JP2006150121A - X-ray computer tomographic imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an X-ray computer tomographic imaging apparatus in which a rack rotating part can be rotated at high speed against a rack fixing part to realize high speed scanning. <P>SOLUTION: This X-ray computer tomographic imaging apparatus is equipped with a rack rotating part which has an X-ray tube 200 placed around an inner space to which a subject is inserted and is rotated around the subject centering thereon, and a rack which houses the rack rotating part, is set corresponding to the inner space, and has an opening part for taking images of the subject. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an X-ray computed tomography apparatus, and more particularly, to an X-ray computed tomography apparatus having a gantry rotating unit provided so as to be rotatable with respect to a gantry fixing unit.

  Conventionally, a gantry of this type of X-ray computed tomography apparatus (hereinafter sometimes abbreviated as an X-ray CT apparatus) has a fixed part and a rotating part, and the gantry rotating part is rotatable with respect to the gantry fixing part. It is provided as such. As shown in FIG. 12, the gantry rotating unit includes a disk-shaped support member 30 having a hole, and an X-ray tube 200 for exposing X-rays, for example, on the surface of the disk-shaped support member 30. A detector 202 for detecting transmitted X-rays that have been exposed from the X-ray tube and transmitted through the subject, and a booster circuit, counterweights 201, 203, and 204 are provided. These devices 200 to 204 (hereinafter, various devices provided in the gantry rotating unit are referred to as units 20) rotate together with the gantry rotating unit during photographing.

  Furthermore, the unit 20 provided in the gantry rotating part and various devices (for example, an image reconstruction device) provided in the gantry fixing part are electrically connected by a slip ring device, and the gantry rotating part is continuously connected to the gantry fixing part. Can be rotated automatically. In addition, if the bed (top) on which the subject is placed is continuously moved in the body axis direction of the subject during continuous rotation of the gantry rotating unit, so-called helical scanning may be performed. it can. According to the helical scan, it is possible to collect images of a wide area of the subject at high speed.

  In recent years, in X-ray CT apparatuses, shortening the scan time is considered to be a major technical problem. Therefore, if the gantry rotating part is rotated at a high speed in order to shorten the scanning time, there is a problem that acceleration in the centrifugal direction applied to the unit increases. More specifically, when the angular velocity and the radius of the gantry rotating part are ω and r, respectively, the acceleration α in the centrifugal direction of the gantry rotating part is expressed by the following equation (1), and the acceleration is increased as the angular velocity ω increases. α increases.

α = rω2 (1)
As described above, when the acceleration in the centrifugal direction increases due to the high-speed rotation of the gantry rotating unit, the conventional X-ray CT apparatus having the configuration in which the unit 20 is arranged as shown in FIG. In addition, each unit 20 is shaken in the centrifugal direction, and each unit 20 has a problem that it cannot maintain the firm fixation to the disk-shaped member 30. As a result, each unit 20 is affected by the operation of the unit 20 and there is a problem that the image quality of the photographed image is deteriorated.

  In general, in X-ray CT apparatuses, as a countermeasure against heat (mainly heat generation of the X-ray tube), forcible air cooling is performed by attaching a ceiling fan to the gantry fixing part, but noise when the ceiling fan operates, etc. There are also problems.

  The present invention has been made to cope with the above-described circumstances, and an object thereof is to provide the following X-ray computed tomography apparatus.

  (1) An X-ray computed tomography apparatus capable of rotating the gantry rotating unit at a high speed relative to the gantry fixing unit and realizing a high scanning speed.

  (2) An X-ray computed tomography apparatus having a simple configuration that can realize cooling by appropriate air circulation with low noise and does not require a ceiling fan.

  To achieve the above object, the present invention provides a gantry fixing portion, an X-ray tube and an X-ray which are supported around the gantry fixing portion and are arranged around an internal space into which a subject is inserted. A unit including a detector, a cylindrical gantry rotating unit rotated around the subject around the subject, a slip ring device for supplying power to the unit, A gantry rotating unit was accommodated, and a gantry provided corresponding to the internal space and having an opening for taking an image of the subject.

  According to the present invention, the following X-ray computed tomography apparatus can be provided.

  (1) An X-ray computed tomography apparatus capable of rotating the gantry rotating unit at a high speed relative to the gantry fixing unit and realizing a high scanning speed.

  (2) An X-ray computed tomography apparatus having a simple configuration that can realize cooling by appropriate air circulation with low noise and does not require a ceiling fan.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 11 is an external view of an X-ray CT apparatus according to an embodiment of the present invention. The present embodiment includes a gantry 1, a bed 2, and a console 3. An opening 4 into which the subject is inserted is provided at the center of the gantry 1. A bed 2 is arranged on the front surface of the gantry 1. The bed 2 is configured to be electrically adjustable in height. A top plate 5 on which the subject is placed is provided on the upper surface of the bed 2. The top plate 5 is configured to be slidable electrically with respect to the fixed base 1. A keyboard 6 (which may include a mouse) and a CRT monitor 7 are arranged on the console 3, and a control unit is housed in the console 3. This control unit is connected to both the gantry 1 and the bed 2 and controls these operations.

  The gantry 1 includes a gantry fixing portion and a gantry rotating portion, and the gantry rotating portion is supported so as to be rotatable with respect to the gantry fixing portion. The gantry rotating unit includes the above-described various units (200 to 204), that is, an X-ray tube that irradiates a subject placed on the top 5 with a fan-shaped X-ray beam, and a focal point of the X-ray tube. A detector array or the like is provided in which a plurality of detectors are arranged in a circular arc centering on the center and X-rays transmitted through the subject are detected in multiple channels.

  More specifically, in the present embodiment, as shown in FIG. 1A, the gantry rotating part has a cylindrical support member 10, and each unit (200 to 204) is attached to the inner wall part of the support member. It has a structure. Each unit 20 is screwed in the centrifugal direction as shown in FIG. Each unit 20 is electrically connected to the gantry fixing part via a slip ring device. A device for supplying electric power, a control signal, or the like to each unit 20 of the gantry rotating unit via a slip ring device is provided in the gantry fixing unit.

  By adopting the structure as described above, each unit 20 can maintain firm adhesion to the support member 10 even when the gantry rotating part rotates at a high speed and thereby a great centrifugal force is applied. Therefore, the gantry rotating part can be rotated at a higher speed with respect to the gantry fixing part, which contributes to shortening of the scan time (for example, scan time within 1 second).

  As another example of the structure of the support member 10 that has a cylindrical shape and attaches the unit to the inner wall thereof, for example, a frame-shaped support member 11 that combines pipe-shaped members as shown in FIG. 2, or FIG. As shown in FIG. 5B, there is a cylindrical support member 12 having a bottom surface, a support member 13 as shown in FIGS. 4A and 4B, or a support member 14 as shown in FIG.

  By the way, when it is set as the structure which attaches a unit to the cylindrical support member as mentioned above, the X-ray CT apparatus which concerns on this embodiment operate | moves, and the heat | fever generate | occur | produced by driving each unit is confined inside a cylinder. Therefore, it cannot be cooled by a ceiling fan provided in a conventional gantry fixing part. Therefore, in the present embodiment, as shown in FIGS. 6A and 6B, a plurality of blade members 400, 401,... 40n are arranged on the support member 10 and these blade members 40 are rotated together with the gantry rotating portion. It is set as the structure which ventilates by and heat-radiates inside a cylinder. Thus, cooling can be performed without providing a ceiling fan, and noise from the ceiling fan is removed. Even when the support member for mounting the unit is not cylindrical but is configured as a disk-like support member 30, as shown in FIGS. 7 (a) and 7 (b), the blade members 500, 501,. By arranging and blowing air, it becomes possible to perform cooling without using a ceiling fan.

  About the direction of ventilation, it is arbitrary according to the direction of a blade member and the rotation direction of a mount frame rotation part. For example, as shown in FIG. 8, it is good also as a white arrow direction or a black arrow direction. In addition, as shown in FIG. 9, for example, as shown in FIG. 9, the outside air is sucked (or discharged) from a desired direction by providing a duct 70 or the like.

  Moreover, you may comprise so that it may control about ventilation volume according to the rotational speed of a base rotation part. FIG. 10 is a block diagram illustrating an example of air flow control according to the rotation speed of the gantry rotating unit. The rotational speed of the motor 62 that rotationally drives the gantry rotating unit is controlled by the gantry rotation control 60, and the rotational speed information at that time is supplied to the air volume control 64. The air volume control 64 can control the angle, size, and number of sheets. The blade member 66 configured as described above is controlled. If comprised in this way, more appropriate air volume control can be performed.

  The present invention is not limited to the above-described embodiment, and can be implemented with various modifications.

The figure which shows the structure of the mount rotation part of the X-ray CT apparatus which concerns on one Embodiment of this invention. The figure which shows the other example (1) of the cylindrical support member which concerns on the said embodiment. The figure which shows the other example (2) of the cylindrical support member which concerns on the said embodiment. The figure which shows the other example (3) of the cylindrical support member which concerns on the said embodiment. The figure which shows the other example (4) of the cylindrical support member which concerns on the said embodiment. The figure which shows the structure which attaches the blade | wing member for ventilation to the cylindrical support member which concerns on the said embodiment. The figure which shows the structure which attaches the blade | wing member for ventilation to the disk shaped support member which concerns on the said embodiment. The figure which shows the example of the direction of ventilation of the said embodiment. The figure which shows the structure for the suction | inhalation (exhaust of ventilation) of the external air of the said embodiment. The block diagram which shows an example of control of the ventilation volume according to the rotational speed of the mount frame rotation part which concerns on the said embodiment. The perspective view which shows the external appearance of the said embodiment. The figure which shows the structure of the conventional frame rotation part.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Cylindrical support member, 20 ... Unit, 40 ... Blade member.

Claims (2)

A gantry fixing part;
The unit includes a unit including an X-ray tube and an X-ray detector that are rotatably supported with respect to the gantry fixing unit and are arranged around an internal space into which the subject is inserted. A cylindrical gantry rotating unit that is rotated around the subject;
A slip ring device for supplying power to the unit;
An X-ray computed tomography apparatus comprising: a gantry that accommodates the gantry rotating unit and has an opening that is provided corresponding to the internal space and shoots an image of the subject. . The X-ray computed tomography apparatus according to claim 1, further comprising a blowing unit that includes a blade member attached to the gantry rotating unit and blows air by rotating with the rotation of the gantry rotating unit.

Images