Speaker
Negar Omidvari
(Nuklearmedizinische Klinik und Poliklinik, Klinikum rechts der Isar, Technische Universität München)
Description
MADPET4 (Munich Avalanche Diode PET 4) is a small animal PET insert for a 7 T MRI scanner, which has two offset layers of scintillation crystals, individually read out by silicon photomultipliers (SiPMs). To reduce the interference between the PET insert and the MRI system, high-gain SiPMs were used and the SiPM charge was transferred to outside the MRI scanner using 1.5 m coaxial cables. In this work, MR-compatibility of the PET insert was assessed by studying the interference between the PET insert and the MRI system, with a 1H/13C radio-frequency (RF) volume coil placed inside the PET insert. The volume coil was used for RF transmission and reception. The coil had a 9 µm copper layer on its outer layer for electromagnetic interference shielding, whereas the PET insert and its readout electronics were not shielded. The effects of PET on the static magnetic field, flip angle distribution, RF noise, and image quality of various MRI sequences were investigated. The effects of fast-switching gradient fields and RF pulses on PET data were studied. Simultaneous operation of the insert with standard MRI pulse sequences was possible with a maximum signal-to-noise ratio degradation of 23-30%, with no discernible artifacts. Use of RF excitation pulses and fast-switching gradient fields had negligible effects on PET data. The achieved performance allows using MADPET4 to investigate applications of simultaneous PET/MRI in future small animal studies.
Primary author
Negar Omidvari
(Nuklearmedizinische Klinik und Poliklinik, Klinikum rechts der Isar, Technische Universität München)
Co-authors
Dr
Geoffrey Topping
(Klinikum rechts der Isar, Technical University of Munich (TUM))
Dr
Jorge Cabello
(Klinikum rechts der Isar, Technical University of Munich (TUM))
Prof.
Markus Schwaiger
(Klinikum rechts der Isar, Technical University of Munich (TUM))
Prof.
Sibylle Ziegler
(Klinikum rechts der Isar, Technical University of Munich (TUM))
Prof.
Stephan Paul
(Physics Department E18, Technical University of Munich (TUM))
