title: Respiratory phase-correlated micro-CT imaging of free-breathing rodents.
abstract: We provide a dedicated phase-correlated imaging procedure for respiratory gating in micro-CT imaging with automatic detection of the optimal data window providing the least amount of motion blurring. A rawdata-based motion function (kymogram) was used for synchronization purposes and for identification of the optimal data window used for phase-correlated image reconstruction. Measurements were performed on a dual-source micro-CT scanner. Projection data were acquired over ten rotations for multi-segment phase-correlated reconstruction. Visual assessment was performed on datasets of ten free-breathing subjects. The kymogram approach provided a reliable synchronization signal for phase-correlated image reconstruction. Also, it allowed for the identification of phase intervals of increased and decreased motion and the corresponding detection of the optimal reconstruction phase. Phase-correlated images showed a strong improvement with respect to motion blurring compared to standard image reconstruction. A reconstruction for the calculated optimal data window provided the least amount of motion blurring and even allowed for the assessment of small structures in the lung. The dedicated retrospective phase-correlated image reconstruction procedure for respiratory gating is a feasible approach for motion-free imaging. A subject-specific optimal reconstruction phase can minimize motion blurring and further improve image quality.
authors.affiliation: Institute of Medical Physics, University of Erlangen-Nürnberg, Erlangen, Germany. Dirk.Ertel@imp.uni-erlangen.de
authors.forename: Dirk
authors.initials: D
authors.lastname: Ertel
authors.forename: Yiannis
authors.initials: Y
authors.lastname: Kyriakou
authors.forename: Robert M
authors.initials: RM
authors.lastname: Lapp
authors.forename: Willi A
authors.initials: WA
authors.lastname: Kalender
mesh_terms: D000465:Algorithms; D000818:Animals; D016477:Artifacts; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008904:Miniaturization; D010363:Pattern Recognition, Automated / Q000379:methods*; D015203:Reproducibility of Results; D015656:Respiratory Mechanics; D055425:Respiratory-Gated Imaging Techniques / Q000379:methods*; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods* / Q000662:veterinary*