Patent ID: 7835782
Filing Date: 2010-11-16
Classification: G01R

Abstract:
1. An integrated positron emission tomography (PET)-magnetic resonance imaging (MRI) scanner, comprising: a main magnet that generates a magnetic field during an MRI process for a subject, wherein the image is generated in a central region of the magnetic field; a PET scanner that detects annihilation photons produced by positron decays within a subject during a PET imaging process, wherein the PET scanner is enclosed by the main magnet, wherein the PET scanner further comprises: at least one ring of scintillators that detect positron annihilation photons and output light photons in response to the detected positron annihilation photons, wherein the ring of scintillators is situated in the central region of the magnetic field; and one or more photodetectors that convert the light photons output by the ring of scintillators into electrical signals, wherein the photodetectors are coupled to the ring of scintillators, such that the photodetectors are located outside of the central region of the magnetic field, and wherein the photodetectors are enclosed by the main magnet, such that length of an optical fiber coupling the photodetectors and the ring of scintillators is below a predetermined value; and a set of radio frequency (RF) coils that transmit signals to and receive signals from the subject during the MRI process, wherein the set of RF coils are enclosed by the PET scanner; and a shield configured to shield the photodetectors and associated circuitry of the PET scanner from the RF signals generated by the RF coils of the MRI; wherein keeping the photodetectors and associated circuitry outside of the central region of the magnetic field reduces the electromagnetic interference (EMI) between the PET scanner and the MRI scanner, and wherein keeping the length of the optical fiber below the predetermined value reduces light transmission loss within the optical fiber.