Liu Xian, Xu Yi-Kai, Huang Qi-Liu, Wu Yuan-Kui
Medical Imaging Center, Nanfang Hospital, First Military Medical University, Guangzhou 510515, China.
Di Yi Jun Yi Da Xue Xue Bao. 2002 Dec;22(12):1061-5.
To evaluate the value of superparamagnetic iron oxide (SPIO)-enhanced magnetic resonance (MR) imaging in the diagnoses of focal liver lesions.
Twenty rat models of hepatocellular carcinoma were induced by feeding the rats with N-nitrosodiethylamine. Before and after SPIO injection into the rats, MR imaging was performed including the sequences of spin-echo (SE) T1WI (390 ms/14 ms), TSE T2WI (4 100 ms/99 ms), SE Dual-echoes (1 800 ms/20 ms/70 ms), GRE FLASH T2*WI (600 ms/15 ms/15 ), and GRE FLASH T1WI (150 ms/14 ms/70 ). Another 5 normal rats were selected as negative control, which also received SPIO and MR imaging in the same manner as described above. The characteristics of SPIO-enhanced MRI of different liver lesions were analyzed.
After SPIO enhancement, the signal intensity of normal liver and cirrhotic liver both decreased, especially on GRE T2WI. The signal intensity of hepatocellular carcinoma (HCC), regenerative nodules (RN), and focal nodule hyperplasia (FNH) all increased on T1WI images. On T2WI and T2-weighted images, the signal intensity of HCC remained high, while significant signal loss occurred in RN and FNH. After SPIO administration, the contrast-to-noise (CNR) of HCC on GRE T2*-weighted images was greater than that of other sequences.
SPIO has not only considerable T2-negative effect but also slightly T1-shortening effect, which is of great value in the differential diagnosis of focal liver lesions.
评估超顺磁性氧化铁（SPIO）增强磁共振（MR）成像在肝脏局灶性病变诊断中的价值。
通过给大鼠喂食N-亚硝基二乙胺诱导建立20个肝细胞癌大鼠模型。在给大鼠注射SPIO前后，进行MR成像，包括自旋回波（SE）T1WI（390 ms/14 ms）、快速自旋回波（TSE）T2WI（4 100 ms/99 ms）、SE双回波（1 800 ms/20 ms/70 ms）、梯度回波快速成像（GRE FLASH）T2*WI（600 ms/15 ms/15）和GRE FLASH T1WI（150 ms/14 ms/70）序列。另选5只正常大鼠作为阴性对照，同样按上述方法接受SPIO及MR成像。分析不同肝脏病变的SPIO增强MRI特征。
SPIO增强后，正常肝脏和肝硬化肝脏的信号强度均降低，尤其是在GRE T2WI上。肝细胞癌（HCC）、再生结节（RN）和局灶性结节性增生（FNH）在T1WI图像上的信号强度均增加。在T2WI和T2加权图像上，HCC的信号强度仍较高，而RN和FNH出现明显信号丢失。注射SPIO后，GRE T2*加权图像上HCC的对比噪声比（CNR）大于其他序列。
SPIO不仅具有显著的T2阴性效应，还具有轻微的T1缩短效应，在肝脏局灶性病变的鉴别诊断中具有重要价值。
