四水合二氯化锰增强MR观察大鼠胆管梗阻

目的 观察口服锰MR对比剂主要成分四水合二氯化锰对大鼠胆管梗阻的造影效果,并与钆喷酸葡胺进行比较。方法 将32只SD大鼠分为4组,分别给予不同处理:组1,造模+四水合二氯化锰灌胃;组2,造模+钆喷酸葡胺注射;组3,假手术+四水合二氯化锰灌胃;组4,假手术+钆喷酸葡胺注射。对组1、组3灌胃之前和之后12、24、48 h行T1W扫描。组2、组4先行平扫T1W及钆喷酸葡胺增强T1W扫描,24 h后再行T1W平扫。结果 假手术组(组3、组4)四水合二氯化锰灌胃24 h后肝脏信号强度基本恢复到造影前水平,造模组(组1、组2)四水合二氯化锰灌胃后延迟MRI中肝脏信号均显著增强,其中24 h信号强度达峰值;注射钆喷酸葡胺立即增强扫描,假手术组和造模组肝脏信号均强化,24 h后信号均恢复正常。结论 四水合二氯化锰灌胃对大鼠肝脏的增强效果优于静脉注射钆喷酸葡胺;四水合二氯化锰灌胃后24 h是MR诊断大鼠胆管梗阻的最佳时间点。

Manganese chloride tetrahydrate enhanced MRI for biliary obstruction in rat models

Objective To assess the effectiveness of manganese chloride tetrahydrate as an oral manganese-based contrast agent for biliary obstruction in rat models, and to compare it with Gd-DTPA. Methods Thirty-two male Sprague Dawley (SD) rats were divided into 4 groups: Group 1, bileduct ligated+manganese chloride tetrahydrate; group 2, bile duct ligated+Gd-DTPA; group 3, sham+manganese chloride tetrahydrate; group 4, sham+Gd-DTPA. T1WI were obtained before and 12 h, 24 h, 48 h after the administration of manganese chloride tetrahydrate (2 mmol/kg) in group 1 and group 3. Group 2 and group 4 were examined with plain T1W and T1W+contrast enhanced TIW MR scanning, while T1WI was obtained again 24 h after intravenous injection of Gd-DTPA. Results In sham group, the signal intensities obtained from the livers returned to plain values 24 h after intragastric administration of manganese chloride tetrahydrate. The liver intensities in model group with manganese chloride tetrahydrate increased at all scanning time, of which the signals reached the highest level after 24 h. In sham and model group, the liver intensities all increased at T1W+contrast enhanced after intravenous injection of Gd-DTPA and normalized after 24 h. Conclusion The signal enhancement in the liver by manganese chloride tetrahydrate in rats is stronger than that of Gd-DTPA. MR scanning can be performed 24 h after oral administration of manganese chloride tetrahydrate to diagnose biliary obstruction of rat models.