JP2000262509A - X-ray computed tomograph - Google Patents
X-ray computed tomographInfo
- Publication number
- JP2000262509A JP2000262509A JP11067123A JP6712399A JP2000262509A JP 2000262509 A JP2000262509 A JP 2000262509A JP 11067123 A JP11067123 A JP 11067123A JP 6712399 A JP6712399 A JP 6712399A JP 2000262509 A JP2000262509 A JP 2000262509A
- Authority
- JP
- Japan
- Prior art keywords
- ray tube
- ray
- container
- refrigerant
- tube container
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 239000003507 refrigerant Substances 0.000 claims abstract description 46
- 238000004846 x-ray emission Methods 0.000 claims description 23
- 238000002591 computed tomography Methods 0.000 claims description 18
- 230000004907 flux Effects 0.000 description 7
- 238000000034 method Methods 0.000 description 7
- 230000002159 abnormal effect Effects 0.000 description 5
- 230000005855 radiation Effects 0.000 description 5
- 238000010586 diagram Methods 0.000 description 4
- 238000001816 cooling Methods 0.000 description 3
- 239000002826 coolant Substances 0.000 description 2
- 238000001514 detection method Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 238000005192 partition Methods 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 1
- 229910052790 beryllium Inorganic materials 0.000 description 1
- ATBAMAFKBVZNFJ-UHFFFAOYSA-N beryllium atom Chemical compound [Be] ATBAMAFKBVZNFJ-UHFFFAOYSA-N 0.000 description 1
Landscapes
- X-Ray Techniques (AREA)
- Apparatus For Radiation Diagnosis (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、Ｘ線管装置から放
射されたＸ線を被検体を介して検出器で検出し、これに
より収集された投影データに基づいて断層像データを再
構成するＸ線コンピュータ断層撮影装置に関するBACKGROUND OF THE INVENTION 1. Field of the Invention The present invention detects X-rays emitted from an X-ray tube apparatus by a detector through a subject, and reconstructs tomographic image data based on the projection data collected thereby. X-ray computed tomography equipment
【０００２】[0002]
【従来の技術】Ｘ線コンピュータ断層撮影装置におい
て、投影データを収集する動作、つまりスキャンは、高
速化の一途を辿っており、近年では、３６０゜分の投影
データを収集するのに要するいわゆるスキャン時間が１
秒を切る高級機種も登場してきている。このスキャンの
高速化に伴って、Ｘ線管の出力も著しく増大させる必要
がある。Ｘ線管の出力を増大させると、それに伴って発
熱量も著しく増大する。このため水冷式のＸ線管装置が
一般的になりつつある。この水冷式のＸ線管装置は、Ｘ
線管をＸ線管容器に収容し、Ｘ線管容器と熱交換器との
間で水等の冷媒を循環させることで、Ｘ線管を強制冷却
するというものである。2. Description of the Related Art In an X-ray computed tomography apparatus, the operation of collecting projection data, that is, scanning, has been steadily increasing in speed. In recent years, the so-called scanning required to collect 360 ° projection data has been performed. Time 1
High-end models that cut seconds are also appearing. As the scanning speed increases, the output of the X-ray tube also needs to be significantly increased. When the output of the X-ray tube is increased, the amount of heat generated also increases significantly. For this reason, water-cooled X-ray tube devices are becoming popular. This water-cooled X-ray tube device
The X-ray tube is housed in an X-ray tube container, and a coolant such as water is circulated between the X-ray tube container and the heat exchanger, thereby forcibly cooling the X-ray tube.
【０００３】しかし、このような水冷式のＸ線管装置で
は次のような問題が発生していた。冷媒の循環系統、特
にＸ線管容器と熱交換器とのジョイントの隙間から気泡
が混入し易い。なお、この気泡の混入を完全にシャット
アウトすることは、コスト等の関係もあって、実際的で
はない。However, such a water-cooled X-ray tube apparatus has the following problems. Bubbles are likely to be mixed in from the refrigerant circulation system, particularly from the gap between the joint between the X-ray tube container and the heat exchanger. It is not practical to completely shut out the inclusion of bubbles due to cost and other factors.
【０００４】ジョイント等の隙間から混入した気泡は、
冷媒と共に循環するうちに、Ｘ線管のＸ線放射窓の前を
横切ることがある。このときＸ線束は、冷媒だけを通過
してＸ線管装置から出力されるＸ線と、冷媒と気泡とを
通過してＸ線管装置から出力されるＸ線とが混在する。
冷媒と気泡とではＸ線吸収率が異なるので、前者のＸ線
と後者のＸ線とでは、強度が異なってしまい、一様なＸ
線束ではなくなってしまう。このため、被検体の組織構
造を反映していない異常陰影、つまりアーチファクトが
断層像に現れてしまう。[0004] Bubbles that enter from gaps such as joints
While circulating with the refrigerant, it may cross the front of the X-ray emission window of the X-ray tube. At this time, in the X-ray flux, X-rays that pass only through the refrigerant and are output from the X-ray tube device and X-rays that pass through the refrigerant and bubbles and are output from the X-ray tube device are mixed.
Since the X-ray absorptivity differs between the refrigerant and the bubble, the intensity differs between the former X-ray and the latter X-ray, and a uniform X-ray is obtained.
It is no longer a flux. Therefore, an abnormal shadow that does not reflect the tissue structure of the subject, that is, an artifact appears in the tomographic image.
【０００５】[0005]
【発明が解決しようとする課題】本発明の目的は、水冷
式のＸ線管装置を備えたＸ線コンピュータ断層撮影装置
において、冷媒中に混入する気泡の影響を解消すること
にある。SUMMARY OF THE INVENTION An object of the present invention is to eliminate the influence of air bubbles mixed in a refrigerant in an X-ray computed tomography apparatus equipped with a water-cooled X-ray tube device.
【０００６】[0006]
【課題を解決するための手段】（１）本発明は、Ｘ線管
装置から放射されたＸ線を被検体を介して検出器で検出
し、これにより収集された投影データに基づいて断層像
データを再構成するＸ線コンピュータ断層撮影装置にお
いて、前記Ｘ線管装置は、Ｘ線管と、前記Ｘ線管を収容
するＸ線管容器と、前記Ｘ線管容器と連結される熱交換
器と、前記Ｘ線管容器と前記熱交換器との間を循環され
る冷媒とを有し、前記Ｘ線管容器には、前記冷媒中に混
入した気泡を捕捉する気泡ポケットが設けられているこ
とを特徴としている。(1) According to the present invention, X-rays emitted from an X-ray tube apparatus are detected by a detector through a subject, and a tomographic image is obtained based on projection data collected thereby. In an X-ray computed tomography apparatus for reconstructing data, the X-ray tube apparatus includes an X-ray tube, an X-ray tube container accommodating the X-ray tube, and a heat exchanger connected to the X-ray tube container. And a refrigerant circulated between the X-ray tube container and the heat exchanger, wherein the X-ray tube container is provided with a bubble pocket for capturing bubbles mixed in the refrigerant. It is characterized by:
【０００７】（２）本発明は、（１）の装置において、
Ｘ線管容器には、前記気泡を前記気泡ポケットに誘導す
るガイドが設けられてることを特徴としている。(2) The present invention relates to the apparatus of (1),
The X-ray tube container is provided with a guide for guiding the bubbles to the bubble pockets.
【０００８】（３）本発明は、（１）の装置において、
気泡ポケットは、前記Ｘ線管装置が前記被検体を中心と
した回転軌道上のいずれの位置にあっても前記捕捉した
気泡を保持するように設けられていることを特徴として
いる。(3) The present invention relates to the device of (1),
The bubble pocket is characterized in that the bubble pocket is provided so as to hold the captured bubble regardless of the position of the X-ray tube device on the rotational trajectory around the subject.
【０００９】（４）本発明は、Ｘ線管装置から放射され
たＸ線を被検体を介して検出器で検出し、これにより収
集された投影データに基づいて断層像データを再構成す
るＸ線コンピュータ断層撮影装置において、前記Ｘ線管
装置は、Ｘ線管と、このＸ線管を収容するＸ線管容器
と、このＸ線管容器と連結される熱交換器と、前記Ｘ線
管容器と前記熱交換器との間を循環される冷媒とを有
し、前記Ｘ線管のＸ線放射窓は、前記Ｘ線管容器にカバ
ーされずに露出されていることを特徴としている。(4) According to the present invention, an X-ray emitted from an X-ray tube apparatus is detected by a detector through a subject, and X-rays for reconstructing tomographic image data based on the projection data collected thereby. In the X-ray computed tomography apparatus, the X-ray tube apparatus includes: an X-ray tube; an X-ray tube container that houses the X-ray tube; a heat exchanger connected to the X-ray tube container; It has a refrigerant circulated between a container and the heat exchanger, and the X-ray emission window of the X-ray tube is exposed without being covered by the X-ray tube container.
【００１０】（５）本発明は、Ｘ線管と、前記Ｘ線管を
収容するＸ線管容器と、前記Ｘ線管容器と連結される熱
交換器と、前記Ｘ線管容器と前記熱交換器との間を循環
される冷媒とを具備するＸ線管装置において、前記Ｘ線
管容器には、前記冷媒中に混入した気泡を捕捉する気泡
ポケットが設けられていることを特徴としている。(5) The present invention provides an X-ray tube, an X-ray tube container accommodating the X-ray tube, a heat exchanger connected to the X-ray tube container, the X-ray tube container and the heat source. In the X-ray tube apparatus including the refrigerant circulated between the exchanger and the refrigerant, the X-ray tube container is provided with a bubble pocket that captures bubbles mixed in the refrigerant. .
【００１１】（６）本発明は、Ｘ線管と、前記Ｘ線管を
収容するＸ線管容器と、前記Ｘ線管容器と連結される熱
交換器と、前記Ｘ線管容器と前記熱交換器との間を循環
される冷媒とを具備するＸ線管装置において、前記Ｘ線
管のＸ線放射窓は、前記Ｘ線管容器にカバーされずに露
出されていることを特徴としている。(6) The present invention provides an X-ray tube, an X-ray tube container accommodating the X-ray tube, a heat exchanger connected to the X-ray tube container, the X-ray tube container and the heat exchanger. An X-ray tube apparatus comprising a refrigerant circulated between the heat exchanger and an exchanger, wherein an X-ray emission window of the X-ray tube is exposed without being covered by the X-ray tube container. .
【００１２】[0012]
【発明の実施の形態】以下、本発明に係るＸ線コンピュ
ータ断層撮影装置を実施形態により説明する。本発明
は、Ｘ線管装置とＸ線検出器とが１体として被検体の周
囲を回転するローテート／ローテートタイプ(ROTATE/RO
TATE-TYPE)と、リング状にアレイされた多数の検出素子
が固定され、Ｘ線管装置のみが被検体の周囲を回転する
固定／ローテートタイプ(STATIONARY/ROTATE-TYPE)との
いずれのタイプのＸ線コンピュータ断層撮影装置にも適
用可能である。ここでは、現在、主流を占めている前者
のローテート／ローテートタイプで説明する。DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an X-ray computed tomography apparatus according to the present invention will be described with reference to embodiments. The present invention relates to a rotating / rotating type in which an X-ray tube device and an X-ray detector rotate as a unit around a subject.
TATE-TYPE) and fixed / rotate type (STATIONARY / ROTATE-TYPE) in which a large number of detectors arranged in a ring are fixed and only the X-ray tube device rotates around the subject. The present invention is also applicable to an X-ray computed tomography apparatus. Here, the former rotating / rotating type, which currently occupies the mainstream, will be described.
【００１３】まず、本発明に係るコンピュータ断層撮影
装置の概要について説明する。スキャン本体（ガントリ
ともいう）は、回転リングにＸ線管装置とＸ線検出器と
が被検体を挟んで対向した状態で配置されている。Ｘ線
管装置とＸ線検出器とは、回転リングの回転に伴って、
被検体の周囲を回転するようになっている。Ｘ線管装置
と被検体との間には、Ｘ線吸収量の体厚依存性を補正す
るためのウェッジフィルタとＸ線質を変えるためのＸ線
フィルタとが配置されている。Ｘ線検出器は、複数の検
出素子がチャンネル方向に沿って一列に配列されてな
る。この検出素子（チャンネル）各々からの出力は、デ
ータ収集システム（ＤＡＳ）で増幅され、ディジタル信
号に変換される。再構成プロセッサは、データ収集シス
テムから出力される３６０゜分の投影データに基づいて
断層像データを再構成する。この断層像データは、モニ
タに送られ表示される。First, an outline of a computer tomography apparatus according to the present invention will be described. The scan main body (also referred to as a gantry) is arranged such that an X-ray tube device and an X-ray detector face each other with a subject interposed therebetween on a rotating ring. The X-ray tube device and the X-ray detector, with the rotation of the rotating ring,
It rotates around the subject. Between the X-ray tube device and the subject, a wedge filter for correcting the body thickness dependence of the X-ray absorption amount and an X-ray filter for changing the X-ray quality are arranged. The X-ray detector has a plurality of detection elements arranged in a line along the channel direction. The output from each of the detection elements (channels) is amplified by a data acquisition system (DAS) and converted to a digital signal. The reconstruction processor reconstructs tomographic image data based on the 360 ° projection data output from the data acquisition system. This tomographic image data is sent to a monitor and displayed.
【００１４】（第１実施形態）図１には、第１実施形態
に係るＸ線コンピュータ断層撮影装置に装備されるＸ線
管装置の構成を示している。Ｘ線管１は、一般的なもの
であり、フィラメント２から放出された熱電子を回転陽
極３のターゲットに衝突させ、そこから発生したＸ線
を、ベリリウム製のＸ線放射窓４から外部に出力するよ
うに構成されている。なお、Ｘ線管１としては、陽極３
が接地（グランド）されている陽極接地方式と、陽極３
が接地されていいない陽極非接地方式とがあるが、ここ
ではそれらのいずれの方式であってもよい。(First Embodiment) FIG. 1 shows a configuration of an X-ray tube device provided in an X-ray computed tomography apparatus according to a first embodiment. The X-ray tube 1 is a general one. The X-ray tube 1 collides thermoelectrons emitted from a filament 2 with a target of a rotating anode 3, and X-rays generated therefrom are emitted from a beryllium X-ray emission window 4 to the outside. It is configured to output. The X-ray tube 1 includes an anode 3
Grounding method where the anode is grounded (ground) and the anode 3
There is an anode non-grounding method in which the electrodes are not grounded, but any of these methods may be used here.
【００１５】周知の通り、フィラメント２から放出され
た熱電子を回転陽極３のターゲットに衝突するとき発熱
し、ときには回転陽極３が数百度、ときには千度を越え
ることもある。また、回転陽極３のターゲットに衝突し
た熱電子の一部は反跳電子としてＸ線放射窓４等にあた
り、そこで熱を発生するので、Ｘ線放射窓４は高温に達
する。このため多くのＸ線管がそうであるように、この
Ｘ線管１も、Ｘ線管１の内部を絶縁油で満たして、熱容
量を高め、耐熱性を向上させている。As is well known, the thermoelectrons emitted from the filament 2 generate heat when colliding with the target of the rotating anode 3, and sometimes the rotating anode 3 exceeds several hundred degrees, and sometimes exceeds 1000 degrees. Some of the thermoelectrons that collide with the target of the rotating anode 3 hit the X-ray emission window 4 and the like as recoil electrons, and generate heat there, so that the X-ray emission window 4 reaches a high temperature. For this reason, like many X-ray tubes, this X-ray tube 1 also fills the inside of the X-ray tube 1 with insulating oil to increase heat capacity and improve heat resistance.
【００１６】このＸ線管装置は、高出力と長い連続ばく
者時間とを獲得するために、水冷式が採用されている。
つまり、Ｘ線管１をＸ線管容器５に収容し、このＸ線管
容器５をジョイント７を介して連結ホース８で熱交換器
（冷却器）６に連結し、Ｘ線管容器５と熱交換器６との
間で水等の冷媒９を循環させることにより、Ｘ線管１を
強制的に冷却するようになっている。This X-ray tube apparatus employs a water-cooled type in order to obtain a high output and a long continuous exposure time.
That is, the X-ray tube 1 is housed in the X-ray tube container 5, and the X-ray tube container 5 is connected to the heat exchanger (cooler) 6 by the connecting hose 8 via the joint 7, and is connected to the X-ray tube container 5. By circulating a coolant 9 such as water between the heat exchanger 6 and the heat exchanger 6, the X-ray tube 1 is forcibly cooled.
【００１７】ところで従来技術のところでも述べたよう
に、このような水冷式のＸ線管装置では、ジョイント７
等の隙間から気泡１４が混入することがある。この気泡
がＸ線放射窓４の前を横切るとき、Ｘ線束の強度分布が
不均一になり、アーチファクトを引き起こす。By the way, as described in the prior art, in such a water-cooled X-ray tube apparatus, the joint 7
Air bubbles 14 may be mixed in from such gaps. When this bubble crosses the front of the X-ray emission window 4, the intensity distribution of the X-ray flux becomes non-uniform, causing an artifact.
【００１８】この問題を解決するために、本実施形態で
は、冷媒９に混入した気泡１４を捕捉するための気泡ポ
ケット１１，１３をＸ線管容器５の内部に設けて、気泡
１４が冷媒９の流れにのって自由に動き回り、Ｘ線管１
のＸ線放射窓４の前を横切るような事態が起こらないよ
うにしている。In order to solve this problem, in this embodiment, bubble pockets 11 and 13 for trapping bubbles 14 mixed in the refrigerant 9 are provided inside the X-ray tube container 5 so that the bubbles 14 Move freely along the flow of the X-ray tube 1
Is prevented from crossing the front of the X-ray emission window 4.
【００１９】上述したようにＸ線管装置は被検体の周囲
を回転するようなタイプであるので、Ｘ線管装置が回転
軌道の何れの位置にあっても、一旦捕捉した気泡１５を
逃さないような工夫が必要とされる。ここでは、図２に
示すように、Ｘ線管装置が上半分、つまり０゜から９０
゜までの範囲と２７０゜から０゜までの範囲とにあると
きに、捕捉した気泡１５を保持するための上部気泡ポケ
ット１１と、Ｘ線管装置が下半分、つまり９０゜から２
７０゜までの範囲とにあるときに、捕捉した気泡１５を
保持するための仕切板１２で仕切られた下部気泡ポケッ
ト１３との２系統を設けている。As described above, since the X-ray tube apparatus is of a type that rotates around the subject, the trapped air bubbles 15 are not escaped regardless of the position of the X-ray tube apparatus in the rotation orbit. Such a device is required. In this case, as shown in FIG. 2, the X-ray tube device is in the upper half, that is, from 0 ° to 90 °.
The upper bubble pocket 11 for holding the captured air bubbles 15 and the lower half of the X-ray tube device, ie, from 90 ° to 2 °, when in the range from ゜ ° to 270 ° to 0 °.
Two systems are provided: a lower bubble pocket 13 partitioned by a partition plate 12 for holding captured bubbles 15 in a range up to 70 °.
【００２０】さらに、主に熱交換器６側からホース８を
通りＸ線管容器５に向かって移動してくる気泡１４が冷
媒９の流れにのってＸ線管１の方に行かないように、つ
まり気泡１４を気泡ポケット１１，１３に誘導するため
に、ガイド板１０を設けている。Further, the air bubbles 14 moving from the heat exchanger 6 side through the hose 8 toward the X-ray tube container 5 do not flow toward the X-ray tube 1 along with the flow of the refrigerant 9. In other words, the guide plate 10 is provided to guide the bubbles 14 to the bubble pockets 11 and 13.
【００２１】このように本実施形態によると、冷媒９に
混入した気泡１４は気泡ポケット１１，１３に捕捉され
ので、気泡１４がＸ線管１のＸ線放射窓４の前を横切る
ことがない。従って、冷媒９だけを通過したＸ線と、冷
媒９と気泡１４とを通過したＸ線とが混在することがな
く、冷媒９だけを通過したＸ線だけの強度が一様なＸ線
束が得られるので、気泡１４に起因する被検体の組織構
造を反映していない異常陰影、つまりアーチファクトが
断層像に現れてしまうことが解消される。As described above, according to the present embodiment, the bubbles 14 mixed in the refrigerant 9 are trapped in the bubble pockets 11 and 13, so that the bubbles 14 do not cross the front of the X-ray emission window 4 of the X-ray tube 1. . Therefore, X-rays that have passed only the refrigerant 9 and X-rays that have passed the refrigerant 9 and the bubbles 14 are not mixed, and an X-ray flux having a uniform intensity of only the X-rays that have passed only the refrigerant 9 is obtained. This eliminates the appearance of abnormal shadows that do not reflect the tissue structure of the subject caused by the bubbles 14, that is, artifacts, in the tomographic image.
【００２２】なお、気泡ポケット１１，１３としては、
図１のような構造に限定されることなく、様間座に変形
することができる。例えば、上部気泡ポケット１１をテ
ーパー形でなく、図３に示すように、方形で形成しても
よいし、またガイド板１０を上部に接続し、下部、つま
り熱交換器６の側を開けて、この下部側を通して冷媒９
を循環させるようにしてもよい。The bubble pockets 11 and 13 include:
The present invention is not limited to the structure shown in FIG. For example, the upper bubble pocket 11 may be formed not in a taper shape but in a square shape as shown in FIG. 3, or the guide plate 10 may be connected to the upper portion and the lower portion, that is, the side of the heat exchanger 6 may be opened. , Through this lower side the refrigerant 9
May be circulated.
【００２３】また、上部気泡ポケット１１を凸状に形成
するのではなく、図４に示すように、ガイド板１０を上
部に接続することで設けるようにしてもよい。さらに、
気泡ポケットとしては、Ｘ線管容器５に設けるのではな
く、熱交換器６の内部の循環経路の任意の場所に設ける
ようにしてもよい。この場合、気泡が過度に溜まったと
き、Ｘ線管装置よりも著しき安価な熱交換器６だけを交
換することで、高価なＸ線管装置を継続的に使用できる
というメリットがある。Further, instead of forming the upper bubble pocket 11 in a convex shape, the upper bubble pocket 11 may be provided by connecting a guide plate 10 to the upper portion as shown in FIG. further,
Instead of being provided in the X-ray tube container 5, the bubble pocket may be provided at an arbitrary position in the circulation path inside the heat exchanger 6. In this case, when the bubbles are excessively accumulated, there is an advantage that the expensive X-ray tube device can be continuously used by replacing only the heat exchanger 6 which is significantly less expensive than the X-ray tube device.
【００２４】（第２実施形態）図５には、第２実施形態
に係るＸ線コンピュータ断層撮影装置に装備されるＸ線
管装置の構成を示している。なお、図１と同じ部分には
同符号を付して詳細な説明は省略する。本実施形態で
は、Ｘ線管１６は、回転陽極１９が接地（グランド）さ
れている陽極接地方式が採用されてる。(Second Embodiment) FIG. 5 shows a configuration of an X-ray tube device provided in an X-ray computed tomography apparatus according to a second embodiment. The same parts as those in FIG. 1 are denoted by the same reference numerals, and detailed description is omitted. In the present embodiment, the X-ray tube 16 employs an anode grounding method in which the rotating anode 19 is grounded.
【００２５】周知の通り、陽極接地方式では、回転陽極
１９が接地されているので、Ｘ線管１６の内部であっ
て、回転陽極１９やＸ線放射窓４の周辺に、反跳電子か
らＸ線放射窓４を遮蔽する遮蔽板や、Ｘ線放射窓４の熱
を放熱する放熱板等の比較的複雑な構造を設置すること
ができる。このためＸ線放射窓４は、陽極非接地方式と
異なって、あまり高温に達することはなく、陽極接地方
式のＸ線管１６では、Ｘ線放射窓４を強制的に冷却する
必要性はさほどではなく、自然冷却で十分であると言え
る。つまり、陽極接地方式のＸ線管１６では、Ｘ線放射
窓４の前には冷媒９を流す必要はないと考えられる。As is well known, in the anode grounding method, since the rotating anode 19 is grounded, X-rays are generated from the recoil electrons inside the X-ray tube 16 around the rotating anode 19 and the X-ray emission window 4. A relatively complicated structure such as a shielding plate that shields the radiation window 4 or a heat radiation plate that radiates heat of the X-ray radiation window 4 can be installed. Therefore, unlike the non-grounded anode method, the X-ray emission window 4 does not reach a very high temperature. In the X-ray tube 16 of the anode grounded method, the necessity of forcibly cooling the X-ray emission window 4 is not so large. Rather, natural cooling is sufficient. That is, in the X-ray tube 16 of the anode grounding type, it is considered that the refrigerant 9 does not need to flow in front of the X-ray emission window 4.
【００２６】これを考慮して、本実施形態では、Ｘ線放
射窓４の前には冷媒９が流れないように、Ｘ線管１６の
Ｘ線放射窓４を、Ｘ線管容器１７でカバーすることな
く、露出した構造を採用している。In consideration of this, in the present embodiment, the X-ray emission window 4 of the X-ray tube 16 is covered with the X-ray tube container 17 so that the refrigerant 9 does not flow in front of the X-ray emission window 4. The exposed structure is adopted without doing.
【００２７】このように本実施形態によると、Ｘ線管１
６のＸ線放射窓４が、Ｘ線管容器１７にカバーされずに
露出されている。このため冷媒９がＸ線放射窓４の前面
には流通しないので、当然にして、冷媒９に混入した気
泡１４がＸ線管１６のＸ線放射窓４の前を横切ることが
ない。従って、冷媒９だけを通過したＸ線と、冷媒９と
気泡１４とを通過したＸ線とが混在することがなく、冷
媒９だけを通過したＸ線だけの強度が一様なＸ線束が得
られる。このため気泡１４に起因する被検体の組織構造
を反映していない異常陰影、つまりアーチファクトが断
層像に現れてしまうことが解消される。As described above, according to the present embodiment, the X-ray tube 1
The X-ray emission window 6 is exposed without being covered by the X-ray tube container 17. For this reason, since the refrigerant 9 does not flow in front of the X-ray radiation window 4, naturally, the bubbles 14 mixed in the refrigerant 9 do not cross the X-ray tube 16 in front of the X-ray radiation window 4. Therefore, X-rays that have passed only the refrigerant 9 and X-rays that have passed the refrigerant 9 and the bubbles 14 are not mixed, and an X-ray flux having a uniform intensity of only the X-rays that have passed only the refrigerant 9 is obtained. Can be Therefore, it is possible to prevent an abnormal shadow, which does not reflect the tissue structure of the subject due to the bubbles 14, that is, an artifact from appearing in the tomographic image.
【００２８】本発明は、上述した実施形態に限定される
ことなく、種々変形して実施可能である。The present invention is not limited to the embodiments described above, but can be implemented with various modifications.
【００２９】[0029]
【発明の効果】本発明では、冷媒に混入した気泡は気泡
ポケットに捕捉される。このため気泡がＸ線管のＸ線放
射窓の前を横切ることがない。従って、冷媒だけを通過
したＸ線と、冷媒と気泡とを通過したＸ線とが混在する
ことがなく、冷媒だけを通過したＸ線だけの強度が一様
なＸ線束が得られる。このため気泡に起因する被検体の
組織構造を反映していない異常陰影、つまりアーチファ
クトが断層像に現れてしまうことが解消される。According to the present invention, bubbles mixed in the refrigerant are trapped in the bubble pockets. For this reason, bubbles do not cross the front of the X-ray emission window of the X-ray tube. Therefore, X-rays that have passed only the refrigerant and X-rays that have passed the refrigerant and the bubbles do not coexist, and an X-ray flux having a uniform intensity is obtained only for the X-rays that have passed only the refrigerant. Therefore, it is possible to prevent an abnormal shadow, which does not reflect the tissue structure of the subject due to the bubbles, that is, an artifact from appearing in the tomographic image.
【００３０】また、本発明では、Ｘ線管のＸ線放射窓
が、Ｘ線管容器にカバーされずに露出されている。この
ため冷媒がＸ線放射窓の前面には流通しないので、当然
にして、冷媒に混入した気泡がＸ線管のＸ線放射窓の前
を横切ることがない。従って、冷媒だけを通過したＸ線
と、冷媒と気泡とを通過したＸ線とが混在することがな
く、冷媒だけを通過したＸ線だけの強度が一様なＸ線束
が得られる。このため気泡に起因する被検体の組織構造
を反映していない異常陰影、つまりアーチファクトが断
層像に現れてしまうことが解消される。In the present invention, the X-ray emission window of the X-ray tube is exposed without being covered by the X-ray tube container. For this reason, since the refrigerant does not flow in front of the X-ray emission window, naturally, bubbles mixed into the refrigerant do not cross the front of the X-ray emission window of the X-ray tube. Therefore, X-rays that have passed only the refrigerant and X-rays that have passed the refrigerant and the bubbles do not coexist, and an X-ray flux having a uniform intensity is obtained only for the X-rays that have passed only the refrigerant. Therefore, it is possible to prevent an abnormal shadow, which does not reflect the tissue structure of the subject due to the bubbles, that is, an artifact from appearing in the tomographic image.
【図１】本発明の第１実施形態に係るコンピュータ断層
撮影装置に装備されるＸ線管装置の構成図。FIG. 1 is a configuration diagram of an X-ray tube device provided in a computed tomography apparatus according to a first embodiment of the present invention.
【図２】図１の気泡ポケットに、Ｘ線管装置が被検体を
中心とした回転軌道上のいずれの位置にあっても捕捉し
た気泡が保持される様子を示す図。FIG. 2 is a diagram showing a state in which trapped bubbles are held in the bubble pocket of FIG. 1 regardless of the position of the X-ray tube apparatus on a rotational trajectory centered on a subject.
【図３】図１の気泡ポケット及びガイド板の変形例を示
す図。FIG. 3 is a diagram showing a modification of the bubble pocket and the guide plate of FIG. 1;
【図４】図１の気泡ポケット及びガイド板の他の変形例
を示す図。FIG. 4 is a view showing another modified example of the bubble pocket and the guide plate of FIG. 1;
【図５】本発明の第２実施形態に係るコンピュータ断層
撮影装置に装備されるＸ線管装置の構成図。FIG. 5 is a configuration diagram of an X-ray tube device provided in a computed tomography apparatus according to a second embodiment of the present invention.
１…Ｘ線管、 ２…フィラメント、 ３…回転陽極、 ４…Ｘ線放射窓、 ５…Ｘ線管容器、 ６…熱交換器、 ７…ジョイント、 ８…循環ホース、 ９…冷媒、 １０…ガイド板、 １１…上部気泡ポケット、 １２…仕切板、 １３…下部気泡ポケット、 １４…気泡、 １５…捕捉された気泡。 DESCRIPTION OF SYMBOLS 1 ... X-ray tube, 2 ... Filament, 3 ... Rotating anode, 4 ... X-ray emission window, 5 ... X-ray tube container, 6 ... Heat exchanger, 7 ... Joint, 8 ... Circulation hose, 9 ... Refrigerant, 10 ... Guide plate, 11: Upper air pocket, 12: Partition plate, 13: Lower air pocket, 14: Air bubbles, 15: Trapped air bubbles.
Claims (6)
を介して検出器で検出し、これにより収集された投影デ
ータに基づいて断層像データを再構成するＸ線コンピュ
ータ断層撮影装置において、 前記Ｘ線管装置は、Ｘ線管と、前記Ｘ線管を収容するＸ
線管容器と、前記Ｘ線管容器と連結される熱交換器と、
前記Ｘ線管容器と前記熱交換器との間を循環される冷媒
とを有し、 前記Ｘ線管容器には、前記冷媒中に混入した気泡を捕捉
する気泡ポケットが設けられていることを特徴とするＸ
線コンピュータ断層撮影装置。An X-ray computed tomography apparatus for detecting X-rays emitted from an X-ray tube device through a subject with a detector and reconstructing tomographic image data based on projection data collected thereby. In the above, the X-ray tube device may include an X-ray tube and an X-ray tube that accommodates the X-ray tube.
A ray tube container, a heat exchanger connected to the X-ray tube container,
Having a refrigerant circulated between the X-ray tube container and the heat exchanger, wherein the X-ray tube container is provided with a bubble pocket for catching bubbles mixed in the refrigerant. Characteristic X
-Ray computed tomography device.
泡ポケットに誘導するガイドが設けられてることを特徴
とする請求項１記載のＸ線コンピュータ断層撮影装置。2. The X-ray computed tomography apparatus according to claim 1, wherein the X-ray tube container is provided with a guide for guiding the bubbles into the bubble pockets.
前記被検体を中心とした回転軌道上のいずれの位置にあ
っても前記捕捉した気泡を保持するように設けられてい
ることを特徴とする請求項１記載のＸ線コンピュータ断
層撮影装置。3. The air bubble pocket is provided so as to hold the captured air bubble regardless of the position of the X-ray tube apparatus on a rotational trajectory around the subject. The X-ray computed tomography apparatus according to claim 1, wherein
を介して検出器で検出し、これにより収集された投影デ
ータに基づいて断層像データを再構成するＸ線コンピュ
ータ断層撮影装置において、 前記Ｘ線管装置は、Ｘ線管と、このＸ線管を収容するＸ
線管容器と、このＸ線管容器と連結される熱交換器と、
前記Ｘ線管容器と前記熱交換器との間を循環される冷媒
とを有し、 前記Ｘ線管のＸ線放射窓は、前記Ｘ線管容器にカバーさ
れずに露出されていることを特徴とするＸ線コンピュー
タ断層撮影装置。4. An X-ray computed tomography apparatus for detecting X-rays emitted from an X-ray tube device via a subject with a detector and reconstructing tomographic image data based on projection data collected thereby. In the above, the X-ray tube apparatus includes an X-ray tube and an X-ray tube that accommodates the X-ray tube.
A ray tube container, a heat exchanger connected to the X-ray tube container,
A refrigerant circulating between the X-ray tube container and the heat exchanger, wherein the X-ray emission window of the X-ray tube is exposed without being covered by the X-ray tube container. A characteristic X-ray computed tomography apparatus.
容器と、前記Ｘ線管容器と連結される熱交換器と、前記
Ｘ線管容器と前記熱交換器との間を循環される冷媒とを
具備するＸ線管装置において、 前記Ｘ線管容器には、前記冷媒中に混入した気泡を捕捉
する気泡ポケットが設けられていることを特徴とするＸ
線管装置。5. An X-ray tube, an X-ray tube container accommodating the X-ray tube, a heat exchanger connected to the X-ray tube container, and a space between the X-ray tube container and the heat exchanger. An X-ray tube device comprising: a refrigerant circulating through the X-ray tube, wherein the X-ray tube container is provided with a bubble pocket for capturing bubbles mixed in the refrigerant.
Wire tube device.
容器と、前記Ｘ線管容器と連結される熱交換器と、前記
Ｘ線管容器と前記熱交換器との間を循環される冷媒とを
具備するＸ線管装置において、 前記Ｘ線管のＸ線放射窓は、前記Ｘ線管容器にカバーさ
れずに露出されていることを特徴とするＸ線管装置。6. An X-ray tube, an X-ray tube container accommodating the X-ray tube, a heat exchanger connected to the X-ray tube container, and a space between the X-ray tube container and the heat exchanger. An X-ray tube device comprising: a refrigerant circulated through the X-ray tube, wherein the X-ray emission window of the X-ray tube is exposed without being covered by the X-ray tube container.
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|---|---|---|---|
| JP06712399A JP4642951B2 (en) | 1999-03-12 | 1999-03-12 | X-ray computed tomography system |
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|---|---|---|---|
| JP2010020549A Division JP2010104819A (en) | 2010-02-01 | 2010-02-01 | X-ray computer tomographic apparatus and x-ray tube device |
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| Publication Number | Publication Date |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1686608A1 (en) * | 2003-10-17 | 2006-08-02 | Kabushiki Kaisha Toshiba | X-ray apparatus |
| JP2012256577A (en) * | 2011-06-10 | 2012-12-27 | Hitachi Medical Corp | X-ray device |
| EP3764752A3 (en) * | 2019-06-17 | 2021-03-17 | GE Precision Healthcare LLC | X-ray tube casing with integral heat exchanger |
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|---|---|---|---|---|
| JPH09500230A (en) * | 1993-07-13 | 1997-01-07 | ヘイビフ、デイビッド・ヴィー・ジュニア | Method and apparatus for extending useful life of X-ray tube |
| WO1997047163A1 (en) * | 1996-06-06 | 1997-12-11 | Varian Associates, Inc. | X-ray generating apparatus with a heat transfer device |
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|---|---|---|---|---|
| JPS53160380U (en) * | 1977-05-23 | 1978-12-15 | ||
| JP3605424B2 (en) * | 1994-11-01 | 2004-12-22 | ジーイー横河メディカルシステム株式会社 | X-ray tube driving method and X-ray tomography apparatus |
| JPH0927394A (en) * | 1995-07-10 | 1997-01-28 | Toshiba Corp | X-ray tube device |
-
1999
- 1999-03-12 JP JP06712399A patent/JP4642951B2/en not_active Expired - Fee Related
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH09500230A (en) * | 1993-07-13 | 1997-01-07 | ヘイビフ、デイビッド・ヴィー・ジュニア | Method and apparatus for extending useful life of X-ray tube |
| WO1997047163A1 (en) * | 1996-06-06 | 1997-12-11 | Varian Associates, Inc. | X-ray generating apparatus with a heat transfer device |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1686608A1 (en) * | 2003-10-17 | 2006-08-02 | Kabushiki Kaisha Toshiba | X-ray apparatus |
| EP1686608A4 (en) * | 2003-10-17 | 2010-01-13 | Toshiba Kk | X-ray apparatus |
| JP2012256577A (en) * | 2011-06-10 | 2012-12-27 | Hitachi Medical Corp | X-ray device |
| EP3764752A3 (en) * | 2019-06-17 | 2021-03-17 | GE Precision Healthcare LLC | X-ray tube casing with integral heat exchanger |
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| LAPS | Cancellation because of no payment of annual fees |