钆剂胶囊磁共振结肠传输试验的初步应用

Preliminary application of gadolinium-based capsule in MR colon transit times

目的针对传统X线结肠传输试验临床应用的局限性,提出应用新型钆剂胶囊的磁共振结肠传输试验方法,用于非侵入性、无辐射检查评估、半定量分析消化道各节段传输功能。材料与方法选择无急慢性胃肠功能紊乱症状的健康志愿者20名及慢传输型便秘患者5例,每名受试者吞服五枚钆剂/0.9%生理盐水胶囊(浓度比为1∶10)。应用1.5 T高场强磁共振扫描仪对摄入的胶囊进行扫描,采集序列选择肝脏快速容积采集(liver acceleration volume acquisition,LAVA)脉冲序列,自吞服后分时间段采集图像后对胶囊进行分析定位直至胶囊完全排空。结果 20名健康志愿者(平均年龄33岁)及5例慢传输型便秘患者(平均年龄34岁),均按照实验设计在规定时间内完成检查,无明显不适。MRI结肠传输试验能达到预期检查目的,所有健康志愿者平均结肠传输时间为(32.3±18.9)h,慢传输型便秘患者平均结肠传输时间为(64.8±9.6)h,慢传输型便秘患者的结肠传输时间明显长于健康对照组。T1WI是显示胶囊的最佳序列。结论 MRI结肠传输试验可准确完整复制X线传输试验的结果,在此基础上还具有无辐射的优势,获得图像资料丰富,可清晰显示结肠形态并定位及半定量标记物,更准确发现残留标记物的数量及位置,在未来可作为结肠动力学的动态功能评估应用于临床常规。

Objective:Radio-opaque markers(ROMs)is a commonly used traditional method for colon dynamics.As the limitation of ionizing radiation of ROMs in clinical use,we proposed a method of gadolinium-based capsules in the measurement of colon dynamics.It can be used in semi-quantitative analysis of digestive tract transmitting ability in a non-invasive way and free of ionizing radiation.Materials and Methods:Twenty healthy volunteers without acute or chronic gastrointestinal function disorders and 5 slow transit constipation patients consumed 5 gadolinium-based capsules simultaneously.Gadolinium-based capsules contained gadolinium/0.9%normal saline(concentration ratio is 1﹕10).After ingestion of capsules,T1WI LAVA sequences using a 1.5 Tesla MR system is obtained at certain time point until all capsules were emptied completely.The location of capsules is analyzed via these imaging data.Results:All of the twenty healthy volunteers(average age:33 years)and five slow transit constipation patients(average age:34 years)successfully underwent MRI colonic transit tests without any discomfort.In healthy volunteers group,the mean transit time is(32.3±18.9)hour.For slow transit constipation patients,the mean transit time is(64.8±9.6)hour,and it is obviously longer than it in healthy group.The best sequence in MR imaging is defined in T1WI sequence.Conclusions:MRI colon transit times is capable of duplicating the result of X-ray colon transit times accurately.Meanwhile,MR colon transit times is free of ionizing radiation with abundant imaging information.It can clearly demonstrate the morphology of colon,location and semi-quantify the remaining markers in the colon.In future,it can be possible dynamic evaluation of the digestive tract transit time and applied to clinical routine.