title: The use of SPAMM to assess spatial distortion due to static field inhomogeneity in dental MRI.
abstract: In planning placement of dental implants using MRI, a SPAMM (spatial modulation of magnetization) magnetization preparation sequence was incorporated into a spin-echo imaging sequence. A phantom was imaged with a ferromagnetic object attached. Spatial distortion due to deviations in Larmor frequency was detected by a deviation of SPAMM lines. Both SPAMM line deviation and interline spacing were found to agree with a deltaB0 map generated from phase images. Imaging of a volunteer with and without typically used metallic implants positioned in a template showed SPAMM line deviations to correlate with expected deviations in vivo. SPAMM lines showed possible distortion due to chemical shift in the bone marrow and the presence of titanium implants to be insignificant. SPAMM may thus be used to provide a qualitative estimate of the accuracy of the MRI image when planning dental implants.
authors.affiliation: Department of Bio-Medical Physics and Bio-Engineering, University of Aberdeen, Foresterhill, UK. ruth.bridcut@royalhospital.n-i.nhs.uk
authors.forename: R R
authors.initials: RR
authors.lastname: Bridcut
authors.forename: T W
authors.initials: TW
authors.lastname: Redpath
authors.forename: C F
authors.initials: CF
authors.lastname: Gray
authors.forename: R T
authors.initials: RT
authors.lastname: Staff
mesh_terms: D002138:Calibration; D003757:Dental Implantation / Q000379:methods*; D015921:Dental Implants; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging; D008280:Magnetics; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed
chemical_list: D015921:Dental Implants