title: In vivo assessment of cold stimulation effects on the fat fraction of brown adipose tissue using DIXON MRI.
abstract: To evaluate the volume and changes of human brown adipose tissue (BAT) in vivo following exposure to cold using magnetic resonance imaging (MRI).
  
  
  
  The clavicular region of 10 healthy volunteers was examined with a 3T MRI system. One volunteer participated twice. A cooling vest that was circulated with temperature-controlled water was used to expose each volunteer to a cold environment. Three different water temperature phases were employed: baseline (23°C, 20 min), cooling (12°C, 90 min), and a final warming phase (37°C, 30 min). Temperatures of the water in the circuit, of the body, and at the back skin of the volunteers were monitored with fiberoptic temperature probes. Applying the 2-point DIXON pulse sequence every 5 minutes, fat fraction (FF) maps were determined and evaluated over time to distinguish between brown and white adipose tissue.
  
  
  
  Temperature measurements showed a decrease of 3.8 ± 1.0°C of the back skin temperature, while the body temperature stayed constant at 37.2 ± 0.9°C. Focusing on the two interscapular BAT depots, a mean FF decrease of -2.9 ± 2.0%/h (P < 0.001) was detected during cold stimulation in a mean absolute volume of 1.31 ± 1.43 ml. Also, a correlation of FF decrease to back skin temperature decrease was observed in all volunteers (correlation coefficients: |r| = [0.51; 0.99]).
  
  
  
  We found that FF decreases in BAT begin immediately with mild cooling of the body and continue during long-time cooling.
  
  
  
  2 J. Magn. Reson. Imaging 2017;45:369-380.
authors.affiliation: Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany.
authors.forename: Vanessa
authors.initials: V
authors.lastname: Stahl
authors.affiliation: Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany.
authors.forename: Florian
authors.initials: F
authors.lastname: Maier
authors.affiliation: Department of Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany.
authors.forename: Martin T
authors.initials: MT
authors.lastname: Freitag
authors.affiliation: Medical and Biological Informatics, German Cancer Research Center (DKFZ), Heidelberg, Germany.
authors.forename: Ralf O
authors.initials: RO
authors.lastname: Floca
authors.affiliation: Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany.
authors.forename: Moritz C
authors.initials: MC
authors.lastname: Berger
authors.affiliation: Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany.
authors.forename: Reiner
authors.initials: R
authors.lastname: Umathum
authors.affiliation: Institute for Diabetes and Cancer IDC Helmholtz Center Munich and Joint Heidelberg-IDC Translational Diabetes Program, Inner Medicine 1, Heidelberg University Hospital, Neuherberg, Germany.
authors.forename: Mauricio
authors.initials: M
authors.lastname: Berriel Diaz
authors.affiliation: Institute for Diabetes and Cancer IDC Helmholtz Center Munich and Joint Heidelberg-IDC Translational Diabetes Program, Inner Medicine 1, Heidelberg University Hospital, Neuherberg, Germany.
authors.forename: Stephan
authors.initials: S
authors.lastname: Herzig
authors.affiliation: Diagnostic and Interventional Radiology, University Hospital of Heidelberg, Heidelberg, Germany.
authors.forename: Marc-André
authors.initials: MA
authors.lastname: Weber
authors.affiliation: Clinical Cooperation Unit Nuclear Medicine, German Cancer Research Center (DKFZ), Heidelberg, Germany.
authors.forename: Antonia
authors.initials: A
authors.lastname: Dimitrakopoulou-Strauss
authors.affiliation: Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany.
authors.forename: Kristian
authors.initials: K
authors.lastname: Rink
authors.affiliation: Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Bachert
authors.affiliation: Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany.
authors.forename: Mark E
authors.initials: ME
authors.lastname: Ladd
authors.affiliation: Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany.|Department of Diagnostic and Interventional Radiology, University Medical Center Ulm, Ulm, Germany.|Institute of Radiology, University Hospital Erlangen, Erlangen, Germany.
authors.forename: Armin M
authors.initials: AM
authors.lastname: Nagel
mesh_terms: D002001:Adipose Tissue, Brown / Q000033:anatomy & histology* / Q000502:physiology*; D050154:Adiposity / Q000502:physiology*; D000328:Adult; D000465:Algorithms; D001831:Body Temperature / Q000502:physiology; D003080:Cold Temperature; D058639:Cold-Shock Response / Q000502:physiology*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D009929:Organ Size; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
keywords: DIXON; MRI; brown adipose tissue; fat fraction; fiberoptic temperature measurements