肝脏液体衰减反转恢复序列最佳参数的选择及临床应用

目的:探讨液体衰减反转恢复(FLAIR)序列肝脏扫描的最佳参数及临床应用价值。方法:体外实验组将6组不同血红蛋白浓度液体和5组不同浓度的肝囊肿穿刺液埋于载体中,经0.5 T超导MR机行T2WI及FLAIR序列(TR6000 ms,TE 100 ms,TI 1500/1700/1900 ms)扫描,检测并分析相同病灶在T2WI及不同TI值的FLAIR成像的信号强度。结果:体外实验结果显示FLAIR成像随液体蛋白浓度(≥1.64 g/dl)升高和TI值延长其信号呈逐渐升高趋势,优选参数FLAIR成像(TI 1700 ms)可鉴别肝囊肿与肝血管瘤(P<0.05)。结论:FLAIR成像可初步判定液体蛋白含量,优选参数的FLAIR成像结合常规SE序列可提高肝脏病变的鉴别诊断。

Application and Optimization of Fluid-Attenuated Inversion Recovery Pulse Sequencce in Hepatic FocaL Lesions

Objective:To discuss the optimal parameters of fast FLAIR sequences imaging and to find out an optimal value for FLAIR imaging in differentiating hepatic focal lesions.Methods:The expermental in vitro study were designed as follows:six groups with different concentration of hemoglobin(embedded in containers) and five groups with different concentration of hepatic cyst liquid(also embedded in containers),were respectively scanned with a 0.5T superconductive MR scanner using conventional T_2WI and FLAIR imaging(TR 6000ms,TE 100ms,TI 1500/1700/1900ms) sequences.Examination and evaluation of MR signal intensity of the same contents with different concentration on T_2WI images and those with various TI values in FLAIR sequence were performed.Results:The experimental in vitro study showed that increased signal intensity was shown in case that the protein concentration in the fluid was increased(>1.64g/dl) and a tendency of gradual increase in signal intensity was also demonstrated in case of increasing the delay of TI.The differentiation between hepatic cyst and hemangioma could be made possible by FLAIR imaging with an optimal TI value(TI 1700ms,P<0.05).Conclusion:Fast FLAIR MR imaging was preliminarily proved uesful in evaluating protein concentration in fluid and the capability of differentiating various liver diseases might be improved by FLAIR imaging with optimal parameters and in combination of the findings with SE sequence.