title: Self-gated radial MRI for respiratory motion compensation on hybrid PET/MR systems.
abstract: Accurate localization and uptake quantification of lesions in the chest and abdomen using PET imaging is challenging due to the respiratory motion during the exam. The advent of hybrid PET/MR systems offers new ways to compensate for respiratory motion without exposing the patient to additional radiation. The use of self-gated reconstructions of a 3D radial stack-of-stars GRE acquisition is proposed to derive a high-resolution MRI motion model. The self-gating signal is used to perform respiratory binning of the simultaneously acquired PET raw data. Matching mu-maps are generated for every bin, and post-reconstruction registration is performed in order to obtain a motion-compensated PET volume from the individual gates. The proposed method is demonstrated in-vivo for three clinical patients. Motion-corrected reconstructions are compared against ungated and gated PET reconstructions. In all cases, motion-induced blurring of lesions in the liver and lung was substantially reduced, without compromising SNR as it is the case for gated reconstructions.
authors: Pattern Recognition Lab, FAU Erlangen, Erlangen, Germany.
authors: Robert
authors: R
authors: Grimm
authors: Department of Nuclear Medicine, TU Munich, Munich, Germany.
authors: Sebastian
authors: S
authors: Fürst
authors: Department of Nuclear Medicine, TU Munich, Munich, Germany.
authors: Isabel
authors: I
authors: Dregely
authors: Pattern Recognition Lab, FAU Erlangen, Erlangen, Germany.
authors: Christoph
authors: C
authors: Forman
authors: Pattern Recognition Lab, FAU Erlangen, Erlangen, Germany.
authors: Jana Maria
authors: JM
authors: Hutter
authors: Department of Nuclear Medicine, TU Munich, Munich, Germany.
authors: Sibylle I
authors: SI
authors: Ziegler
authors: Department of Nuclear Medicine, TU Munich, Munich, Germany.
authors: Stephan
authors: S
authors: Nekolla
authors: Siemens Healthcare MR, Erlangen, Germany.
authors: Berthold
authors: B
authors: Kiefer
authors: Department of Nuclear Medicine, TU Munich, Munich, Germany.
authors: Markus
authors: M
authors: Schwaiger
authors: Pattern Recognition Lab, FAU Erlangen, Erlangen, Germany.
authors: Joachim
authors: J
authors: Hornegger
authors: Department of Radiology, NYU Langone Medical Center, New York City, NY, USA.
authors: Tobias
authors: T
authors: Block
mesh_terms: D000465:Algorithms; D016477:Artifacts; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008175:Lung Neoplasms / Q000175:diagnosis*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009038:Motion; D064847:Multimodal Imaging / Q000379:methods*; D049268:Positron-Emission Tomography / Q000379:methods*; D015203:Reproducibility of Results; D015656:Respiratory Mechanics; D055425:Respiratory-Gated Imaging Techniques / Q000379:methods*; D012680:Sensitivity and Specificity