JP2002085401A - X-ray ct system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an X-ray CT system that can efficiently image tomograms from a subject by prescribing a contrast medium to the subject. SOLUTION: For this X-ray CT system, the conditions for image tomograms from the subject by prescribing the contrast medium to the subject are first inputted to and set in a contrast imaging condition setting section 11a by operating a console 10 and a mouse 15. The set conditions are inputted to a simple imaging condition calculating section 11b and the section 11b automatically calculates the conditions for simple imaging which is performed before the contrast medium is prescribed to the subject. When the operator of the system wants to change the calculated contents after confirming the calculated simple imaging conditions, the operator changes the set conditions through a manual setting changing section 11c by operating the console 10 and mouse 15. In a word, when the operator does not want to change the conditions for the simple photographing calculated from the contrast imaging conditions, the operator can start imaging after setting the imaging conditions one time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray CT apparatus used in the medical field, and more particularly to a technique for setting imaging conditions when a contrast medium is administered to a subject to perform imaging.

[0002]

2. Description of the Related Art In order to obtain a tomographic image in which a capillary or the like at a site of interest of a subject is clear, a method of performing X-ray CT imaging by administering a contrast agent to the subject has been implemented. This X
Line CT imaging is roughly divided into imaging of a transmission image of a subject,
Imaging of a tomographic image before administration of the contrast agent and imaging of a tomographic image when the contrast agent is administered are performed in this order. Hereinafter, this procedure will be specifically described.

[0003] An operator first captures a transmission image of a subject and projects it on a monitor. Then, from the projected transmission image of the subject, the start point and the end point of the imaging range including the region of interest to be imaged are input by operating a cursor on the screen with a mouse. Further, for example, imaging conditions such as a tube voltage and a tube current of the X-ray high-voltage device, a slice thickness of a tomographic image, and a position of a top plate are input from the console and the mouse. When this input is completed, the operator executes tomographic image capturing before the contrast agent is administered.

When imaging before administration of a contrast agent is completed,
The operator inputs imaging conditions for administering a contrast agent to the subject and performing imaging. In other words, when the imaging position and range are the same as the imaging before administration of the contrast agent, and when the contrast agent administered to the subject spreads over the details of the capillaries, the change in the penetration of the contrast agent may occur. A condition setting for acquiring a tomographic image that is not influenced by the image, that is, a condition for acquiring a tomographic image corresponding to a plurality of images by performing imaging at a fixed interval within a fixed time is input. When the input is completed, an imaging is performed by actually administering a contrast agent to the subject.

As another method, standard imaging conditions statistically obtained for each object to be imaged, such as a tube voltage and a tube current stored in association with each other in the case of a lung. There is a method using standard data. When actual imaging is performed, the imaging range is determined by operating the mouse from the transmitted image of the subject displayed on the monitor. Then, the monitor is switched to a screen for setting an imaging condition, and an imaging target is selected from a list of setting items. Then, the imaging conditions of the X-ray CT apparatus are automatically set from the stored standard data.

[0006]

However, the prior art having such a structure has the following problems. That is, generally, a method of performing imaging by administering a contrast agent to a subject is performed by inputting imaging conditions before administering the contrast agent and inputting imaging conditions for performing imaging by administering the contrast agent. Have to be done individually. That is, when the imaging before administration of the contrast agent is completed, the input setting items are initialized, and before the administration of the contrast agent, and a screen for inputting imaging conditions for imaging by administering the contrast agent. May be provided individually. Originally, in the imaging condition before administration of the contrast agent and the imaging condition in which the imaging is performed by administering the contrast agent, the condition regarding the imaging position must be the same. It is necessary to re-enter the same items as the imaging conditions before administration of the agent. Also, regarding the setting regarding the X-ray intensity, the operator must calculate and input an appropriate value for each imaging.

In the case of using the stored data of the imaging object, the data is set to a default value.
There is a problem that cannot be changed. That is, fine adjustment cannot be performed based on the individual difference of the subject.

The present invention has been made in view of such circumstances, and simplifies a procedure for administering a contrast agent to a subject to perform imaging and also enables efficient X-ray C
The main purpose is to realize a T device.

[0009]

The present invention has the following configuration to achieve the above object. That is, according to the first aspect of the present invention, when a tomographic image is taken by administering a contrast agent to a subject, an imaging condition for imaging (simple imaging) a tomographic image before administering the contrast agent is set. An X-ray CT apparatus comprising: a simple imaging condition setting unit for performing imaging and a contrast imaging condition setting unit for setting an imaging condition for imaging a tomographic image (contrast imaging) while administering a contrast agent. The setting means is (a) a contrast imaging condition setting means for setting imaging conditions for administering a contrast agent to a subject and performing imaging before setting the imaging conditions for simple imaging. The condition setting means includes: (b) a simple imaging condition calculation means for calculating an imaging condition for simple imaging based on the imaging conditions set by the contrast imaging condition setting means; and (c) an imaging condition for the calculated simple imaging. Manually change Consisting of a constant change means.

[Operation] The operation of the present invention is as follows. That is, in the X-ray CT apparatus according to the first aspect, various imaging conditions when a contrast agent is administered to a subject to perform imaging are first set. Based on the set conditions, a condition for imaging without administration of a contrast agent is calculated from the simple imaging condition calculation means. In other words, if the imaging conditions are input and set to the contrast imaging condition setting means, both the simple imaging and the contrast imaging before the administration of the contrast agent are set at once, so that a series of operations for imaging is efficiently performed. Also,
Regarding the imaging conditions calculated by the simple imaging condition calculation means,
There are cases where the surgeon needs to change the settings or wants to make any changes. In this case, the operator manually changes the setting of the imaging condition for the item to be changed via the manual setting changing unit.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration and functions of an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing the overall configuration of an embodiment of the X-ray CT apparatus according to the present invention. Hereinafter, a specific description will be given.

As shown in FIG. 1, an X-ray CT apparatus according to an embodiment has an X-ray tube disposed so as to face a movable top plate 1 on which a subject M is mounted, and to face the subject M therebetween. 2 and an X-ray detector 3. Further, an imaging system rotation drive unit 4 is provided which rotates the X-ray tube 2 and the X-ray detector 3 around the body axis of the subject M in the direction indicated by the arrow RA while maintaining the facing state.

The top board 1 is configured to be movable in the front-rear direction while the subject M is placed thereon. The movement of the top 1 is performed by the top driving unit 5. The X-ray tube 2 is rotating,
Under the control of the irradiation control unit 6 including a high-voltage generator and the like, the subject M is irradiated with the fan beam FB according to set irradiation conditions such as a tube voltage and a tube current.

The X-ray detector 3 is a multi-channel detector in which, for example, about 1000 X-ray detection elements 3a are arranged along the spread of the fan beam FB. The X-ray detector 3 that rotates together with the X-ray tube 2 outputs X-ray detection data in accordance with the irradiation of the fan beam FB from the X-ray tube 2.

The imaging system of the embodiment includes a rotating ring 8 to which the X-ray tube 2 and the X-ray detector 3 are fixed, and a pulley 9a.
And a ring rotating mechanism 9 composed of a belt 9b and the X-ray tube 2 and the X-ray detector 3 as the ring rotating mechanism 9 rotates the rotating ring 8 under the control of the imaging system rotation driving unit 4. Are linked to rotate. Further, the rotation ring 8 can be provided with an inclination angle, so that the irradiation angle of the fan beam FB from the X-ray tube 2 irradiating the subject can be changed. The rotation of the rotary ring 8 is performed by the gantry tilt drive unit 7. Note that the basic controls by the imaging system rotation drive unit 4, the top plate drive unit 5, the irradiation control unit 6, and the gantry tilt drive unit 7 are all performed by the imaging control unit 11 according to the input settings from the console 10 or the like.
This is performed in accordance with a command signal that is sent from the computer in a timely manner. The description of the imaging control unit 11 will be described later.

In the apparatus of the embodiment, a data acquisition unit (DA) for acquiring transmitted X-ray detection data is provided at a stage subsequent to the X-ray detector 3.
S) 12 and the transmission X collected by the data collection unit 12
A data processing unit 13 is provided to process the line detection data to obtain an X-ray CT image or an X-ray transmission image. In addition, a monitor 14 for displaying an X-ray CT image, an X-ray transmission image, and the like is provided. When the imaging system is driven in the CT imaging mode, an X-ray CT image is displayed on the screen of the monitor 14.
When driven in the transmission imaging mode, the monitor 1
4, an X-ray transmission image is projected.

The data processing unit 13 has a detection data memory 13 for recording transmission X-ray data of a digital signal output from the data acquisition unit (DAS) 12 in the CT imaging mode.
an image reconstruction unit 13b for performing an image reconstruction process for creating an X-ray CT image based on the data stored in the detection data memory 13a, and an X-ray of a desired cross section created by the image reconstruction unit 13b A CT tomographic image memory 13c for storing CT images is provided. Further, a transmission image memory 13d for storing transmission X-ray detection data of a digital signal output from the data collection unit 12 in the transmission imaging mode as one X-ray transmission image is provided. CT
The images stored in the tomographic image memory 13c and the transmission image memory 13d are read out in a timely manner and displayed on the screen of the monitor 14. Note that the imaging control unit 11 is also connected to the data processing unit 13.

Further, the apparatus of this embodiment has various characteristic structures useful for administering a contrast agent to the subject M and imaging. That is, the embodiment apparatus includes the imaging control unit 11 that controls the above-described imaging system and the data processing unit 13. The imaging control unit 11a sets an imaging condition for administering a contrast agent to the subject M to capture a tomographic image (hereinafter, referred to as “contrast imaging” as appropriate) 11a.
A simple imaging condition calculation unit 11b that calculates an imaging condition for acquiring a tomographic image before administration of a contrast agent (hereinafter, appropriately referred to as “simple imaging”), and a calculated imaging condition of the simple imaging. Manual setting change unit 11c for making changes
And Hereinafter, the function of each unit will be specifically described. The contrast imaging condition setting unit 11a includes a simple imaging condition calculation unit 11b in the contrast imaging condition setting unit of the present invention.
Represents a simple imaging condition calculation unit, and the manual setting change unit 11c corresponds to a manual setting change unit.

The contrast imaging condition setting section 11a is configured to input and set the imaging conditions of the contrast imaging by operating the console 10 and the mouse 15 before the simple imaging. That is, the transmission image of the subject M, which is captured in advance and stored in the transmission image memory 13d, is displayed on the monitor 14. Then, as shown in FIG. 2, the transmission image H projected on the screen is displayed.
The user operates the mouse 15 to set the cursor by clicking each of the start point A and the end point B of the range in which the tomographic image is captured.

Next, although not shown, the screen of the monitor 14 is switched, and the items of the respective imaging conditions over the details of the imaging system rotation drive unit 4, the top plate drive unit 5, the irradiation control unit 6, and the gantry tilt drive unit 7 are displayed. For example, for example, the X-ray intensity (tube voltage / tube current), the slice thickness of the tomographic image, the position of the top 1 are input and set. At this time, imaging conditions that are important in contrast imaging are input and set at the same time. That is, in order to obtain a tomographic image in which the capillaries at the site of interest of the subject M are sharp, an imaging condition for obtaining a tomographic image in which the contrast agent has spread to the details of the capillaries is set. When the contrast agent is actually administered to the subject M, it takes several minutes for the contrast agent to reach the details of the capillaries. Therefore, as shown in FIG. 3, an input is set so that tomographic imaging is performed at regular intervals (20 seconds) after administration of the contrast agent. By doing so, it is possible to compare and confirm the state until the contrast agent reaches the details of the capillaries. Although the imaging interval is set to 20 seconds in this embodiment, the imaging interval is not limited to 20 seconds because the penetration of the contrast agent differs depending on the imaging target.

Further, the simple imaging condition calculation unit 11b includes various types of input and setting of the imaging system rotation drive unit 4, the top plate drive unit 5, the irradiation control unit 6, and the gantry tilt drive unit 7 which are input by the contrast imaging condition setting unit 11a. From the items, conditions according to simple imaging,
For example, the same conditions as contrast imaging, such as the imaging range, the position of the top 1, and the slice thickness of a tomographic image, and the values of X-ray intensity (tube voltage / tube current) changed depending on whether or not a contrast agent is administered, etc. Calculated automatically. Then, based on the calculated imaging conditions, imaging of a tomographic image when no contrast agent is administered is executed.

Further, the manual setting change section 11c allows the operator to confirm the imaging conditions calculated by the simple imaging condition calculation section 11b and to change the settings when there is an item to be changed. It can be changed manually.
For example, depending on the type of the contrast agent, it may have an extreme influence on the X-ray transmittance. Therefore, the X-ray intensity set by the contrast imaging condition setting unit 11a and the simple imaging condition calculation unit 1
Comparing the X-ray intensities calculated in 1b, it is conceivable that an extreme difference in the set values occurs between the two. In such a case, for example, when the operator wants to change the setting of the X-ray intensity calculated by the simple imaging condition calculation unit 11b in consideration of the balance between the two in a direction approaching the set value of the contrast imaging condition And the like. Since the manual setting change unit 11c is independent of the contrast imaging condition setting unit 11a, the imaging conditions of the contrast imaging condition setting unit 11a are not changed.

In the case of this embodiment, the imaging control section 11 and the data processing section 13 are mainly composed of a computer and its operation program (software).

Next, the operation of the apparatus which administers a contrast agent to the subject M to capture a tomographic image by using the apparatus having the above-described configuration will be described with reference to the drawings. FIG. 4 is a flowchart showing a progress state until a tomographic image is obtained by administering a contrast agent.

[Step S1] Obtaining a Transmission Image H of the Subject M With the subject M placed on the top 1, X-rays are emitted from the X-ray tube 2 to a portion, such as the chest, where imaging is planned in advance. . Then, the projection data detected by the X-ray detector 3 is collected by the data collection unit 12 and stored as a transmission image H in the transmission image memory 13d.

[Step S2] Imaging of Imaging Conditions for Contrast Imaging The transmission image H of the subject M stored in the transmission image memory 13d is displayed on the monitor 14, and the start point A and the end point B of the imaging range are operated by operating the mouse 15. Click each to set the input. Then, the display screen is switched to the monitor 14.
The input setting is performed in accordance with the item of the imaging condition of the contrast imaging which is displayed on the screen.

[Step S3] Calculation of Imaging Conditions for Simple Imaging The imaging conditions for simple imaging are automatically calculated by the simple imaging condition calculation unit 11b based on the imaging conditions for contrast imaging.

[Step S4] Confirmation of the calculated imaging condition of simple imaging The operator himself confirms the imaging condition of simple imaging displayed on the monitor 14. If there is no change in the imaging conditions,
Proceed to step S6. If it is desired to change the imaging conditions, the process proceeds to step S5.

[Step S5] Change of imaging conditions for simple imaging To change the simple imaging conditions, the operator manually operates the console 10 or the mouse 15 to manually input and set items to be changed. When the setting is completed, the process returns to step S4 again to check. If there is no change, step S6
Proceed to.

[Step S6] Execution of Simple Imaging When the simple imaging is executed, the detected projection data is transferred to the data collection unit 12, the detection data 13a, and the image reconstruction unit 13
b, as a tomographic image to which no contrast agent is administered, C
It is stored in the T tomographic image memory 13c. When the simple imaging ends, the process proceeds to step S7 of contrast imaging.

[Step S7] Execution of Contrast Imaging When the contrast imaging is executed, the detected projection data is transferred to the data collection unit 12, the detection data 13a, and the image reconstruction unit 13.
After b, the tomographic image when the contrast agent is administered is accumulated in the CT tomographic image memory 13c, and the contrast imaging ends.

When the range from the start point A to the end point B for capturing a tomographic image is wider than the slice thickness of the tomographic image, the entire area of the imaging range is divided by the slice thickness, and imaging is performed for each divided portion. Will be That is, the operations of steps S1 to S3 are repeatedly performed for each of the divided imaging locations.

According to the X-ray CT apparatus of the embodiment described above, the surgeon inputs and sets the imaging conditions for imaging the subject M by administering a contrast agent to the contrast imaging condition setting unit 11a. For example, based on the set conditions, the conditions for imaging performed before administration of the contrast agent are automatically calculated by the simple imaging condition calculation unit 11b, and thus the calculated results may be confirmed. Then, if there is a portion to be changed in the calculation result, the operator can manually change the setting of the portion that needs to be changed by operating the console 9 and the mouse 15 via the manual setting change portion 11c. . Furthermore, if there is no change in the calculated result, the operator only needs to set the condition for administering the contrast agent and imaging once. That is, it is not necessary to set all of the imaging conditions for each imaging, so that work efficiency can be improved.

The present invention is not limited to the above embodiment, but can be modified as follows. (1) In the above-described embodiment, the tomographic image is captured in the order of imaging of the transmission image of the subject M, simple imaging, and contrast imaging. However, when the region of interest of the imaging target can be specified by the projector, Step S1 of capturing a transmission image can be omitted.

(2) In the above embodiment, after the simple imaging conditions are calculated, the operator confirms the imaging conditions and then manually changes the imaging conditions as necessary.
However, after the end of the simple imaging, it is necessary to change the setting conditions of the contrast imaging after confirming the acquired tomographic image,
Alternatively, the setting of the imaging conditions may be manually changed by the operator when the operator determines that the setting is to be changed. That is, between step S6 (confirmation of imaging conditions for contrast imaging) shown in FIG. 4 and step S7 (start of contrast imaging), step S6A (setting change of imaging conditions for contrast imaging) not shown is provided. Is also good.

[0036]

As is clear from the above description, according to the X-ray CT apparatus of the first aspect, first, the conditions for administering the contrast agent and imaging are set in the contrast imaging condition setting means. Based on the set conditions, the conditions for imaging without administration of the contrast agent are automatically calculated by the simple imaging condition calculation means. In other words, the surgeon can set imaging conditions only once for the first time, and continuously perform imaging when no contrast agent is administered and imaging when a contrast agent is administered. Further, when there is an item to be changed in the condition calculated by the simple imaging condition calculating means, the operator can manually change the setting of the condition by himself / herself through the manual setting changing means.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an overall configuration of an X-ray CT apparatus according to an embodiment.

FIG. 2 is a diagram showing an imaging range of a transmission image and a tomographic image of a subject.

FIG. 3 is a diagram showing a relationship between a process in which a contrast agent permeates a subject and contrast imaging in an example.

FIG. 4 is a flowchart illustrating a procedure of capturing a tomographic image by the apparatus according to the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Top plate 2 ... X-ray tube 3 ... X-ray detector 4 ... Imaging system rotation drive unit 5 ... Top plate drive unit 6 ... Irradiation control unit 7 ... Gantry tilt drive unit 11 ... Imaging control unit 11a ... Contrast imaging condition setting Unit 11b: Simple imaging condition calculation unit 11c: Manual setting change unit 13: Data processing unit 14: Monitor 15: Mouse M: Subject FB: Fan beam

Claims (1)

[Claims] 1. A simple imaging condition setting means for setting an imaging condition for imaging (simple imaging) a tomographic image before administering a contrast agent when administering a contrast agent to a subject and imaging a tomographic image. An X-ray CT apparatus comprising: a contrast imaging condition setting unit configured to set an imaging condition for imaging a tomographic image (contrast imaging) while administering a contrast agent. A) a contrast imaging condition setting unit for setting imaging conditions for administering a contrast agent to a subject to perform imaging before setting the imaging conditions for simple imaging, wherein the simple imaging condition setting unit includes: b) simple imaging condition calculation means for calculating imaging conditions for simple imaging based on the imaging conditions set by the contrast imaging condition setting means;
(C) X-ray CT, comprising: manual setting change means for manually changing the calculated imaging condition of the simple imaging.
apparatus.