title: In vivo imaging of the progression of acute lung injury using hyperpolarized [1-13C] pyruvate.
abstract: OBJECTIVE
  To investigate pulmonary metabolic alterations during progression of acute lung injury.
  
  
  METHODS
  Using hyperpolarized [1-13C] pyruvate imaging, we measured pulmonary lactate and pyruvate in 15 ventilated rats 1, 2, and 4 h after initiation of mechanical ventilation. Lung compliance was used as a marker for injury progression. 5 untreated rats were used as controls; 5 rats (injured-1) received 1 ml/kg and another 5 rats (injured-2) received 2 ml/kg hydrochloric acid (pH 1.25) in the trachea at 70 min.
  
  
  RESULTS
  The mean lactate-to-pyruvate ratio of the injured-1 cohort was 0.15 ± 0.02 and 0.15 ± 0.03 at baseline and 1 h after the injury, and significantly increased from the baseline value 3 h after the injury to 0.23 ± 0.02 (P = 0.002). The mean lactate-to-pyruvate ratio of the injured-2 cohort decreased from 0.14 ± 0.03 at baseline to 0.08 ± 0.02 1 h after the injury and further decreased to 0.07 ± 0.02 (P = 0.08) 3 h after injury. No significant change was observed in the control group. Compliance in both injured groups decreased significantly after the injury (P < 0.01).
  
  
  CONCLUSIONS
  Our findings suggest that in severe cases of lung injury, edema and hyperperfusion in the injured lung tissue may complicate interpretation of the pulmonary lactate-to-pyruvate ratio as a marker of inflammation. However, combining the lactate-to-pyruvate ratio with pulmonary compliance provides more insight into the progression of the injury and its severity. Magn Reson Med 78:2106-2115, 2017. © 2017 International Society for Magnetic Resonance in Medicine.
authors.affiliation: Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA.|Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
authors.forename: Mehrdad
authors.initials: M
authors.lastname: Pourfathi
authors.affiliation: Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA.|Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
authors.forename: Yi
authors.initials: Y
authors.lastname: Xin
authors.affiliation: Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Kadlecek
authors.affiliation: Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
authors.forename: Maurizio F
authors.initials: MF
authors.lastname: Cereda
authors.affiliation: Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
authors.forename: Harrilla
authors.initials: H
authors.lastname: Profka
authors.affiliation: Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA.|Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
authors.forename: Hooman
authors.initials: H
authors.lastname: Hamedani
authors.affiliation: Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA.|Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
authors.forename: Sarmad M
authors.initials: SM
authors.lastname: Siddiqui
authors.affiliation: Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
authors.forename: Kai
authors.initials: K
authors.lastname: Ruppert
authors.affiliation: Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
authors.forename: Nicholas A
authors.initials: NA
authors.lastname: Drachman
authors.affiliation: School of Medicine, Stanford University, Stanford, California, USA.
authors.forename: Jennia N
authors.initials: JN
authors.lastname: Rajaei
authors.affiliation: Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
authors.forename: Rahim R
authors.initials: RR
authors.lastname: Rizi
mesh_terms: D055371:Acute Lung Injury / Q000000981:diagnostic imaging*; D000818:Animals; D002247:Carbon Isotopes / Q000737:chemistry*; D018450:Disease Progression; D006851:Hydrochloric Acid / Q000737:chemistry; D007091:Image Processing, Computer-Assisted; D007249:Inflammation; D019344:Lactic Acid / Q000737:chemistry*; D008168:Lung / Q000000981:diagnostic imaging*; D008279:Magnetic Resonance Imaging; D008297:Male; D019289:Pyruvic Acid / Q000737:chemistry*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012121:Respiration, Artificial; D014132:Trachea / Q000000981:diagnostic imaging
chemical_list: D002247:Carbon Isotopes; D019344:Lactic Acid; D019289:Pyruvic Acid; D006851:Hydrochloric Acid
keywords: ALI; ARDS; CSI; DNP; MRI; MRSI; carbon-13; hyperpolarization; lung injury; lungs; pyruvate