不同加速因子对3D mDixon Quant序列全胰腺脂肪与体积定量的影响

Effects of Different Acceleration Factors on 3D mDixon Quant Sequences in Quantifying Pancreatic Fat and Volume

目的探讨不同加速因子(AF)对3D mDixon Quant全胰腺脂肪与体积定量的影响。方法搜集30名健康志愿者在3.0 T磁共振(Ingenia CX,Philips)上应用3D mDixon Quant序列行上腹扫描。男14名,女16名,年龄22~69岁(中位年龄48岁);体质指数(BMI)17.71~32.59 kg/m^(2)(中位BMI 24.57 kg/m^(2))。3D mDixon Quant序列扫描参数:视野(FOV)375 mm×300 mm×168 mm,TR 6.0 ms,TE 1.05 ms,翻转角(FA)3°,体素大小2.3 mm×2.31 mm×5.0 mm,矩阵164×130×67,敏感性编码(SENSE)AF分别为2、4和压缩感知技术(CS)AF分别为2、4、5、6。重组图像导入Philips ISP(Intelli Space Portal,Philips)工作站,两名观察者(影像诊断经验分别为3年和5年)采用双盲法应用半自动分割技术获得全胰腺脂肪分数与胰腺体积。通过SPSS 25.0对数据进行处理分析。采用Shapiro-Wilk检验对数据进行正态性检验。采用组内相关系数(ICC)分析两位观察者所测得数据一致性。使用Friedman检验对胰腺脂肪与体积的数据进行差异性检验。结果两位观察者所测量的胰腺脂肪与体积数据一致性良好(ICC值均>0.75)。不同AF全胰腺脂肪分数与胰腺体积差异无统计学意义(P>0.05)。相比于SENSE AF为2时,CS AF为6的扫描时间减少了65.54%。结论不同AF对胰腺体积和全胰腺脂肪分数无影响,并且增加AF可以缩短扫描时间。

Objective To investigate the effects of different acceleration factors(AF)in quantifying pancreatic fat and volumeusing 3 D mDixon Quant sequence.Methods Healthy subjects whounderwent upper abdomen 3.0 T MR(Ingenia CX,Philips)including 3 D mD ixon Quant sequences were collected.Thirty healthy subjects were enrolled,including 14 males and 16 females,age range22-69 years(median age,48 years),BMI range17.71-32.59 kg/m^(2)(median,24.57 kg/m^(2)).Scan parameters of 3 D mD ixon Quant sequence were as follows:FOV=375×300×168 mm3,TR/TE=6.0 ms/1.05 ms,flip angle=3°,voxel size=2.3 mm×2.31 mm×5.0 mm,matrix=164×130×67,The AF of SENSE=2,4 and thatof Compressed SENSE(CS)=2,4,5,6.After scanning,the images were imported into ISP(IntelliS pace Portal,Philips)workstation.The whole pancreatic fat fraction(PFF)and pancreatic volume(PV)were obtained using semi-automatic segmentation method by two observers(observer 1 and observer 2,with 6 and 10 years of experience in abdominal MR imaging,respectively)with double-blind method.The data were analyzed by SPSS25.0.Shapiro-Wilk test was used to test the normality of the data.The intra-class correlation coefficients(ICC)were used to analyze the consistency of the data.The Friedman test was used to analyze difference in the data of pancreatic fat and volume.Results The data measured by the two observers were in good agreement(ICC values>0.75).There was no significant difference inP FF and PV with different AFs(P>0.05).Compared with the SENSE AF=2,the scanning time of CSAF=6 decreased by 65.54%.Conclusion Different AFs have no effect on quantifying the whole PFF and PV,andincreased AF can decrease the scan time.