• Journal of the Korean Society of Radiology
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• v.17 no.7
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• pp.1133-1138
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• 2023

This study analyzed the relationship between image parameters and specific absorption rate (SAR) in various sequence environments to optimize SAR. For this purpose, image parameters were adjusted for T2, T1, STIR, T1 FLAIR, and T2 FLAIR sequences in a 3.0T MRI, and the whole body (WB) SAR and head SAR calculated by the device were measured. Then, the SAR was evaluated by adjusting the number of images and the flip angle (FA) of the refocusing RF. As a result, SAR increased as the number of image increased in all sequences. T1 and T1 FLAIR had correlation coefficients (r) of 0.876, 0.876 (WB SAR, head SAR), 0.867, 0.867 (WB SAR, head SAR), respectively, and STIR had the highest correlation with 0.898 and 0.899 (WB SAR, head SAR). showed (p<0.05). When applied by increasing the refocusing FA, WB SAR and head SAR increased overall in all sequences. The T1 and T2 sequences showed high correlation with correlation coefficients (r) of 0.897, 0.898 (WB SAR, head SAR) and 0.914, 0.915 (WB SAR, head SAR), respectively, while the sequences to which the inversion recovery technique was applied had relatively low FA, showed less sensitivity to increase. Therefore, in a sequence with a relatively low TR, minimizing the number of image and applying the fast spin echo to reduce the refocusing FA in a sequence with a high duty cycle are effective in reducing SAR.