Methods and systems of combining magnetic resonance and nuclear imaging
View Patent ↗A multi-modality imaging system for imaging of an object under study, e.g., a whole body or parts of the body of animals such as humans, other primates, swine, dogs, rodents (especially mice and rats), that includes a magnetic resonance imaging apparatus and a cadmium zinc telluride (CZT)-family semiconductor, single-photon imaging apparatus in close proximity such that sequential or simultaneous imaging can be done with the two modalities using the same support bed of the object under study in the same, uninterrupted imaging session.
1. A combined magnetic resonance and single photon nuclear imaging system, the system comprising:
at least one semiconductor detector configured to directly convert incident gamma photons into electron-hole charge carriers;
at least one collimator for single photon nuclear imaging an object under study with the at least one semiconductor detector;
at least one magnet for producing a magnetic field suitable for magnetic resonance imaging; and
at least one transceiver for magnetic resonance imaging the object under study with the at least one magnet,
wherein the at least one semiconductor detector is configured to single photon nuclear image the object under study under an influence of the magnetic field suitable for magnetic resonance imaging,
wherein the at least one semiconductor detector is a compound semiconductor detector; and
wherein the at least one semiconductor detector comprises a semiconductor detector ring placed symmetrically with the at least one magnet.
2. The system of claim 1 , wherein the at least one semiconductor detector comprises a material selected from the group consisting of cadmium telluride (CdTe), mercuric iodide (HgI 2 ), thallium bromide (TlBr), gallium arsenide (GaAs), cadmium zinc telluride (CdZnTe), and cadmium manganese telluride (CdMnTe).
3. The system of claim 1 , wherein the at least one semiconductor detector is a cadmium zinc telluride (CZT) detector.
4. The system of claim 1 , wherein the at least one semiconductor detector comprises:
at least one semiconductor substrate for producing the charge carriers through interaction with the gamma photons; and
a plurality of electrodes for collecting the charge carriers.
5. The system of claim 1 , wherein the semiconductor detector ring comprises a plurality of semiconductor linear sides.
6. The system of claim 5 , wherein each of the plurality of semiconductor linear sides comprises a plurality of semiconductor modules.
7. The system of claim 1 , wherein the semiconductor detector ring comprises a plurality of semiconductor module rings.
8. The system of claim 7 , wherein the plurality of semiconductor module rings comprises a first ring having a plurality of first modules and a second ring having a plurality of second modules.
9. The system of claim 8 , wherein the first modules of the first ring are aligned with the second modules of the second ring along an axial direction.
10. The system of claim 8 , wherein the first modules of the first ring have an angular offset with the second modules of the second ring along an axial direction.
11. The system of claim 1 , wherein the at least one collimator is configured to be positioned between the object under study and the at least one semiconductor detector.
12. The system of claim 1 , wherein the at least one semiconductor detector is a stationary detector.
13. The system of claim 1 , wherein the at least one magnet comprises a central opening, and wherein the at least one semiconductor is configured to single photon nuclear image the object under study within the central opening such that the object under study is capable of being single photon imaged and magnet resonance imaged in a substantially simultaneous manner.
14. The system of claim 13 , further comprising a gradient coil attached to the at least one magnet, wherein the at least one transceiver comprises a radio frequency (RF) coil, and wherein the at least one semiconductor is configured to be between the RF coil and the gradient coil.
15. The system of claim 14 , wherein the at least one collimator is attached to the RE coil.
16. The system of claim 14 , wherein the at least one semiconductor is attached to the gradient coil.
17. The system of claim 1 , further comprising a correction processor, wherein the at least one semiconductor detector comprises at least one semiconductor substrate for producing electrons upon an interaction with the gamma photons, and wherein the correction processor is adapted to compensate for a Lorentz-force effect on the electrons traveling within the at least one semiconductor substrate and under the influence of the magnetic field suitable for magnetic resonance imaging such that a drift of the electrons is compensated.
18. The system of claim 1 , wherein the at least one semiconductor detector is adapted to detect at least one of the gamma photons outputted by the object under study and to generate a direct detection signal in response, wherein a signal processor is adapted to receive the detection signal and comprises a plurality of electronics adapted to amplify, address, and process the detection signal, and wherein the signal processor is positioned away from the magnetic field suitable for magnetic resonance imaging to remove an interference effect of the magnetic field suitable for magnetic resonance imaging.
19. A method of combining magnetic resonance and single photon nuclear imaging an object under study injected with a radioactive isotope, the method comprising:
symmetrically placing a semiconductor detector ring of at least one semiconductor detector with at least one magnet;
directly converting gamma photons from the radioactive isotope within the object under study by the at least one semiconductor detector into electron-hole charge carriers;
single photon nuclear imaging the object under study with at least one collimator positioned between the object under study and the at least one semiconductor detector;
producing a magnetic field suitable for magnetic resonance imaging by the at least one magnet; and
magnetic resonance imaging the object under study with at least one transceiver positioned between the object under study and the at least one magnet,
wherein the object under study is single photon nuclear imaged under an influence of the magnetic field suitable for magnetic resonance imaging, and
wherein the at least one semiconductor detector is a compound semiconductor detector.
20. The method of claim 19 , the detecting of the gamma photons comprising:
interacting the gamma photons with at least one semiconductor substrate of the at least one semiconductor detector; and
collecting charge carriers produced by the interaction of the gamma photons with the at least one semiconductor substrate.
21. The method of claim 19 , wherein the semiconductor detector ring of the at least one semiconductor detector comprises a first modular ring having a plurality of first modules and a second modular ring having a plurality of second modules.
22. The method of claim 21 , wherein the object under study is single photon nuclear imaged by aligning the first modules of the first modular ring with the second modules of the second modular ring along an axial direction.
23. The method of claim 21 , wherein the object under study is single photon nuclear imaged by angular offsetting the first modules of the first modular ring with the second modules of the second modular ring along an axial direction.
24. The method of claim 19 , wherein the object under study is single photon nuclear imaged by not moving the at least one semiconductor detector.
25. The method of claim 19 , wherein the at least one magnet comprises a central opening, and wherein the object under study is single photon nuclear imaged by the at least one semiconductor within the central opening such that the object under study is capable of being single photon imaged and magnet resonance imaged in a substantially simultaneous manner.
26. The method of claim 19 , further comprising:
correcting for a Lorentz-force effect on electrons traveling within at least one semiconductor substrate of the at least one semiconductor detector and under the influence of the magnetic field suitable for magnetic resonance imaging.
27. The method of claim 19 , further comprising:
generating at least one direct detection signal in response to detecting the gamma photons by the at least one semiconductor detector;
receiving the detection signal by a signal processor comprising a plurality of electronics adapted to amplify, address, and process the detection signal; and
removing an interference effect of the magnetic field suitable for magnetic resonance imaging on the single photon nuclear imaging by positioning the signal processor away from the magnetic field suitable for magnetic resonance imaging.
28. A combined magnetic resonance and single photon nuclear imaging system, the system comprising;
at least one semiconductor detector configured to directly convert incident gamma photons into electron-hole charge carriers;
at least one collimator for single photon nuclear imaging an object under study with the at least one semiconductor detector;
at least one magnet for producing a magnetic field suitable for magnetic resonance imaging and having a central opening; and
at least one transceiver for magnetic resonance imaging the object under study with the at least one magnet,
wherein the at least one semiconductor detector is configured to single photon nuclear image the object under study under an influence of the magnetic field suitable for magnetic resonance imaging,
wherein the at least one semiconductor detector is a compound detector; and
wherein the at least one semiconductor detector comprises a semiconductor detector ring placed symmetrically with the at least one magnet and within the central opening of the at least one magnet.