title: Acquisition of 3D temperature distributions in fluid flow using proton resonance frequency thermometry.
abstract: Proton resonance frequency thermometry is well established for monitoring small temperature changes in tissue. Application of the technique to the measurement of complex temperature distributions within fluid flow is of great interest to the engineering community and could also have medical applications. This work presents an experimental approach to reliably measure three-dimensional (3D) temperature fields in fluid flow using proton resonance frequency thermometry.
  
  
  
  A velocity-compensated three-dimensional gradient echo sequence was used. A flexible pumping system was attached to an MR compatible double pipe heat exchanger. The temperature of two separate flow circuits could be adjusted to produce various three-dimensional spatial temperature distributions within the fluid flow. Validation was performed using MR compatible temperature probes in a uniformly heated flow. A comparative study was conducted with thermocouples in the presence of a spatially varying temperature distribution.
  
  
  
  In uniformly heated flow, temperature changes were accurately measured to within 0.5 K using proton resonance frequency thermometry, while spatially varying temperature changes measured with MR showed good qualitative agreement with pointwise measurements using thermocouples.
  
  
  
  Proton resonance frequency thermometry can be used in a variety of complex flow situations to address medical as well as engineering questions. This work makes it possible to gain new insights into fundamental heat transfer phenomena. Magn Reson Med 76:145-155, 2016. © 2015 Wiley Periodicals, Inc.
authors: Department of Radiology, University Medical Center Freiburg, Medical Physics, Freiburg, Germany.
authors: Waltraud B
authors: WB
authors: Buchenberg
authors: Department of Fluid Mechanics and Aerodynamics, Technische Universität Darmstadt, Darmstadt, Germany.
authors: Florian
authors: F
authors: Wassermann
authors: Department of Fluid Mechanics and Aerodynamics, Technische Universität Darmstadt, Darmstadt, Germany.
authors: Sven
authors: S
authors: Grundmann
authors: Interventional and Pediatric Radiology, University Hospital, Institute of Diagnostic, Bern, Switzerland.
authors: Bernd
authors: B
authors: Jung
authors: Department of Radiology, University Medical Center Freiburg, Medical Physics, Freiburg, Germany.
authors: Robin
authors: R
authors: Simpson
mesh_terms: D000465:Algorithms; D004867:Equipment Design; D007090:Image Interpretation, Computer-Assisted / Q000295:instrumentation / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000295:instrumentation / Q000379:methods*; D018810:Magnetic Resonance Angiography / Q000295:instrumentation / Q000379:methods*; D019047:Phantoms, Imaging; D066244:Proton Magnetic Resonance Spectroscopy / Q000295:instrumentation / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013696:Temperature; D013817:Thermography / Q000295:instrumentation* / Q000379:methods
keywords: double pipe heat exchanger; fluid flow; in vitro models; laminar mixed convection flow; magnetic resonance thermometry; proton resonance frequency (PRF); three-dimensional (3D) temperature measurements