Mergo P J, Engelken J D, Helmberger T, Ros P R
Department of Radiology, University of Florida College of Medicine, Gainesville, USA.
J Magn Reson Imaging. 1998 Sep-Oct;8(5):1073-8. doi: 10.1002/jmri.1880080511.
The purpose of this study was to compare small and ultrasmall superparamagnetic iron oxide particles (SPIO and USPIO, respectively) as MR contrast agents for the evaluation of focal hepatic disease. In two different patient groups (SPIO [n = 53], USPIO [n = 27]), with focal liver disease (metastases, hepatocellular carcinoma [HCC], hepatocellular adenoma [HCA], and focal nodular hyperplasia [FNH]), spin-echo T1- and T2-weighted images (T1WI, T2WI) were obtained at 1.0T, before and after intravenous contrast administration. The percentage signal-to-noise ratio (SNR) change and lesion-to-liver contrast (LLC) were measured and statistically compared. The liver decreased in signal intensity (SI) after SPIO administration (-28%) and increased after USPIO administration (+16%) on T1WI. On T2WI, the liver decreased in SI on postcontrast images with both agents (-78% SPIO, -73% USPIO). This difference was not statistically significantly different (P < or = .07). Both SPIO and USPIO provided >500% improvement in LLC on T2WI. On T1WI, LLC was increased in metastases (120%) and HCC (325%) with SPIO. Post-USPIO, LLC was increased on T1WI only in metastases (>500%). Both SPIO and USPIO show excellent hepatic uptake, presumed secondary to reticuloendothelial activity, based on the degree of %SI change seen in the liver after administration of contrast on T2WI. However, USPIO preparations exhibit blood pool activity that may aid in further characterization of focal liver lesions, as is evidenced by their greater T1 effect in the liver and in some focal liver lesions.
本研究的目的是比较超小型和极超小型超顺磁性氧化铁颗粒（分别为SPIO和USPIO）作为磁共振成像（MR）对比剂用于评估局灶性肝病的效果。在两组不同的患者中（SPIO组[n = 53]，USPIO组[n = 27]），患有局灶性肝病（转移瘤、肝细胞癌[HCC]、肝细胞腺瘤[HCA]和局灶性结节性增生[FNH]），在静脉注射对比剂前后于1.0T场强下获取自旋回波T1加权和T2加权图像（T1WI、T2WI）。测量信号噪声比（SNR）变化百分比和病变与肝脏的对比（LLC）并进行统计学比较。在T1WI上，注射SPIO后肝脏信号强度（SI）降低（-28%），注射USPIO后升高（+16%）。在T2WI上，使用两种对比剂后肝脏在增强后图像上的SI均降低（SPIO为-78%，USPIO为-73%）。这种差异无统计学意义（P≤0.07）。SPIO和USPIO在T2WI上均使LLC提高了>500%。在T1WI上，SPIO使转移瘤（120%）和HCC（325%）的LLC增加。注射USPIO后，仅转移瘤在T1WI上的LLC增加（>500%）。基于T2WI上注射对比剂后肝脏中SI变化百分比的程度，SPIO和USPIO均显示出良好的肝脏摄取，推测是继发于网状内皮系统活性。然而，USPIO制剂表现出血池活性，这可能有助于对局灶性肝病变进行进一步特征描述，其在肝脏和一些局灶性肝病变中的更大T1效应证明了这一点。
