title: Navigator accuracy requirements for prospective motion correction.
abstract: Prospective motion correction in MRI is becoming increasingly popular to prevent the image artifacts that result from subject motion. Navigator information is used to update the position of the imaging volume before every spin excitation so that lines of acquired k-space data are consistent. Errors in the navigator information, however, result in residual errors in each k-space line. This paper presents an analysis linking noise in the tracking system to the power of the resulting image artifacts. An expression is formulated for the required navigator accuracy based on the properties of the imaged object and the desired resolution. Analytical results are compared with computer simulations and experimental data.
authors.affiliation: Medical Physics, Department of Diagnostic Radiology, University Hospital Freiburg, Freiburg, Germany. julian.maclaren@uniklinik-freiburg.de
authors.forename: Julian
authors.initials: J
authors.lastname: Maclaren
authors.forename: Oliver
authors.initials: O
authors.lastname: Speck
authors.forename: Daniel
authors.initials: D
authors.lastname: Stucht
authors.forename: Peter
authors.initials: P
authors.lastname: Schulze
authors.forename: Jürgen
authors.initials: J
authors.lastname: Hennig
authors.forename: Maxim
authors.initials: M
authors.lastname: Zaitsev
mesh_terms: D016477:Artifacts; D001921:Brain / Q000033:anatomy & histology*; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009038:Motion; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity