Comparative MR study of hepatic fat quantification using single-voxel proton spectroscopy, two-point Dixon and three-point IDEAL
Comparative MR study of hepatic fat quantification using single-voxel proton spectroscopy, two-point Dixon and three-point IDEAL
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DOI：
10.1002/mrm.21561
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发表时间：
2008-03-01
影响因子：
3.3
通讯作者：
Constable, R. Todd
中科院分区：
文献类型：
--
作者：
Kim, Hyeonjin;Taksali, Sara E.;Constable, R. Todd
采用单体素质子波谱（MRS）、两点狄克逊（2 PD）和三点迭代水和脂肪分解回波不对称和最小二乘估计（IDEAL）方法（3 PI）测量28名瘦/肥胖人群的肝脂肪分数（HFF）。对于瘦型、肥胖型和总体受试者组，MRS测量的HFF范围分别为0.3-3.5%（1.1 +/- 1.4%）、0.3-41.5%（11.7 +/- 12.1）和0.3-41.5%（10.1 +/- 11.6%）。对于相同的组，2 PD测量的HFF为-6.3-2.2%（-2.0 +/- 3.7%），-2.4-42.9%（12.9 +/- 13.8%）和-6.3-42.9%（10.5 ± 13.7%），3 PI分别为7.9-12.8%（10.1 ± 2.0%）、11.1-49.3%（22.0 ± 12.2%）和7.9-49.3%（20.0 ± 11.8%）。MRS测量的HFF与2 PD（r = 0.954，P < 0.001）和3 PI（r = 0.973，P < 0.001）测量的HFF高度相关。以MRS资料为参考，MRI方法对正常肝和脂肪肝的正确区分率为68-93%（2 PD）和64-89%（3 PI）。我们的研究表明，通过MRI方法测量的表观HFF可以根据水-脂肪分离方法和序列的选择而显著变化。这种可变性可能限制MRI方法的临床应用，特别是当需要进行早期脂肪肝的诊断时。因此，可能需要建立方案特定的肝脏脂肪含量临界值。
Hepatic fat fraction (HFF) was measured in 28 lean/obese humans by single-voxel proton spectroscopy (MRS), a two-point Dixon (2PD), and a three-point iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL) method (3PI). For the lean, obese, and total subject groups, the range of HFF measured by MRS was 0.3-3.5% (1.1 +/- 1.4%), 0.3-41.5% (11.7 +/- 12.1), and 0.3-41.5% (10.1 +/- 11.6%), respectively. For the same groups, the HFF measured by 2PD was -6.3-2.2% (-2.0 +/- 3.7%), -2.4-42.9% (12.9 +/- 13.8%), and -6.3-42.9% (10.5 +/- 13.7%), respectively, and for 3PI they were 7.9-12.8% (10.1 +/- 2.0%), 11.1-49.3% (22.0 +/- 12.2%), and 7.9-49.3% (20.0 +/- 11.8%), respectively. The HFF measured by MRS was highly correlated with those measured by 2PD (r = 0.954, P < 0.001) and 3PI (r = 0.973, P < 0.001). With the MRS data as a reference, the percentages of correct differentiation between normal and fatty liver with the MRI methods ranged from 68-93% for 2PD and 64-89% for 3PI. Our study demonstrates that the apparent HFF measured by the MRI methods can significantly vary depending on the choice of water-fat separation methods and sequences. Such variability may limit the clinical application of the MRI methods, particularly when a diagnosis of early fatty liver needs to be performed. Therefore, protocol-specific establishment of cutoffs for liver fat content may be necessary.