Keywords:
MR physics, Molecular imaging, Ultrasound physics, MR, CT, Ultrasound, Experimental investigations, Physics, Imaging sequences, Biological effects, Image verification, Image registration
Authors:
J. Blackwell, W. van der Putten, B. Tuohy, N. Colgan; Galway/IE
DOI:
10.1594/ecr2018/C-1382
Aims and objectives
During an MR procedure,
most of the transmitted RF power is transformed into heat within the patients’ tissue resulting from resistive losses,
referred to as the specific energy absorption rate(SAR) (2).
The EU standardisation has mandated that all scanners must measure SAR in patients and develop system safeguards to ensure that the limits(IEC60602-3-33) are not exceeded.
Accurate estimation of SAR is critical in safeguarding patients who may be unconscious/sedated,
have implants or are pregnant.
Modern MRI systems can easily exceed safe SAR levels (1) requiring the independent verification of manufacturers SAR estimations.
The purpose of this research was to develop a protocol to verify the patient specific SAR.
To determine RF power deposition experimentally,
a T1 doped MR phantom in a birdcage head coil was used,
heated solely by the RF fields produced by the imaging coil.