MR/PET imaging systems

An imaging system comprising:

• a magnetic resonance scanner comprising a main magnet, a magnetic field gradient assembly, and a whole-body radio frequency screen;
• a local radio frequency coil having a radio frequency screen including an end-cap portion and a flanged open portion, the flanged portion sized such that an annular edge of the flange portion is proximate to the whole-body radio frequency screen;
• and
• an annular ring of positron emission tomography (PET) detectors mounted on the local radio frequency coil completely outside of the radio frequency screen of the local radio frequency coil to view the interior of the local radio frequency coil through the radio frequency screen of the local radio frequency coil.

An imaging system comprising:

• a bore-type magnetic resonance scanner having a scanner bore containing an examination region and comprising a main magnet, a magnetic field gradient assembly, and a generally cylindrical radio frequency screen arranged coaxially with the scanner bore, the generally cylindrical radio frequency screen having a main cylindrical radio frequency screen portion of radius R2 and a central annular groove formed by a groove radio frequency screen portion at a smaller radius R1 compared with the radius R2 that is connected with the main cylindrical radio frequency screen portion;
• and
• one or more radiation detectors received into the annular groove of the generally cylindrical radio frequency screen and operatively coupled with electronics to perform radiation detection, the one or more radiation detectors including a radiation collimator or radiation shielding comprising an electrically non-conductive and non-ferromagnetic heavy atom oxide material, the one or more radiation detectors being outside of the generally cylindrical radio frequency screen with the groove radio frequency screen portion interposed between the one or more radiation detectors received into the annular groove and the examination region such that probative radiation emitted from the examination region passes through the groove radio frequency screen portion before reaching the one or more radiation detectors.

An apparatus comprising:

• an annular ring of positron emission tomography (PET) detectors;
• and
• a generally cylindrical radio frequency screen having a radius respective to a central axis, the generally cylindrical radio frequency screen having a central annular groove at which the generally cylindrical radio frequency screen has a smaller radius compared with the radius;
• wherein the annular ring of PET detectors is disposed in the central annular groove of the generally cylindrical radio frequency screen with the annular ring of PET detectors surrounded on three sides by the generally cylindrical radio frequency screen.