Challenges in Acquiring Clinical Simultaneous SPECT-MRI on a PET-MRI Scanner

• Published in: IEEE transactions on radiation and plasma medical sciences Vol. 7; no. 7; p. 1
• Main Authors: Morahan, Ashley J., D'Adda, Ilenia, Erlandsson, Kjell, Carminati, Marco, Rega, Marilena, Walls, Darren, Fiorini, Carlo, Hutton, Brian F.
• Format: Journal Article
• Language: English
• Published: Piscataway IEEE 01.09.2023; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Clinical; Collimators; CsI(Tl); Data acquisition; Detectors; Head; Image acquisition; Imaging; Inhomogeneity; Magnetic fields; Magnetic heads; Magnetic resonance imaging; Medical imaging; MRI; Multimodal Imaging; Neuroimaging; Photomultiplier tubes; Positron emission; Positron emission tomography; Single photon emission computed tomography; SiPM; SPECT; Tungsten
• ISSN: 2469-7311; 2469-7303
• DOI: 10.1109/TRPMS.2023.3287639

The INSERT is the world's first clinical SPECTMRI brain imaging system based on scintillation detectors with a SiPM readout. Here we demonstrate its use within a clinical MRI environment for the first time. Using a standard transmit-receive head coil, and with an appropriate selection of a custom MRI sequence (GRE), we overcome mutual interference. The INSERT and its bulky 50 kg tungsten collimator introduce magnetic field inhomogeneity. Due to the specific MRI-compatible collimator design, inhomogeneity is compensated by shimming, leading to simultaneous acquisition. We process the SPECT data acquired alongside the MRI sequence to evaluate the SPECT system performance and the impact of the MRI. Finally, we present a set of simultaneous SPECT-MRI acquisitions, demonstrating multimodal imaging capabilities, albeit with a limited MRI sequence.