Hybrid imaging apparatus

1. A hybrid imaging apparatus comprising

a magnetic resonance imaging (MRI) arrangement having a radio frequency (RF) resonator structure and a gradient coil system with a longitudinal axis,

an emission tomography (ET) arrangement having a detector device comprising a photosensor and a circuit board arrangement with at least one readout circuit board on which an ET electronics is arranged,

an internal shielding device configured to mutually shield the ET electronics of the ET arrangement and the RF resonator structure of the MRI arrangement,

wherein the photosensor is arranged, in relation to the longitudinal axis, radially inside the circuit board arrangement and radially outside the RF resonator structure, and

wherein the internal shielding device is arranged, in relation to the longitudinal axis, radially outside the photosensor and/or integrated into the photosensor.

2. The hybrid imaging apparatus as claimed in claim 1 , wherein the emission tomography arrangement is a positron emission tomography (PET) arrangement, wherein the photosensor comprises a plurality of circularly arranged sensor elements.

3. The hybrid imaging apparatus as claimed in claim 1 , wherein the internal shielding device comprises a plurality of shielding faces made from an electrically conductive material.

4. The hybrid imaging apparatus as claimed in claim 3 , wherein the plurality of shielding faces are overlapping shielding faces.

5. The hybrid imaging apparatus as claimed in claim 3 , wherein the shielding faces are integrated into at least one circuit board of the circuit board arrangement or are arranged on at least one circuit board of the circuit board arrangement, and wherein the at least one circuit board is a readout circuit board and/or a sensor circuit board of the ET arrangement.

6. The hybrid imaging apparatus as claimed in claim 5 , wherein the circuit board arrangement is multilayered and comprises at least partially a plurality of shielding faces, wherein the plurality of shielding faces are distributed within the circuit board arrangement over a plurality of layers of the circuit board arrangement.

7. The hybrid imaging apparatus as claimed in claim 5 , wherein the shielding faces within the circuit board arrangement are capacitively connected to one another.

8. The hybrid imaging apparatus as claimed in claim 7 , wherein the capacitive connection of the shielding faces within the circuit board arrangement is configured through an overlay of the shielding faces within the circuit board arrangement.

9. The hybrid imaging apparatus as claimed in claim 1 , wherein the internal shielding device forms a closed RF shield face.

10. The hybrid imaging apparatus as claimed in claim 1 , further comprising an external shielding device that is arranged radially outside the detector device and the circuit board arrangement.

11. The hybrid imaging apparatus as claimed in claim 10 , wherein the external shielding device is electrically connected or electromagnetically coupled to the internal shielding device.

12. The hybrid imaging apparatus as claimed in claim 10 , wherein components of the ET electronics are arranged between the internal shielding device and the external shielding device.

13. The hybrid imaging apparatus as claimed in claim 10 , further comprising signal and supply lines of the ET electronics arranged between the internal shielding device and the external shielding device.

14. The hybrid imaging apparatus as claimed in claim 1 ,

wherein the internal shielding device is integrated into at least one sensor circuit board of the circuit board arrangement and the at least one sensor circuit board comprises vias configured to receive signal and supply lines or

wherein the internal shielding device is integrated into the photosensor and the photosensor comprises vias through the internal shielding device that is integrated into the photosensor.

15. The hybrid imaging apparatus as claimed in claim 1 , wherein the detector device is a silicon photomultiplier (SiPM).