title: Clinical use of oxygen-enhanced T1 mapping MRI of the lung: reproducibility and impact of closed versus loose fit oxygen delivery system.
abstract: OBJECTIVE
  To evaluate the reproducibility of oxygen-enhanced magnetic resonance imaging (MRI), and the influence of different gas delivery methods, in a clinical environment.
  
  
  METHODS
  Twelve healthy volunteers were examined on two visits with an inversion recovery snapshot fast low angle shot sequence on a 1.5 T system. Coronal slices were obtained breathing room air as well as 100% oxygen with a flow rate of 15 L/min. For oxygen delivery a standard nontight face mask and a full closed air-cushion face mask were used. T1 relaxation times and the oxygen transfer function (OTF) were calculated.
  
  
  RESULTS
  The mean T1 values did not change significantly between the two visits (P > 0.05). The T1 values breathing 100% oxygen obtained using the full closed mask were significantly lower (1093 ± 38 msec; P < 0.05) compared to the standard mask (1157 ± 52 msec). Accordingly, the OTF was significantly higher for the full closed mask (P < 0.05). The OTF changed significantly on the second visit using the standard mask (P < 0.05). The full closed mask showed lower interindividual variation for both the T1 values (3.5% vs. 4.5%) as well as the OTF (12.4% vs. 22.0%) and no difference of the OTF on the second visit (P > 0.05).
  
  
  CONCLUSIONS
  Oxygen-enhanced T1 mapping MRI produces reproducible data when using a full closed face mask.
authors: Diagnostic and Interventional Radiology, Hannover Medical School, Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Center for Lung Research, Hannover, Germany.
authors: Julius
authors: J
authors: Renne
authors: Peer
authors: P
authors: Lauermann
authors: Jan
authors: J
authors: Hinrichs
authors: Christian
authors: C
authors: Schönfeld
authors: Sajoscha
authors: S
authors: Sorrentino
authors: Marcel
authors: M
authors: Gutberlet
authors: Peter
authors: P
authors: Jakob
authors: Frank
authors: F
authors: Wacker
authors: Jens
authors: J
authors: Vogel-Claussen
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D003287:Contrast Media / Q000008:administration & dosage; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007091:Image Processing, Computer-Assisted; D008168:Lung / Q000033:anatomy & histology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008397:Masks; D010100:Oxygen / Q000008:administration & dosage*; D015203:Reproducibility of Results; D012119:Respiration
chemical_list: D003287:Contrast Media; D010100:Oxygen
keywords: IR-snapshot FLASH; T1 mapping; oxygen-enhanced MRI; pulmonary MRI