JP2005243469A - Radiographic device and radiographic system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radiographic device and a radiographic system taking images by decreasing waiting time. <P>SOLUTION: In a step S205, the temperature of an X-ray tube during scan is estimated and an optimization parameter such as cooling time or tube voltage is optimized by a optimization means. If the optimization parameter still exceeds an appropriate value, a control processing device changes an allowable temperature T0 to a higher allowable temperature T1 using a display and an operation device in steps S221 and 222 and re-optimizes it to fall within the allowable temperature T1. Thus, for example, when the cooling time which is waiting time is long even in an emergency, there is no waiting time or it is made shorter if any so that a scan is immediately performed with the scanning parameters required by an operator. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an X-ray imaging apparatus and an X-ray imaging system that control heat generation of an X-ray tube.

  In recent years, the spread of X-ray imaging apparatuses such as an X-ray CT apparatus makes imaging using these apparatuses routine, and has led to a significant increase in the frequency of use. Among them, in these medical devices, opportunities for performing emergency imaging when a subject is urgently brought in are steadily increasing.

Under such circumstances, the output of the X-ray tube is increased to improve the imaging efficiency. In this method, since the heat generation amount of the X-ray tube increases more than before, the heat generation amount of the X-ray tube is predicted in advance, and the control parameters of the X-ray tube are controlled so as to be within the limits. (For example, see Patent Document 1). Here, the allowable value of the control parameter is set with a margin by taking into account the X-ray tube life deterioration when high output is frequently used.
JP-A-2001-231775, (pages 2 to 3, FIGS. 6 and 7)

  However, according to the background art described above, in an emergency, there may be a case where a waiting time occurs or imaging cannot be performed under a desired condition. That is, when the frequency of use is originally high, the heat generation amount of the X-ray tube is close to the limit, and a waiting time for cooling is generated even in an emergency. Alternatively, it is necessary to change the control parameters of the X-ray tube to those that generate less heat different from the desired conditions.

  In particular, for a user who frequently uses the X-ray imaging apparatus, a waiting time for cooling the X-ray tube occurs even in a normal routine inspection. This waiting time not only lowers the imaging efficiency but is not preferable for the subject to be imaged.

  From these facts, for users who use frequently, how to realize an X-ray imaging apparatus and an X-ray imaging system that perform imaging while reducing waiting time even if the exchange frequency of replaceable X-ray tubes is increased. Is more important.

  The present invention has been made to solve the above-described problems caused by the background art, and an object thereof is to provide an X-ray imaging apparatus and an X-ray imaging system that perform imaging while reducing waiting time.

  In order to solve the above-described problems and achieve the object, an X-ray imaging apparatus according to a first aspect of the invention includes an X-ray tube that generates an X-ray beam and an X-ray detector that detects the X-ray beam. A data acquisition unit that controls the X-ray tube and the X-ray detector that are arranged opposite to each other with the subject interposed therebetween, and heat generation of the X-ray tube during the imaging An estimation means for estimating a quantity, a control processing device for optimizing a control parameter for controlling the X-ray tube at the time of imaging so that the estimated value of the calorific value does not exceed an allowable value, and the allowable value Changing means for changing the value.

  In the invention according to the first aspect, an X-ray beam is generated by an X-ray tube, an X-ray beam is detected by an X-ray detector, and an X-ray tube and an X-ray tube arranged opposite to each other with a subject sandwiched by a data acquisition unit The X-ray tube at the time of imaging is estimated by the estimation processing unit, and the control parameter for controlling the X-ray tube at the time of imaging is estimated by the control means. The estimated value of the calorific value is optimized so as not to exceed the allowable value, and the allowable value is changed by the operator or maintenance worker using the changing means.

An X-ray imaging apparatus according to the second aspect of the invention is an X-ray CT apparatus.
In the invention of the second aspect, a tomographic image is acquired.
The X-ray imaging apparatus according to the invention of the third aspect is characterized in that the heat generation amount uses the temperature of the X-ray tube as an index.
In the third aspect of the invention, the calorific value is based on the temperature of the X-ray tube.

The X-ray imaging apparatus according to the invention of a fourth aspect is characterized in that the imaging is prevented beforehand by the control processing device when the amount of heat generation exceeds the allowable value.
In the fourth aspect of the invention, the control processing device prevents imaging when the heat generation amount exceeds the allowable value.

The X-ray imaging apparatus according to the fifth aspect of the invention is characterized in that the control parameter includes at least one of a tube current and a tube voltage supplied to the X-ray tube.
In the fifth aspect of the invention, the control parameter includes at least one of a tube current and a tube voltage supplied to the X-ray tube.

  The X-ray imaging apparatus according to the invention of the sixth aspect is characterized in that the control parameter includes a cooling time of the tube current that is intermittently passed, which is a time during which the tube current is not passed.

In the invention of the sixth aspect, the control parameter includes a cooling time which is a time during which the tube current is not passed.
In the X-ray imaging apparatus according to the seventh aspect of the invention, the changing unit includes an on / off emergency setting unit, and the allowable value is set as a standard setting value when the emergency setting unit is off. When the emergency setting means is turned on, the emergency setting value exceeds the standard setting value.

In the seventh aspect of the invention, the changing means sets the allowable value as a standard setting value when the emergency setting means is off, and an emergency setting value that exceeds the standard setting value when the emergency setting means is on.
The X-ray imaging apparatus according to the invention of the eighth aspect is characterized in that the changing unit includes a switching unit that switches the allowable value stepwise in accordance with the use frequency of the operator.

In the eighth aspect of the invention, the changing means switches the allowable value step by step by the switching means.
The X-ray imaging apparatus according to a ninth aspect of the invention is characterized in that the changing means includes variable means for continuously changing the allowable value in accordance with the imaging frequency of an operator.

In the ninth aspect of the invention, the changing means continuously changes the allowable value by the variable means.
An X-ray imaging system according to a tenth aspect of the present invention is an X-ray tube that generates an X-ray beam, an X-ray detector that detects the X-ray beam, and the oppositely arranged with a subject interposed therebetween. A data acquisition unit that controls the X-ray tube and the X-ray detector to image the subject, an estimation unit that estimates the amount of heat generated by the X-ray tube during the imaging, and the imaging A control processing device for optimizing the control parameters for controlling the X-ray tube so that the estimated value of the heat generation amount does not exceed the allowable value, and a change for changing the allowable value via a general-purpose communication line And means.

  According to the tenth aspect of the invention, an X-ray beam is generated by an X-ray tube, an X-ray beam is detected by an X-ray detector, and an X-ray tube and an X-ray tube are arranged to face each other with a subject sandwiched by a data acquisition unit. The control parameters for controlling the X-ray tube at the time of imaging by controlling the X-ray tube at the time of imaging by estimating the heat generation amount of the X-ray tube at the time of imaging by the estimation means by controlling the line detector Then, the estimated value of the calorific value is optimized so as not to exceed the allowable value, and the allowable value is changed by changing means via a general-purpose communication line.

  As described above, according to the present invention, the X-ray beam is generated by the X-ray tube, the X-ray beam is detected by the X-ray detector, and the X-ray is disposed opposite to the subject with the data acquisition unit interposed therebetween. The subject is imaged by controlling the tube and the X-ray detector, the heat generation amount of the X-ray tube at the time of imaging is estimated by the estimating means, and the X-ray tube at the time of imaging is controlled by the control processing device. The control parameter is optimized so that the estimated value of the heat generation does not exceed the allowable value, and the allowable value is changed within the allowable X-ray tube replacement frequency by the operator or maintenance worker using the changing means. So, if there is a waiting time for cooling the X-ray tube in emergency or high-frequency imaging, change the allowable value to a high value within the range that does not cause X-ray tube failure, and eliminate the waiting time? Or it can be short and the imaging effect As well as improved, thereby reducing the load to a subject by a reduction in latency.

Exemplary embodiments of an X-ray imaging apparatus and an X-ray imaging system according to the present invention will be described below with reference to the accompanying drawings. Note that the present invention is not limited thereby.
(Embodiment 1)
First, the overall configuration of the X-ray CT apparatus 1 which is an example of the X-ray imaging apparatus according to the first embodiment will be described. FIG. 1 shows a block diagram of the X-ray CT apparatus 1. As shown in FIG. 1, the apparatus includes a scanning gantry 2, an operation console 6, and a high voltage generator 10.

  The scanning gantry 2 has an X-ray tube 20. The X-ray tube 20 forms a heat generating portion, and an X-ray (not shown) emitted from the X-ray tube 20 is shaped by a collimator so as to be, for example, a cone-shaped X-ray beam (beam). The X-ray detector 24 is irradiated.

  The high voltage generator 10 is a voltage generator that supplies a high voltage to the X-ray tube 20. Here, the X-ray tube 20 has a voltage of approximately 120 to 140 kV and a power of 8 to 9 HU (heat unit) is supplied from the high voltage generator 10.

  The X-ray detector 24 has a plurality of X-ray detection elements arranged two-dimensionally in the spreading direction of the cone-shaped X-ray beam. The X-ray detector 24 is a multi-channel detector in which a plurality of X-ray detection elements are arranged in an array.

  The X-ray detector 24 as a whole forms an X-ray incident surface curved in a cylindrical concave shape. The X-ray detector 24 is composed of, for example, a combination of a scintillator and a photodiode. However, the present invention is not limited to this. For example, a semiconductor X-ray detection element using cadmium tellurium (CdTe) or an ionization chamber type X-ray detection element using Xe gas (gas) may be used. The X-ray tube 20, the collimator, and the X-ray detector 24 constitute an X-ray irradiation / detection device.

  The X-ray detector 24 is connected to a data collection unit 26. The data collection unit 26 images detection data of individual X-ray detection elements of the X-ray detector 24. X-ray irradiation from the X-ray tube 20 is controlled by an X-ray controller 28. The illustration of the connection between the X-ray tube 20 and the X-ray controller 28 and the connection between the X-ray controller 28 and the high voltage generator 10 are omitted.

  The above components from the X-ray tube 20 to the X-ray controller 28 are mounted on the rotating unit 34 of the scanning gantry 2. Here, the subject or phantom is placed on a cradle in a bore 29 located at the center of the rotating unit 34. The rotator 34 rotates while being controlled by the rotation controller 36, bombards X-rays from the X-ray tube 20, and transmits X-rays of the subject and the phantom in the X-ray detector 24 for each view (view). Detect as projection data. The connection relationship between the rotation unit 34 and the rotation controller 36 is also omitted from the illustration.

  The operation console 6 has a control processing device 60. The control processing device 60 is configured by, for example, a computer. A control interface (interface) 62 is connected to the control processing device 60. Further, the scanning gantry 2 is connected to the control interface 62. Here, the control processing device 60 controls the scanning gantry 2 through the control interface 62.

  The data acquisition unit 26, the X-ray controller 28, and the rotation controller 36 in the scanning gantry 2 are controlled through a control interface 62. Note that illustration of individual connections between these units and the control interface 62 is omitted.

  A display device 68 and an operation device 70 are connected to the control processing device 60. Here, the control processing device 60, the display device 68, and the operation device 70 constitute an allowable temperature changing means to be described later. The display device 68 displays tomographic image information and other information output from the control processing device 60. The operation device 70 is operated by an operator, and scan parameters, various instructions and information, and an allowable temperature, which is an allowable value described later, are used by using a keyboard or a mouse. To the control processing device 60. The operator operates the apparatus interactively using the display device 68 and the operation device 70.

  Here, the control processing device 60 generates a control parameter for controlling the scanning gantry 2 and the high voltage generator 10 from the scanning parameter input by the operator. This control parameter is transmitted to each part of the scanning gantry 2 via the control interface 62, and imaging, that is, scanning is performed. Note that the control processing device 60 includes an estimation unit that estimates overheating of the X-ray tube 20 and an optimization unit that optimizes the control parameter when generating the control parameter.

  The control processing device 60 is connected to a data imaging buffer (buffer) 64. The data imaging buffer 64 is connected to the data collection unit 26 of the scanning gantry 2, and inputs projection data captured by the data collection unit 26 to the control processing device 60.

  The control processing device 60 performs image reconstruction using a transmission X-ray signal imaged through the data imaging buffer 64, that is, projection data. A storage device 66 is also connected to the control processing device 60. The storage device 66 stores projection data imaged in the data imaging buffer 64, reconstructed tomographic image information, a program (program) for realizing the functions of this device, and the like.

  Next, the operation of the control processing device 60 will be described. FIG. 2 is a flowchart showing the operation of the control processing device 60 according to the present invention. First, the operator sets scan parameters from the operation device 70 (step S201). In setting the scan parameters, settings such as a scan range, the number of slices, a slice thickness, a scan mode, and a matrix size (matrix size) at the time of image reconstruction are performed.

  Thereafter, the control processing device 60 calculates a control parameter from the set scan parameter (step S202). In this calculation, control parameters for controlling the scanning gantry, particularly parameters such as an X-ray tube voltage, an X-ray tube current, a scan time, a tube cooling time, and the number of irradiations are calculated.

Thereafter, the control processing device 60 estimates the temperature T of the X-ray tube 20 from the control parameters (step S205). Here, for example, the temperature of the rotating anode of the X-ray tube 20 is estimated from the control parameters such as tube voltage, tube current, scan time, and cooling time. That is,
T = f (tube current, tube voltage, scan time, cooling time, ...)
It is determined by the function form of

  Thereafter, the control processing device 60 compares the temperature of the X-ray tube 20 estimated in step S205 with an allowable temperature T0 that does not cause overheating (step S206). The permissible temperature, which is the permissible value, is read in advance by the control processing device 60 and is unique to the X-ray tube 20. The permissible temperature of each part constituting the X-ray tube 20, and further, the comprehensive X-ray tube It is a value determined in consideration of a life with a margin of 20 or the like. The maximum allowable temperature Tmax is determined from the shortest allowable life of the X-ray tube.

  Thereafter, the control processing device 60 determines whether or not the temperature T exceeds the allowable temperature T0 (step S207). If T ≦ T0 and the allowable temperature T0 is not exceeded (Yes at step S207), the process proceeds to step S212 to be described later, and the scan is performed as it is.

  If T> T0 and the allowable temperature T0 is exceeded (No at step S207), it is determined that the allowable temperature T0 has been exceeded, and scan impossibility is displayed on the display device 68 (step S208). Then, the operator determines whether or not to optimize the control parameter using the optimization unit of the control processing device 60 (step S209). Here, when the optimization is not performed (No at Step S209), the process proceeds to Step S201, and the scan parameter is set again.

  Further, when performing the optimization (Yes at Step S209), the control processing device 60 performs an optimization process using the optimization means (Step S210). In this optimization processing, the value of the control parameter is changed, and both the X-ray tube and the high-voltage generator 10 search for the maximum control parameter value that is lower than the allowable temperature, and display the result on the display device 68.

  FIG. 3 is a flowchart showing the operation of the optimization process in step S210. The operation of the optimization process will be described with reference to FIG. In this optimization process, an example using a binary search is shown. First, the operator selects a control parameter P for optimization using the operation device 70 from the control parameters (step S301). For example, a tube current is selected as the optimization parameter P. Then, in the variable range of the control parameter P, the maximum value is maxP, the minimum value is minP, maxP is substituted for the variable PH, and minP is substituted for the variable PL (step S302). Here, the variables PH and PL are successively reduced so that the variable region sandwiched between PH and PL always includes the optimum value, and finally becomes a value approximated to the optimum value. When optimization is performed using tube current as an optimization parameter, maxP is the maximum tube current output from the high voltage generator 10, and minP is the minimum tube current output from the high voltage generator 10. Become.

  Thereafter, the optimization unit substitutes (PH + PL) / 2, which is an intermediate value between PH and PL, for the variable PM (step S303). Then, using this intermediate value PM, temperatures T of X-ray tube 20 and high voltage generator 10 are estimated using functions f and g used in steps S203 and 205 of FIG. 2 (step S304).

  Thereafter, the optimization unit determines whether all the estimated temperatures T are within the allowable temperature T0 that is the upper limit of the allowable range (step S305). If the temperature exceeds the allowable temperature (Yes at Step S305), the value of the variable PM is substituted into the variable PH as a new maximum value (Step S307). If the temperature does not exceed the allowable temperature (No at Step S305), the value of the variable PM is substituted into the variable PL as a new minimum value (Step S306).

  Thereafter, the optimization unit substitutes PH-PL for the difference ΔP between the variable PM and the variable PL (step S308), and determines whether ΔP exceeds the set minimum resolution R (step S309). Here, when the optimization parameter is the tube current, the minimum resolution R is determined from the minimum setting range of the tube current output from the high voltage generator 10 or the minimum resolution of the X-ray output energy. If ΔP exceeds the set minimum resolution R (Yes at step S309), the process proceeds to step S303, and the processes of steps S303 to S308 are performed. This process is repeated until ΔP becomes equal to or less than the minimum resolution R.

  FIG. 4 schematically shows a process of repeatedly performing steps S303 to S308 to obtain an optimum value. FIG. 4 illustrates processes 1 to 5 for obtaining an optimum value for the optimization parameter P. In the process 1, the initial setting is performed, and the case where the temperature T when the value of the optimization parameter PM is used satisfies T> T0. Therefore, in process 2, PM becomes a new PH and the same processing is performed. One process corresponding to steps S303 to S308 is sequentially repeated, and the difference ΔP between the variable PM and the variable PL is halved for each process, and the existence range of the optimum value is gradually limited.

  Thereafter, returning to FIG. 3, if ΔP does not exceed the set minimum resolution R (No at Step S309), the optimization unit repeats Steps S303 to S308 further and makes ΔP small, meaningless. Therefore, the value of the variable PH or variable PL is substituted for the value of the optimization variable P (step S310), and the value of the optimization variable P is displayed on the display device 68 (step S311).

  Moreover, although the example which optimizes the tube current of the X-ray tube 20 was shown in FIG.3 and FIG.4, tube voltage can also be made into an optimization parameter similarly, and also the cooling time of the X-ray tube 20 is optimized. It can also be a parameter. As shown in FIG. 5, the cooling time is a time during which no tube current flows, and as shown in FIG. 5B, the tube current flowing through the X-ray tube 20 shown in FIG. Therefore, the temperature of the X-ray tube 20 goes up and down. Here, by setting the cooling time to be long, the X-ray tube 20 can be cooled and maintained within the allowable temperature, while the waiting time becomes long and the imaging efficiency is lowered and the mental load on the subject is increased. To do. Note that, if the cooling time is lengthened, the temperature becomes lower, and therefore the processes in steps S306 and S307 are interchanged in the flowchart of FIG.

  Thereafter, returning to FIG. 2, the operator determines whether or not the value of the control parameter, which is the value of the optimization parameter P to be displayed, is valid (Step S211). It is determined whether the scan is urgent (step S221). For example, it is determined whether the cooling time is too long in light of the urgency of this scan. If it is urgent (Yes at Step S221), the allowable temperature T0 is changed (Step S222). Here, for example, a screen as shown in FIG. 6 is displayed on the display device 68. From this screen, high power is set using the cursor of the operation device 70 or the like. Thereby, the allowable temperature T1 (T1 ≦ Tmax) higher than the allowable temperature T0 is reset. Note that the standard power is selected as the initial setting.

  Thereafter, the control processing device 60 makes a positive determination in step S209 and performs the optimization process again. In step S210, an optimization process using a high allowable temperature T1 is performed to obtain a control parameter value. As a result, the optimized control parameter value becomes a value within a reasonable range or a value that approximates even a value outside the range.

  Thereafter, when the displayed control parameter value, which is the value of the optimization variable P, is valid (Yes at Step S211), the operator performs scanning (Step S212), acquires projection data, and performs this processing. finish.

  As described above, in the present embodiment, the temperature during the scanning of the X-ray tube 20 is estimated, and the optimization parameter such as the cooling time or the tube voltage is optimized by the optimization unit, and then the optimization parameter is determined. When the value exceeds a reasonable value, the allowable temperature T0 is changed to a high allowable temperature T1 (T1 ≦ Tmax), and the optimization is performed again so that the allowable temperature T1 falls within the allowable temperature T1. When the cooling time is long, it is assumed that there is no waiting time or even a short waiting time, and scanning with the scanning parameters desired by the operator can be performed quickly.

In the present embodiment, the temperatures of the X-ray tube 20 and the high voltage generator 10 are controlled. However, it is also possible to perform control using the accumulated heat amount or other physical amount related to heat generation in exactly the same manner. .
(Embodiment 2)
In the first embodiment, the allowable temperature T0 is changed to a higher allowable temperature T1 in an emergency, but may be changed according to the number of routine inspections. Therefore, the second embodiment shows a case where the number of routine inspections is changed according to the number of routine inspections.

  7 and 8 are examples of power mode setting screens of the X-ray tube 20 displayed on the display device 68 according to the second embodiment. FIG. 7 is an example of a power mode setting screen in which the allowable temperature is divided in stages, and is an example divided into three stages of high power, medium power, and low power. Here, permissible temperatures TH, TM, and TL, which are permissible values, are set according to the selection of high power, medium power, and low power. The allowable temperatures TH, TM, and TL are in a relationship of Tmax> TH> TM> TL.

  FIG. 8 is an example of a power mode setting screen in which the allowable temperature is continuously changed. By moving the cursor in FIG. 8, allowable temperatures TH to TL that change continuously from high power to low power according to the cursor position are set.

  FIG. 9 is a flowchart showing the operation of the control processing device 60 according to the second embodiment. The operations in steps S201 to S212 are the same as those shown in FIG. 2 except that steps S221 and 222 are omitted. Therefore, detailed description thereof is omitted here.

  In FIG. 9, the operator first selects a power mode (step S200). This selection is made on the selection screen shown in FIG. The user of the X-ray CT apparatus 1 is classified into several types according to the frequency of use of the apparatus based on experience. For example, it is a heavy user (heavy user) that is very frequently used, a light user (light user) that is not frequently used, and the like.

  Here, in the case of a heavy user, the operator sets the cursor at a position close to high power on the selection screen shown in FIG. 7 or on the selection screen shown in FIG. Further, in the case of a light user, the operator sets a cursor at a position close to low power on the selection screen shown in FIG. 7 or on the selection screen shown in FIG. Thereby, the allowable temperature according to the usage frequency is set in the control processing device 60.

Thereafter, the control processing device 60 performs each process of steps S201 to S212 based on the set allowable temperature.
As described above, in the second embodiment, the operator selects a power mode at the beginning of setting, determines whether scanning is impossible using an allowable temperature corresponding to the selected power, and is optimized. Since processing is also performed, scanning can be performed using scan parameters suitable for a heavy user or a light user, and in particular, in the case of a heavy user, the waiting time due to the cooling time can be reduced.
(Embodiment 3)
In the second embodiment, the operator changes the setting of the allowable temperature. However, the contract fee for the maintenance service between the hospital and the manufacturer that uses the X-ray CT apparatus 1 includes the replacement cost of the X-ray tube 20. In some cases, the setting change by the operator is not preferable. Therefore, in the third embodiment, a case where the setting of the allowable temperature is changed from the operation console connected to the outside of the hospital will be shown.

  FIG. 10 is a diagram illustrating an overall configuration of an X-ray imaging system according to the third embodiment. The operation console 7 of the X-ray CT apparatus 1 is connected to the operation console 8 via a communication line 9 such as a telephone line. The operation console 7 is obtained by adding a communication interface 65 to the operation console 6. In FIG. 10, illustration is omitted except for the control processing device 60 and the communication interface 65. The communication interface 65 reads information from the operation console 8 into the control processing device 60. Here, in the case of an analog telephone line, the communication interface 65 includes a modem, a transmission control device, and the like.

  The operation console 8 is a means for changing the allowable temperature, and includes a CPU, a memory, a communication interface 65, and the like. However, the operation console 8 is not necessarily the same as the operation console 7, and a PC (Personal Computer) or the like can be used. Then, the operation console 8 changes the allowable temperature that is the allowable value of the X-ray tube 20 set in the control processing device 60.

  Here, the relationship between the allowable temperature and lifetime of the X-ray tube 20 will be described. When the allowable temperature is set high, the X-ray tube 20 is rapidly deteriorated, and as a result, the lifetime is shortened. Therefore, when the maintenance service fee including the replacement cost of the X-ray tube 20 is set, setting the allowable temperature high by the operator increases the replacement frequency of the X-ray tube 20 and maintenance on the manufacturer side. Service costs may increase.

  Next, the operation of the X-ray imaging system according to the third embodiment will be described. First, a maintenance contract including the replacement cost of the X-ray tube 20 is concluded between the hospital that purchases the X-ray CT apparatus 1 and the manufacturer that sells the X-ray CT apparatus 1. In this contract, for example, a heavy user with a high usage frequency or a light user with a low usage frequency is selected according to the usage frequency of the X-ray CT apparatus 1. In response to this selection, if the manufacturer is a heavy user, for example, the allowable temperature of the X-ray tube 20 is set high from the operation console 8 installed in the manufacturer. Set the allowable temperature low.

  The maintenance service contract fee is set high because the replacement frequency of the X-ray tube 20 is high for a heavy user, and is set low because the replacement frequency of the X-ray tube 20 is low for a light user. The This contract fee is calculated based on, for example, statistical measurement data of the allowable temperature and the replacement frequency of the X-ray tube 20.

  As described above, in the third embodiment, the manufacturer uses the operation console 8 based on the maintenance contract between the hospital that purchases the X-ray CT apparatus 1 and the manufacturer that sells the X-ray CT apparatus 1. Since the allowable temperature of the X-ray tube 20 of the X-ray CT apparatus 1 installed in the hospital is set, the manufacturer can set the allowable temperature and the usage frequency preferred by the user without causing an increase in maintenance service costs. A scan with a low waiting time can be performed.

It is a block diagram which shows the whole structure of a X-ray CT apparatus. 3 is a flowchart showing the operation of the first embodiment. It is a flowchart which shows the operation | movement of an optimization process. It is a figure which shows the binary search method in the case of an optimization process. It is a figure which shows the cooling time and allowable temperature of an X-ray tube. 6 is a diagram showing an emergency mode setting screen according to the first embodiment. FIG. FIG. 12 is a diagram showing a power mode setting screen according to the second embodiment (part 1); It is a figure which shows the setting screen of the power mode of Embodiment 2 (the 2). 10 is a flowchart showing the operation of the second embodiment. 6 is a block diagram illustrating an overall configuration of an X-ray imaging system according to Embodiment 3. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 X-ray CT apparatus 2 Scanning gantry 6, 7, 8 Operation console 9 Communication line 10 High voltage generator 20 X-ray tube 24 X-ray detector 26 Data acquisition part 28 X-ray controller 34 Rotation part 36 Rotation controller 60 Control processing apparatus 62 control interface 64 data imaging buffer 65 communication interface 66 storage device 68 display device 70 operation device

Claims (10)

An X-ray tube for generating an X-ray beam;
An X-ray detector for detecting the X-ray beam;
A data collection unit for imaging the subject by controlling the X-ray tube and the X-ray detector disposed opposite to each other with the subject interposed therebetween;
Estimating means for estimating the amount of heat generated by the X-ray tube during the imaging;
A control processing device that optimizes a control parameter for controlling the X-ray tube at the time of imaging so that the estimated value of the heat generation amount does not exceed an allowable value;
Changing means for changing the tolerance;
An X-ray imaging apparatus comprising:   The X-ray imaging apparatus according to claim 2, wherein the X-ray imaging apparatus is an X-ray CT apparatus.   The X-ray imaging apparatus according to claim 1, wherein the heat generation amount uses the temperature of the X-ray tube as an index.   The X-ray imaging apparatus according to claim 1, wherein the control processing apparatus prevents the imaging in advance when the amount of heat generation exceeds the allowable value.   The X-ray imaging apparatus according to claim 1, wherein the control parameter includes at least one of a tube current and a tube voltage supplied to the X-ray tube.   6. The X-ray imaging according to claim 1, wherein the control parameter includes a cooling time of the tube current that is intermittently passed, which is a time during which the tube current is not passed. apparatus.   The changing means includes an on / off emergency setting means, and the allowable value is set as a standard setting value when the emergency setting means is off, and an emergency setting exceeding the standard setting value when the emergency setting means is on. The X-ray imaging apparatus according to claim 1, wherein the X-ray imaging apparatus is a value.   The X-ray imaging apparatus according to claim 1, wherein the changing unit includes a switching unit that switches the allowable value in a stepwise manner according to an operator's use frequency.   The X-ray imaging apparatus according to claim 1, wherein the changing unit includes a variable unit that continuously varies the allowable value according to an imaging frequency of an operator. . An X-ray tube for generating an X-ray beam;
An X-ray detector for detecting the X-ray beam;
A data collection unit for imaging the subject by controlling the X-ray tube and the X-ray detector disposed opposite to each other with the subject interposed therebetween;
Estimating means for estimating the amount of heat generated by the X-ray tube during the imaging;
A control processing device that optimizes a control parameter for controlling the X-ray tube at the time of imaging so that the estimated value of the heat generation amount does not exceed an allowable value;
Changing means for changing the tolerance value via a general-purpose communication line;
An X-ray imaging system comprising:

Images