title: Assessment and compensation of susceptibility artifacts in gradient echo MRI of hyperpolarized 3He gas.
abstract: The effects of macroscopic background field gradients upon 2D gradient echo images of inhaled (3)He in the human lung were investigated at 1.5 T. Effective compensation of in-slice signal loss in (3)He gradient echo images was then demonstrated using a multiple acquisition interleaved single gradient echo sequence. This method restores signal dephasing through a combination of separate images acquired with different slice refocusing gradients. In vivo imaging of volunteers with the sequence shows substantial restoration of signal at the lung periphery and close to blood vessels. The technique presented may be useful when using (3)He MRI for volumetric measurements of lung ventilation and in studies using (3)He combined with intravenous contrast as a means of assessing lung ventilation/perfusion (V/Q).
authors.affiliation: Unit of Academic Radiology, University of Sheffield, Sheffield, UK. j.m.wild@sheffield.ac.uk
authors.forename: Jim M
authors.initials: JM
authors.lastname: Wild
authors.forename: Stan
authors.initials: S
authors.lastname: Fichele
authors.forename: Neil
authors.initials: N
authors.lastname: Woodhouse
authors.forename: Martyn N J
authors.initials: MN
authors.lastname: Paley
authors.forename: Andrew
authors.initials: A
authors.lastname: Swift
authors.forename: Larry
authors.initials: L
authors.lastname: Kasuboski
authors.forename: Edwin J R
authors.initials: EJ
authors.lastname: van Beek
mesh_terms: D016477:Artifacts; D003287:Contrast Media; D006371:Helium / Q000008:administration & dosage; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007554:Isotopes; D008168:Lung / Q000033:anatomy & histology*; D008279:Magnetic Resonance Imaging; D012123:Pulmonary Ventilation
chemical_list: D003287:Contrast Media; D007554:Isotopes; D006371:Helium