Influence of Fat on Liver T1 Measurements Using Modified Look-Locker Inversion Recovery (MOLLI) Methods at 3T
Influence of Fat on Liver T1 Measurements Using Modified Look-Locker Inversion Recovery (MOLLI) Methods at 3T
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DOI：
10.1002/jmri.25146
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发表时间：
2016-07-01
影响因子：
4.4
通讯作者：
Robson, Matthew D.
中科院分区：
文献类型：
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作者：
Mozes, Ferenc E.;Tunnicliffe, Elizabeth M.;Robson, Matthew D.
目的：探讨脂肪对肝脏改良Look-Locker反转恢复(Molli)T-1图的影响。在3T时，平衡稳态自由进动(BSSFP)序列使水和脂肪信号在重复时间(Tr)=2.3毫秒时具有相反的相位。在同时含有脂肪和水的体素中，Molli T-1的测量受到Tr.材料和方法的选择的影响。材料和方法：使用Bloch方程模拟肝脏的Molli T-1测量，同时改变肝脂含量(HLC)。使用Molli和自旋回波反转恢复序列对人造黄油模体进行幻影扫描。结果：在3T时，HLC在0-35%范围内，当TR5为2.3ms时，脂肪分数越高，Molli T-1值越长。患者在高HLC时的Molli T-1(T-1=929+/-97毫秒)高于低HLC时的Molli T-1(T-1 5870+/-44毫秒)。结论：在3T时，Molli T-1值受HLC的影响，在一个临床相关的脂肪含量范围内显著改变Molli T-1。
Purpose: To characterize the effect of fat on modified Look-Locker inversion recovery (MOLLI) T-1 maps of the liver. The balanced steady-state free precession (bSSFP) sequence causes water and fat signals to have opposite phase when repetition time (TR) = 2.3 msec at 3T. In voxels that contain both fat and water, the MOLLI T-1 measurement is influenced by the choice of TR.Materials and Methods: MOLLI T-1 measurements of the liver were simulated using the Bloch equations while varying the hepatic lipid content (HLC). Phantom scans were performed on margarine phantoms, using both MOLLI and spin echo inversion recovery sequences. MOLLI T-1 at 3T and HLC were determined in patients (n = 8) before and after bariatric surgery.Results: At 3T, with HLC in the 0-35% range, higher fat fraction values lead to longer MOLLI T-1 values when TR 5 2.3 msec. Patients were found to have higher MOLLI T-1 at elevated HLC (T-1 = 929 +/- 97 msec) than at low HLC (T-1 5 870 +/- 44 msec).Conclusion: At 3T, MOLLI T-1 values are affected by HLC, substantially changing MOLLI T-1 in a clinically relevant range of fat content.