Title :
Predicting temperature increase through local SAR estimation by B1 mapping: A phantom validation at 7T
Author :
Xiaotong Zhang ; Jiaen Liu ; Schmitter, Sebastian ; Van de Moortele, Pierre-Francois ; Bin He
Author_Institution :
Dept. of Biomed. Eng., Univ. of Minnesota, Minneapolis, MN, USA
Abstract :
It has been shown that Electrical Properties d(EPs) of biological tissues can be derived from MR-based B1 measurement. A strong appeal for these `Electrical Property Tomography´ (EPT) methods is to estimate real-time and subject-specific local specific absorption rate (SAR) induced by RF transmission. In order to investigate the feasibility of EPT-based local SAR estimation, following previously proposed EPT protocols, induced local SAR has been firstly estimated under one B1 shim setting for a heating sequence at 7T; whereas with the same acquired B1 information, induced local SAR under a different B1 shim setting has been further predicted. Both of the SAR results have been compared to measured temperature changes using MRI Thermometry based on the proton chemical shift.
Keywords :
bioelectric phenomena; biological tissues; biomedical MRI; biothermics; heating; phantoms; temperature measurement; EPT-based local SAR estimation; MR-based B1 measurement; MRI thermometry; biological tissues; electrical property tomography methods; heating sequence; magnetic flux density 7 T; phantom validation; proton chemical shift; radiofrequencytransmission; real-time SAR estimation; specific absorption rate; subject-specific local SAR estimation; temperature change measurement; Coils; Estimation; Heating; Magnetic resonance imaging; Radio frequency; Temperature measurement;
Conference_Titel :
Engineering in Medicine and Biology Society (EMBC), 2014 36th Annual International Conference of the IEEE
Conference_Location :
Chicago, IL
DOI :
10.1109/EMBC.2014.6943788
