title: Measurement of Hypothalamic Glucose Under Euglycemia and Hyperglycemia by MRI at 3T.
abstract: To evaluate the feasibility of using a clinical magnetic resonance (MR) system and MR spectroscopy (MRS) to measure glucose concentration changes in the human hypothalamus, a structure central to whole-body glucose regulation.
  
  
  
  A time series of MR spectra (semi-LASER, TE = 28 msec), localized to the bilateral hypothalamus (∼1.6 ml) were obtained at 3T in six healthy subjects at baseline (euglycemia) and during a ∼65-70-minute-long hyperglycemic clamp in 11-minute blocks with interleaved T1FLASH images to retrospectively assess head motion, and track changes in cerebrospinal fluid (CSF) partial volume. The LCModel was used to quantify the sum of glucose and taurine concentrations, [Glc+Tau], along with their associated Cramér-Rao lower bounds (CRLB).
  
  
  
  Spectral quality allowed quantification of [Glc+Tau] (sum reported due to high negative correlation between these metabolites) with CRLB <25% in 35/36 timepoints during hyperglycemia. Increased [Glc+Tau] was observed with hyperglycemia in all subjects, but most reliably in those with plasma glucose targets ≥300 mg/dl. For these subjects, [Glc+Tau]baseline(n = 4) was 1.5 (±0.3, SD) mM, and increased to 4.5 (±1.1) mM (n = 16) for timepoints acquired ≥25 minutes after onset of the clamp, with 15/16 timepoints having no overlap of 95% confidence intervals (CIs) between baseline and hyperglycemia. Preliminary analysis revealed a linear (1:5) relationship between hypothalamus-blood glucose concentrations.
  
  
  
  It is feasible to measure glucose concentration changes in the human hypothalamus using a standard 3T scanner and a short-echo semi-LASER sequence by utilizing retrospective motion tracking, CSF correction, predetermined quality acceptance criteria, and hyperglycemic blood glucose levels ≥300 mg/dl.
  
  
  
  2 J. Magn. Reson. Imaging 2017;45:681-691.
authors.affiliation: Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, Minnesota, USA.
authors.forename: James M
authors.initials: JM
authors.lastname: Joers
authors.affiliation: Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, Minnesota, USA.
authors.forename: Dinesh K
authors.initials: DK
authors.lastname: Deelchand
authors.affiliation: Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, University of Minnesota, Minneapolis, Minnesota, USA.
authors.forename: Anjali
authors.initials: A
authors.lastname: Kumar
authors.affiliation: Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, University of Minnesota, Minneapolis, Minnesota, USA.
authors.forename: Amir
authors.initials: A
authors.lastname: Moheet
authors.affiliation: Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, University of Minnesota, Minneapolis, Minnesota, USA.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Seaquist
authors.affiliation: Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, Minnesota, USA.
authors.forename: Pierre-Gilles
authors.initials: PG
authors.lastname: Henry
authors.affiliation: Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, Minnesota, USA.
authors.forename: Gülin
authors.initials: G
authors.lastname: Öz
mesh_terms: D000328:Adult; D005240:Feasibility Studies; D005260:Female; D005947:Glucose / Q000378:metabolism*; D015309:Glucose Clamp Technique; D006801:Humans; D006943:Hyperglycemia / Q000000981:diagnostic imaging* / Q000378:metabolism*; D007031:Hypothalamus / Q000000981:diagnostic imaging* / Q000378:metabolism*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D057054:Molecular Imaging / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014018:Tissue Distribution
chemical_list: D005947:Glucose
keywords: cerebrospinal fluid; glucose transport; hyperglycemic clamp; hypothalamus; proton magnetic resonance spectroscopy