JPWO2020043559A5

JPWO2020043559A5 -

Info

Publication number: JPWO2020043559A5
Application number: JP2021510403A
Authority: JP
Publication date: 2022-08-26

Claims

an anode;
an electron emission unit for generating a pulsed electron beam on the anode, the electron emission unit comprising a grid switch for generating the pulsed electron beam;
a rotating mechanism for rotating the anode;
A computed tomography x-ray tube for generating pulsed x-rays, comprising:
The rotating mechanism rotates the anode at a time-varying angular velocity,
The rotating mechanism rotates the anode such that the temporal change in the angular velocity is a temporally continuous, periodic oscillation about an average angular velocity ω _o ;
the rotation frequency of the anode and the switching frequency of the grid switch do not match ;
X-ray tube for computed tomography.

the rotating mechanism includes a combination of a stator and a rotor that rotates the anode;
The rotating mechanism varies the frequency of the current in the stator to vary the angular velocity of the anode over time; and/or the rotating mechanism varies the angular velocity of the anode over time. varying the power in the stator to cause
The X-ray tube for computed tomography according to claim 1.

3. The computer according to claim 1 or 2, wherein the rotation mechanism temporally varies the angular velocity of the anode according to a predetermined time evolution such that the rotation frequency of the anode need not be measured and controlled. X-ray tube for tomography.

4. An X-ray tube for computed tomography according to claim 1, embodied as a stereo tube in which two focal points of the electron beam are alternately generated.

Computed tomography according to any one of claims 1 to 4, wherein the angular velocity ω(t) varies in time according to the formula: ω(t) = ω _o + Δω sin Ωt, where ω _o is the average angular velocity. X-ray tube for imaging.

5, wherein Δω satisfies one of 1% ω _o ≤ Δω ≤ 6% ω _o , 2% ω _o ≤ Δω ≤ 5% ω _o , and 3% ω _o ≤ Δω ≤ 4% ω _o X-ray tube for computed tomography according to .

7. Computed tomography X-ray tube according to claim 5 or 6, wherein [Omega] is 2[pi]2 Hz.

said electron emission unit generating said pulsed electron beam having a pulse duration of between 10 microseconds and 500 milliseconds, between 10 microseconds and 250 milliseconds, or between 10 microseconds and 100 milliseconds; An X-ray tube for computed tomography according to any one of claims 1 to 7.

A computed tomography device for producing an image of a patient, comprising:
an X-ray tube according to any one of claims 1 to 8;
a gantry;
including
rotating the gantry during imaging;
the angular velocity of the anode and the rotational motion of the gantry during imaging are desynchronized by temporal changes in the angular velocity of the anode;
Computed tomography device.

A method of producing pulsed X-ray radiation using a rotating anode and a pulsed electron beam, comprising:
emitting said pulsed electron beam onto an anode ;
rotating the anode at a time-varying angular velocity;
including
the anode is rotated such that the temporal variation of the angular velocity is a continuous periodic oscillation in time about an average angular velocity ω _o ;
the pulsed electron beam is pulsed by a grid switch;
the rotation frequency of the anode and the switching frequency of the grid switch do not match ;
Method.

driving rotation of the anode by a stator and rotor combination;
varying the frequency of the current in the stator, thereby producing a time-continuous oscillation of the angular velocity of the anode about a mean angular velocity ω _o ; varying, thereby causing a time-continuous oscillation of said angular velocity of said anode about a mean angular velocity ω _o ;
11. The method of claim 10, comprising: