MRI scanner-independent specific absorption rate measurements using diffusion coefficients

Youngseob Seo, Zhiyue J. Wang

Research output: Contribution to journalArticlepeer-review

8 Scopus citations


Objective: The purpose of this study was to measure specific absorption rate (SAR) during MRI scanning using a human torso phantom through quantification of diffusion coefficients independently of those reported by the scanner software for five 1.5 and 3 T clinical MRI systems from different vendors. Methods: A quadrature body coil transmitted the RF power and a body array coil received the signals. With diffusion tensor imaging, SAR values for three MRI sequences were measured on the five scanners and compared to the nominal values calculated by the scanners. Results: For the GE 1.5 T MRI system, the MRI scanner-reported SAR value was 1.58 W kg-1 and the measured SAR value was 1.38 W kg-1. For the Philips 1.5 T MRI scanner, the MRI system-reported SAR value was 1.48 W kg-1 and the measured value was 1.39 W kg-1. For the Siemens 3 T MRI system, the reported SAR value was 2.5 W kg-1 and the measured SAR value was 1.96 W kg-1. For two Philips 3 T MRI scanners, the reported SAR values were 1.5 W kg-1 and the measured values were 1.94 and 1.96 W kg-1. The percentage differences between the measured and reported SAR values on the GE 1.5 T, Philips 1.5 T, Siemens 3 T, and Philips 3 T were 13.5, 6.3, 24.2, 25.6, and 26.6% respectively. Conclusion: The scanner-independent SAR measurements using diffusion coefficients described in this study can play a significant role in estimating accurate SAR values as a standardized method.

Original languageEnglish (US)
Pages (from-to)224-229
Number of pages6
JournalJournal of applied clinical medical physics
Issue number4
StatePublished - Jul 1 2017


  • Diffusion coefficient
  • Diffusion tensor imaging
  • Human torso phantom
  • MR safety
  • Specific absorption rate

ASJC Scopus subject areas

  • Radiation
  • Instrumentation
  • Radiology Nuclear Medicine and imaging


Dive into the research topics of 'MRI scanner-independent specific absorption rate measurements using diffusion coefficients'. Together they form a unique fingerprint.

Cite this