JPH05300901A - X-ray ct system - Google Patents

X-ray ct system

Info

Publication number
JPH05300901A
JPH05300901A JP4110524A JP11052492A JPH05300901A JP H05300901 A JPH05300901 A JP H05300901A JP 4110524 A JP4110524 A JP 4110524A JP 11052492 A JP11052492 A JP 11052492A JP H05300901 A JPH05300901 A JP H05300901A
Authority
JP
Japan
Prior art keywords
ray
rotating frame
vacuum container
subject
target
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.)
Pending
Application number
JP4110524A
Other languages
Japanese (ja)
Inventor
Takayuki Takemoto
隆之 竹本
Masahiro Saito
正弘 斎藤
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Shimadzu Corp
Original Assignee
Shimadzu Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Shimadzu Corp filed Critical Shimadzu Corp
Priority to JP4110524A priority Critical patent/JPH05300901A/en
Publication of JPH05300901A publication Critical patent/JPH05300901A/en
Pending legal-status Critical Current

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  • Apparatus For Radiation Diagnosis (AREA)

Abstract

PURPOSE:To constitute the system so that X-ray transmission data in a plane being vertical to a rotation center axis of an X-ray beam is obtained, and also, length in the body axial direction of an examinee is short and compact, and a high speed scan can be executed. CONSTITUTION:This system is provided with an annular vacuum vessel 1, an annular target 2 provided opposingly in its vacuum vessel 1 and a rotary frame 3 provided so as to be rotatable, a filament 6 and a detector train 10 attached to positions opposed each other to this rotary frame 3, a magnetic bearing 5 for floating and supporting the rotary frame so as to be freely rotatable, and a driving means 4 for rotating the rotary frame 3.

Description

【発明の詳細な説明】Detailed Description of the Invention

【0001】[0001]

【産業上の利用分野】この発明は、X線CT装置、特に
医療用X線CT装置に関する。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray CT apparatus, and more particularly to a medical X-ray CT apparatus.

【0002】[0002]

【従来技術】X線CT装置では、回転中心軸付近の置か
れる被検体のまわりを、少なくとも180度以上の角度
でX線を回転走査し、種々の方向からのX線透過データ
をX線検出器によって測定し、得られた多方向からのX
線透過データを画像再構成処理して被検体の断層像を得
る。これまでいわゆる第3世代のCT装置では、回転フ
レームにX線管と検出器列とを対向して装着し、被検体
のまわりを回転しながらX線を被検体へ照射し、被検体
を透過したX線量を検出器列により電気信号に変換する
ことで、多方向からのX線透過データを収集している。
2. Description of the Related Art In an X-ray CT apparatus, an X-ray is rotationally scanned around an object placed near the center axis of rotation at an angle of at least 180 degrees or more to detect X-ray transmission data from various directions. X from multiple directions obtained by measuring with a measuring instrument
Image reconstruction processing is performed on the line transmission data to obtain a tomographic image of the subject. Until now, in so-called third-generation CT apparatuses, an X-ray tube and a detector row are mounted on a rotating frame so as to face each other, and while rotating around the subject, the subject is irradiated with X-rays and transmitted through the subject. The X-ray transmission data from multiple directions is collected by converting the X-ray dose into an electric signal by the detector array.

【0003】さらに最近では、スリップリングを用いる
ことによりケーブルの処理をなくし、回転フレームの回
転動作を止めることなくX線照射およびデータ収集を行
う方式、いわゆる連続回転型第3世代CT装置が開発さ
れ、実用に供されている。これらの装置では、透過デー
タの電気信号は、スリップリングを介してデータ処理装
置に伝送する方法の他に、特表平2−501623号に
示されているような発光−受光素子を用い光学手段によ
りデータを伝送するようにしている。
More recently, a so-called continuous rotation type 3rd generation CT apparatus has been developed in which a slip ring is used to eliminate the processing of cables and to perform X-ray irradiation and data collection without stopping the rotation operation of the rotating frame. Has been put to practical use. In these devices, in addition to the method of transmitting an electric signal of transmitted data to a data processing device via a slip ring, an optical means using a light emitting-light receiving element as shown in JP-A-2-501623 is used. To transmit data.

【0004】また、第4世代のCT装置としては、スリ
ップリングを用いるものの他に、特公昭62−5449
9号、特開昭59−94347号に示されているような
電場や磁場によって電子ビームを偏向させることにより
機械的運動部分をなくした、電子ビーム偏向型X線CT
装置が一部実用に供されている。
Further, as the fourth-generation CT apparatus, in addition to the one using a slip ring, there is a Japanese Patent Publication No. 62-5449.
9 and JP-A-59-94347, an electron beam deflection type X-ray CT in which a mechanical moving part is eliminated by deflecting an electron beam by an electric field or a magnetic field.
Part of the device is put to practical use.

【0005】[0005]

【発明が解決しようとする課題】しかしながら、上記の
ような第3世代CT装置では、回転フレームの駆動手段
が電動モーターであるため、高速の回転に対して、大型
の電導モーターが必要となると同時に、この電動モータ
ーから伝わる振動がX線管や検出器に振れを生じさせ、
良好な断層像を得るためのデータ収集ができないという
問題があり、毎秒1回転程度以上には高速回転が不可能
であった。
However, in the above-mentioned third-generation CT apparatus, since the driving means for the rotating frame is an electric motor, a large conductive motor is required for high-speed rotation and at the same time. , The vibration transmitted from this electric motor causes the X-ray tube and the detector to shake,
There is a problem that data cannot be collected to obtain a good tomographic image, and high-speed rotation cannot be performed at about 1 rotation per second or more.

【0006】電子ビーム走査型の第4世代CT装置で
は、放射されるX線ビームが被検体に到達する間に検出
器によって遮られないようにする必要があるため、回転
中心軸に対してX線ビームが垂直にならず、傾斜を持っ
て走査する構造になる。このため本来同じデータである
はずの180度回転したX線透過データが走査面からわ
ずかに傾斜する経路を通るために良好なデータ収集がで
きず、また、第4世代CT装置では、円周360度すべ
てにわたり検出器を設けているため、検出器数が増加
し、製造コスト増加の要因となっている。
In the fourth-generation electron beam scanning CT apparatus, it is necessary to prevent the emitted X-ray beam from being blocked by the detector while it reaches the object. The structure is such that the line beam is not vertical and scans with an inclination. Therefore, the X-ray transmission data rotated by 180 degrees, which is supposed to be the same data, passes through a path slightly inclined from the scanning surface, so that good data collection cannot be performed. Further, in the fourth generation CT apparatus, the circumference 360 Since detectors are installed all over, the number of detectors increases, which is a factor of increasing manufacturing cost.

【0007】さらに、電子ビーム偏向型CT装置に用い
られるX線管は、電子ビームがリング型ターゲットに衝
突する円周面に対して直角な方向に電子ビームを走査さ
せながら偏向させる構成になっているため、リング型タ
ーゲットのつくる平面に直角な方向に大きい形状を有
し、また、電子ビーム源とは反対側に患者用ベットを配
置しなければならないため、被検体軸方向に対して非常
に長く広い設置面積を要する。さらに、電子ビーム源側
は閉ざされた空間となるため、被検者に不安を与え、第
3世代CT装置のような開放型のCT装置はその構造
上、不可能である。この発明は、このような事情を鑑み
てなされたものでありその目的は、X線ビームが回転中
心軸に対して垂直な平面上を走査し、電子ビーム偏向型
並の高速走査を可能とすると共に被検体の体軸方向の長
さがコンパクトで、開放型のX線CT装置を提供するこ
とにある。
Further, the X-ray tube used in the electron beam deflection type CT apparatus is constructed so as to deflect the electron beam while scanning the electron beam in a direction perpendicular to the circumferential surface where the electron beam collides with the ring target. Since it has a large shape in the direction perpendicular to the plane formed by the ring-shaped target, and the patient bed must be placed on the side opposite to the electron beam source, it is extremely It requires a long and wide installation area. Furthermore, since the electron beam source side is a closed space, it gives anxiety to the subject, and an open type CT device such as the third generation CT device is impossible due to its structure. The present invention has been made in view of the above circumstances, and an object thereof is to allow an X-ray beam to scan on a plane perpendicular to the rotation center axis, thereby enabling high-speed scanning comparable to an electron beam deflection type. Another object of the present invention is to provide an open type X-ray CT apparatus in which the length of the subject in the body axis direction is compact.

【0008】[0008]

【課題を解決するための手段】上記目的を達成するため
に、この発明によるX線CT装置は、環状の真空容器の
内部に、環状ターゲットと、このターゲットと対向し磁
気浮上方式を用いた駆動手段により回転する回転フレー
ムを収容するとともに、前記回転フレームに前記ターゲ
ットに向けて電子線を放出する少なくとも一個の陰極と
電子線の照射でターゲットより放射され被検体を透過し
たX線を検出するX線検出器列とを設けたことを特徴と
する。
In order to achieve the above object, an X-ray CT apparatus according to the present invention is provided with an annular target inside a ring-shaped vacuum container and a drive device which faces the target and uses a magnetic levitation method. X-rays for accommodating a rotating frame which is rotated by means, and for detecting X-rays emitted from the target and transmitted through the subject by irradiation of the rotating frame with at least one cathode that emits an electron beam toward the target. And a line detector array.

【0009】[0009]

【作用】この発明の構成によれば、回転フレームに陰極
と検出器列が取り付けられているので、フレームの回転
に伴い被検体に対して多方向から回転中心軸に垂直な面
でX線を照射し、被検体を透過したX線量を検出器列に
よって検出し、良好なX線透過データを収集できる。ま
た、回転フレームは磁気浮上により非接触状態であるの
で、高速に回転でき、X線透過データを高速に収集でき
る。
According to the structure of the present invention, since the cathode and the detector row are attached to the rotating frame, X-rays are emitted from a plurality of directions relative to the subject in a plane perpendicular to the central axis of rotation as the frame rotates. The X-ray dose irradiated and transmitted through the subject can be detected by the detector array, and good X-ray transmission data can be collected. Further, since the rotating frame is in a non-contact state due to magnetic levitation, it can rotate at high speed, and X-ray transmission data can be collected at high speed.

【0010】[0010]

【実施例】以下この発明の一実施例を図面を参照しなが
ら説明する。図1は一実施例の構成を示す縦断面を、図
2は図1のA−A′断面を図で、駆動コイルは省略され
ている。図において、1は中心に被検体挿通孔1′が形
成された環状の真空容器、2は真空容器1内に図示しな
い碍子等の支持手段を介して固定された陽極をなす環状
ターゲットで、その表面が後述の電子線照射で発生した
X線Xが前記真空容器1の軸心Oと垂直な平面に指向す
るように傾斜されている。また、ターゲット内部は冷却
油や冷却ガスを循環し冷却することが望ましい。
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a vertical cross-sectional view showing the structure of one embodiment, and FIG. 2 is a cross-sectional view taken along the line AA ′ in FIG. 1, with the drive coil omitted. In the figure, reference numeral 1 is an annular vacuum container in which a sample insertion hole 1'is formed in the center, and 2 is an annular target which serves as an anode and is fixed in the vacuum container 1 through a supporting means such as an insulator (not shown). The surface is inclined so that X-rays X generated by electron beam irradiation, which will be described later, are directed to a plane perpendicular to the axis O of the vacuum container 1. Further, it is desirable to circulate cooling oil or cooling gas inside the target for cooling.

【0011】3は、前記真空容器1内に回転自在に組み
込まれた環状回転フレームで、ロータ部を形成する円筒
部31 と、それと一体のフランジ部32 とよりなる。4
は、前記真空容器1の外周に近設して配設された駆動手
段としての環状のステータで、このステータ4の通電制
御によって回転フレーム3は毎秒10〜100回転で回
転駆動される。5は、回転フレーム3を回転自在に浮上
支持する磁気軸受用コイルで、容器1の外囲および外周
側面の周方向に複数箇所に装備されている。
Reference numeral 3 denotes an annular rotary frame which is rotatably incorporated in the vacuum container 1, and is composed of a cylindrical portion 3 1 forming a rotor portion and a flange portion 3 2 integral therewith. Four
Is an annular stator as a driving means arranged near the outer periphery of the vacuum container 1. The rotating frame 3 is rotationally driven at 10 to 100 revolutions per second by controlling the energization of the stator 4. Reference numeral 5 denotes a magnetic bearing coil that rotatably supports the rotating frame 3 in a floating manner.

【0012】6は、回転フレーム3に前記ターゲット2
に対向して配設された熱電子を放出するフィラメント
(陰極)、7は熱電子の照射によりターゲットより軸心
O方向で、且つ、軸心Oに垂直な方向に放射されるX線
Xを図2中点線で示すようにファンビームにするコリメ
ータで、腕33 を介して回転フレーム3に固定されてい
る。
Reference numeral 6 designates the target 2 on the rotary frame 3.
The thermoelectron-emitting filament (cathode) 7 disposed opposite to the X-ray emits X-rays X emitted from the target in the direction of the axis O by the irradiation of thermions and in the direction perpendicular to the axis O. As shown by the dotted line in FIG. 2, it is a collimator that forms a fan beam, and is fixed to the rotating frame 3 via an arm 3 3 .

【0013】9はスライス幅を規制するコリメータで一
対の環状体よりなり、前記真空容器1または真空容器1
を収容する図示しないガントリに間隔が調整できるよう
に配備されている。なお、コリメータ9はスライス幅の
調整を必要としない場合は真空容器1内の回転フレーム
に取り付けることも可能である。
Numeral 9 is a collimator for restricting the slice width, which is composed of a pair of annular members, and is the vacuum container 1 or the vacuum container 1.
The gantry (not shown) accommodating the is arranged so that the interval can be adjusted. The collimator 9 can be attached to the rotating frame in the vacuum container 1 when the slice width does not need to be adjusted.

【0014】10は被検体11を透過したX線を検出
し、電気信号に変換する検出器列で、回転フレーム3に
それのフランジ32 より水平に延びる腕34 を介して前
記フィラメント6と対向し、且つ、ターゲット2より軸
心Oに垂直方向のX線Xを検出する位置に配設されてい
る。検出器としては、これまでのX線CT装置で使われ
ている種々のものが使用でき、代表的なものとしては、
キセノンガス電離箱やシンチレータと光電素子よりなる
X線検出器ないし半導体検出器などを1mm以下の間隔で
数百個を図2に示すように円弧状に配置する。
Numeral 10 is a detector array for detecting X-rays transmitted through the subject 11 and converting it into an electric signal, which is connected to the filament 6 through the arm 3 4 extending horizontally from the flange 3 2 of the rotary frame 3. It is arranged at a position facing each other and detecting the X-ray X perpendicular to the axis O from the target 2. As the detector, various ones used in the conventional X-ray CT apparatus can be used, and as a typical one,
Several hundreds of xenon gas ionization chambers, scintillators and X-ray detectors or semiconductor detectors composed of photoelectric elements are arranged in an arc shape at an interval of 1 mm or less as shown in FIG.

【0015】なお、フィラメント6への給電ないし、フ
ィラメント6−ターゲット2間への高電圧(医療用CT
装置では一般に100KVから150KV程度である)の給
電は、図示しないスリップリング方式やガリウム合金な
どの常温で液化する液体金属を用いる方式で行なう。
It should be noted that power is not supplied to the filament 6 or high voltage (medical CT) is applied between the filament 6 and the target 2.
Power is generally 100 KV to 150 KV in the apparatus) is supplied by a slip ring system (not shown) or a system using a liquid metal such as a gallium alloy which is liquefied at room temperature.

【0016】上記構成のX線CT装置において、ステー
タ4に通電すると磁気浮上している回転フレーム3が磁
気誘導作用で回転する。フィラメント6から放出された
電子線は陽極である環状ターゲット2に引きつけられ、
ターゲット2に衝突し、その衝突位置からX線が発生す
る。電子線のターゲット2上での衝突位置が回転フレー
ム3の回転とともに移動し、X線が被検体11を円周方
向から照射する。このX線は軸心Oに垂直な面内で放射
されるようコリメータで制限され被検体11を透過し、
検出器列10に入射する。
In the X-ray CT apparatus having the above-mentioned structure, when the stator 4 is energized, the magnetically levitated rotating frame 3 rotates by a magnetic induction action. The electron beam emitted from the filament 6 is attracted to the annular target 2 which is an anode,
The target 2 collides, and X-rays are generated from the collision position. The collision position of the electron beam on the target 2 moves as the rotating frame 3 rotates, and the X-ray irradiates the subject 11 from the circumferential direction. This X-ray is limited by a collimator so that it is emitted in a plane perpendicular to the axis O and passes through the subject 11,
It is incident on the detector array 10.

【0017】検出器列10からの電気信号は、多重化・
重層化したスリップリングや発光−受光素子を用いた光
学的手法により固定部にデータ転送され、図示しないデ
ータ収集回路を経た後、画像再構成され、断層像が得ら
れる。なお、実施例では、回転フレームに一個の陰極と
一個の検出器列を設けたが、例えば120°ピッチで3
系列設ければ、回転フレームを120°回転するのみで
被検体の全周を走査してデータを得ることができ、より
高速走査によるデータ収集が可能となる。
The electrical signals from the detector array 10 are multiplexed and
Data is transferred to a fixed part by an optical method using a slip ring and light emitting / receiving elements which are layered, and after passing through a data acquisition circuit (not shown), an image is reconstructed to obtain a tomographic image. In addition, in the embodiment, one cathode and one detector row are provided on the rotating frame, but, for example, 3 at a 120 ° pitch.
If the series is provided, data can be obtained by scanning the entire circumference of the subject only by rotating the rotating frame by 120 °, and data can be collected by higher speed scanning.

【0018】[0018]

【効果】この発明のX線CT装置によれば、陰極と検出
器列を支持する回転フレームを磁気浮上方式で回転駆動
しているので高速に回転でき、X線の発生位置を被検体
周囲の円周上で高速に走査し、X線透過データを短時間
で収集できるので、被検体である患者にとって負担の少
ない検査が可能となる。また、環状真空容器に回転可能
に浮上支持した回転フレームに陰極と共に検出器列が配
設されているので、X線ビームの回転中心軸に垂直な平
面内のX線透過データが得られるので、良好なデータ収
集ができる。
According to the X-ray CT apparatus of the present invention, since the rotating frame supporting the cathode and the detector array is rotationally driven by the magnetic levitation method, the rotating frame can be rotated at a high speed, and the X-ray generation position can be set around the subject. Since the X-ray transmission data can be collected in a short time by scanning the circumference at a high speed, it is possible to perform an examination with less burden on the patient who is the subject. Further, since the detector row is arranged together with the cathode on the rotary frame that is rotatably supported in the annular vacuum container, it is possible to obtain X-ray transmission data in a plane perpendicular to the central axis of rotation of the X-ray beam. Good data collection is possible.

【0019】さらに、真空容器が中心に被検体の挿入通
孔を形成したリング状の開放型であるため、被検体の長
さに制約がなく、一度挿入した被検体の任意の部位を能
率よく高速走査でき、且つ挿入孔が軸心方向に短い貫通
孔であるので、頭から挿入されても被検体に圧迫感を与
えることがなく、被検体は安心して診断を受けることが
でき、且つ、設置面積の小さいCT装置が得られる。
Further, since the vacuum container is a ring-shaped open type in which an insertion hole for the subject is formed in the center, there is no restriction on the length of the subject, and any portion of the subject once inserted can be efficiently used. Since high-speed scanning is possible and the insertion hole is a through hole that is short in the axial direction, it does not give a feeling of pressure to the subject even when it is inserted from the head, and the subject can be safely diagnosed, and A CT device with a small installation area can be obtained.

【図面の簡単な説明】[Brief description of drawings]

【図1】この発明の一実施例を側面からみた模式的な断
面図である。
FIG. 1 is a schematic sectional view of an embodiment of the present invention as viewed from the side.

【図2】図1のA−A′断面図である。FIG. 2 is a sectional view taken along the line AA ′ in FIG.

【符号の説明】[Explanation of symbols]

1…環状真空容器 2…環状ターゲット(陽極)
3…回転フレーム 4…ステータ(駆動手段) 5…磁気軸受用コイル 6…フィラメント(陰極) 7,9…コリメータ
10…検出器列 O…軸心
1 ... Annular vacuum container 2 ... Annular target (anode)
3 ... Rotating frame 4 ... Stator (driving means) 5 ... Magnetic bearing coil 6 ... Filament (cathode) 7, 9 ... Collimator
10 ... Detector row O ... Shaft center

Claims (1)

【特許請求の範囲】[Claims] 【請求項1】 環状真空容器と、前記真空容器内に配設
された環状ターゲットと、前記真空容器内において前記
ターゲットに対して電子線を放出する少なくとも一個の
陰極を装備して前記真空容器の軸心周りに回転する回転
フレームと、 前記回転フレームの前記陰極と対向する側に配設された
被検体透過X線を検出するX線検出器列と、前記回転フ
レームを回転可能に浮上支持する浮上手段と、前記回転
フレームを回転駆動する駆動手段とを備えたことを特徴
とするX線CT装置。
1. A vacuum container provided with an annular vacuum container, an annular target disposed in the vacuum container, and at least one cathode for emitting an electron beam to the target in the vacuum container. A rotating frame that rotates around an axis, an X-ray detector array that is disposed on the side of the rotating frame that faces the cathode, and detects X-rays transmitted through the subject, and rotatably supports the rotating frame so as to be rotatable. An X-ray CT apparatus comprising a levitation means and a drive means for rotationally driving the rotating frame.
JP4110524A 1992-04-28 1992-04-28 X-ray ct system Pending JPH05300901A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP4110524A JPH05300901A (en) 1992-04-28 1992-04-28 X-ray ct system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP4110524A JPH05300901A (en) 1992-04-28 1992-04-28 X-ray ct system

Publications (1)

Publication Number Publication Date
JPH05300901A true JPH05300901A (en) 1993-11-16

Family

ID=14537992

Family Applications (1)

Application Number Title Priority Date Filing Date
JP4110524A Pending JPH05300901A (en) 1992-04-28 1992-04-28 X-ray ct system

Country Status (1)

Country Link
JP (1) JPH05300901A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101232421B1 (en) * 2011-04-25 2013-02-12 경희대학교 산학협력단 computed tomography system including small-size x-ray source

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101232421B1 (en) * 2011-04-25 2013-02-12 경희대학교 산학협력단 computed tomography system including small-size x-ray source

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