Fat Suppression에 대한 fast spin echo fat saturation와IDEAL - FSE 기법의 유용성 비교 연구

Abstract

This study is intended to implement images using fast spin echo fat saturation and IDEALtechniques as the fat suppression of reducing fat signal phase artifact caused by chemical shiftphenomena on the boundary interface between water and fat, and the consecutive qualitative analysiswas carried out in order to compare the availabilities of those imaging techniques. The comparison wasconducted by applying the fast spin echo (FSE) T2 weighted pulse sequence and IDEAL techniques tothe test. 1.5 Tesla MR scanner (Signa HDxt, GE, USA) and 16 channel CTL coil were employed in thetest as the MR imaging devices. For image point, FSE technique was applied to gain images as follows:TR as 2617 / 4250 ms, TE as 85 / 110 ms, Matrix as 320 × 192 / 320 × 224, ETL as 22 / 24, FOV as330 ㎜, and slice thickness as 40 mm. For those by IDEAL technique, the image implantation was carriedout under the following conditions: TR as 4250 ms, TE as 110 ms, FOV as 330 ㎜, Slice thickness as 40,Matrix as 320 × 224, ETL as 24, Band width as 62.50 ㎐, and NEX as 2. As the qualitative analysismethod, the signal to noise ratio and the contrast to noise ratio were obtained from the areas ofinterest in each group, and the values among each group were comparatively analyzed to determine thehigher availabilities between the fast spin echo fat saturation and IDEAL-FSE techniques for the fatsuppression. As results of imaging, the SNR values of fat at the given points for FSE technique were0.933, 0.926, 0.953, and 0.956, respectively, while that for IDEAL technique was 0.97. The SNR valuesfor water for FSE technique were 0.316, 0.233, 0.296, and 0.196, respectively while that for IDEALtechnique was 0.44. The required time for FSE technique were 1 minutes 40 seconds, 2 minutes 54seconds, 1 minute 29 seconds, and two minutes 54 seconds while that for IDEAL technique was fourminutes 28 seconds. When FSE imaging and IDEAL techniques that used the identical image points withIDEAL technique were compared among other FSE techniques, SNR of IDEAL technique was 1.017 timesof that in FSE, and the time requirement was 3.011 times larger. Though IDEAL technique required3.011 times longer time than that of FSE T2 technique, but SNR was just 1.017 time higher while CNRbecame 0.896 times lower. Implication by the study results may include that IDEAL technique may beused to obtain images of uniform fat suppression with excellent SNR, but FSE T2 needs to be used topromote the convenience of patients based on relatively short test time.