新型口服对比剂茶在MRCP中的临床试用

目的评价一种新型口服对比剂——茶叶（日照绿茶）为原料研制的磁共振口服阴性对比剂在腹部MRCP诊断中的价值和可行性，为临床MRCP检查应用提供一种理想对比剂，以进一步促进MRCP检查的发展。方法以水为参照物，将不同浓度的茶对比剂置于磁共振中进行同一序列的扫描，比较不同浓度的茶对比剂对成像信号的影响。在相同情况下选择17例志愿者对口服茶对比剂前后进行MRCP成像，对检查结果进行分析、综合。结果不同浓度的茶对比剂产生不同的信号，清晰度不同，经体外试验确定最佳浓度的茶中，锰的浓度为12．04±0．22mg／L。此浓度下的茶对比剂，信号与水相反，即T1高信号，T2低信号。MRCP成像抑制了胃、十二指肠道内的液体高信号，使胰胆管周围背号干净，突出胰胆管内的液体高信号成分，图像质量显著性提高（p〈0．05）。结论茶作为天然饮品，服用后安全，无毒副作用，对胃肠道无刺激，在肠腔内不发酵，不产生气体，充盈肠腔充分，保证肠腔内信号均匀一致。利用茶叶中锰的特性将茶作为磁共振MRCP检查口服阴性对比剂，不需要经过药物试验即可应用。在MRCP检查中应是一种理想的口服对比剂。

Clinical application of Chinese tea as an oral negative contrast agent for MRCP

Objective To evaluate the efficacy of a kind of Chinese tea （Rizhao green tea） administration as an oral negative contrast agent for magnetic resonance cholangiopancreatography （MRCP） studyso as to provide an ideal negative contrast agent which is natural, safe, inexpensive and palatable; and to assist MRCP analysis for further development of. Methods MR imaging of phantoms comprising cylinders of tea at various concentrations and water as a control were performed under the identical scanning sequence to compare the effect of tea concentration on the image signal. MRCP was subsequently performed in 17 selected volunteers, before and after ingestion of tea. Quantitative and qualitative comparison between pre- and post-tea oral administration was obtained systematically. Results The various tea concentrations resulted in different outcomes in terms of signal intensity and clarify. High manganese concentration of 12.04 mg/L was detected in the optimum tea dosage. In contrast to water, tea decreased the T2 relaxation time of the fluid in the stomach and duodenum. The intraluminal signal of the gastrointestinal tract on T2W imaging was reduced, due to the paramagnetic properties of high manganese content in tea. There was statistically significantly （p 〈 0.05） improvement in conspicuity of the common bile duct and main pancreatic duct after tea ingestion. Conclusion Tea ,as a natural drinking ,is safe, no side effect, no irritation, no fermentation and gas generation. It can adequately fill the gastrointestinal duct and result in consistent MR signals. No clinical trial has to perform before application of tea as an oral negative contrast agent for MRCP. Therefore, tea is an ideal oral negative contrast agent in MRCP.