title: A technique to reduce motion artifact for externally triggered cine-MRI(EC-MRI) based on detecting the onset of the articulated word with spectral analysis.
abstract: One issue in externally triggered cine-magnetic resonance imaging (EC-MRI) for the dynamic observation of speech organs is motion artifact in the phase-encoding direction caused by unstable repetitions of speech during data acquisition. We propose a technique to reduce such artifact by rearranging the k-space data used to reconstruct MR images based on the analysis of recorded speech sounds. We recorded the subject's speech sounds during EC-MRI and used post hoc acoustical processing to reduce scanning noise and detect the onset of each utterance based on analysis of the recorded sounds. We selected each line of k-space from several data acquisition sessions and rearranged them to reconstruct a new series of dynamic MR images according to the analyzed time of utterance onset. Comparative evaluation showed significant reduction in motion artifact signal in the dynamic MR images reconstructed by the proposed method. The quality of the reconstructed images was sufficient to observe the dynamic aspects of speech production mechanisms.
authors.affiliation: Brain Activity Imaging Center, ATR-Promotions Inc., Kyoto, Japan. shimada@atr.jp
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Shimada
authors.forename: Hironori
authors.initials: H
authors.lastname: Nishimoto
authors.forename: Takanori
authors.initials: T
authors.lastname: Kochiyama
authors.forename: Ichiro
authors.initials: I
authors.lastname: Fujimoto
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Mano
authors.forename: Shinobu
authors.initials: S
authors.lastname: Masaki
authors.forename: Kenya
authors.initials: K
authors.lastname: Murase
mesh_terms: D016477:Artifacts; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D009038:Motion; D009055:Mouth / Q000502:physiology; D013060:Speech