An anatomically realistic temperature phantom for radiofrequency heating measurements

Magn Reson Med. 2015 Jan;73(1):442-50. doi: 10.1002/mrm.25123. Epub 2014 Feb 18.


Purpose: An anthropomorphic phantom with realistic electrical properties allows for a more accurate reproduction of tissue current patterns during excitation. A temperature map can then probe the worst-case heating expected in the unperfused case. We describe an anatomically realistic human head phantom that allows rapid three-dimensional (3D) temperature mapping at 7T.

Methods: The phantom was based on hand-labeled anatomical imaging data and consists of four compartments matching the corresponding human tissues in geometry and electrical properties. The increases in temperature resulting from radiofrequency excitation were measured with MR thermometry using a temperature-sensitive contrast agent (TmDOTMA(-)) validated by direct fiber optic temperature measurements.

Results: Acquisition of 3D temperature maps of the full phantom with a temperature accuracy better than 0.1°C was achieved with an isotropic resolution of 5 mm and acquisition times of 2-4 minutes.

Conclusion: Our results demonstrate the feasibility of constructing anatomically realistic phantoms with complex geometries incorporating the ability to measure accurate temperature maps in the phantom. The anthropomorphic temperature phantom is expected to provide a useful tool for the evaluation of the heating effects of both conventional and parallel transmit pulses and help validate electromagnetic and temperature simulations.

Keywords: MR safety; local SAR; parallel transmit; phantom; temperature estimation; thermometry.

Publication types

  • Evaluation Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Body Temperature / physiology*
  • Body Temperature / radiation effects*
  • Equipment Design
  • Equipment Failure Analysis
  • Hot Temperature
  • Humans
  • Image Interpretation, Computer-Assisted / methods*
  • Magnetic Resonance Imaging / instrumentation*
  • Magnetic Resonance Imaging / methods
  • Phantoms, Imaging*
  • Radiation Dosage
  • Radio Waves
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Thermography / instrumentation*
  • Thermography / methods