title: Pulmonary ultrashort echo time 19F MR imaging with inhaled fluorinated gas mixtures in healthy volunteers: feasibility.
abstract: OBJECTIVE
  To perform static breath-hold fluorine 19 ((19)F) three-dimensional (3D) ultrashort echo time (UTE) magnetic resonance (MR) imaging of the lungs in healthy volunteers by using a mixture of 79% perfluoropropane (PFP) and 21% O2.
  
  
  METHODS
  This study protocol was approved by the local research ethics board and by Health Canada. All volunteers provided written informed consent. Ten healthy volunteers underwent MR imaging at 3.0 T. Fluorine 19 3D UTE MR images were acquired during a 15-second breath hold according to one of two breathing protocols: protocol A, a 1-L inhalation of a mixture of 79% PFP and 21% O2, and protocol B, continuous breathing from a 5-L bag of a mixture of 79% PFP and 21% O2 followed by a 1-L inhalation of the same PFP-O2 mixture from a separate bag and a subsequent breath hold. The signal-to-noise ratio (SNR) was measured in the three most central image sections and was compared between breathing protocols by using an unpaired t test.
  
  
  RESULTS
  Overall, the SNR was significantly greater for breathing protocol B (continuous breathing) than for breathing protocol A (single breath) (P = .018). The mean SNRs were 18 ± 6 (standard deviation) and 32 ± 6 for images acquired by using breathing protocols A and B, respectively. Breathing protocol B improves SNR by "washing out" the air from the lungs and increasing the PFP concentration prior to (19)F imaging.
  
  
  CONCLUSIONS
  This study demonstrates the feasibility of (19)F 3D UTE static breath-hold MR imaging of human lungs with inert fluorinated gases.
authors.affiliation: From the Thunder Bay Regional Research Institute, 980 Oliver Rd, Thunder Bay, ON, Canada P7B 6V4 (M.J.C., I.K.B., T.L., M.S.F., S.L.L., M.S.A.); Lakehead University, Thunder Bay, ON, Canada (M.J.C., T.L., M.S.A.); Thunder Bay Regional Health Sciences Centre, Thunder Bay, ON, Canada (B.B.); Northern Ontario School of Medicine, Thunder Bay, ON, Canada (B.B.); and Department of Medicine, McMaster University, Hamilton, ON, Canada (B.B.).
authors.forename: Marcus J
authors.initials: MJ
authors.lastname: Couch
authors.forename: Iain K
authors.initials: IK
authors.lastname: Ball
authors.forename: Tao
authors.initials: T
authors.lastname: Li
authors.forename: Matthew S
authors.initials: MS
authors.lastname: Fox
authors.forename: Shalyn L
authors.initials: SL
authors.lastname: Littlefield
authors.forename: Birubi
authors.initials: B
authors.lastname: Biman
authors.forename: Mitchell S
authors.initials: MS
authors.lastname: Albert
mesh_terms: D000328:Adult; D005240:Feasibility Studies; D005260:Female; D005461:Fluorine / Q000008:administration & dosage*; D005466:Fluorocarbons / Q000008:administration & dosage*; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D021621:Imaging, Three-Dimensional; D008168:Lung / Q000033:anatomy & histology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000008:administration & dosage*; D059629:Signal-To-Noise Ratio
chemical_list: D005466:Fluorocarbons; D005461:Fluorine; C042852:perflutren; D010100:Oxygen