title: Non-invasive detection and quantification of human foetal brain lactate in utero by magnetic resonance spectroscopy.
abstract: OBJECTIVE
  To assess the feasibility of foetal cerebral lactate detection and quantification by proton magnetic resonance spectroscopy ((1)H-MRS) in pregnancies at increased risk of cerebral hypoxia, using a clinical 1.5 T magnetic resonance imaging (MRI) system.
  
  
  METHODS
  Localised (1)H-MRS was performed in four patients with pregnancies in their third trimester complicated by intrauterine growth restriction (IUGR). A long echo time (TE) of 288 ms was used to maximise detection and conspicuity of the lactate methyl resonance, together with a short TE MRS acquisition to check for the presence of lipid contamination. Individual peaks in the resulting spectra were measured, corrected for relaxation and referenced to the unsuppressed water signal to provide metabolite concentrations.
  
  
  RESULTS
  A resonance peak consistent with the presence of lactate was observed in all cases. In one subject, this was confounded by the identification of significant lipid contamination in the short TE MRS acquisition. The range of measured lactate concentrations was 2.0-3.3 mmol/kg and compared well with preterm neonatal MRS studies.
  
  
  CONCLUSIONS
  The non-invasive detection and quantification of foetal cerebral lactate by MRS is achievable on a clinical 1.5 T MRI system.
authors.affiliation: Department of Medical Physics, Guy's & St Thomas' NHS Foundation Trust, London, UK. geoff.charles-edwards@kcl.ac.uk
authors.forename: Geoffrey D
authors.initials: GD
authors.lastname: Charles-Edwards
authors.forename: Wajanat
authors.initials: W
authors.lastname: Jan
authors.forename: Meekai
authors.initials: M
authors.lastname: To
authors.forename: Darryl
authors.initials: D
authors.lastname: Maxwell
authors.forename: Stephen F
authors.initials: SF
authors.lastname: Keevil
authors.forename: Richard
authors.initials: R
authors.lastname: Robinson
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000032:analysis; D001921:Brain / Q000196:embryology / Q000378:metabolism*; D001923:Brain Chemistry; D005260:Female; D005317:Fetal Growth Retardation / Q000378:metabolism; D005311:Fetal Hypoxia / Q000175:diagnosis / Q000378:metabolism; D005333:Fetus / Q000378:metabolism*; D006801:Humans; D002534:Hypoxia, Brain / Q000196:embryology / Q000378:metabolism*; D019344:Lactic Acid / Q000032:analysis / Q000378:metabolism*; D008279:Magnetic Resonance Imaging / Q000295:instrumentation; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D010927:Placental Insufficiency / Q000175:diagnosis / Q000378:metabolism; D011247:Pregnancy; D011263:Pregnancy Trimester, Third
chemical_list: D015415:Biomarkers; D019344:Lactic Acid