超顺磁性氧化铁诊断肝脏小病灶的临床应用价值初探

目的：探讨超顺磁性氧化铁（商品名为菲立磁，Feridex)对肝脏小病灶的临床应用价值，以及滴注后的最佳扫描时间。方法：17例经B超或CT检查发现肝脏内小病灶患者，经常规MR平扫和增强扫描1－3d后，经静脉滴注菲立 （0.05ml/kg)，并于0.5,3.6h后进行扫描。主观目测菲立磁增强后肝脏小病灶的显示情况，定量分析菲立磁增强后肝脏信号下降情况。结果；菲立磁增强后扫描可显著肝脏内直径小于1cm的病灶21个，明显多于常规MR检查（8个）。菲立磁应用后小肝癌和容易与肝癌混淆的局灶性结节增生和再生结节信号变化明显不同。菲立磁增强后扫描，肝脏T2WI，T1WI信号均较增强前下降（P＜0．01），滴注菲立磁后0.5,3,6h扫描，T2WI各时间点的脏脏信号下降统计学上差异无显著性意义（P＞0．05）。结论：菲立磁能显著提高肝脏小病灶的检出率，而且对肝脏小病灶的鉴别诊断可提供有利的依据。

Preliminary study of the value of clinical applications of superparamagnetic iron oxide in diagnosing small lesions of liver

Objective To evaluate the value of Feridex in demonstrating small focal lesions of the liver on MRI and to discuss the optimal scan time after intravenous administration of Feridex. Methods Small focal lesions in the liver were found on ultrasound or CT in 17 patients. Conventional MR plain scan and Gd-DTPA enhanced scan were performed. One to three days later, T 2 weighted imaging was repeated at 0.5 h, 3 h, and 6 h after Feridex was administered intravenously over 30-40 min at a dose of 0.05 ml/kg. The pre- and post-contrast T 2WI were compared and analyzed in terms of lesion detectability and signal change. Results Twenty-one lesions with diameter smaller than 1 cm were found on the Feridex enhanced images, and only 8 lesions were found on the conventional MR images. The small hepatic cancers, focal nodular hyperplasia (FNH), and regenerated nodules had different signal changes on the Feridex images, which made the differential diagnoses easier. The signal of the liver decreased significantly (P<0.01), no significant difference was found among 0.5 h, 3 h, and 6 h scans after administrations of Feridex (P>0.05). Conclusion Fridex enhanced MR images could not only improve the detection of small focal lesions, but also provide evidence for differential diagnoses.