing] or [exception processing 1] to [exception processing 3] is performed again, so that, for example, as shown in FIG. The voltage V1 and the second tube voltage V2 are calculated and displayed on the monitor 24. At the same time, the “*” mark indicating the waiting for designation is deleted and a confirmation button 88 is displayed. When the doctor, engineer, or operator operates the confirmation button 88, the first tube voltage V1 and the second tube voltage V2 are determined.

  When the first tube voltage V1 and the second tube voltage V2 are determined, the tube voltage output unit 74 outputs the first tube voltage V1 and the second tube voltage V2 registered in the data memory to the radiation source control unit 17.

  The radiation imaging system 10 according to the present embodiment is basically configured as described above, and the operation thereof will be described next.

  First, patient information of a patient 12 (subject) as an imaging target is registered in advance in the console 30 prior to imaging. If the imaging region and imaging method are determined in advance, these imaging conditions are also registered in advance. By this registration, the radiation source 14 and the radiation detector 18 to be used, and the engineer and doctor who are engaged are automatically specified, and the specified content is, for example, as shown in FIG. 13, the monitor 24 connected to the console 30. Displayed as a designated screen. Of course, when automatically changing the designated content or newly designating an undesignated item, the doctor, engineer or operator designates it through the input device 28, RFID, barcode reader, or the like.

  When all the information about the radiation source 14 and the radiation detector 18 to be used and the technicians and doctors engaged are designated, the corresponding actual value is obtained by the above-mentioned [normal processing] or [exception processing 1] to [exception processing 3]. The actual value is read from the table 80 and registered in the data memory 70 as the second tube voltage V2 for normal photographing. Thereafter, the voltage difference is subtracted in accordance with the above-described processing, and the first tube voltage V1 for energy sub imaging is calculated and registered in the data memory 70, and the first tube voltage V1 and the second tube voltage V2 are displayed on the monitor 24. The If the information related to the doctor is not specified, the second tube voltage V2 for normal imaging and the first tube voltage V1 for energy sub imaging are newly calculated and registered in the data memory 70 by the specification. At the same time, the first tube voltage V1 and the second tube voltage V2 are displayed on the monitor 24.

  The doctor, engineer, or operator operates the confirmation button 88 displayed on the monitor 24 to determine the tube voltages V1 and V2, and the information is transferred (transmitted) to the radiation source control unit 17.

  Thereafter, when taking radiographic image information in an operating room, a medical examination, a round-trip in the hospital, etc., the doctor or radiologist, for example, places the irradiation surface on the radiation source 14 side at a predetermined position between the patient 12 and the bed. The radiation detection apparatus 20 is installed in the state described above.

  Next, after appropriately moving the radiation source 14 to a position facing the radiation detection apparatus 20, the doctor or the radiographer operates the imaging switch of the radiation source 14 to perform imaging.

  At this time, the radiation source 14 is controlled with the first tube voltage V1 and tube current for energy sub imaging to irradiate the subject 12 with the first radiation Xa, thereby performing the first shot imaging (energy sub imaging).

The first radiation Xa that has passed through the subject 12 is converted into an electrical signal by the photoelectric conversion layer 51 of each pixel 50 that constitutes the sensor substrate 38 of the radiation detector 18, and is stored as a charge in the storage capacitor 53. Next, the charge information, which is the radiation image information S ₁ of the first shot of the subject 12 stored in each storage capacitor 53, is supplied from the timing control circuit 48 to the gate line driving circuit 44 and the signal readout circuit 46. Accordingly, the data is read from the sensor substrate 38.

That is, the gate line driving circuit 44 selects one of the gate lines 54 in accordance with the timing control signal from the timing control circuit 48 and supplies a driving signal to the base of each TFT 52 connected to the selected gate line 54. . On the other hand, the signal readout circuit 46 selects the signal line 56 connected to the charge detection circuit 57 while sequentially switching in the row direction in accordance with the timing control signal from the timing control circuit 48. The charge information related to the radiation image information S ₁ stored in the storage capacitor 53 of the pixel 50 corresponding to the selected gate line 54 and signal line 56 is supplied to the image processing unit 22 as an image signal. After the image signal is read from each pixel 50 arranged in the row direction, the gate line drive circuit 44 selects the next gate line 54 in the column direction and supplies a drive signal, and the signal read circuit 46 Similarly, an image signal is read from the TFT 52 connected to the selected gate line 54. By repeating the above operation, the two-dimensional first radiation image information S ₁ stored in the sensor substrate 38 is read and supplied to the image processing unit 22.

  Next, the radiation source control unit 17 controls the radiation source 14 with the second tube voltage V2 and tube current for normal imaging to irradiate the subject 12 with the second radiation Xb, thereby capturing the second shot (normal imaging). )I do. Since the second shot is taken immediately after the first shot based on preset shooting conditions, the motion caused by the movement of the subject 12 between the first and second shots. Artifacts do not occur.

The second shot second radiation image information S ₂ detected by the radiation detector 18 is read in the same manner as the first shot first radiation image information S ₁ and supplied to the image processing unit 22.

The image processing unit 22 records the supplied first radiation image information S ₁ and second radiation image information S ₂ in the image memory 60.

Thereafter, normal image display unit 62 displays on the monitor 24 as the first radiation Xb of the second radiation image information S ₂ of normal imaging radiation image of high energy (normal image). On the other hand, the weighted subtraction processing unit 64 performs weighted subtraction processing on the first radiation image information S ₁ and the second radiation image information S ₂ to obtain a radiation image (energy sub image Sd) of energy sub imaging. The energy sub image display unit 66 displays the obtained energy sub image Sd on the monitor 24.

  As described above, in the radiation imaging system 10 according to the present embodiment, the first tube voltage V1 for energy sub imaging is automatically calculated based on the actual values from the patient information and the imaging conditions. Therefore, it is not necessary to obtain the first tube voltage V1 by trial and error, and the time required for energy sub imaging can be greatly reduced. In addition, since the first tube voltage V1 for energy sub imaging is calculated based on the actual value in normal imaging, the image quality of the radiation image obtained by normal imaging and the radiation image obtained by energy sub imaging is the same level. The necessary medical information can be obtained. This leads to easier interpretation and diagnosis.

  In the above-described example, an example of referring to all of the tube-based actual value table 80A, the patient-specific actual value table 80B, the engineer-specific actual value table 80C, and the doctor-specific actual value table 80D has been shown. A value table may be referred to or a combination of two or more actual value tables may be referred to.

  In the above-described example, the radiation detector 18 uses a method (direct conversion method) in which incident radiation is directly converted into an electric signal by the photoelectric conversion layer 51. Instead, the incident radiation is converted by a scintillator. Once converted into visible light, a radiation detector that converts the visible light into an electrical signal using a solid state detection element such as amorphous silicon (a-Si) may be used (indirect conversion method: Patent No. 1). 3494683).

  Furthermore, radiation image information can also be acquired using a light readout type radiation detector. In this optical readout type radiation detector, when radiation is incident on the solid detection elements arranged in a matrix, an electrostatic latent image corresponding to the dose is accumulated and recorded on the solid detection elements. When reading the electrostatic latent image, the radiation detector is irradiated with reading light, and the value of the generated current is acquired as radiation image information. After the radiation image information is read, the radiation image information, which is a remaining electrostatic latent image, can be erased and reused by irradiating the radiation detector with erasing light (Japanese Patent Laid-Open No. 2000-105297). See the official gazette).

  In the radiation detector 18 described above, an example in which the TFT 52 is used has been described. Alternatively, the radiation detector 18 may be implemented in combination with another imaging element such as a CMOS (Complementary Metal-Oxide Semiconductor) image sensor. Furthermore, it can be replaced by a CCD (Charge-Coupled Device) image sensor that transfers charges while shifting the charges by a shift pulse corresponding to the gate signal referred to in the TFT 52.

  Moreover, although the case where the subject is a human is shown as an example in the above-described example, it may be applied to nondestructive inspection for industrial use.

  The image display system, the recording medium, the program, and the image display method according to the present invention are not limited to the above-described embodiments, and various configurations can be adopted without departing from the gist of the present invention. .

It is a block diagram which shows the structure of the radiography system which concerns on this Embodiment. It is a block diagram which shows the circuit structure of a radiation detector. FIG. 3A is an explanatory view showing a state in which the first type radiation detection apparatus is irradiated with the first radiation (low energy), and FIG. 3B shows the second type radiation (high energy) with respect to the first type radiation detection apparatus. It is explanatory drawing which shows the state which irradiated. It is a functional block diagram which shows the structure of an image process part. It is a functional block diagram which shows the structure of a tube voltage setting part. It is explanatory drawing which shows the breakdown of the performance value table classified by pipe. It is explanatory drawing which shows the breakdown of the results value table classified by patient. It is explanatory drawing which shows the breakdown of the performance value table classified by engineer. It is explanatory drawing which shows the breakdown of the performance value table classified by doctor. It is explanatory drawing which shows the breakdown of a default table. It is explanatory drawing which shows the breakdown of a voltage difference table. It is explanatory drawing which shows the breakdown of a priority table. It is explanatory drawing which shows the state by which all the items (identification code) were designated and the 1st tube voltage and the 2nd tube voltage were displayed. It is explanatory drawing which shows the example of a display of the state which the information regarding a doctor is undesignated.

Explanation of symbols

10 ... Radiography system 12 ... Subject (patient)
14 ... Radiation source 16 ... Tube voltage setting unit 17 ... Radiation source control unit 18 ... Radiation detector 20 ... Radiation detection device 22 ... Image processing unit 24 ... Monitor 28 ... Input device 30 ... Console 70 ... Data memory 72 ... Tube voltage calculation Unit 74 ... Tube voltage output unit 80 ... Actual value table 80A ... Actual value table for each tube 80B ... Actual value table for each patient 80C ... Actual value table for each technician 80D ... Actual value table for each doctor 82 ... Default table 84 ... Voltage difference table 86 ... priority table

Claims (10)

At least two types of radiation image information are acquired by irradiating a subject with radiation having energy distribution for normal imaging and radiation having energy distribution for energy subtraction imaging, and weighting is performed between each radiation image information. A radiography system that performs subtraction processing above to obtain a normal captured image and an extracted image of a specific object,
A storage unit that stores the actual value of each imaging region of the tube voltage supplied to the radiation source during normal imaging,
The actual value of the same imaging part as the imaging part in the energy subtraction imaging is read from the actual value for each imaging part, and the tube voltage supplied to the radiation source at the time of the energy subtraction imaging is based on the read actual value. A tube voltage calculation unit to calculate,
And the tube voltage calculating the actual value read in part, have a radiation source control unit for irradiation with respect to the subject based on the calculated the tube voltage,
The tube voltage calculation unit
A radiation imaging system , wherein when there are two or more types of actual values of the same imaging region as the imaging region in the energy subtraction imaging, one actual value is selected and read according to a preset priority . The radiation imaging system according to claim 1 ,
The tube voltage calculation unit
In selecting one achievement value from the two or more kinds of achievement values,
A radiography system that performs a display prompting the designation of specific information with high priority when specific information with low priority is designated and specific information with high priority is not designated. The radiation imaging system according to claim 1 or 2 ,
The tube voltage calculation unit
When there is no actual value corresponding to the imaging region in the energy subtraction imaging in the actual value for each imaging region, a preset voltage value corresponding to the imaging region is read as the actual value, and based on the actual value And calculating a tube voltage supplied to the radiation source during the energy subtraction imaging. In the radiography system of any one of Claims 1-3,
A radiation imaging system comprising input means for inputting information relating to an imaging region in energy subtraction imaging before imaging. In the radiography system of any one of Claims 1-4 ,
The actual value stored for each imaging region stored in the storage unit is further stored in association with at least identification information for specifying a radiation source used during the normal imaging. . In the radiography system of any one of Claims 1-5 ,
The radiographic imaging system, wherein the actual value for each imaging region stored in the storage unit is further stored in association with at least identification information for identifying a subject imaged during the normal imaging. In the radiography system of any one of Claims 1-6 ,
The radiographic imaging system, wherein the actual value for each imaging region stored in the storage unit is further stored in association with at least identification information for identifying a person engaged in normal imaging. The radiation imaging system according to claim 5 , wherein
The actual value corresponding to the same imaging region and radiation source as the imaging region and radiation source in the energy subtraction imaging is read out from the actual value for each imaging region, and the energy subtraction is based on the read actual value. A radiation imaging system that calculates a tube voltage supplied to a radiation source during imaging. The radiographic system according to claim 6 .
The actual value corresponding to the imaging region and subject that is at least the same as the imaging region and subject in the energy subtraction imaging is read from the actual value for each imaging region, and the energy subtraction imaging is performed based on the read actual value. A radiation imaging system characterized by calculating a tube voltage supplied to a radiation source. The radiation imaging system according to claim 7 ,
From the actual value for each imaging region, at least the actual value corresponding to the imaging region and the worker as the imaging region and the worker in the energy subtraction imaging is read out, and based on the read actual value, the energy subtraction A radiation imaging system that calculates a tube voltage supplied to a radiation source during imaging.

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