title: Feasibility, tolerability and safety of pediatric hyperpolarized129Xe magnetic resonance imaging in healthy volunteers and children with cystic fibrosis.
abstract: BACKGROUND
  Hyperpolarized129Xe is a promising contrast agent for MRI of pediatric lung function, but its safety and tolerability in children have not been rigorously assessed.
  
  
  OBJECTIVE
  To assess the feasibility, safety and tolerability of hyperpolarized129Xe gas as an inhaled contrast agent for pediatric pulmonary MRI in healthy control subjects and in children with cystic fibrosis.
  
  
  METHODS
  Seventeen healthy control subjects (ages 6-15 years, 11 boys) and 11 children with cystic fibrosis (ages 8-16 years, 4 boys) underwent129Xe MRI, receiving up to three doses of129Xe gas prepared by either a commercially available or a homebuilt129Xe polarizer. Subject heart rate and SpO2were monitored for 2 min post inhalation and compared to resting baseline values. Adverse events were reported via follow-up phone call at days 1 and 30 (range ±7 days) post-MRI.
  
  
  RESULTS
  All children tolerated multiple doses of129Xe, and no children withdrew from the study. Relative to baseline, most children who received a full dose of gas for imaging (10 of 12 controls and 8 of 11 children with cystic fibrosis) experienced a nadir in SpO2(mean -6.0 ± standard deviation 7.2%, P≤0.001); however within 2 min post inhalation SpO2values showed no significant difference from baseline (P=0.11). There was a slight elevation in heart rate (mean +6.6 ± 13.9 beats per minute [bpm], P=0.021), which returned from baseline within 2 min post inhalation (P=0.35). Brief side effects related to the anesthetic properties of xenon were mild and quickly resolved without intervention. No serious or severe adverse events were observed; in total, four minor adverse events (14.3%) were reported following129Xe MRI, but all were deemed unrelated to the study.
  
  
  CONCLUSIONS
  The feasibility, safety and tolerability of129Xe MRI has been assessed in a small group of children as young as 6 years. SpO2changes were consistent with the expected physiological effects of a short anoxic breath-hold, and other mild side effects were consistent with the known anesthetic properties of xenon and with previous safety assessments of129Xe MRI in adults. Hyperpolarized129Xe is a safe and well-tolerated inhaled contrast agent for pulmonary MR imaging in healthy children and in children with cystic fibrosis who have mild to moderate lung disease.
authors: Center for Pulmonary Imaging Research, Division of Pulmonary Medicine and Department of Radiology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., MLC 5033, Cincinnati, OH, 45229, USA.
authors: Laura L
authors: LL
authors: Walkup
authors: Center for Pulmonary Imaging Research, Division of Pulmonary Medicine and Department of Radiology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., MLC 5033, Cincinnati, OH, 45229, USA.|Department of Physics, Washington University in St. Louis, St. Louis, MO, USA.
authors: Robert P
authors: RP
authors: Thomen
authors: Center for Pulmonary Imaging Research, Division of Pulmonary Medicine and Department of Radiology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., MLC 5033, Cincinnati, OH, 45229, USA.|Biomedical Engineering Program, University of Cincinnati, Cincinnati, OH, USA.
authors: Teckla G
authors: TG
authors: Akinyi
authors: Center for Pulmonary Imaging Research, Division of Pulmonary Medicine and Department of Radiology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., MLC 5033, Cincinnati, OH, 45229, USA.
authors: Erin
authors: E
authors: Watters
authors: Center for Pulmonary Imaging Research, Division of Pulmonary Medicine and Department of Radiology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., MLC 5033, Cincinnati, OH, 45229, USA.
authors: Kai
authors: K
authors: Ruppert
authors: Division of Pulmonary Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.
authors: John P
authors: JP
authors: Clancy
authors: Center for Pulmonary Imaging Research, Division of Pulmonary Medicine and Department of Radiology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., MLC 5033, Cincinnati, OH, 45229, USA.|Department of Physics, Washington University in St. Louis, St. Louis, MO, USA.
authors: Jason C
authors: JC
authors: Woods
authors: Center for Pulmonary Imaging Research, Division of Pulmonary Medicine and Department of Radiology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., MLC 5033, Cincinnati, OH, 45229, USA. zackary.cleveland@cchmc.org.|Biomedical Engineering Program, University of Cincinnati, Cincinnati, OH, USA. zackary.cleveland@cchmc.org.
authors: Zackary I
authors: ZI
authors: Cleveland
mesh_terms: D000293:Adolescent; D002648:Child; D003287:Contrast Media / Q000009:adverse effects*; D003550:Cystic Fibrosis / Q000000981:diagnostic imaging*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D008168:Lung / Q000000981:diagnostic imaging; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D014979:Xenon Isotopes / Q000009:adverse effects
chemical_list: D003287:Contrast Media; D014979:Xenon Isotopes
keywords: Children; Cystic fibrosis; Hyperpolarized xenon; Lungs; Magnetic resonance imaging