对比剂对MRI非对称回波三点法水脂分离测量肝脏脂肪和铁的影响

A preliminary study on the effect of contrast agents on the quantification of liver fat and iron using MRI IDEAL-IQ sequence

目的:探讨对比剂对非对称回波三点法水脂分离-定量测定(IDEAL-IQ)肝脏脂肪和铁定量的影响。方法:22例注射钆喷酸葡胺(Gd-DTPA,A组)和33例注射钆塞酸二纳(Gd-EOB-DTPA,B组)患者于注射前、后不同时间点(注射后5 min、10 min、15 min、20 min)行IDEAL-IQ扫描,在FatFrac图和R2~*图分别测定质子脂肪含量(PDFF)及R2~*值,并行组内配对t检验。结果:A1-A2配对分析,PDFF(t=0.996,P=0.330)及R2~*(t=0.656,P=0.519)的差异均无统计学意义;B1-B2、B1-B5配对分析,PDFF(t=-3.159、-2.459,P=0.003、0.024)及R2~*(t=-3.619、-3.191,P=0.001、0.005)的差异有统计学意义;B1-B3配对分析,PDFF的差异无统计学意义(t=-1.429,P=0.181),而R2~*的差异有统计学意义(t=-2.724,P=0.024)。结论:注射Gd-DTPA后5 min行IDEAL-IQ扫描,对肝脏脂肪及铁定量无显著影响;而注射Gd-EOB-DTPA后5 min及20 min行IDEAL-IQ扫描,对肝脏脂肪及铁定量有显著影响。

Objective:To explore the effect of contrast agents on the quantification of liver fat and iron using MRI IDEAL-IQ sequence. Methods:Twenty-two patients underwent MRI IDEAL-IQ scan before and after injection of gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA)(group A) and 33 patients with gadolinium ethoxybenzyl dieathylenetriamine pentaacetic acid (Gd-EOB-DTPA)(group B) at different time points (15min,10min,15min,20min after injection).PDFF and R2^* were measured respectively on Fat Frac map and R2^* map,and in-group paired t test was performed. Results:There were not statistical difference found between the A1-A2 paired (PDFF: t =0.996, P = 0.330;R2^*: t =0.656, P =0.519),but between the B1-B2 paired (PDFF: t =-3.159, P =0.003;R2^*: t =-3.619, P =0.001),B1-B5 paired (PDFF: t =-2.459, P =0.024;R2^*: t =-3.191, P =0.005),with the PDFF and the R2^*.The PDFF ( t =-1.429, P =0.181) was not statistically different,while the R2^*( t =-2.724, P =0.024) was statistically significant between B1-B3 paired. Conclusion:Compared with pre-injection scan, Gd-DTPA has not significant effect on the quantification of hepatic fat and iron 5min after injection.However,Gd-EOB-DTPA,has significant effect on the quantification of liver fat and iron at 5min and 20min after administration.