Relaxation effects in the quantification of fat using gradient echo imaging
Relaxation effects in the quantification of fat using gradient echo imaging
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DOI：
10.1016/j.mri.2007.08.012
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发表时间：
2008-04-01
影响因子：
2.5
通讯作者：
Sirlin, Claude B.
中科院分区：
文献类型：
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作者：
Bydder, Mark;Yokoo, Takeshi;Sirlin, Claude B.
已利用从多个梯度回波获取的图像对脂肪进行量化研究。在已知脂肪和水成分的体模以及21名脂肪肝研究对象中，测量了信号随回波时间和翻转角的变化。将数据与不同的信号方程模型进行比较，其中每个模型对T1和/或T2*弛豫效应有不同的假设。对一系列的T1、T2*、脂肪分数和回波数量进行了研究，以涵盖与临床成像相关的情况。结果表明，在低翻转角（以最小化T1效应）和少量回波（以最小化频谱展宽效应）的情况下量化最准确。在短回波时间时，频谱展宽效应表现为脂肪成分的表观T2较短。（c）2008爱思唯尔公司。保留所有权利。
Quantification of fat has been investigated using images acquired from multiple gradient echos. The evolution of the signal with echo time and flip angle was measured in phantoms of known fat and water composition and in 21 research subjects with fatty liver. Data were compared to different models of the signal equation, in which each model makes different assumptions about the T1 and/or T2* relaxation effects. A range of T1, T2*, fat fraction and number of echos was investigated to cover situations of relevance to clinical imaging. Results indicate that quantification is most accurate at low flip angles (to minimize T1 effects) with a small number of echos (to minimize spectral broadening effects). At short echo times, the spectral broadening effects manifest as a short apparent T2 for the fat component. (c) 2008 Elsevier Inc. All rights reserved.