자기공명영상을 이용한 지방간 정량화 기법의 유용성: Screening Dixon, Multi Echo Dixon, HISTO와 Ultrasonography의 비교

Purpose : This study tries to compare Screening Dixon, Multi Echo Dixon, and High-speed T2-corrected Multi Echo acquisition at 1H MR spectroscopy in liver magnetic resonance image with ultrasonography in terms of fatty liver evaluation, and thereby to find availability of the fatty liver evaluation in liver magnetic resonance imaging. Material and Methods : The study subjects were 138 patients (men: 101, women: 37, average age: 60.2 years)who had visited this hospital from Aug. 2014 to Aug. 2015 and had both liver magnetic resonance imaging, underwent ultrasonography three months ago and later. The applied equipment was Magnetom Skyra 3.0T(Siemens Healthcare, Germany). With the system, Screening Dixon, Multi Echo Dixon, and High-speed T2-corrected Multi Echo acquisition at 1H MR spectroscopy(HISTO) were applied. Also the applied ultrasonography equipment was iu22(Philips healthcare, Netherlands), E9(GE healthcare, America) with C3-5 convex probe. The evaluation results were compared with ultrasonography results. In the analysis on fatty liver, Screening Dixon was compared with Multi Echo Dixon, HISTO in terms of whether there is fatty liver so as to find the significance of MRI fatty liver test techniques. In comparison between Multi Echo Dixon and HISTO, and between the two techniques and ultrasonography, fatty content was categorized in ‘normal’(less than 5%), ‘mild’(5~33%), ‘moderate’(33~66%), and ‘severe’(more than 66%); and the significance was analyzed with SPSS21 based person χ2(chisquare). Results : According to the comparison between Screening Dixon and Multi Echo Dixon, between Screening Dixon and HISTO. Screening Dixon had the largest patients with fatty liver, but there was no statistical difference (p>0.05). According to the comparison between Multi Echo Dixon and HISTO in the category of ‘normal’, ‘mild’, ‘moderate’, and ‘severe’, the two techniques had no patients with moderate and more fatty liver, and therefore they were not different (p>0.05). However, according to the comparison between Multi Echo Dixon and ultrasonography, between HISTO and ultrasonography, ultrasonography had the largest patients with fatty liver. While the number of patients in the normal group decreased significantly and ultrasonography had more ‘moderate’ and ‘severe’ patients with fatty liver(p<0.05). Conclusion : In terms of fatty liver evaluation, Screening Dixon, Multi Echo Dixon, and High-speed T2-corrected Multi Echo acquisition at 1H MR spectroscopy(HISTO) in liver magnetic resonance imaging, and ultrasonography were compared. As a result, there was no significant difference between the techniques using magnetic resonance imaging. However, in comparison with ultrasonography, there was a significant difference. In the case of a MRI based examination, the additional examination in liver magnetic resonance imaging helps to quantify fatty liver in a short time.