X-ray imaging apparatus and monochromatic x-ray generating method
An X-ray imaging apparatus according to an embodiment of the present disclosure includes an X-ray tube, a photon counting X-ray detector, and a filter unit. A generating unit of the X-ray tube is configured to generate X-rays. The photon counting X-ray detector is configured to count photons contained in the X-rays. The filter unit is provided between the X-ray tube and the photon counting X-ray detector. The filter unit includes a first filter and a second filter. The first filter is configured to shape a spectrum of the X-rays. The second filter is configured to generate X-ray fluorescence on the basis of X-rays related to a spectrum resulting from the shaping by the first filter.
1. An X-ray imaging apparatus comprising:
an X-ray tube configured to generate X-rays;
a photon counting X-ray detector configured to count photons contained in the X-rays; and
a filter unit provided between the X-ray tube and the photon counting X-ray detector, wherein
the filter unit includes:
a first filter configured to shape a spectrum of the X-rays; and
a second filter configured to generate X-ray fluorescence on a basis of X-rays related to a spectrum resulting from the shaping by the first filter.
2. The X-ray imaging apparatus according to claim 1 , further comprising: processing circuitry configured to calibrate outputs of a plurality of detecting elements included in the photon counting X-ray detector, on a basis of the X-ray fluorescence.
3. The X-ray imaging apparatus according to claim 1 , wherein, with respect to the spectrum of the X-rays radiated from the X-ray tube, the first filter passes such X-rays that are in an energy region higher than energy of the X-ray fluorescence.
4. The X-ray imaging apparatus according to claim 1 , wherein the first filter includes a plurality of types of metal.
5. The X-ray imaging apparatus according to claim 4 , wherein the first filter includes one or both of aluminum and copper.
6. The X-ray imaging apparatus according to claim 1 , wherein the second filter includes heavy metal.
7. The X-ray imaging apparatus according to claim 6 , wherein the second filter includes one selected from a group consisting of molybdenum, tin, tungsten, and lead.
8. The X-ray imaging apparatus according to claim 1 , wherein the filter unit is arranged between a couchtop and the X-ray tube, the couchtop being arranged between the X-ray tube and the photon counting X-ray detector.
9. The X-ray imaging apparatus according to claim 1 , wherein the filter unit is arranged between a couchtop and the photon counting X-ray detector, the couchtop being arranged between the X-ray tube and the photon counting X-ray detector.
10. The X-ray imaging apparatus according to claim 8 , further comprising:
a supporting frame configured to support the filter unit so as to be insertable in a radiation range of the X-rays generated by the X-ray tube; and
processing circuitry configured to control moving of a wedge filter to an outside of the radiation range and moving of the filter unit into the radiation range.
11. A monochromatic X-ray generating method comprising:
causing X-rays to become incident to a first filter configured to shape a spectrum of the X-rays;
causing X-rays related to a spectrum resulting from the shaping by the first filter to become incident to a second filter arranged on an X-ray exit side of the first filter; and
causing a second filter to generate monochromatic X-rays by using the X-rays related to the spectrum resulting from the shaping by the first filter.