肝硬化或慢性肝炎患者中，超顺磁性氧化铁增强磁共振成像显示铁摄取增加的肝细胞病变：四种磁共振序列对病变显示清晰度的比较

Hepatocellular lesions with increased iron uptake on superparamagnetic iron oxide-enhanced magnetic resonance imaging in cirrhosis or chronic hepatitis: comparison of four magnetic resonance sequences for lesion conspicuity.

作者信息

Tanabe Masahiro, Ito Katsuyoshi, Shimizu Ayame, Fujita Takeshi, Onoda Hideko, Yamatogi Shigenari, Washida Yasuo, Matsunaga Naofumi

机构信息

Department of Radiology, Yamaguchi University Graduate School of Medicine, Yamaguchi 755-8505, Japan.

出版信息

Magn Reson Imaging. 2009 Jul;27(6):801-6. doi: 10.1016/j.mri.2008.11.006. Epub 2009 Jan 13.

DOI:10.1016/j.mri.2008.11.006

PMID:19144487

Abstract

PURPOSE

The aim of this study was to determine the adequate MR sequence for the lesion conspicuity of hepatocellular lesions with increased iron uptake on superparamagnetic iron oxide (SPIO)-enhanced MRI.

MATERIALS AND METHODS

SPIO-enhanced MRI was performed using a 1.5-T system. Among 25 patients with hypovascular hepatocellular nodules on contrast-enhanced dynamic CT (no early enhancement at arterial phase and hypoattenuation at equilibrium phase), 39 lesions with increased iron uptake on SPIO-enhanced MRI were evaluated. SPIO-enhanced MRI included (1) T1-weighted in-phase gradient recalled echo (GRE) images, (2) T2-weighted fast spin echo (FSE) images, (3) T2*-weighted GRE with moderate TE (7 ms) and (4) long TE (12 ms). The lesion-to-liver contrast-to-noise ratios of the hepatocellular nodule and the signal-to-noise ratio (SNR) of the hepatic parenchyma were calculated by one radiologist for a quantitative assessment. MR images were reviewed retrospectively by two independent radiologists to compare the subjective lesion conspicuity in each image set based on a four-point rating scale.

RESULT

The mean lesion-to-liver contrast-to-noise ratios with T2*-weighted GRE with moderate TE (7 ms) was highest (5.79+/-3.71) and was significantly higher than those with T1-weighted, in-phase images (3.79+/-3.23, P<.01), T2-weighted images (2.72+/-1.52, P<.001) and T2*-weighted GRE with long TE (12 ms) (3.93+/-2.69, P<.05). The subjective rating of lesion conspicuity was best on the T2*-weighted GRE with moderate TE (7 ms), followed by that on the T2*-weighted GRE with moderate TE (7 ms; P<.05).

CONCLUSION

T2*-weighted GRE sequence with moderate TE (7 ms) showed high lesion-to-liver contrast-to-noise ratios in hepatocellular lesions with increased iron uptake on SPIO-enhanced MRI, indicating better lesion conspicuity of hypointense hepatocellular nodules in cirrhosis or chronic hepatitis.

摘要

目的

本研究的目的是确定在超顺磁性氧化铁（SPIO）增强磁共振成像（MRI）上，对于铁摄取增加的肝细胞病变，何种磁共振序列能使其显示得更清晰。

材料与方法

使用1.5-T系统进行SPIO增强MRI检查。在25例经动态对比增强CT显示为乏血供肝细胞结节（动脉期无早期强化且平衡期呈低密度）的患者中，对39个在SPIO增强MRI上铁摄取增加的病变进行评估。SPIO增强MRI包括：（1）T1加权同相位梯度回波（GRE）图像；（2）T2加权快速自旋回波（FSE）图像；（3）具有中等回波时间（TE）（7毫秒）的T2加权GRE图像；（4）长TE（12毫秒）的T2加权GRE图像。由一名放射科医生计算肝细胞结节的病变与肝脏对比噪声比以及肝实质的信噪比，进行定量评估。两名独立的放射科医生对MR图像进行回顾性分析，基于四点评分量表比较各图像组中病变的主观显示清晰度。

结果

具有中等TE（7毫秒）的T2加权GRE图像的平均病变与肝脏对比噪声比最高（5.79±3.71），显著高于T1加权同相位图像（3.79±3.23，P<0.01）、T2加权图像（2.72±1.52，P<0.001）以及具有长TE（12毫秒）的T2加权GRE图像（3.93±2.69, P<0.05）。病变显示清晰度的主观评分在具有中等TE（7毫秒）的T2加权GRE图像上最佳，其次是具有长TE（12毫秒）的T2加权GRE图像（P<0.05）。