JP2006340910A - X-ray irradiation dose management device and x-ray image diagnostic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an X-ray irradiation dose management device capable of optimizing the irradiation dose to a subject, and an X-ray image diagnostic apparatus equipped with the same. <P>SOLUTION: The X-ray irradiation dose management device comprises an input part 202 for inputting subject information and X-ray examination information, a reference value determining part 213 for determining a reference value for the irradiation dose based on the subject information, an estimation part 215 for estimating the irradiation dose based on the X-ray examination information, a comparing part 216 for comparing the determined reference value with the estimated irradiation dose, and a warning display signal generating part 205 for generating a signal for the display of warning when the estimated irradiation dose exceeds the determined reference value. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an X-ray irradiation dose management apparatus that manages an irradiation dose of an examination using radiation using an X-ray computed tomography apparatus, an X-ray diagnostic apparatus, and the like, and an X-ray image diagnostic apparatus including the same.

  FIG. 8 shows a conventional inspection procedure. Basic information related to the subject and examination, such as age, weight, sex, patient name, examination type, examination management number, etc., is input. After entering the basic information, select an inspection site to be inspected, and further select an inspection protocol managed for each inspection purpose. The examination protocol is a set of many conditions required for the progress of a series of radiological examinations from imaging (shot, scan, data collection) to signal processing (image reconstruction) by a medical imaging apparatus. For example, in the case of an X-ray CT apparatus, parameters such as tube voltage, tube current, scan time (time required for one rotation), imaging slice thickness, number of imaging slices, scan pitch, total scan time, and the like are included. They are classified according to the inspection purpose. After selecting the examination protocol, the parameters are adjusted and changed according to the subject to be examined. Then, the scan is started by pressing the scan start button.

However, conventionally, when imaging is performed under a selected examination protocol or an examination protocol in which parameters are changed, it is not possible to confirm in advance whether the irradiation dose to the actual subject is within an appropriate range. Also, I did not know the direction of how to correct the parameters.
JP-A-5-68680

  The objective of this invention is providing the X-ray irradiation dose management apparatus which can optimize the irradiation dose with respect to a test object, and an X-ray image diagnostic apparatus provided with the same.

  In one aspect of the present invention, an X-ray irradiation dose management apparatus includes an input unit that inputs subject information and X-ray examination information, and a reference value determination that determines a reference value of an irradiation dose based on the subject information. A means for estimating an irradiation dose based on the X-ray examination information, a comparison unit for comparing the determined reference value and the estimated irradiation dose, and the estimated irradiation dose determined by the determination unit. A warning display signal generator for generating a warning display signal when the determined reference value is exceeded.

  According to the present invention, the reference value of the irradiation dose according to the subject can be determined, so that the irradiation dose can be optimized.

  Embodiments of an X-ray irradiation dose management apparatus according to the present invention will be described below with reference to the drawings. In addition, the X-ray irradiation dose management apparatus according to the present invention alone or in addition to the scan planning apparatus, X-rays such as an X-ray image diagnostic apparatus and an X-ray computed tomography apparatus that generate an X-ray plane image may be used. An X-ray generation unit (X-ray tube unit) that generates and an X-ray detector that detects X-rays that have passed through the subject are incorporated in a radiological medical device. Here, the X-ray irradiation dose management apparatus according to the present invention will be described as being incorporated in an X-ray computed tomography apparatus.

  FIG. 1 shows the configuration of an X-ray computed tomography apparatus incorporating an X-ray irradiation dose management apparatus according to this embodiment. The X-ray computed tomography apparatus has a gantry 100 configured to collect multidirectional projection data relating to a subject. The gantry 100 includes an X-ray tube 101 and a single slice type or multi-slice type X-ray detector 103 in which a plurality of X-ray detection elements are arranged in a single row or multiple rows. The X-ray tube 101 and the X-ray detector 103 are mounted on an annular rotating frame 102. The rotating frame 102 is driven to rotate about the Z axis by a gantry rotating mechanism 107. A central portion of the rotating frame 102 is opened, and a subject placed on a couchtop (not shown) is inserted into the opening. A tube voltage is applied between the cathode and anode of the X-ray tube 101 from the high voltage generator 109 via the slip ring 108, and the filament of the X-ray tube 101 is supplied from the high voltage generator 109 via the slip ring 108 to the filament. Current is supplied. X-rays are generated from the X-ray tube 101 by applying a tube voltage and supplying a filament current.

  A data acquisition device 104 generally called a DAS (data acquisition system) converts a signal output from the detector 103 for each channel into a voltage signal, amplifies it, and further converts it into a digital signal. This data (raw data) is sent to the pre-processing device 106 of the computer unit via a non-contact data transmission device 105 using light or magnetism. The pre-processing device 106 performs correction processing such as sensitivity correction on the raw data from the data collection device 104 and outputs projection data. The projection data is sent to and stored in the data storage device 112. The computer system includes a pre-processing device 106 and a data storage device 112, a system controller 110, an input device 115 including a keyboard and a mouse, a display 113, a reconstruction device 114, a scan planning device 116, and an irradiation dose management device 117. Is done. The reconstruction device 114 reconstructs tomographic image data from projection data.

  The scan planning device 116 is provided to assist an engineer in determining a scan plan (also referred to as an inspection plan or an imaging plan in other types of devices), and has a main function of providing an inspection protocol, and correcting and changing the protocol. It is said. FIG. 4 shows an example of a scan plan screen constructed by the scan plan apparatus 116. The scan plan screen includes patient information and a scanogram image, an imaging protocol selected or selected by the operator, parameters of an inspection protocol selected according to an inspection purpose, or parameters of an inspection protocol modified from the irradiation dose management device 117. The irradiation dose estimated from the reference value of the irradiation dose corresponding to the physique and the examination site of the provided subject, the selected examination protocol provided from the irradiation dose management device 117 or the parameter of the modified examination protocol is displayed. The As the irradiation dose, typically, “CTDI” (CT Dose Index) representing the irradiation dose determined by the US Food and Drug Administration is used, but is not limited thereto. OLP and the like are also handled as irradiation dose information. The parameters of the inspection protocol include a scan start position, a scan end position, a tube voltage “kV”, a tube current “mA”, a scan speed, the number of slices (number of used columns), a helical pitch, a slice thickness, and the like.

  FIG. 2 shows a configuration of the irradiation dose management apparatus 117 of FIG. The irradiation dose management device 117 includes an input / output unit 200. The input / output unit 200 includes an irradiation dose reference value mode change input unit 201, a target patient information input unit 202, a protocol data input unit 203, a protocol use access stop signal generation unit 204, a warning display signal generation unit 205, and a detailed information display signal generation. Part 206. The irradiation dose reference value mode change input unit 201 receives from the input device 115 a reference value mode change signal input by the operator via the input device 115. As reference value modes (types of reference values), ACR guideline, EC guideline, last month distribution value, six month distribution value, individual setting, and no setting options are prepared. The ACR guideline is a reference value for the radiation dose issued by the American College of Radiology. The EC guideline is a reference value of the irradiation amount issued from European EC. The last month distribution value is a reference value of an irradiation dose determined in accordance with a predetermined rule from irradiation dose data obtained by inspection for one month last month. The 6-month distribution value is a reference value of an irradiation dose determined according to a predetermined rule from irradiation dose data obtained in the past six months. The individual setting is a reference value set uniquely for the user site. If there is no setting, the reference value is not set.

  The target patient information input unit 202 inputs information on the subject (hereinafter referred to as subject information) from the scan planning device 116. The information about the subject typically includes age, weight, examination site, EP name, examination classification code, examination type, and the like. The protocol parameter input unit 203 inputs information related to the inspection planned by the scan planning apparatus 116 (hereinafter referred to as inspection information) from the scan planning apparatus 116. Information related to inspection typically includes inspection such as scan start position, scan end position, tube voltage “kV”, tube current “mA”, scan speed, number of slices (number of columns used), helical pitch, slice thickness, etc. Contains protocol items.

  In the protocol use access stop signal generation unit 204, the irradiation dose estimated from the examination information by the later-described predicted irradiation dose calculation unit 215 exceeds the reference value determined from the subject information by the irradiation reference value extraction unit 213 described later. When a signal indicating this is received from the comparison result determination unit 217 together with a signal indicating the action content corresponding to the excess, a protocol use access stop signal is generated according to the action content. Further, when the protocol use access stop signal generation unit 204 receives from the comparison result determination unit 217 a signal indicating that the irradiation dose estimated from the examination information is below the reference value determined from the subject information, Generates a usage access permission signal. The system controller 110 that has received the protocol use access stop signal rejects the instruction and stops the test start even if it receives an instruction to start the test from the input device 115. The system controller 110 that has received the protocol use access permission signal waits for the input of the inspection start instruction from the input device 115, and starts the inspection upon receiving the inspection start instruction.

  The warning display signal generation unit 205 confirms that the irradiation dose estimated from the examination information by the later-described predicted irradiation dose calculation unit 215 exceeds the reference value determined from the subject information by the irradiation reference value extraction unit 213 described later. When a signal indicating the action content corresponding to the excess is received from the comparison result determination unit 217, a signal for displaying a message warning the excess is generated according to the action content. When the irradiation dose estimated from the examination information approaches the reference value determined from the subject information, the warning display signal generation unit 205 indicates that, for example, it exceeds 95% of the reference value and is equal to or less than the reference value. When a signal representing the action content corresponding to the approach is received from the comparison result determination unit 217, a signal for displaying a message notifying the approach is generated. The warning result log data storage unit 219 is provided to store the generation of a signal for warning / notification display and the generation of a protocol use access stop signal as log information.

  The comparison unit 216 compares the irradiation dose estimated from the examination information by the predicted irradiation dose calculation unit 215 and the reference value determined from the subject information by the irradiation reference value extraction unit 213. When the irradiation dose estimated from the examination information is below the reference value determined from the subject information according to the comparison result of the comparison unit 216, the comparison result determination unit 217 displays a signal indicating the state as a protocol use access stop signal. This is supplied to the generator 204. According to the comparison result of the comparison unit 216, the comparison result determination unit 217 causes the irradiation dose estimated from the examination information by the predicted irradiation dose calculation unit 215 to exceed the reference value determined from the subject information by the irradiation reference value extraction unit 213. When there is, the signal indicating the excess is supplied to the protocol use access stop signal generating unit 204 and the warning display signal generating unit 205 together with the signal indicating the action content corresponding to the excess stored in the action content guide storage unit 218. To do. The action content corresponding to the fact that the irradiation dose estimated from the examination information by the predicted irradiation dose calculation unit 215 exceeds the reference value determined from the subject information by the irradiation reference value extraction unit 213 is, initially, For example, as described above, displaying a message for warning the excess and prohibiting the start of scanning can be arbitrarily changed.

  According to the comparison result of the comparison unit 216, the comparison result determination unit 217 causes the irradiation dose estimated from the examination information by the predicted irradiation dose calculation unit 215 to approach the reference value determined from the subject information by the irradiation reference value extraction unit 213. For example, when it exceeds 95% of the reference value and is equal to or less than the reference value, a signal indicating the approach is displayed together with a signal indicating the action content corresponding to the approach stored in the action content guide storage unit 218. To the warning display signal generator 205. The action content corresponding to the fact that the irradiation dose estimated from the examination information in the predicted irradiation dose calculation unit 215 is close to the reference value determined from the subject information in the irradiation reference value extraction unit 213 is, initially, For example, as described above, a message for notifying the approach is displayed, but can be arbitrarily changed.

  When the predicted irradiation dose calculation unit 215 performs an inspection using a plurality of parameters such as tube voltage, tube current, number of slices, slice thickness, etc. in the inspection protocol information input from the protocol parameter input unit 203 , For example, CTDIw. The estimated irradiation dose data is supplied to the comparison unit.

  The irradiation dose history record data storage unit 212 for each inspection stores, for example, data related to the inspection protocol and the corresponding irradiation dose for all inspections performed after the installation time. The inspection protocol and the corresponding radiation dose data are typically received from the scan planner 116. The reference value creation unit 211 creates a reference value for each weight, age, and examination site from the irradiation doses for all examinations within a specific period stored in the data storage unit 212. As a reference value, for example, a median value (median) when irradiation doses are arranged according to the value is set. The specific period is set to the last one month and the last six months. Therefore, as reference values, reference values are created for each body weight, age, and inspection site based on the latest one month's test results, and based on the latest six months' test results for each weight, age, and test site. Each value is created. The creation of the reference value is periodically repeated every month, for example. The created reference value data is stored in the reference value data storage unit 214. The reference value data storage unit 214 includes reference value data created from test results, reference values based on ACR guidelines, reference values based on EC guidelines, and reference values individually set by the user according to weight, age, and inspection site. It is remembered. The irradiation reference value extraction unit 213 is designated by the operator via the reference value mode (reference value type) designated by the operator via the reference value mode change input unit 201 and the reference value mode change input unit 201. And the reference value corresponding to the weight, age, or examination part of the subject information based on the distinction is extracted from the examination-specific irradiation dose history record data storage unit 212 and supplied to the comparison unit 216. To do.

  FIG. 3 shows an inspection procedure according to this embodiment. Under the support of the scan planning device 116, basic information related to the subject and examination, such as age, weight, sex, patient name, examination type, examination management number, is input via the input apparatus 115 (S1). . In addition, an examination site to be examined is selected via the input device 115 (S2). Furthermore, an appropriate inspection protocol is selected from a plurality of inspection protocol candidates provided from the scan planning device 116 according to the inspection site, inspection purpose, and the like (S3). The examination protocol is a set of many conditions required for the progress of a series of radiation examination operations from imaging (shot, scan, data acquisition) to signal processing (image reconstruction) by a medical imaging device, For example, in the case of an X-ray CT apparatus, parameters such as tube voltage, tube current, scan time (time required for one rotation), imaging slice thickness, number of imaging slices, scan pitch, total scan time, and the like are included. These parameters are arbitrarily changed and set via the input device 115 (S4).

  The comparison unit 216 of the irradiation dose management apparatus 117 compares the irradiation dose estimated by the predicted irradiation dose calculation unit 215 with the parameters set in S4 and the reference value determined from the subject information by the irradiation reference value extraction unit 213. (S5). In the irradiation reference value extraction unit 213, a reference value corresponding to a reference value mode (type of reference value) selectively specified via the reference value mode change input unit 201 on the reference value mode selection window illustrated in FIG. Is extracted from the examination-specific irradiation dose history data storage unit 212 and supplied to the comparison unit 216.

  When the irradiation dose estimated by the predicted irradiation dose calculation unit 215 exceeds the reference value, a warning is issued according to the signal indicating the excess from the comparison result determination unit 217 and the signal indicating the action content corresponding to the excess. The display signal generation unit 205 generates a signal for displaying a message window warning the excess illustrated in FIG. 5 on the scan plan screen of the display 113 (S6). When the irradiation dose estimated from the examination information exceeds, for example, 95% of the reference value determined from the subject information and is equal to or less than the reference value, the warning display signal generation unit 205 performs the approach illustrated in FIG. A signal for generating a notification message window in a superimposed manner on the scan plan screen of the display 113 is generated.

  When the “detailed information display” button on the window of FIGS. 4 and 5 is clicked, the detailed information display signal generation unit 206, as exemplified in FIG. 6, sets the parameters of the examination protocol corresponding to the reference value for each weight. Then, the test protocol parameters corresponding to the age-specific reference values, together with the parameters set in S4, are easily compared and displayed in a table format to generate a signal for display on the display 113 (S7). In many cases, the operator changes an arbitrary parameter to an arbitrary value on the detailed information display with reference to the inspection protocol parameter corresponding to the reference value. When the parameter is changed to an arbitrary value, the process returns to S5, where the comparison unit 216 of the irradiation dose management apparatus 117 recalculates the irradiation dose recalculated by the predicted irradiation dose calculation unit 215 with the parameter changed in S4, and the reference value. And compare again.

  In S5, when the irradiation dose estimated from the parameter of S4 does not exceed the reference value, or the irradiation dose estimated from the parameter of S4 via S7 exceeds 95% of the reference value Regardless, when the scan start confirmation button is clicked by the operator, a protocol use access permission signal is generated from the protocol use access stop signal generation unit 204. The system controller 110 that has received the protocol use access permission signal waits for the input of the scan start instruction when the scan button is pressed by the input device 115, and starts the inspection upon receiving the inspection start instruction (S8, S9).

  As described above, in the present embodiment, when an inspection protocol that predicts an irradiation dose that exceeds the reference value is selected or a parameter is set to such a value, a warning is generated. High irradiation dose inspection can be stopped in advance. It also suggests which parameter should be corrected to what value for the protocol that causes high irradiation irradiation, so it does not take time for the correction operation time.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

The figure which shows the structure of an X-ray computed tomography apparatus provided with the X-ray irradiation dose management apparatus which concerns on embodiment of this invention. The figure which shows the structure of the X-ray irradiation dose management apparatus of FIG. The figure which shows the test | inspection procedure by this embodiment. The figure which shows the warning display screen example of FIG. The figure which shows the other example of the warning display screen of FIG. The figure which shows the example of a detailed information display screen of FIG. The figure which shows the selection display screen example of threshold value mode in this embodiment. The figure which shows the conventional test | inspection procedure.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 100 ... Gantry, 101 ... X-ray tube, 102 ... Rotating frame, 103 ... X-ray detector, 104 ... Data acquisition device (DAS), 106 ... Pre-processing device, 107 ... Gantry rotation mechanism, 108 ... Slip ring, 109 ... High voltage generator, 110 ... system controller, 112 ... data storage device, 113 ... display, 114 ... reconstruction device, 115 ... input device, 116 ... scan planning device, 117 ... irradiation dose management device.

Claims (8)

An input unit for inputting subject information and X-ray examination information;
A reference value determining unit for determining a reference value of an irradiation dose based on the subject information;
Means for estimating an irradiation dose based on the X-ray examination information;
A comparison unit for comparing the determined reference value with the estimated irradiation dose;
An X-ray irradiation dose management apparatus, comprising: a warning display signal generation unit that generates a warning display signal when the estimated irradiation dose exceeds the determined reference value. The X-ray irradiation dose management apparatus according to claim 1, wherein the reference value determination unit has a function of determining a plurality of types of reference values. The X-ray irradiation dose management apparatus according to claim 1, wherein the reference value determination unit determines the reference value based on age and weight included in the subject information. 2. The X-ray according to claim 1, further comprising a prohibition signal generation unit that generates a signal for prohibiting the start of inspection when the estimated irradiation dose exceeds the determined reference value. Irradiation dose management device. 2. The imaging condition signal generating unit for generating a signal for displaying an imaging condition corresponding to the determined reference value and an imaging condition included in the X-ray examination information. X-ray irradiation dose management device. The X-ray irradiation dose management apparatus according to claim 1, further comprising a trunk portion that stores generation of a signal for warning display as log information. The X-ray irradiation dose management apparatus according to claim 4, further comprising a prosthetic unit that stores generation of a signal for prohibiting the start of the inspection as log information. X-ray generation means for generating X-rays;
X-ray detection means for detecting X-rays transmitted through the subject;
An X-ray irradiation dose management device for managing the X-ray irradiation dose;
The X-ray irradiation dose management device
An input unit for inputting subject information and X-ray examination information;
A reference value determining unit for determining a reference value of an irradiation dose based on the subject information;
Means for estimating an irradiation dose based on the X-ray examination information;
A comparison unit for comparing the determined reference value with the estimated irradiation dose;
An X-ray diagnostic imaging apparatus, comprising: a warning display signal generator that generates a warning display signal when the estimated irradiation dose exceeds the determined reference value.

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