Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Asanbyeongwon-gil 86, Songpa-Gu, Seoul 138-736, Korea.
Magn Reson Imaging. 2013 Jul;31(6):911-7. doi: 10.1016/j.mri.2013.02.002. Epub 2013 Apr 15.
To evaluate the image findings of focal fat deposition (FFD) in the liver on gadobenate dimeglumine (Gd-BOPTA)- and gadoxetic acid (Gd-EOB-DTPA)-enhanced MRI, particularly during the hepatobiliary phase (HBP), and the relationship between relative enhancement (RE) and fat signal fraction (FSF) of FFD.
Twenty-one patients with 27 FFDs (mean diameter, 21.9mm), which showed low signal intensity on opposed-phase compared with in-phase MRI, were retrospectively evaluated. RE of the liver (REliver) and FFD (REFFD) and liver-to-lesion contrast-to-noise ratio (CNR) of FFD were measured on dynamic phases and HBP images with fat-saturated in-phase gradient-echo sequence. The FSF of each FFD was measured on in- and opposed-phase dual gradient-echo images. We qualitatively analyzed imaging findings of FFDs, including signal intensity, shape, margin, and homogeneity on HBP images, and enhancement pattern during dynamic phases. The correlations between REFFD and FSF and between CNR and FSF on HBP images were evaluated using Pearson's correlation tests and a simple linear regression model.
There were no significant differences between REFFD and REliver in dynamic phases and HBP, regardless of contrast agents (p≥0.075). On HBP images, CNR (p=0.008) but not REFFD (p=0.122) was significantly correlated with FSF of FFDs (mean FSF, 19%). On HBP images, 21 of the 27 (77.8%) FFDs were hypointense, and 17 (63%) were homogeneous. Of the 21 hypointense FFDs, 12 (57.1%) had an ovoid shape and 11 (52.4%) were well margined. Although the 27 FFDs showed various enhancement patterns, 17 (63%) showed no enhancement.
Most FFDs appeared as hypointense lesions on Gd-BOPTA- and Gd-EOB-DTPA-enhanced MRI during HBP, with various enhancement patterns during dynamic contrast-enhanced phases. REFFD on HBP images was not significantly correlated with FSF of low grade FFDs.
评估钆贝葡胺（Gd-BOPTA）和钆塞酸二钠（Gd-EOB-DTPA）增强 MRI 中肝脏局灶性脂肪沉积（FFD）的影像学表现，尤其是在肝胆期（HBP），并探讨 FFD 的相对增强（RE）与脂肪信号分数（FSF）之间的关系。
回顾性分析了 21 例 27 个 FFD（平均直径 21.9mm）患者的资料，这些 FFD 在反相位 MRI 上与同相位 MRI 相比表现为低信号。在动态相和 HBP 图像（脂肪饱和同相位梯度回波序列）上测量肝实质（REliver）和 FFD（REFFD）的相对增强以及 FFD 的肝与病灶对比噪声比（CNR）。在同相位和反相位双梯度回波图像上测量每个 FFD 的 FSF。我们定性分析了 HBP 图像上 FFD 的影像学表现，包括信号强度、形状、边缘和均匀性，以及动态相的增强模式。使用 Pearson 相关检验和简单线性回归模型评估 HBP 图像上 REFFD 与 FSF 以及 CNR 与 FSF 之间的相关性。
在动态相和 HBP 中，无论使用哪种对比剂，REFFD 与 REliver 之间均无显著差异（p≥0.075）。在 HBP 图像上，CNR（p=0.008）而不是 REFFD（p=0.122）与 FFD 的 FSF 显著相关（平均 FSF，19%）。在 HBP 图像上，27 个 FFD 中有 21 个（77.8%）呈低信号，17 个（63%）呈均匀性。在 21 个低信号 FFD 中，12 个（57.1%）呈卵圆形，11 个（52.4%）呈边界清晰。尽管 27 个 FFD 显示出各种增强模式，但 17 个（63%）无增强。
在 Gd-BOPTA 和 Gd-EOB-DTPA 增强 MRI 的 HBP 期间，大多数 FFD 呈低信号病变，在动态对比增强期显示出各种增强模式。HBP 图像上的 REFFD 与低级别 FFD 的 FSF 无显著相关性。
