title: Motion compensation for brain PET imaging using wireless MR active markers in simultaneous PET-MR: phantom and non-human primate studies.
abstract: Brain PET scanning plays an important role in the diagnosis, prognostication and monitoring of many brain diseases. Motion artifacts from head motion are one of the major hurdles in brain PET. In this work, we propose to use wireless MR active markers to track head motion in real time during a simultaneous PET-MR brain scan and incorporate the motion measured by the markers in the listmode PET reconstruction. Several wireless MR active markers and a dedicated fast MR tracking pulse sequence module were built. Data were acquired on an ACR Flangeless PET phantom with multiple spheres and a non-human primate with and without motion. Motions of the phantom and monkey's head were measured with the wireless markers using a dedicated MR tracking sequence module. The motion PET data were reconstructed using list-mode reconstruction with and without motion correction. Static reference was used as gold standard for quantitative analysis. The motion artifacts, which were prominent on the images without motion correction, were eliminated by the wireless marker based motion correction in both the phantom and monkey experiments. Quantitative analysis was performed on the phantom motion data from 24 independent noise realizations. The reduction of bias of sphere-to-background PET contrast by active marker based motion correction ranges from 26% to 64% and 17% to 25% for hot (i.e., radioactive) and cold (i.e., non-radioactive) spheres, respectively. The motion correction improved the channelized Hotelling observer signal-to-noise ratio of the spheres by 1.2 to 6.9 depending on their locations and sizes. The proposed wireless MR active marker based motion correction technique removes the motion artifacts in the reconstructed PET images and yields accurate quantitative values.
authors.affiliation: Center for Advanced Medical Imaging Sciences, Division of Nuclear Medicine and Molecular Imaging, Department of Imaging, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Radiology, Harvard Medical School, Boston, MA 02115, USA. Electronic address: huang.chuan@mgh.harvard.edu.
authors.forename: Chuan
authors.initials: C
authors.lastname: Huang
authors.affiliation: Department of Radiology, Harvard Medical School, Boston, MA 02115, USA; Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA 02129, USA. Electronic address: jerry@nmr.mgh.harvard.edu.
authors.forename: Jerome L
authors.initials: JL
authors.lastname: Ackerman
authors.affiliation: Center for Advanced Medical Imaging Sciences, Division of Nuclear Medicine and Molecular Imaging, Department of Imaging, Massachusetts General Hospital, Boston, MA 02114, USA; Laboratoire d'imagerie fonctionnelle (LIF), UMRS-678, INSERM, Université Pierre et Marie Curie, CHU Pitié-Salpêtrière, Paris, France. Electronic address: petibon@pet.mgh.harvard.edu.
authors.forename: Yoann
authors.initials: Y
authors.lastname: Petibon
authors.affiliation: Center for Advanced Medical Imaging Sciences, Division of Nuclear Medicine and Molecular Imaging, Department of Imaging, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Radiology, Harvard Medical School, Boston, MA 02115, USA. Electronic address: normandin.marc@mgh.harvard.edu.
authors.forename: Marc D
authors.initials: MD
authors.lastname: Normandin
authors.affiliation: Center for Advanced Medical Imaging Sciences, Division of Nuclear Medicine and Molecular Imaging, Department of Imaging, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Radiology, Harvard Medical School, Boston, MA 02115, USA. Electronic address: tom@nmr.mgh.harvard.edu.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Brady
authors.affiliation: Center for Advanced Medical Imaging Sciences, Division of Nuclear Medicine and Molecular Imaging, Department of Imaging, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Radiology, Harvard Medical School, Boston, MA 02115, USA. Electronic address: elfakhri@pet.mgh.harvard.edu.
authors.forename: Georges
authors.initials: G
authors.lastname: El Fakhri
authors.affiliation: Center for Advanced Medical Imaging Sciences, Division of Nuclear Medicine and Molecular Imaging, Department of Imaging, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Radiology, Harvard Medical School, Boston, MA 02115, USA. Electronic address: ouyang.jinsong@mgh.harvard.edu.
authors.forename: Jinsong
authors.initials: J
authors.lastname: Ouyang
mesh_terms: D000465:Algorithms; D000818:Animals; D016477:Artifacts; D004562:Electrocardiography; D019416:Head Movements; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods* / Q000706:statistics & numerical data*; D008253:Macaca mulatta; D008279:Magnetic Resonance Imaging / Q000295:instrumentation* / Q000379:methods* / Q000706:statistics & numerical data; D019047:Phantoms, Imaging; D049268:Positron-Emission Tomography / Q000295:instrumentation* / Q000379:methods* / Q000706:statistics & numerical data; D019275:Radiopharmaceuticals; D059629:Signal-To-Noise Ratio; D059015:Wireless Technology
chemical_list: D019275:Radiopharmaceuticals
keywords: Active marker; Brain PET; Motion correction; Simultaneous PET–MR