Abstract:
Objective To identify appropriate protective approaches to magnetic resonance scanning by evaluating the cumulative specific absorption dose (CSAD) of different body parts.
Methods A signa EXITE HD 1.5 Tesla TwinSpeed magnetic resonance system (GE, US) with 8-channel high resolution brain coil and 8-channel abdominal phased array coil was applied in this study. CSADs of conventional head and abdomen sequences (including plain and enhanced) were estimated by peak specific absorption rate provided by the system and scanning time of each sequence.
Results The first-10-min adjusted CSAD in head was 2.548 9 W/kg in plain scanning and the second-10-min was 1.291 5 W/kg in axial 3D FSPGR enhanced scanning (2.714 6 W/kg for conventional position enhanced scanning, 2.1 times that of the former). The first-5-min CSAD in abdomen was 1.507 1 W/kg and the second-5-min was 0.894 0 W/kg.
Conclusion Both head and abdominal CSADs by 1.5 T magnetic resonance scanning are within the FDA safety limit, but electromagnetic radiation dose varies significantly using different pulse sequences. It is advisable to make a reasonable optimization on pulse sequence selection to shorten examination time and effectively reduce electromagnetic radiation doses and potential hazards subsequently.
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