Characterizing a short T2 * signal component in the liver using ultrashort TE chemical shift-encoded MRI at 1.5T and 3.0T.
Characterizing a short T2 * signal component in the liver using ultrashort TE chemical shift-encoded MRI at 1.5T and 3.0T.
复制标题
使用 1.5T 和 3.0T 的超短 TE 化学位移编码 MRI 表征肝脏中的短 T2 * 信号分量。
DOI：
10.1002/mrm.27876
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发表时间：
2019
影响因子：
3.3
通讯作者：
Reeder,ScottB
中科院分区：
文献类型：
--
作者：
Zhu,Ante;Hernando,Diego;Johnson,KevinM;Reeder,ScottB
目的最近的研究表明肝脏中存在短T2* 信号，当使用短回波时间（TE）时，这可能会混淆化学位移编码（CSE）脂肪定量。本研究的目的是表征肝脏信号在短回波时间，并确定其对肝脏脂肪quantitation.MethodsAn超短回波时间（UTE）化学位移编码的MRI（CSE-MRI）技术和多组分重建的影响被开发来表征短T2* 肝脏信号。随后，使用短TE（第一TE = 0.7 ms）和UTE CSE-MRI采集定量肝脏脂肪分数，并与标准CSE-MRI（第一TE = 1.2 ms）进行比较。结果在1.5 T和3.0 T下成像的所有健康志愿者的肝脏中始终观察到短T2* 信号。在3.0 T时，在健康志愿者、肝病患者和肝脂肪变性（但无肝硬化）患者中分别测量到短T2* 信号分数为9.6 ± 1.5%、7.0 ± 1.7%和7.4 ± 1.7%，T2* 为0.23 ± 0.05 ms、0.20 ± 0.05 ms和0.10 ± 0.02 ms。对于质子密度脂肪分数（PDFF）估计，在1.5T下使用短TE CSE-MRI和使用UTE CSE-MRI成像的受试者中分别观察到1.7%（P< .01）和3.4%（P< .01）偏倚。通过排除小于1 ms的短回波，偏差分别降低至0.4%和-0.7%。（P< .01）在使用3.0T下的UTE CSE-MRI成像的受试者中观察到，通过排除<1 ms的短回波，将其降低至0.1%。在CSE-MRI中使用短回波时间时，始终观察到信号成分，并显示其混淆肝脏脂肪定量。
PurposeRecent studies have suggested the presence of short‐T2* signals in the liver, which may confound chemical shift‐encoded (CSE) fat quantification when using short echo times (TEs). The purpose of this study was to characterize the liver signal at short echo times and to determine its impact on liver fat quantification.MethodsAn ultrashort echo time (UTE) chemical shift‐encoded MRI (CSE‐MRI) technique and a multicomponent reconstruction were developed to characterize short‐T2* liver signals. Subsequently, liver fat fraction was quantified using a short‐TE (first TE = 0.7 ms) and UTE CSE‐MRI acquisitions and compared with a standard CSE‐MRI (first TE = 1.2 ms).ResultsShort‐T2* signals were consistently observed in the liver of all healthy volunteers imaged at both 1.5T and 3.0T. At 3.0T, short‐T2* signal fractions of 9.6 ± 1.5%, 7.0 ± 1.7%, and 7.4 ± 1.7% with T2* of 0.23 ± 0.05 ms, 0.20 ± 0.05 ms, and 0.10 ± 0.02 ms were measured in healthy volunteers, patients with liver cirrhotic disease, and patients with hepatic steatosis (but no cirrhosis), respectively. For proton density fat fraction (PDFF) estimation, 1.7% (P< .01) and 3.4% (P< .01) biases were observed in subjects imaged using short‐TE CSE‐MRI and using UTE CSE‐MRI at 1.5T, respectively. The biases were reduced to 0.4% and −0.7%, respectively, by excluding short echoes less than 1 ms. A 3.2% bias (P< .01) was observed in subjects imaged using UTE CSE‐MRI at 3.0T, which was reduced to 0.1% by excluding short echoes <1 ms.ConclusionsA liver short‐T2* signal component was consistently observed and was shown to confound liver fat quantification when short echo times were used with CSE‐MRI.