JPH09140698A - X-ray ct apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To confirm a scannable scope directly by eyes and make the condition setting of spiral scanning easy in an emergency by arithmetically processing a possible scanning scope under the previously set conditions and by visualizing the starting position and the ending position. SOLUTION: When scanning setting conditions including d moving velocity of a table 6, a tube current for X-ray tube, scanning scope, etc., are inputted in an input unit, a controlling apparatus operates a possible spiral scanning scope at the time defined by the heat capacity of X-ray tube, the moving velocity of the table 6 and tube current this time paint. The controlling unit sends the possible scope to a controller of a lighting device 14. The controller moves each of light projectors 14b and 14c along a rail 14a so as to confirm the spiral scanning scope possible by eyes on real time and lights a starting point P1 by one light projector 14b and an ending point P2 by another projector 14c to visualize.

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 capable of performing spiral scan.

[0002]

2. Description of the Related Art As an X-ray CT apparatus, an X-ray irradiating apparatus is orbited with respect to a subject on a mounting table and is moved in one direction relatively, so that the X-ray irradiating apparatus can be moved at a plurality of positions along a body axis direction of a human body. There is one that can perform a spiral scan to obtain a tomographic image of.

When performing a spiral scan,
Conditions such as the feed rate of the mounting table, the tube current of the X-ray irradiation device, and the scan range are set, and the X-ray CT device is controlled by the control device according to the set conditions.

The possible range of the spiral scan is limited to a range in which the amount of heat generated by the X-ray tube does not become excessive during scanning.

Therefore, when the setting conditions are input, the conventional control device calculates the spiral scannable range determined by the heat capacity of the X-ray tube at that time, the set platform feed speed, and the tube current, and the calculation is performed. The scannable range that has been set is compared with the set scanable range, and if the scan set range exceeds the scannable range, it is displayed, for example, by a display device that spiral scanning cannot be performed.

[0006]

The operator of the X-ray CT apparatus responds by changing the setting condition when a message indicating that such a spiral scan cannot be performed is displayed.

However, the operator cannot know the spiral scan range by merely displaying the fact that the spiral scan cannot be performed. Especially when it is necessary to perform an urgent scan, the heat capacity of the X-ray tube changes according to the cooling time, so that the spiral scannable range at the start of scanning cannot be obtained in advance. Therefore, there is a problem in that it is difficult to set scan conditions.

Therefore, it is possible to display the scannable range calculated by the controller as a numerical value.
Depending on the numerical value, the scannable range cannot be directly checked directly.

An object of the present invention is to provide an X-ray CT apparatus which can solve the above problems.

[0010]

According to the present invention, in an X-ray CT apparatus capable of spiral scanning, a means for calculating a spiral scanable range under a set scanning condition, and a calculation of the calculated spiral scanable range. At least a start point position and an end point position are visualized.

According to the configuration of the present invention, the spiral scannable range under the set conditions can be directly visually confirmed in real time.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

The X-ray CT apparatus 1 shown in FIG.
And a short cylindrical rotating part 3 supported by the supporting part 2 so as to be rotatable about 360 ° about the axis, an X-ray irradiating device 4 attached to the rotating part 3, and an X-ray image receiving device 5. And a mounting table 6 which can be reciprocally driven along the axial direction of the rotating portion 3. By rotating the rotating part 3 continuously and moving the mounting table 6 in one direction, the X-ray irradiating device 4 irradiates X-rays and the image receiving device 5 receives an X-ray image. It is possible to perform spiral scan to obtain tomographic images at a plurality of positions along the body axis direction of the subject 7 above.

As shown in FIG. 2, a controller 11 for a drive mechanism (not shown) for the rotating part 3 and the mounting table 6,
The voltage application unit 4b to the X-ray tube 4a in the X-ray irradiation device 4 is connected to the control device 12 configured by a computer, and the control device 12 is connected to the input device 13.
, The controller 15 of the light projecting device 14, and the display device 16
And are connected.

As shown in FIG. 3, the light projecting device 14 is
The rail 14a is arranged above the mounting table 6 along the moving direction of the mounting table 6, and the two projectors 14b and 14c supported by the rail 14a. Each floodlight 1
4b and 14c are composed of a drive mechanism for reciprocating along the rail 14a and a light source of the planar light beam L1 for irradiating the subject 7 on the mounting table 6 along a direction orthogonal to the moving direction of the mounting table 6. It is configured.

The control device 12 receives the setting conditions of the spiral scan, such as the feed rate of the mounting table 6, the tube current of the X-ray tube 4a, and the scan range, from the input device 13, and the X-ray tube at that time is input. The spiral scannable range at the present time, which is determined according to the heat capacity of 4a, the set platform feed rate, and the tube current, is calculated. The heat capacity of the X-ray tube 4a is obtained, for example, by previously storing the cooling characteristic indicating the relationship between the cooling time and the heat capacity of the X-ray tube 4a and measuring the cooling time from the previous X-ray irradiation to the present time. To be The possible range of the spiral scan is set to be equal to or less than a preset allowable value so that the heat generation amount of the X-ray tube 4a does not become excessive during scanning.

The control device 12 sends the calculated spiral scannable range to the controller 15 of the light projecting device 14. The controller 15 moves each of the light projectors 14b and 14c along the rail 14a so that the spiral scannable range can be directly visually confirmed in real time, and the start point position P of the spiral scannable range is set.
1 is visualized by irradiating with one of the projectors 14b, and the end point position P2 is visualized by irradiating with the other of the projectors 14c.

Further, the control device 12 compares the calculated scannable range with the set scan range,
If the scan setting range exceeds the scannable range,
The fact that the spiral scan cannot be performed is displayed on the display device 16, for example.

The operator of the X-ray CT apparatus changes the setting condition when the display that the spiral scan cannot be performed is displayed. At this time, since the operator can directly check the spiral scannable range with his / her eyes, the setting condition can be easily changed.

When the scan setting range does not exceed the scannable range, the control device 12 drives the rotating unit 3 and the mounting table 6 via the controller 11, and the voltage applying unit 4
By applying a voltage to the X-ray tube 4a via b, the X-ray CT apparatus 1 is controlled according to the set conditions to perform the spiral scan.

According to the above-described embodiment, the operator of the X-ray CT apparatus 1 can directly visually confirm the spiral scannable range at the present time under the set scanning conditions in real time. It becomes possible to easily set the scanning conditions.

The present invention is not limited to the above embodiment.

For example, instead of the light projecting device 14 shown in FIG.
As shown in the first modified example of FIG. 5, the single light projecting device 24 is fixed to the fixing portion outside the drawing above the mounting table 6, and the subject 7 on the mounting table 6 is moved in the moving direction of the mounting table 6. The light source 24a of the light ray L2 that can be illuminated over a certain range along the line and the diaphragm mechanism 24b that can change the irradiation range of the subject 7 by the light ray L2 from the range shown by the solid line in the figure to the range shown by the broken line.
You may use what is comprised by. By controlling the aperture degree of the light beam L2 by the aperture mechanism 24b according to the spiral scannable range, the start point position P1 and the end point position P2 of the spiral scannable range can be visualized.

Further, instead of the light projecting device 14, as shown in the second modification of FIG. 5, there are provided a plurality of indicators 34 fixed to the side surface of the mounting table 6 along the moving direction of the mounting table 6. A light source lamp may be used. By lighting one of the plurality of light source lamps in the spiral scannable range, the start point position P1 and the end point position P2 of the spiral scannable range can be visualized.

[0025]

According to the X-ray CT apparatus of the present invention, the operator can directly check the spiral scan range and can easily set the spiral scan condition especially in an emergency.

[0026]

DETAILED DESCRIPTION OF THE INVENTION In the X-ray CT apparatus of the present invention,
The start position and end position of the spiral scan range are
It is preferably visualized by a light beam that illuminates the subject. As a result, the spiral scannable range of the subject can be confirmed more accurately.

[Brief description of the drawings]

FIG. 1 is a front view of an X-ray CT apparatus according to an embodiment of the present invention.

FIG. 2 is a structural explanatory view of an X-ray CT apparatus according to an embodiment of the present invention.

FIG. 3 is an explanatory diagram of a light projecting device according to an embodiment of the present invention.

FIG. 4 is an explanatory diagram of a light projecting device according to a first modification of the present invention.

FIG. 5 is an explanatory view of a light projecting device of a second modified example of the invention.

[Explanation of symbols]

 1 X-ray CT device 12 Control device 14 Projector P1 Start point position P2 End point position

Claims (1)

[Claims] 1. An X-ray CT apparatus capable of spiral scan, comprising means for calculating a spiral scannable range under set scan conditions, and at least a start point position and an end point position of the calculated spiral scannable range. An X-ray CT apparatus comprising: a means for visualizing.