JP4313866B2 - X-ray CT system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an imaging apparatus and imaging method suitable for use in, for example, an X-ray CT apparatus, an X-ray diagnostic apparatus, a nuclear magnetic resonance apparatus (MRI apparatus), a SPECT apparatus (Single Photon Emission Computed Tomograph), The present invention relates to a photographing apparatus that can easily change photographing conditions during photographing by dividing a photographing program into a plurality of photographing programs.
[0002]
[Prior art]
As conventional imaging apparatuses, an X-ray CT apparatus, an X-ray diagnostic apparatus, a nuclear magnetic resonance apparatus (MRI apparatus), a SPECT apparatus, and the like are known. These photographing apparatuses set an expert plan (EP) that is a photographing program in the form of a preset prior to photographing.
[0003]
For example, in an X-ray CT apparatus, when performing a scan from the lung field to the abdomen of a subject, a scan with a small X-dose is sufficient for the lung field, whereas a scan with a large X-dose is performed for the abdomen. Since it is necessary, an expert plan is set such that the first scan is performed with a small X-ray dose, and the second scan is performed with a large X-ray dose.
[0004]
FIG. 5 shows an example of an expert plan that is set when scanning from the lung field to the abdomen of the subject. In the example of FIG. 5, the scan method is set to be executed in the order of “S & V scan → S & S scan → helical scan”. In the case of “S & V scan”, the tube voltage is 100 kV, the tube current is 200 mA, The slice thickness is set to 5 mm, and the focus size is set to L size. In the case of “S & S scan”, the tube voltage is set to 120 kV, the tube current is set to 300 mA, the slice thickness is set to 3 mm, and the focus size is set to the L size. In the case of “helical scan”, the tube voltage is set to 135 kV, the tube voltage. The current is set to 500 mA, the slice thickness is set to 1 mm, and the focus size is set to S size.
[0005]
The “S & V scan” is a scanning method in which scanning and image reconstruction display are performed alternately, such as scanning again after an image is reconstructed and displayed after the scan is performed. This is a scanning method used when confirming the position or confirming whether or not the contrast medium has reached a desired site. “S & S scan” is a scan-prioritized scan method that continuously scans and reconstructs and displays an image following each scan. “Helical scan” is a method of placing a subject. In this scanning method, a subject is scanned in a spiral shape by moving the bed at a predetermined pitch to obtain a continuous tomographic image.
[0006]
All such expert plans are transferred to the gantry control system as a set of data when scanning is started. The gantry control system controls the gantry rotating unit based on the expert plan, and executes, for example, a scan from the lung field to the abdomen.
[0007]
Here, there is a case where it is desired to change a part (or all) of the set expert plan after the scan is started. In such a case, in the conventional X-ray CT apparatus, the scan is temporarily stopped, an expert plan is newly set, and all scans are performed again.
[0008]
[Problems to be solved by the invention]
However, if it is necessary to change the set expert plan after the scan starts, if the scan is canceled and all scans are performed again, all the images scanned before the cancellation are wasted, and the subject also Repeated exposure is not preferred. In contrast agent inspection, if scanning is stopped, a time loss may occur and scan timing may be lost.
[0009]
If the expert plan is changed after the scan is started, the input expert plan after the change is supplied to the gantry control system, and the currently set expert plan and the newly entered expert plan are input to the gantry control system. By detecting the difference with the changed expert plan and rewriting the expert plan in the gantry control system, and controlling the gantry rotating part based on this rewritten expert plan, the expert plan can be changed without stopping the scan. Although changes can be made, this is not practical because it requires a troublesome and large-scale configuration such as difference detection between old and new expert plans and rewriting control to new expert plans.
[0010]
The present invention has been made in view of the above-described problems, and can easily change an expert plan after the start of scanning. When a need to change an expert plan occurs after the start of scanning, An object of the present invention is to provide a photographing apparatus and a photographing method capable of preventing the inconvenience of canceling a scan and newly performing a whole scan again with the changed expert plan.
[0011]
[Means for Solving the Problems]
  In order to solve the above-mentioned problem, the present invention according to claim 1 is provided.X-ray CTThe deviceMultiple imaging ranges and multiple imaging conditions for different subjectsA series of shooting programs for each predetermined shooting unit,pluralSplit this into a split programpluralAccording to the split programContinuouslyAn imaging apparatus for performing imaging, wherein a program changing unit for changing the division program and imaging at the stage of execution of shooting by a division program that has been changed by the program changing unit after the start of imaging And a shooting control means for restarting shooting by the changed divided program after the change of the divided program is completed. According to the invention of claim 2X-ray CTThe deviceDefine multiple imaging ranges and multiple imaging conditions for one subjectA series of shooting programs is divided into a plurality of dividing programs for each predetermined shooting unit.pluralAccording to the split programContinuouslyAn imaging apparatus that performs imaging, and a program change unit for changing the division program, and when the program is changed by the program change unit after the start of imaging, the division during the program change And a shooting control unit that skips the program, executes shooting by the next divided program, and executes shooting by the changed divided program after the change of the divided program is completed.
[0012]
Accordingly, it is possible to divide and handle a series of photographing programs into a plurality of divided programs, and it is possible to change the program partially for each divided program.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of a photographing apparatus and a photographing method according to the present invention will be described in detail with reference to the drawings. The imaging apparatus and imaging method according to the present invention can be applied to an X-ray CT apparatus as shown in FIG.
[0018]
[Configuration of the embodiment]
As shown in FIG. 1, the X-ray CT apparatus of this embodiment includes a gantry rotating unit 1 that scans a tomographic image of a subject, and scanning conditions such as a scanning method, tube voltage, tube current, slice thickness, and focus size. It is possible to interact with the X-ray CT system by controlling the display unit 9 to display the operation unit 2 for inputting an expert plan, etc., and the message corresponding to the operation of the operation unit 2 and the numerical value of the expert plan. The dialogue control unit 3, the scan condition generation unit 4 that forms control data of each unit according to the expert plan set via the operation unit 2, and the frame according to the control data from the scan condition generation unit 4 And a scan control unit 5 that performs scan control of the rotation unit 1.
[0019]
In addition, this X-ray CT apparatus includes a data collection unit 6 that collects collected data corresponding to a tomographic image of a subject scanned by the gantry rotating unit 1, and a ramachandra, for example, for collected data from the data collection unit 6. A filter processing unit 7 that performs a filtering process using a convolution filter such as Ranchandran, and an image reconstruction unit that reconstructs a tomographic image using a filtered back projection method based on the collected data filtered by the filter processing unit 7 8 and the message formed by the dialogue control unit 3, the numerical value of the expert plan, and the tomographic image formed by the image reconstruction unit 8, for example, a cathode ray tube (CRT), a liquid crystal display unit (LCD), etc. Display section 9.
[0020]
The gantry rotating unit 1 has a gantry 13 at a substantially center of the gantry 13 to the extent that the subject placed on the bed 14 can pass through. An X-ray tube 11 and an X-ray detector 12 that rotate while maintaining a mutually opposing positional relationship are provided on the inner peripheral portion of the gantry 13. The subject placed on the bed 14 is exposed to X-rays, and a tomographic image is scanned by, for example, a helical scan.
[0021]
The operation unit 2 is connected to an input device such as a mouse device or a keyboard, and is provided with a start button 20 and a confirm button 21. The start button 20 is turned on to designate the start of scanning. The expert plan changed by turning on the confirm button 21 is approved.
[0022]
[Operation of the embodiment]
Next, the operation of the X-ray CT apparatus of the embodiment having such a configuration will be described.
[0023]
(A series of scanning operations based on the expert plan)
In the X-ray CT apparatus, an expert plan is set prior to scanning. The expert plan is set via the operation unit 2. For example, as shown in FIG. 2, the scan method, the tube voltage, the tube current, the slice thickness, the focus size, and the like are input. FIG. 2 shows an example of an expert plan that is set when, for example, a scan from the lung field to the abdomen of a subject is performed. The scan method is executed in the order of “S & V scan → S & S scan → helical scan”. Is set to In the case of “S & V scan”, the tube voltage is set to 100 kV, the tube current is set to 200 mA, the slice thickness is set to 5 mm, and the focus size is set to the L size. In the case of “S & S scan”, the tube voltage is set to 120 kV, the tube current is set to 300 mA, the slice thickness is set to 3 mm, and the focus size is set to the L size. In the case of “helical scan”, the tube voltage is set to 135 kV, the tube voltage. The current is set to 500 mA, the slice thickness is set to 1 mm, and the focus size is set to S size.
[0024]
The dialogue control unit 3 divides the series of expert plans input in this way into “elements (or boxes)” which are the minimum inspection units. Specifically, the dialogue control unit 3 converts the series of expert plans into an element for performing an “S & V scan” in which the tube voltage is 100 kV, the tube current is 200 mA, the slice thickness is 5 mm, and the focus size is L size, and the tube voltage. 120kV, tube current 300mA, slice thickness 3mm, focus size L size "S & S scan" element, tube voltage 135kV, tube current 500mA, slice thickness 1mm, focus size S size " For example, it is divided into elements for each scanning method, such as dividing into elements that perform “helical scanning”. For example, ID = 1 for an element that performs “S & V scan”, ID = 2 for an element that performs “S & S scan”, ID = 3 for an element that performs “helical scan”, etc. An identification number is added every time.
[0025]
Further, the dialog control unit 3 controls display of each element on the display unit 9 as an image of an expert plan as shown in FIG. In addition, a “P” or “I” command is displayed for each element. The command “P” is a stop command indicating a scan stop, and the command “I” is a command indicating a scan continuation (through). Since FIG. 2 is before the start of scanning, the stop command “P” is added to the element of “S & V scan”, which is the first scanning method, and is displayed. When the scan is started, the stop command “P” added to the “S & V scan” element is changed to the “I” command to continue the scan, and “S & V scan → S & S scan → helical scan” is displayed. Scanning by each scanning method is performed successively in sequence.
[0026]
Next, when the setting of the expert plan is completed in this way, the dialogue control unit 3 controls the lighting of the start button 20 of the operation unit 2 and prompts the operator to turn on the start button 20. Then, at the timing when the start button 20 is turned on, first, the “S & V scan” element, which is the first element in this case, is supplied to the scan condition generation unit 4 among all expert plans. The scan condition generation unit 4 generates control data for each unit corresponding to this element, and supplies these to the scan control unit 5. The scan control unit 5 performs scanning based on the control data, and after the image obtained by the scan is reconstructed and displayed, the scan and the image reconstruction display are alternately performed such that the scan is performed again. The rotational speed of the gantry rotating unit 1, the tube current of the X-ray tube 11, the tube voltage, the X-ray exposure timing, and the moving speed of the bed 14 are controlled.
[0027]
The data collection unit 6 collects the collected data collected by the X-ray detector 12 by such “S & V scan” and supplies this to the filter processing unit 7. The filter processing unit 7 performs a filtering process on the collected data using a predetermined convolution filter, and supplies this to the image reconstruction unit 8. The image reconstruction unit 8 reconstructs the tomographic image for each scan by the filtered back projection method based on the collected data filtered by the filter processing unit 7 and supplies the tomographic image to the display unit 9. As a result, the tomographic image scanned by the “S & V scan” is displayed on the display unit 9.
[0028]
Next, when such “S & V scan” is completed, the dialogue control unit 3 supplies the element “S & S scan”, which is the next element in this case, to the scan condition generation unit 4. The scan condition generation unit 4 generates control data for each unit corresponding to this element, and supplies these to the scan control unit 5. Based on this control data, the scan control unit 5 continuously scans and rotates the gantry so as to perform scan priority scans such as reconstructing and displaying an image following each scan. The rotational speed of the unit 1, the tube current of the X-ray tube 11, the tube voltage, the X-ray exposure timing, and the moving speed of the bed 14 are controlled. The collected data obtained by the “S & S scan” is reconstructed by the image reconstruction unit 8 and supplied to the display unit 9 as in the case of the “S & V scan” described above. As a result, the tomographic image scanned by the “S & S scan” is displayed on the display unit 9.
[0029]
Next, when the “S & S scan” is completed, the dialogue control unit 3 supplies the “helical scan” element, which is the next element in this case, to the scan condition generation unit 4. The scan condition generation unit 4 generates control data for each unit corresponding to this element, and supplies these to the scan control unit 5. Based on this control data, the scan control unit 5 determines the rotational speed of the gantry rotating unit 1, the tube current of the X-ray tube 11, the tube voltage, and the X-ray exposure timing so as to scan the subject in a spiral manner. While controlling, the moving speed etc. of the bed 14 are controlled. The collected data obtained by the “helical scan” is reconstructed by the image reconstruction unit 8 and supplied to the display unit 9 in the same manner as in the “S & V scan” and “S & S scan” described above. As a result, the tomographic image scanned by the “helical scan” is displayed on the display unit 9.
[0030]
(Element change operation)
Here, there are cases where it is desired to change the inspection conditions after the start of such a scan. In this case, the operator performs a click operation by moving the cursor on the display unit 9 to a numerical value or the like desired to be changed using, for example, a mouse device connected to the operation unit 2.
[0031]
Specifically, for example, when it is desired to change the scan method to be performed after the “S & V scan”, the cursor is moved to the display area of the scan method currently displayed as “S & S scan” as shown in FIG. And click. When this operation is performed, the dialogue control unit 3 stops the scan continuation of the “I” command for continuing the scan that is currently added to the “S & S scan” element as indicated by the diagonal lines in FIG. The change command is displayed in the “P” stop command shown, and each selectable scan method is displayed in a list as shown in FIG. 5B to prompt the operator to select a desired scan method.
[0032]
The operator performs a click operation by moving the cursor to a display area of a desired scan method among the scan methods displayed in the list. For example, when “helical scan” is selected by the click operation as shown by hatching in FIG. 3B, the dialogue control unit 3 displays the current “S & S scan” as shown in FIG. The display is changed to the selected “helical scan”. This allows the operator to recognize that the scanning method has been changed from “S & S scan” to “helical scan”.
[0033]
Next, for example, when it is desired to change the tube voltage of the “helical scan” selected in this way, the cursor is moved to the display region of the corresponding tube voltage and a click operation is performed. When this operation is performed, the dialogue control unit 3 displays a list of “other” characters together with characters of tube voltages such as 80 kV, 100 kV, 110 kV,. Prompts the user to select a desired tube voltage.
[0034]
The operator moves the cursor to a display area of a desired tube voltage among the tube voltages displayed in the list and performs a click operation. For example, when a tube voltage of 135 kV is selected by the click operation, the dialogue control unit 3 controls display of a character of 135 kV in the corresponding display area. As a result, the operator can recognize that the tube voltage has been changed to 135 kV.
[0035]
On the other hand, when the desired tube voltage does not exist among the tube voltages displayed in the list, the operator moves the cursor to the display area where the characters “other” are displayed and performs a click operation. Do. When this operation is performed, the dialog control unit 3 displays a dialog box in the corresponding area as shown in FIG. 3D and prompts the operator to input a desired numerical value. An operator inputs a numerical value of a desired tube voltage to the dialog box using a numeric keypad. Thereby, the input of desired tube voltages other than the tube voltage prepared beforehand can also be performed.
[0036]
The tube current and the slice thickness can be changed by a numerical value selection operation or an input operation in the same manner as the tube voltage change. Further, the focal size is changed by selecting a desired size from among L, (M), and S sizes.
[0037]
(Scan operation after element change)
Next, the scanning operation by the element thus changed will be described with reference to the flowchart shown in FIG. The flowchart shown in FIG. 4 is started when the start button is turned on after the expert plan is set and scanning is started, and the process proceeds to step S1.
[0038]
In step S1, the dialogue control unit 3 determines whether or not the above-described scan condition (element) has been changed. If NO, the step S1 is repeatedly executed until the element is changed. Advances to step S2.
[0039]
As described above, the dialog control unit 3 handles a series of expert plans by dividing them into elements, and each element is assigned an identification number. Therefore, when the element is changed and the process proceeds to step S2, the dialogue control unit 3 supplies data indicating the identification number of the changed element to the scan control unit 5 and proceeds to step S3. In step S3, the dialogue control unit 3 determines whether or not the element change has been completed. If YES, the process proceeds to step S6, and if NO, the process proceeds to step S4.
[0040]
In step S4, the dialogue control unit 3 determines whether or not scanning of the element preceding the element being changed has been completed. If NO, repeat step S3 and step S4, and if YES, Proceed to step S5. In step S5, since the scanning of the element before the element being changed has been completed and the change of the element being changed has not been completed, the dialogue control unit 3 performs the gantry rotating unit 1 via the scan control unit 5. The scanning operation is temporarily controlled and the process returns to step S3.
[0041]
That is, when the operations of step S3 to step S5 are described again, for example, when there is a first element and a second element, the second element is being scanned while the first element is being scanned. If the change of the second element is completed and the confirm button described later is turned on while the first element is being scanned, the first element is scanned. Is not stopped, and the scan of the second element is executed continuously (step S6 and subsequent steps). On the other hand, if the change operation of the second element is not completed before the scan of the first element is finished, the scan is temporarily stopped after the scan of the first element is finished (step S5) Waits for the second element to be changed (steps S3 to S5).
[0042]
This is possible only when the X-ray CT apparatus deals with a series of expert plans divided into elements. Therefore, in the X-ray CT apparatus, even after the scan is started, the inspection conditions can be changed without stopping the scan (meaning all scans in a series of expert plans).
[0043]
For example, in the case where there are the first element to the third element, in the above description, the change operation of the second element has been completed before the scan of the first element is completed. If there is no change, the scan is temporarily stopped after the scan of the first element. However, if the change of the second element is not completed, the scan by the second element is performed. Alternatively, the scan of the third element may be executed after the scan of the first element.
[0044]
As a result, it is possible to execute all scans based on a series of expert plans without temporarily stopping the scan operation. In this case, there is a concern that the continuity of data cannot be obtained, but the write address is controlled so that the data obtained for each scan is arranged in the order of each element in the memory (physical or logical is acceptable). As a result, data continuity can be ensured.
[0045]
Next, when the change of the desired element is completed and the process proceeds to step S6, in this step S6, the dialogue control unit 3 transfers the changed element to the scan control unit 5 and proceeds to step S7. When the change of the element is completed, the dialogue control unit 3 controls the confirm button 21 provided on the operation unit 2 to be lit (or blinking) so as to prompt the operator to approve the changed element. The operator turns on the confirm button 21 when the changed element is acceptable. In step S7, the dialogue control unit 3 determines whether or not the confirm button 21 has been turned on. If the confirm button 21 has not been turned on, the dialog control unit 3 determines whether or not the confirm button 21 has been turned on. If S7 is repeatedly executed and the confirm button 21 is turned on, the process proceeds to step S8.
[0046]
In step S8, when the scan is temporarily stopped due to the element change, the dialogue control unit 3 deletes the stop command “P” described with reference to FIGS. The display unit 9 is controlled and the process proceeds to step S9. In step S9, the scan control unit 5 controls the gantry rotation unit 1 based on the changed element transferred from the dialogue control unit 3 via the scan condition generation unit 4, thereby restarting the scan and proceeds to step S10. move on. In step S10, the dialogue control unit 3 determines whether or not all scans based on a series of expert plans have been completed. If NO, the process returns to step S1 and repeatedly executes the routines of steps S1 to S10. In the case of YES, all the routines in the flowchart shown in FIG.
[0047]
As is apparent from the above description, the X-ray CT apparatus of the present embodiment has a simple configuration by handling an expert plan, which is a series of inspection condition programs, divided into a plurality of elements (minimum inspection units). Since the inspection conditions can be changed for each element, the expert plan can be easily changed. For this reason, when changing the expert plan after the start of scanning, it is possible to prevent the inconvenience of making a change by stopping a series of scans based on all expert plans. Therefore, it is possible to perform an optimal inspection in a minimum time.
[0048]
In addition, scanning is performed for each element, and when the corresponding element has not been changed at the time of scanning, a series of expert plans are scanned at the scanning stage of that element. Since the operation is temporarily stopped and the scan is resumed after completion of the change, it is possible to prevent the inconvenience that the scan is executed under the final change inspection condition.
[0049]
In the above-described embodiment, the imaging apparatus and imaging method according to the present invention are applied to an X-ray CT apparatus. However, as long as a desired object can be imaged, an industrial X In addition to the line CT apparatus, the present invention may be applied to other imaging apparatuses such as an X-ray diagnostic apparatus, a nuclear magnetic resonance apparatus (MRI apparatus), and a SPECT apparatus (Single Photon Emission Computed Tomograph). Of course, various modifications can be made in accordance with the design and the like other than this embodiment as long as they do not depart from the spirit of the invention.
[0050]
【The invention's effect】
  According to the present inventionX-ray CTEquipment, ShootingWhen it is necessary to change the shooting program after the start of shadowing, it is possible to prevent the inconvenience of once stopping shooting and starting a new shot again with the changed shooting program..
[0052]
  Or when shooting, MinutesSince the split program is skipped and shooting by the next split program is executed, a series of shooting operations can be executed without stopping.
[Brief description of the drawings]
FIG. 1 is a block diagram of an X-ray CT apparatus according to an embodiment to which an imaging apparatus and an imaging method according to the present invention are applied.
FIG. 2 is a diagram showing an example of a series of expert plans and elements forming the X-ray CT apparatus according to the embodiment.
FIG. 3 is a diagram for explaining an inspection condition changing operation in the X-ray CT apparatus according to the embodiment;
FIG. 4 is a flowchart for explaining a scanning operation when changing the inspection condition of the X-ray CT apparatus according to the embodiment;
FIG. 5 is a diagram showing an example of an expert plan of a conventional X-ray CT apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Mount rotation part, 2 ... Operation part, 3 ... Dialog control part, 4 ... Scan condition production | generation part, 5 ... Scan control part, 6 ... Data collection part, 7 ... Filter processing part, 8 ... Image reconstruction part, 9 ... Display unit, 11 ... X-ray tube, 12 ... X-ray detector, 13 ... Gantry, 14 ... Bed, 20 ... Start button, 21 ... Confirm button

Claims (2)

A series of imaging programs defining a plurality of imaging ranges and a plurality of imaging conditions for one subject is divided into a plurality of division programs for each predetermined imaging unit, and imaging is continuously performed according to the plurality of division programs. An imaging device to perform,
Program changing means for changing the divided program;
After the start of shooting, the shooting is temporarily stopped at the stage of shooting execution by the divided program whose program has been changed by the program changing means, and after the change of the divided program is completed, shooting by the changed divided program is performed. An X-ray CT apparatus comprising: an imaging control unit that resumes. A series of imaging programs defining a plurality of imaging ranges and a plurality of imaging conditions for one subject is divided into a plurality of division programs for each predetermined imaging unit, and imaging is continuously performed according to the plurality of division programs. An imaging device to perform,
Program changing means for changing the divided program;
If the program has been changed by the program changing means after the start of shooting, the division program being changed is skipped, shooting is performed using the next division program, and the change is completed after the change of the division program is completed. An X-ray CT apparatus comprising: an imaging control unit that performs imaging using the changed division program.

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