title: Effect of respiratory and cardiac gating on the major diffusion-imaging metrics.
abstract: The effect of respiratory gating on the major diffusion-imaging metrics and that of cardiac gating on mean kurtosis (MK) are not known. For evaluation of whether the major diffusion-imaging metrics-MK, fractional anisotropy (FA), and mean diffusivity (MD) of the brain-varied between gated and non-gated acquisitions, respiratory-gated, cardiac-gated, and non-gated diffusion-imaging of the brain were performed in 10 healthy volunteers. MK, FA, and MD maps were constructed for all acquisitions, and the histograms were constructed. The normalized peak height and location of the histograms were compared among the acquisitions by use of Friedman and post hoc Wilcoxon tests. The effect of the repetition time (TR) on the diffusion-imaging metrics was also tested, and we corrected for its variation among acquisitions, if necessary. The results showed a shift in the peak location of the MK and MD histograms to the right with an increase in TR (p ≤ 0.01). The corrected peak location of the MK histograms, the normalized peak height of the FA histograms, the normalized peak height and the corrected peak location of the MD histograms varied significantly between the gated and non-gated acquisitions (p < 0.05). These results imply an influence of respiration and cardiac pulsation on the major diffusion-imaging metrics. The gating conditions must be kept identical if reproducible results are to be achieved.
authors.affiliation: Department of Radiological Technology, Hokkaido University Hospital, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Hamaguchi
authors.affiliation: Department of Radiobiology and Medical Engineering, Hokkaido University Graduate School of Medicine, Japan Global Station for Quantum Medical Science and Engineering, Global Institution for Collaborative Research and Education, Hokkaido University, Japan kktha@med.hokudai.ac.jp.
authors.forename: Khin Khin
authors.initials: KK
authors.lastname: Tha
authors.affiliation: Department of Radiological Technology, Hokkaido University Hospital, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Sugimori
authors.affiliation: Division of Radiology, Sapporo Medical University Hospital, Japan.
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Nakanishi
authors.affiliation: Department of Psychiatry, Hokkaido University Hospital, N-14, W-5, Kita-ku, Sapporo, 060-8648, Japan.
authors.forename: Shin
authors.initials: S
authors.lastname: Nakagawa
authors.affiliation: Department of Radiological Technology, Hokkaido University Hospital, Japan.
authors.forename: Taro
authors.initials: T
authors.lastname: Fujiwara
authors.affiliation: Department of Radiological Technology, Hokkaido University Hospital, Japan.
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Yoshida
authors.affiliation: Department of Radiological Technology, Hokkaido University Hospital, Japan.
authors.forename: Sayaka
authors.initials: S
authors.lastname: Takamori
authors.affiliation: Department of Radiobiology and Medical Engineering, Hokkaido University Graduate School of Medicine, Japan Global Station for Quantum Medical Science and Engineering, Global Institution for Collaborative Research and Education, Hokkaido University, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Shirato
mesh_terms: D000328:Adult; D016880:Anisotropy; D001921:Brain / Q000000981:diagnostic imaging* / Q000502:physiology; D055424:Cardiac-Gated Imaging Techniques; D004058:Diffusion; D056324:Diffusion Tensor Imaging; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008297:Male; D012119:Respiration; D055815:Young Adult
keywords: Mean kurtosis; cardiac gating; diffusion-imaging; fractional anisotropy; mean diffusivity; respiratory gating